Sr.No. Index Page No.

1. The Year Plan

2. Selection Of The Sub-Units

3. The Unit Plan

4. The Lesson Plan

5. Weightage Table

6. The Blue-Print

7. The Question Bank

8. Selection Of The Test Item

9. Grouping Of The Test Item

10. Scheme Of Option

11. Instruction To The Examinees.

12. The Scoring Key

13. The Marking Scheme

14. The Unit Test Paper

15. Critical Evaluation By The Expert

16. Analysis And Interpretation Of The Results.

Calculation Of The Mean Calculation Of The S.D.

17. Graphical Interpretation Of The Scores

Histogram The Frequency Polygon

1

The Year Plan

Number of periods available per week =6

Number of days in a year =365

Number of days not available for teaching =220

Number of days available for teaching

= Number of days in a year – Number of Holidays

=365-220

=145

Number of weeks available for teaching

= Number of days available for teaching/5

=145/5

=29

Number of periods available for teaching

=Number of weeks*Number of period per week

=29*6

=174 periods

Total number of periods used

=Number of teaching period + Number of testing period

=128+46

=174 periods

2

Name of the Topics

KN

OW

LED

GE

UN

DER

STA

ND

AP

PLIC

ATIO

N

SK

ILL

INTER

ES

T

ATTIT

UD

E

AP

PR

EC

IATIO

TeachingPeriods

TestingPeriods

TO

TA

L

Unit-I

1.Natural Resources. 7 3 10

2.Water-A natural resource. 5 1 6

3.Properties of Water. 6 2 8

Unit-II

4.Propogation of Light. 7 3 10

Unit-III5.Electric Charge. 9 3 12

Unit-IV

6.Transmission of Heat 7 3 107.Effects of Heat 9 3 12Unit-V8.Sound-Production of Sound. 8 3 11

9.Propogation of Sound. 8 3 11Unit-VI

10.Food & Nutrition. 9 3 1211.Food & Production of Food. 9 3 1212.Health & Disease. 6 2 8Unit-VII

13.The Organization of Living Things.

6 2 3

14.Reproduction of Living Things.

5 2 7

15.Circulation of Blood. 8 3 1116.Control & Co-ordination 9 3 12Unit-VIII

17.Classification of Substances. 7 3 10Unit-IX18.Acids,Bases and Salts. 3 1 4TOTAL 128 46 174

SELECTION OF THE SUB-UNITS

3

Subject: ScienceTopic: Acids,Bases and SaltsStd.: VII

SUB-UNIT- 1 First Property of Acid & Bases Concept & Definitions of Indicators. Litmus Test Activity. Second Property of Acid & Bases. Definition of Neutral substances

SUB-UNIT- 2 Test of Oxides of Metals(Basic) Test of Oxides of Non-metals(Acidic) Definitions of Neutralization.

SUB-UNIT- 3 Classification of Salts. Use of Acids & Bases.

THE UNIT PLAN

Content Objectives(with Learning Evaluatio

4

Analysis Specifications.) Experience,Learning Situations,Learning Activity

n

Sub-Unit-I(First property of Acids and Bases, Indicators, Litmus Test Activity, Second property of

Acids and Bases, Neutral Substances.)Stage-I

1.First property of Acids & Bases.

sour to taste

Astringent taste

2. Indicators. Natural Chemic

al

Knowledge:1.The pupil recalls that lemon juice is sour to taste.2.The pupil recognizes that sour substances are acids & astringent substances are bases.Understanding: 1.The pupil discriminates between acid & bases.Application:1.The pupil cites examples of more substances which are sour to taste.Skill:1.Thepupil records observations accurately.

The teacher describes the first property of acids and bases by showing some known substances such as lemon ,lime ,soap and vinegar as acids are sour to taste and bases are astringent to taste. She explains ,it is wrong to taste or touch substances to find whether the substance is an acid or a base. Then, she introduces substances like litmus,turmeric ,phenolphthalein and methyl orange as those substances which help us to identify an acid or a base, tems them as indicators and classifies them as natural and chemical indicators.

Stage-II1.Litmus Test Activity.2.Second property of Acids & Bases.

Turns blue litmus red(acid).

Turns red litmus blue(base).

3.Neutral Substances.

Knowledge:1.The pupil recalls that indicators are used to identify given substances.2.The pupil recognizes that indicators are of two types.Understanding: 1.The pupil discriminates between acid , bases and neutral substances.Application:1.The pupil gives reason for change in colour of litmus paper when dipped on different solutions.Skill:1.Thepupil records observations of litmus test activity accurately.

The teacher performs the litmus test activity on different substances such as hydrochloric acid, sulphuric acid ,sodium hydroxide ,lime solution and she concludes that acid turns blue litmus paper red while red litmus remains unchanged , bases turns red litmus paper blue while blue litmus remains unchanged and the substance which has no effect on red or blue litmus paper are called as neutral substances.

Content Analysis Objectives(with Specifications.)

Learning Experience,Learnin

Evaluation

5

g Situations,Learning

ActivitySub-Unit-II

(Simulation of Oxides of metals , Oxides of non-metalsAnd demonstration of Neutralization.)

Stage –I Oxides of

metals. Oxides of non-

metals

Knowledge:1.The pupil recalls that elements are classified into metals and non-metals.2.The pupil recognizes that oxides are formed by combination of oxygen with any substance.Understanding: 1.The pupil discriminates between oxides of metals and non-metals.2.The pupil generalizes that oxides of metals are basic and oxides of non-metals are acidic in nature.Application:1.The pupil analyzes that SO2 is formed by burning of sulphur.2.The pupil predicts the nature of the newly formed chemical substance.Skill:1.The pupil records observations accurately.

The teacher stimulates the experiment of formation of sulphurous acid and simultaneously she writes the chemical reactions on the B.B.: S + O2 SO2

SO2 + H2O H2SO3

and does the litmus test activity similarly she stimulates the formation of magnesium hydroxide and simultaneously she writes the chemical reactions on the B.B.:2Mg + O2 2MgO2MgO + H2O Mg(OH)2

and does the litmus test activity

Stage –II(Neutralization reaction)

Demonstration of Neutralization reaction.

Definition Chemical

Reaction

Knowledge:1.The pupil recalls that .acids and bases have equally opposite properties2.The pupil recognizes that salt and water are formed as a chemical reaction between acids and bases .

The teacher demonstrates the neutralization reaction as follows:She takes NaOH in one test-tube and puts a drop of phenolphthalein in

6

Understanding: 1.The pupil discriminates between acids, bases and salts.2.The pupil sees a relationship between acid,bases and salts in neutralization reaction.Application:1.The pupil predicts the new product in a neutralization reaction.Skill:1.The pupil records observations of the chemical reaction accurately.

it and asks the students to observe the change in colour. she takes HCl in other test-tube and puts a drop of phenolphthalein in it and asks the students to observe the change in colour. Then, she pours NaOH into HCl and puts a drop of phenolphthalein in it and asks the students to observe the change in colour.

7

Content Analysis Objectives(with Specifications.)

Learning Experience,Learning Situations,Learning

Activity

Evaluation

Sub-Unit-III(Classification of Salts and Uses of Acids and Bases.)

Stage –I(Classification of Salts)

Classification of Salts

Neutral salts

Acidic salts Basic salts

Knowledge:1.The pupil recalls 2.The pupil recognizes that Understanding: 1.The pupil discriminates between Application:1.The pupil Skill:1.The pupil records observations accurately.

The teacher Classifies the salts into Neutral ,Acidic and Basic .Then she gives some examples of each of the different types of salts.

Stage –II(Uses of Acids and Bases )

Uses of Acids and Bases:Acids:1.Citric Acid.2.Tartaric Acid.3.Lactic Acid.4.Benzoic Acid5.Acetic Acid.6.Hydrochloric Acid.Bases:1.Magnesium hydroxide2.Quicl lime.

Knowledge:1.The pupil recalls that . 2.The pupil recognizes that Understanding: 1.The pupil discriminates between Application:1.The pupil formulates a hypothesis that an acid can be neutralized by a base. Skill:1.The pupil records observations of the chemical reaction accurately.

The teacher explains the different uses of acids and bases in everyday life. She describes that some acids make our food tasty.some are used as preservatives.Some are used as disinfectant. Even bases are used in medicines.

8

WEIGHTAGE TABLES

WEIGHTAGE OF THE OBJECTIVES:-

Knowledge Understanding Application Skill Total

20 40 20 20 100

Marks 4 8 4 4 20

WEIGHTAGE OF THE AREA OF CONTENT:-

Sub-unit-1 Sub-unit-1 Sub-unit-1 Total

35 40 25 100

Marks 7 8 5 20

WEIGHTAGE TO DIFFICULTY LEVEL:-

Easy Average Difficult Total

30 40 30 100

Marks 6 8 6 20

WEIGHTAGE OF THE FORMAT OF QUESTIONS:-

Essay Short-answer Objective Total

30 50 20 100

Marks 6 10 4 20

THE BLUE-PRINT9

Objectives

Knowledge Understanding Application Skill Total

Sub-units E S O E S O E S O E S O

I - - 22 13 - - - - 12 - - - 7

II - - 22 - - 22 - - - - 24 - 8

III - - - 13 - - - - 12 - - - 5

Total 4 8 4 4 20

10

THE QUESTION BANK

SUB-UNIT-1

Sr.no.

Questions Objectives Specifications

Form Marks Time

I. Fill in the blanks:1……. do not shows the properties of either acids or bases.2……..is obtained from plants called lichens.3.Acids and bases have mutually ……….properties.4.Acids turns ………litmus red.5.Bases turns …….litmus blue.

Knowledge

Knowledge

Knowledge

Knowledge

Knowledge

Recalls

Recalls

Recalls

Recalls

Recalls

Objective

Objective

Objective

Objective

Objective

01

01

01

01

01

½

½

½

½

½

II. Match the following:-1.Acids –Sour to taste.2.Bases – Astringent taste. 3.Litmus – Indicator.4.Water – Neutral.

Knowledge

Knowledge

Knowledge

Knowledge

RecognizesRecognizesRecognizesRecognizes

Objective

Objective

Objective

Objective

01010101

½½½½

III. State True or False;-1.Neutral substances shows the properties of both acids and bases.2.Acids turns blue litmus paper red.3.Bases turns red litmus paper blue.

Knowledge

Knowledge

Knowledge

Recalls

Recalls

Recalls

Objective

Objective

Objective

01

01

01

½

½

½

IV. Classify the following into acids,bases and neutral:HCl,H2SO4,NaOH,CaCO3,H2O,NaCl

Understanding

Compare Objective

02 1

11

V. Find the odd man out:-1.HCl,H2SO4,HNO3,NaCl2.Ca2(OH),NaOH,NH4OH,CH3COOH

Understanding

Understanding

CompareCompare

Objective

Objective

0101

½½

VI. Name the following:-1.Natural indicator to detect acid or base.2.Plant from where litmus is obtained.3.Substances which do not affect indicators.

Knowledge

Knowledge

Knowledge

Recalls

Recalls

Recalls

Objective

Objective

Objective

01

01

01

½

½

½

VII. Give Scientific reasons:-1.Tamarind makes our teeth go on edge when we eat it.2.Blue litmus turns red when added to lemon juice.

Application

Application

Give reasons

Give reasons

ShortAnswer

ShortAnswer

02

02

3

3

VIII.

Define giving example:-1.Indicators2. Neutral substances

KnowledgeKnowledge

Recalls Recalls

ShortAnswer Short Answer

02 02

3 3

IX. State the effect of red litmus & blue litmus paper on HC1,H2SO4,Ca(OH)2

,NaOH,NaClUnderstandi

ngRecalls Short

Answer

02

3

X. Write a short note:-1.Indicators.2.Effect of Litmus and Phelophthalein on acids and bases.

Understanding

Understanding

Explains

Explains

Essay

Essay

03

03

5

5

SUB-UNIT-2Sr.no. Questions Objectives Specificatio

nsForm Marks Tim

eI. Fill in the blanks:-

1.The main constituent of an acid

Knowledge Recalls Objective

01 ½

12

is……….2. The main constituent of an base is……….3.The Chemical reaction that takes place between an acid and a base is called ……….4.Bases that dissolve in water are called ……….

Knowledge

Knowledge

Knowledge

Recalls

Recalls

Recalls

Objective

Objective

Objective

01

01

01

½

½

½

II.

Match the following:-1.Oxides of metal – Bases2.Oxides of non-metal –Acids3.Sulphur – Non-Metal4.Magnesium –Metal

KnowledgeKnowledge

KnowledgeKnowledge

RecognizesRecognizes

RecognizesRecognizes

ObjectiveObjective

ObjectiveObjective

01 01 01 01

½ ½ ½ ½

III. State whether true/false:-1.Oxides of metals are acidic.2.Common salt is acidic.3.Bases are formed by neutralization reaction between acids and salts.

Knowledge

Knowledge

Knowledge

Recalls

Recalls

Recalls

Objective

Objective

Objective

01 01

01

½

½

½

IV.

Find the co-orelation:-1.Oxides of metal:Basic::Oxides of non-metal:………2.Acid:H::Base:…….

Understanding

Understanding

Compare

Compare

Objective

Objective

01

01

½

½

V. Find the odd man out:-1.MgO,CaO,H2O,Na2O.2.NaCl,C12H12O11,KCl,CuSO4

. 3.NaHCO3,NaOH,NH4OH,CH3COOH.

Understanding

Understanding

Understanding

Understandin

ComparesCompares

Compares

Compares

Objective

Objective

Objective

Objecti

01 01

01

01

½½

½

½

13

4.HCl,H2SO4,HNO3,NaCl.

g ve

VI.Classify the following into acidic,basic and neutral:-HCl,NaCl,MgO,KCl,CaO, H2SO4,HNO3, H2O,Na2CO3

Understanding

Understanding

ComparesCompares

Objective

Objective

01 01

½½

VII.

Name the following:-1.Chemical formed when an element combines with a oxygen.2.Acid formed when sulphur dioxide dissolves in water.3.Base formed when magnesium oxide dissolves in water.4.Bases that dissolves in water.

Knowledge

Knowledge

Knowledge

Knowledge

Recalls

Recalls

Recalls

Recalls

Objective

Objective

Objective

Objective

01

01

01

01

½

½

½

½

½

VIII. Give Scientific reasons:-1.Pheolphthalein solution turns to pink when added to a solution of magnesium hydroxide or lime solution.2.Hydroxides of copper have to be prepared by chemical reactions and not by dissolving an oxide.OR2.Copper hydroxide is basic but not aan alkali in water.

Application

Application

Give reasons

Give reasons

ShortAnswer

ShortAnswer

02

02

3

3

IX.

Distinguish between:-1.Acids and Bases.2.Base and Alkali.

UnderstandingUnderstanding

DifferentiatesDifferentiates

Short Answer

0202

33

X. Define giving examples:-1.Neutralization.2.Alkali.

KnowledgeKnowledge

RecallsRecalls

Short Answer

0202

33

14

XI. Explain what happens:Or Give chemical reaction:-

1.Hydrochloric acid reacts with ammonium hydroxide.2.Sulphur dioxide reacts with water.3.Magnesium reacts with oxygen.4.Sulphur reacts with oxygen.

Skill

Skill

Skill

Skill

Describes/Explains

Describes/Explains

Describes/Explains

Describes/Explains

ShortAnswer

ShortAnswerShort

AnswerShort

Answer

02 02 02

02

½

½

½

½

XII. Answer briefly:-1.Short note on Neutralization.

2.Explain the formation of Sulphurous acid.

3.Explain the formation of Magnesium hydroxide.

Understanding

Understanding

Understanding

Describes/Explains

Describes/Explains

Describes/Explains

Essay

Essay

Essay

03

03

03

5

5

5

XIII. Describe an experiment to show an acid can be neutralized by base.

Knowledge/Understandi

ng

Recalls/Describes/Explains

Essay 03 5

SUB-UNIT-3

15

Sr.no.

Questions Objectives Specifications

Form Marks Time

I.

Fill in the blanks:-1.Tartaric acid is a………acid.

2. Acetic acid and benzoic acid are used for preserving ……….. and …………3.To get acidic salts………..acids are used.4.There is a………..acid in our stomach.

Knowledge

Knowledge

Knowledge

Knowledge

Recalls

Recalls

Recalls

Recalls

Objective

Objective

Objective

Objective

01

01

01

01

½

½

½

½

II.Match the following:-1.Tamarind – Tartaric acid.2.Yoghurt –Lactic acid.3.Lemon – Citric acid.4.Vinegar –Acetic acid.

Knowledge

KnowledgeKnowledgeKnowledge

Recognizes

RecognizesRecognizesRecognizes

Objective

ObjectiveObjectiveObjective

01

01 01 01

½

½ ½ ½

III. State whether true or false:-1.To get acidic salts,,weak acid is used.2. To get basic salts,strong acid is used .3. To get neutral salts,strong acid and a weak base is used.

Knowledge

Knowledge

Knowledge

Recalls

Recalls

Recalls

Objective

Objective

Objective

01

01

01

½

½

½

16

IV.

Name the following:-1.Acidic salt.2.Basic salt.3.Neutral salt.4.Vitamin present in Citrus fruit.5.Acid in tamarind.6.Substances added to acidic soil to increase fertility.7.Substances added to make alkaline soil fertile.

KnowledgeKnowledgeKnowledgeKnowledge

KnowledgeKnowledge

Knowledge

RecognizesRecognizesRecognizesRecognizes

RecognizesRecognizes

Recognizes

ObjectiveObjectiveObjectiveObjective

ObjectiveObjective

Objective

01 01 01 01

01 01

01

½ ½ ½ ½

½ ½

½

V. Give Scientific reasons:-1.Medicine containing magnesium hydroxide is given to a patient suffering from stomach ache caused due to acidity.2.Quick lime or slaked lime is sometimes added to soil.

Application

Application

Give reasons

Give reasons

ShortAnswer

ShortAnswer

02

02

3

3

VI. Write a short note on:-1.Different types of salts.2.Uses of acids and bases

UnderstandingUnderstanding

ExplainsExplains

EssayEssay

0303

55

VII.

Answer briefly:-1.Statues of marble get spoiled when exposed to vehicular pollution.

Understanding

Explains Essay 03 5

17

SELECTION OF TEST-ITEMS

SUB-UNIT-1

Sr.no.

Questions Objectives Specifications

Form Marks

Time

I. Fill in the blanks:1.……..is obtained from plants called lichens Knowledge Recalls Objectiv

e 01 ½

II. State True or False;-1.Neutral substances shows the properties of both acids and bases.

Knowledge Recognizes Objective

01 ½

III. Give Scientific reasons:-1.Tamarind makes our teeth go on edge when we eat it.

Application Give Reasons

ShortAnswer

02 3

IV. Write a short note:-1.Indicators. Understandi Describes Essay 03 3

18

ng

SUB-UNIT-2

Sr.no.

Questions Objectives Specifications

Form Marks

Time

I. Fill in the blanks:-1.Bases that dissolve in water are called ……….

Knowledge Recalls Objective 01 ½

II. State whether true or false:-1.Oxides of metals are acidic.

Knowledge Recognizes Objective 01 ½

III.

Find the odd man out:-1.MgO,CaO,H2O,Na2O.

2.NaCl,C12H12O11,KCl,CuSO.

3.NaHCO3,NaOH,NH4OH,CH3COOH.

4.HCl,H2SO4,HNO3,NaCl.

Understanding

Understanding

Understanding

Understanding

Compares

Compares

Compares Compares

Objective

Objective

Objective

Objective

½

½

½

½

½

½]½

½

IV.

Explain what happens:Or Give chemical reaction:-1.Hydrochloric acid reacts with ammonium hydroxide.

2.Sulphur dioxide reacts with water.

3.Magnesium reacts with oxygen.

Skill

Skill

Skill

Describes

Describes

Describes

ShortAnswer

ShortAnswerShort

Answer

02

02

02

3

3

3

V. Give Scientific reasons:-1.Pheolphthalein solution turns to pink when added to a solution of magnesium hydroxide or lime

Application Give reasons ShortAnswer

02

3

19

solution.

SUB-UNIT-3

Sr.no.

Questions Objectives Specifications

Form Marks

Time

I. Give Scientific reasons:-1.Quick lime or slaked lime is sometimes added to soil.

Application

Give Reasons

ShortAnswe

r

02 3

II.Write a short note on:-1.Different types of salts.2.Uses of acids and bases.

Understanding

Understanding

DescribesDescribes

EssayEssay

0303

55

GROUPING OF TEST-ITEMSGroupin

gQuestions Objectives Specificatio

nsForm Marks Tim

eI Fill in the blanks:-

1.……..is obtained from plants called lichens.2.Bases that dissolve in water are called ……….

Knowledge

Knowledge

Recalls

Recalls

Objective

Objective

01

01

½

½

II Find the odd man out:-1.MgO,CaO,H2O,Na2O.2.NaCl,C12H12O11,KCl,CuSO4.

UnderstandingUnderstandingUnderstanding

ComparesComparesCompares

Compares

Objective

Objective

Objecti

½½½

½

½½½

½

20

3.NaHCO3,NaOH,NH4OH,CH3COOH. 4.HCl,H2SO4,HNO3,NaCl.

Understanding

ve

Objective

III State True or False;-1.Neutral substances shows the properties of both acids and bases.2.Oxides of metals are acidic.

Knowledge

Knowledge

Recognizes

Recognizes

Objective

Objective

01

01

½

½

IV Explain what happens:Or Give chemical reaction:-1.Hydrochloric acid reacts with ammonium hydroxide.2.Sulphur dioxide reacts with water.3.Magnesium reacts with oxygen.

Skill

Skill

Skill

Describes/Explains

Describes/Explains

Describes/Explains

ShortAnswerShort

AnswerShort

Answer

02

02

02

3

3

3

V Give Scientific reasons:-1.Tamarind makes our teeth go on edge when we eat it.2.Pheolphthalein solution turns to pink when added to a solution of magnesium hydroxide or lime solution.3. Quick lime or slaked lime is sometimes added to soil.

Application

Application

Application

Give reasons

Give reasons

Give reasons

ShortAnswerShort

Answer

ShortAnswer

02

02

02

3

3

3

VI Write a short note:-1.Indicators.2.Different types of salts.3.Uses of acids and bases

Understanding

Understanding

Understanding

DescribesDescribesDescribes

EssayEssayEssay

030303

555

21

SCHEME OF OPTION

IV. Explain what happens when OR Give chemical reactions and balance it :-(any 2 out of 3)

V. Give Scientific reasons :-(any 2 out of 3)

VI. Write a short note on :-(any 2 out of 3)

INSRTUCTION TO THE EXAMINEES

22

The following general instructions were given to the examinees at the beginning of the question paper.

a) Questions I,II & III are compulsory.b) Questions IV,V & VI have internal options.c) Read each question carefully.d) Figure to the right indicates maximum number of marks obtainable in

each question.e) The total number of marks carried is 20.

THE SCORING KEY

Objective Type Questions:- I.Fill in the Blanks II.State whether True or False III.Find the Odd man out

Sr.No. Expected Answer:- Marks Special Instructions

I. Fill in the Blanks1. Litmus 1 Nil2. Alkali 1 Nil

II. Find the Odd man out:-1. H2O ½ Nil2. C12H12O11 ½ Nil3. CH3COOH ½ Nil4. NaCl ½ Nil

III. State whether True or False:-1. False 1 Nil2. False 1 Nil

THE MARKING SCHEME

23

Short Answer/Essay Type Answer:-IV.Give Chemical Reactions V.Give Scientific Reasons VI.Write Short Note on

Sr.No. Expected Answer:- Marks Special Instructions

IV. Explain What happens/Give Chemical reactions1. When hydrochloric acid reacts with

ammonium hydroxide,then ammonium chloride and water are formed.

2 Nil

2. When sulphur dioxide reacts with water then sulphurous acid is formed.

2 Nil

3. When magnesium reacts with oxygen then magnesium oxide is formed

2 Nil

V. Give Scientific reasons1. 1.Tamarind has tartaric acid.

2.The sour taste of acid is very strong.Hence,tamarind makes our teeth to go on edge when we eat it.

2 Nil

2. 1. Phenolphthalein is an indicator which changes colour in acids andbases. 2.In acid it is colourless and in a base it is pink.3. Magnesium hydroxide solution is a base prepared from oxide of a magmesium metal.4.Lime solution is a base prepared from oxide of a calcium metal. Hence,phenolphthalein solutions turns to pink when added to a solution of magnesium hydroxide or lime solution.

2 Nil

3. 1.Overuse of chemical fertilizers makes the soil acidic.2. Quick lime is basic in nature.Hence,quick lime is sometimes added to the soil.

2 Nil

VI. Write short note on1. 1.Indicators:

Ans:a.Certain substances are used to find 3 Nil

24

whether the given substance is acid or a base.such substances are called indicators.b.When an indicator is added to an acidic or a basic solution it changes colour.c.Litmus and turmeric are examples of natural indicators.d.Phenolphathalein and methyl orange are examples of chemical indicators.

2. 3.Types of SaltsAns:Salts are formed when an acid reacts with a base.Salts are of 3 types:a.Neutral Salts:They are formed as a result of chemical reaction between a strong acid and a strong base.e.g. NaCl (sodium chloride),etc.b.Acidic salts: They are formed as a result of chemical reaction between a strong acid and a weak base.e.g. NH4Cl (ammonium chloride),etc.c.Basic Salts:- They are formed as a result of chemical reaction between a weak acid and a strong base.e.g. Washing soda,Baking soda.etc

3 Nil

3. 4.Use of acids and basesa.Citric acid is found in natural foods such as lemons,oranges,sweetlimes.we get Vitamin C from these fruits.b.Tartaric acid in tamarind and lactic Acid in yoghurt make our food tastier.c.hydrochloric acid is used for cleaning toilets.d.Acetic acid,benzoic acid is used in food preservation.e. magnesium hydroxide is used in medicines for neutralizing extra acid in the stomach.f.Quick lime/Slaked lime is added to acidic soil to neutralize the acid in the soil.

3 Nil

THE UNIT-TEST PAPERSt. Paul High School ,Dadar

SUB: Science

25

Std: VII Marks: 20Date: 10.02.2014 Time: 30 min

General Instructions:-a) Questions I , II & III are compulsory.b) Questions IV ,V & VI have internal options.c) Read each question carefully.d) Figure to the right indicates maximum number of marks obtainable

in each question.e) The total number of marks carried is 20.

I.Fill in the blanks:- 21………is obtained from the plant lichens.2. Bases that dissolves in water are called ………..

II.Find the odd man out:- 21.MgO,CaO,H2O,Na2O.2.NaCl,C12H12O11,KCl,CuSO4.3.NaHCO3,NaOH,NH4OH,CH3COOH.4.HCl,H2SO4,HNO3,NaCl.

III.State Whether True or False:- 21.Oxides of metals are acidic.2.Neutral Substances shows the properties of both acids and salts.

IV.Explain what happens when OR Give chemical reactions and balance it :-(any 2) 41.Hydrochloric acid reacts with ammonium hydroxide.2.Sulphur dioxide reacts with water.3.Magnesium reacts with Oxygen.

V.Give Scientific reasons :-(any 2) 41.Tamarind makes our teeth go on edge when we eat it.2.Phenolphathalein solution turns to pink when added to a solution of magnesium hydroxide or lime solution.3.Quick lime or Slaked lime is sometimes added to soil.

VI.Write a short note on :-(any 2) 61.Indicators.2.Use of Acids and Bases.3.Different Types of Salts.

Critical Evaluation by the Expert

26

This project in Education Evaluation has been evaluated by professor Mrs. Sheela Philip who is my method

expert.

Thank you mam for guiding me throughout this year.

Notes given to the students1.Fill in the blanks:-1.The main constituent of an acid is H .

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2.The main constituent of a base is OH .3.Tartaric acid is a organic acid.4.To get acidic salts strong acids are used.5.Litmus is obtained from plants called lichens.6. Bases that dissolves in water are called alkalis.

2.Odd man out :- 1.MgO,CaO,H2O,Na2O. Ans:- H2O (neutral)2.NaCl,C12H12O11,KCl,CuSO4. Ans:- C12H12O11(sugar)3.NaHCO3,NaOH,NH4OH,CH3COOH. Ans:- CH3COOH (acid)4.HCl,H2SO4,HNO3,NaCl. Ans:- NaCl (salt)5. HCl,H2SO4,HNO3,CH3COOH Ans:- CH3COOH(weak acid)

3.True or False :- 1.Oxides of metals are acidic .Ans:-False2.Neutral Substances shows the properties of both acids and salts. Ans:-False3.Common salt is acidic. Ans:-False4.Salt is neutral. Ans:-True5.Salts are formed by neutralization reaction between acids and bases. Ans:-True

4.Chemical reactions:1.Sulphur reacts with oxygen.Ans:When Sulphur reacts with oxygen,then Sulphur dioxide is formed. S + O2 SO2

2.Hydrochloric acid reacts with ammonium hydroxide.Ans:-When hydrochloric acid reacts with ammonium hydroxide,then ammonium chloride and water is formed. HCl + NH4OH NH4Cl + H2O

3.Sulphur dioxide reacts with water.Ans:-When Sulphur dioxide reacts with water,then Sulphurous acid is formed. SO2 + H2O H2SO3

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4.Magnesium Oxide reacts with water.Ans:- When magnesium oxide reacts with water,then magnesium hydroxide is formed. 2MgO + H2O Mg(OH)2

5. Magnesium reacts with oxygen.Ans:-When magnesium reacts with oxygen,then magnesium oxide is formed. 2Mg + O2 2MgO

5.Give scientific reasons:-1.Tamarind makes our teeth go on edge when we eat it.Ans:- a.Tamarind has tartaric acid. b.The sour taste of acid is very strong. Hence,tamarind makes our teeth go on edge when we eat it.

2.Blue litmus turns red when added to lemon juice.Ans:-a. Litmus is an indicator which changes colour in acids andbases..b.In acid it is red and in a base it is blue..c.Lemon juice contains citric acid. Hence, blue litmus turns red when added to lemon juice.

3.Phenolphthalein solutions turns to pink when added to a solution of magnesium hydroxide or lime solution.Ans:-a. Phenolphthalein is an indicator which changes colour in acids andbases. b.In acid it is colourless and in a base it is pink.c. Magnesium hydroxide solution is a base prepared from oxide of a magmesium metal.d.Lime solution is a base prepared from oxide of a calcium metal. Hence,phenolphthalein solutions turns to pink when added to a solution of magnesium hydroxide or lime solution.4.Butter milk kept in copper vessel gets spoiled.Ans:- a.Butter milk has lactic acid.b.Copper is a metal, which reacts with lactic acid.Hence, Butter milk kept in copper vessel gets spoiled.

5.Quick lime is sometimes added to the soil.Ans:-a.Overuse of chemical fertilizers makes the soil acidic.b. Quick lime is basic in nature.Hence,quick lime is sometimes added to the soil.

5.Short notes:1.Indicators:Ans:a.Certain substances are used to find whether the given substance is acid or a base.such substances are called indicators.b.When an indicator is added to an acidic or a basic solution it changes colour.c.Litmus and turmeric are examples of natural indicators.d.Phenolphathalein and methyl orange are examples of chemical indicators.

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2.NeutralizationAns:-a.The Chemical reaction that takes place between acid and bases is called as Neutralization.b.It results in the formation of salts and water.c. When hydrochloric acid reacts with ammonium hydroxide,then ammonium chloride and water is formed. HCl + NH4OH NH4Cl + H2O

3.Types of SaltsAns:Salts are formed when an acid reacts with a base.Salts are of 3 types:a.Neutral Salts:They are formed as a result of chemical reaction between a strong acid and a strong base.e.g. NaCl (sodium chloride),etc.b.Acidic salts: They are formed as a result of chemical reaction between a strong acid and a weak base.e.g. NH4Cl (ammonium chloride),etc.c.Basic Salts:- They are formed as a result of chemical reaction between a weak acid and a strong base.e.g. Washing soda,Baking soda.etc

4.Use of acids and basesa.Citric acid is found in natural foods such as lemons,oranges,sweetlimes.we get Vitamin C from these fruits.b.Tartaric acid in tamarind and lactic Acid in yoghurt make our food tastier.c.hydrochloric acid is used for cleaning toilets.d.Acetic acid,benzoic acid is used in food preservation.e. magnesium hydroxide is used in medicines for neutralizing extra acid in the stomach.f.Quick lime/Slaked lime is added to acidic soil to neutralize the acid in the soil.

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ANALYSIS AND INTERPRETATION OF THE RESULTS

1.Calculation of Mean

Class Interval Frequency x x' fx'0-2 0 1 -6 03-5 4 4 -3 -126-8 19 7 0 09-11 10 10 3 3012-14 17 13 6 10215-17 10 16 9 9018-20 7 19 12 84

N=67 ∑fx'=294

Mean = A.M+ ∑fx'/ N =7+ 294/67 =7+4.38 Mean =11.38

Interpretation:-It means that the central value of the distribution is 11.38

OR that most of the students in the distribution lie above or below 11.38.Most of the students have scored around 11.38.

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2.Calculation of Median

Class Interval Frequency(f) F

0-2 0 0

3-5 04 4

6-8 19 23

9-11 10 33

12-14 17 50

15-17 10 60

18-20 7 67

N=67 N/2=33.5

Median = L+ ((N/2 –F)/f *I)

=5.5+(33.5-4/19*3)

=5.5+4.66

Median =10.16

Interpretation:-It is the positional average of the distribution. It divides the distribution into two equal halves.It implies that 50% of the students lie below or above 10.16. If N=67,then 33.5 students lie below 10.16 and 33.5 students lie above it.

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3.Calculation of S.D.

Marks

Frequenc

y0 0 1 02 03 14 15 26 47 88 79 310 611 112 1213 314 215 216 217 618 319 220 2

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M + 1S.D. =68.26% of casesM + 2S.D. =95.44% of casesM + 3S.D. =99.73% of casesMean=11.38 and S.D.=4.38M + 1S.D. =11.38 +4.38=15.76=16M -1S.D. =11.38 -4.38=7Thus, Range lies between 7-16.Therefore Number of cases falling within this range =8+7+3+6+1+12+3+2+2+2=46

N= 53 Out of 67………46casesOut of 100…………. ?

=(100*46)/67=68.66%

Interpretation:- This means that M + 1S.D. covers 68.66% of the cases. But according to the formulae, in a normal distribution ,M + 1S.D. covers 68.26% of the cases.This implies that the given distribution is normal.

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GRAPHICAL INTERPRETATION OF THE SCORES

1.THE HIISTOGRAM

Class Interval Frequency

0-2 0

3-5 4

6-8 19

9-11 10

12-14 17

15-17 10

18-20 7

0-2 3-5 6-8 9-11 12-14 15-17 18-200

2

4

6

8

10

12

14

16

18

20

0

4

19

10

17

10

7

THE HISTOGRAM

Frequency

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2. FREQUENCY POLYGON

0-2 3-5 6-8 9-11 12-14 15-17 18-20 21-230

2

4

6

8

10

12

14

16

18

20

0

4

19

10

17

10

7

0

Frequency Polygon

Frequency

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Class Interval Frequency

0-2 0

3-5 4

6-8 19

9-11 10

12-14 17

15-17 10

18-20 7

21-23 0

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