Page 1 of 16

Year 9 CHEMISTRY REVISION WORKSHEET

1. Substances can be pure or they can be mixtures.

(a) Which of these is a mixture? (1)

(b) An impure substance (1)

A. lowers boiling point

B. increases boiling point

C. no change in melting point

D. increases melting point

(c)Water would be helpful in separating a mixture of (1)

A. sand and salt.

B. iron and sulfur.

C. iron and sand.

D sand and sulfur.

(d) Figure shows some mixtures to be separated and possible methods of separation.

Place a tick in one box in each row of the table to show the best method to separate the first named

substance from each of the mixtures. (3)

Page 2 of 16

(e) Use the drawing below to answer the next question.

The salt and water was separated from the insoluble impurities (dirt) using the apparatus shown on

the right.

The salt and water was collected at X. Explain why the insoluble impurities were held at Y . (1)

……………………………………………………………………………………………………………..

……………………………………………………………………………………………………………..

(f) P, Q, R and S are mixtures of food colourings. They are investigated using paper chromatography.

Figure shows the chromatogram at the end of the experiment.

(i) Which piece of apparatus is needed to make measurements in a paper chromatography experiment? (1)

Page 3 of 16

(ii)Which mixture contains an insoluble food colouring? (1)

(iii)Give a change that could be made to the experiment to obtain Rf value for the insoluble colouring.(1)

……………………………………………………………………………………………………………..

……………………………………………………………………………………………………………..

(iv) Explain, by referring to Figure , which mixture is separated into the greatest number of soluble food

colourings by this chromatography experiment. (2)

……………………………………………………………………………………………………………..

……………………………………………………………………………………………………………..

……………………………………………………………………………………………………………..

(g) Paper chromatography was used to find the composition of brown ink in a pen. The same liquid, paper

and pen were used in each of the three experiments shown. They were started at different times, C first

then B and finally A.

(i) Why is the ink dot above the level of the liquid in each beaker? (1)

……………………………………………………………………………………………………………..

……………………………………………………………………………………………………………..

Page 4 of 16

(ii)What caused the dots of ink on the papers B and C to spread upwards? (1)

……………………………………………………………………………………………………………..

……………………………………………………………………………………………………………..

(iii)Why were colours, other than brown, seen in B and C as the ink moved up the paper? (1)

……………………………………………………………………………………………………………..

……………………………………………………………………………………………………………..

(h)Charles carried out a chromatography experiment to test which food colouring was present in a

coloured drink.

He used samples of three food colourings, X, Y and Z. He also tested a sample of the colouring in the

drink. Charles obtained this chromatogram.

(i) Food colouring Y is banned.

Explain how Charles can tell that the drink that he tested did not contain the banned food colouring. (1)

……………………………………………………………………………………………………………..

……………………………………………………………………………………………………………..

(ii) Calculate the Rf value for the coloured substance in food colouring X. (2)

……………………………………………………………………………………………………………..

……………………………………………………………………………………………………………..

……………………………………………………………………………………………………………..

Page 5 of 16

(i)Examine the diagram.

(i) Complete the table correctly matching the labels A – D in the diagram with the words in the table. (2)

(ii)Name the separation process shown in the diagram. (1)

……………………………………………………………………………………………………………..

(iii)Identify the part of item C which is connected to the cold tap. Label in the diagram (1)

(iv)How could you show that the water collected contains no salt? (1)

……………………………………………………………………………………………………………..

Thermometer

Round bottomed flask

Tripod stand

Bunsen

Condenser

Beaker

Page 6 of 16

2. The freezing point of water is 0°C.

(a) Describe how the movement and arrangement of water particles changes when water is cooled from

10°C to –10°C. (2)

……………………………………………………………………………………………………………..

……………………………………………………………………………………………………………..

……………………………………………………………………………………………………………..

……………………………………………………………………………………………………………..

(b) A sample of water is heated from a liquid at 400C to a gas at 110

0C.

On the heating curve diagram, label each of the following regions: (2)

Liquid only : Gas only : Phase change:

(c ) The graph below represents the heating curve of a substance that starts as a solid below its freezing

point

What is the melting point of this substance? (1)

A 300C B 55

0 C C 90

0C D 120

0C

Page 7 of 16

3. Calcium nitrate contains calcium ions and nitrate ions.

(a)Calculate the relative formula mass of calcium nitrate, Ca(NO3 ) 2 . (2)

relative atomic masses: Ca = 40, N = 14, O = 16)

……………………………………………………………………………………………………………..

……………………………………………………………………………………………………………..

……………………………………………………………………………………………………………..

(b) Explain why calcium nitrate is neutral . (1)

……………………………………………………………………………………………………………..

……………………………………………………………………………………………………………..

4. Ionic compounds contain ions.

(a) The numbers of electrons, neutrons and protons in four particles, W, X, Y and Z, are shown in Figure .

Explain which particle, W, X, Y or Z, is a negative ion. (2)

……………………………………………………………………………………………………………..

……………………………………………………………………………………………………………..

……………………………………………………………………………………………………………..

……………………………………………………………………………………………………………..

……………………………………………………………………………………………………………..

Page 8 of 16

*(b) Figure shows the ability of different substances to conduct electricity.

Explain these results by referring to the structures of the substances. (6)

……………………………………………………………………………………………………………..

……………………………………………………………………………………………………………..

……………………………………………………………………………………………………………..

……………………………………………………………………………………………………………..

……………………………………………………………………………………………………………..

……………………………………………………………………………………………………………..

……………………………………………………………………………………………………………..

……………………………………………………………………………………………………………..

……………………………………………………………………………………………………………..

……………………………………………………………………………………………………………..

……………………………………………………………………………………………………………..

(c)Magnesium chloride (MgCl2 ) is an ionic compound.

(Atomic Number of Magnesium = 12 ,Chlorine =17)

(i)Draw the diagram shows the electronic configurations of atoms of magnesium and chlorine. (2)

Page 9 of 16

(ii)Identify the group and period of chlorine in the periodic table. Explain your answer. (4)

……………………………………………………………………………………………………………..

……………………………………………………………………………………………………………..

……………………………………………………………………………………………………………..

……………………………………………………………………………………………………………..

……………………………………………………………………………………………………………..

(iii) Describe how magnesium atoms and chlorine atoms form magnesium ions and chloride ions. (2)

……………………………………………………………………………………………………………..

……………………………………………………………………………………………………………..

……………………………………………………………………………………………………………..

……………………………………………………………………………………………………………..

……………………………………………………………………………………………………………..

……………………………………………………………………………………………………………..

……………………………………………………………………………………………………………..

……………………………………………………………………………………………………………..

(iv) Draw a diagram to represent the electronic configurations of each of the ions in magnesium chloride.

Show the charge on each ion. (3)

Page 10 of 16

(d)The table shows some properties of four substances A, B, C and D.

(i) Use the information in the table to identify the substance that contains oppositely charged ions (1)

(ii)Some of the substances in the table are compounds. What is meant by the term compound? (2)

………………………………………………………………………………………………………………..

………………………………………………………………………………………………………………...

(e)Barium sulfate contains barium ions, Ba2+

sulfate ions, SO42–

(i) Give the formula of barium sulfate. (1)

………………………………………………………………………………………………………………..

(ii) Give the meaning of the term ion. (2)

………………………………………………………………………………………………………………..

………………………………………………………………………………………………………………...

(iii) State the total number of atoms in the compound (1)

………………………………………………………………………………………………………………..

[Total marks for Q 4 = 26 ]

Page 11 of 16

5. An atom of an element has an atomic number of 9 and a mass number of 19.

(a) Using this information, complete the table to show the numbers of protons, neutrons and electrons in

one atom of this element. (2)

(b) The Periodic Table shows the positions of five elements, J, Q, T, X and Z. The letters do not represent

the symbols for the elements.

(c)(i)How many electrons are there in the outer shell of an atom of X? (1)

……………………………………………………………………………………………………………..

(ii)There are 31 protons in an atom of X. Using this information, explain how many protons there are in an

atom of Z (1)

……………………………………………………………………………………………………………..

(iii)What is the electronic configuration of an atom of Q? (1)

……………………………………………………………………………………………………………..

(iv) State one similarity and one difference between the electronic configurations of atoms of J and T. (2)

similarity ……………………………………...……………………………………………………………..

difference ……………………...……………………………………………………………………………..

[Total marks for Q 5 = 7 ]

Page 12 of 16

6. This question is about the elements hydrogen and oxygen.

(a) The circles in the diagrams represent molecules of hydrogen.

Place a cross (X ) in the box under the diagram that represents hydrogen gas. (1)

(b) The diagram below shows two different atoms of hydrogen.

(i) The particle furthest from the centre of each atom is (1)

(ii) The particle present in atom Y but not in atom X is (1)

(iii) Both atoms are neutral because they have the same number of (1)

Page 13 of 16

(c)An atom has the symbol Which value determines the position in the periodic table? (1)

(d)Different atoms of oxygen can be represented as Select words or phrases from the box to complete the

sentence about these atoms of oxygen.

You may use each word or phrase once, more than once or not at all. (3)

atomic numbers isotopes mass numbers numbers of electrons

These atoms of oxygen are called ...................................................................................because their

.......................................................... are the same but their .................................................................. are

different.

(e)The symbols of two isotopes of bromine are

(i) Complete the table to show the number of protons, neutrons and electrons (3)

(iii)Element X has three isotopes. The table gives the mass number of each isotope and its percentage

abundance in a sample of element X. (3)

Page 14 of 16

Calculate the relative atomic mass (Ar ) of element X. Give your answer to one decimal place.

……………………………………………………………………………………………………………..

……………………………………………………………………………………………………………..

……………………………………………………………………………………………………………..

……………………………………………………………………………………………………………..

……………………………………………………………………………………………………………..

……………………………………………………………………………………………………………..

7. Use the the Periodic Table to answer this question.

(a) (i) The symbol for silver is (1)

(ii) The element with an atomic number of 40 is (1)

(b) The table shows the electronic configurations of four elements.

(i)Why is argon an unreactive element? (1)

………………………………………………………………………………………………………………..

………………………………………………………………………………………………………………...

Page 15 of 16

(ii) Krypton is an unreactive element in the same group of the Periodic Table as argon, but in Period 4. It

has an atomic number of 36. Deduce the electronic configuration of krypton. (1)

8. Complete the sentence which is based on Mendeleev’s periodic table

(a)Mendeleev listed elements in order of increasing ………………………………………………….. (1)

(b) What property is used today for the order of the elements? (1)

………………………………………………………………………………………………………………..

……………………………………………………………………………………………………………….

(c ) Which particle within the atom is responsible for this property? (1)

……………………………………………………………………………………………………………….

(d)Give one difference and similarity between the table produced by Mendeleev and modern periodic

table. (2)

………………………………………………………………………………………………………………..

………………………………………………………………………………………………………………..

9. Potassium reacts with water.In a class demonstration, a teacher drops a piece of potassium on to water.

The teacher ties back her hair and wears a laboratory coat and goggles.

(i)Explain another safety precaution that the teacher should take. (2)

………………………………………………………………………………………………………………..

………………………………………………………………………………………………………………...

(ii) The word equation for this reaction is given below. Two of the state symbols have been given.

Complete the spaces provided. (3)

potassium(s) + water (l) → potassium hydroxide(. . . . ) + ………………….(. . . .)

(iii) Describe what you see when potassium is added to water. (1)

………………………………………………………………………………………………………………

Page 16 of 16

10. Construct formulae for the following ionic compounds. Write the formulae / name in the spaces. (7)

Compound Formula

Na2CO3

Potassium sulfate

Calcium bromide

MgS

Aluminium hydroxide

Iron(III) iodide

Ammonium chloride