Warm Up Predict the products of the following 2 reactions: 1.NaCl + MgF2 → ? + ? 2.Calcium oxide and barium sulfide → ? and ?

Warm Up

Predict the products of the following 2 reactions:

1. NaCl + MgF2 → ? + ?

2. Calcium oxide and barium sulfide → ? and ?

Take 1

What to do???

• Make sure you have a tracking sheet (all versions are the same)

• Get calculators from the bin. Return them when finished

• Complete ALL parts of tracking sheet

• Raise hand to ask questions

• You may track a classmate’s for extra credit…make sure to put their name on it

Chemical ReactionsSituation where atoms

rearrange to make new substances.

Reactants

BEFORE

•What you start with.

•What reacts or rearranges

Reactants Products

BEFORE

•What you start with.

•What reacts or rearranges

AFTER

•What you end with.

•What is produced.

Double Replacement

• How to predict products?– Just switch partners– Cations (positive ions) still come first in the

formula– Anions (negative ions) still come last in the

formula– Polyatomic ions move as a unit– Example?

Practice Double Replacement (aka partner switch!)

What forms from:

1. Calcium sulfide and magnesium oxide

2. Potassium chloride and hydrogen carbonate

3. Sodium hydroxide and lithium bromide

Practice Double Replacement (aka partner switch!)

What forms from:

1. NaCl and LiF

2. CaO and MgS

3. MgCl2 and CaI2

4. CaF2 and Li2O

Kris Kross Method!

Ca3As2

Ca2+As3-

http://aix2.uottawa.ca/~s1539179/ko.gif

http://aix2.uottawa.ca/~s1539179/ko.gif

Write down the stable ions and cross the oxidation

numbers (charges) to make them subscripts

Na1+Cl1-

NaClPb4+O2-

Pb2O4



Na1+Cl1-

NaClPb4+O2-

Pb2O4



Na1+Cl1-

NaClPb4+O2-

Pb2O4

Extra Rules

• DON’T cross signs (+ or -)

• DON’T cross 1’s

• If the numbers are the same, DON’T cross them (if both are 3’s, don’t cross them)

• Reduce final subscripts if able to

Ionic Compounds

K F Ba N

Ga O Ca Cl

K Si Group 1 2 3 4 5 6 7 8Charge 1

+2+

3+

4-

3-

2-

1-

0

Ionic Compounds

K+F- Ba N

Ga O Ca Cl


+2+

3+

4-

3-

2-

1-

0

Ionic Compounds

KF Ba N

Ga O Ca Cl


+2+

3+

4-

3-

2-

1-

0

Ionic Compounds

KF Ba2+N3-

Ga O Ca Cl

K Si Group 1 2 3 4 5 6 7 8

Charge 1+

2+

3+

4-

3-

2-

1-

0

Ionic Compounds

KF Ba3N2

Ga O Ca Cl

K Si Group 1 2 3 4 5 6 7 8

Charge 1+

2+

3+

4-

3-

2-

1-

0

Ionic Compounds

KF Ba3N2

Ga3+O2- Ca Cl

K Si Group 1 2 3 4 5 6 7 8

Charge 1+

2+

3+

4-

3-

2-

1-

0

Ionic Compounds

KF Ba3N2

Ga2O3 Ca Cl

K Si Group 1 2 3 4 5 6 7 8

Charge 1+

2+

3+

4-

3-

2-

1-

0

Ionic Compounds

KF Ba3N2

Ga2O3 Ca2+Cl-

K Si Group 1 2 3 4 5 6 7 8

Charge 1+

2+

3+

4-

3-

2-

1-

0

Ionic compounds

KF Ba3N2

Ga2O3 CaCl2

K Si Group 1 2 3 4 5 6 7 8

Charge 1+

2+

3+

4-

3-

2-

1-

0

Ionic compounds

KF Ba3N2

Ga2O3 CaCl2

K+Si4- Group 1 2 3 4 5 6 7 8

Charge 1+

2+

3+

4-

3-

2-

1-

0

Balancing Chemical Reactions

KF Ba3N2

Ga2O3 CaCl2

K4Si Group 1 2 3 4 5 6 7 8

Charge 1+

2+

3+

4-

3-

2-

1-

0

Remastery quiz

• Work silently and alone for full credit

Matter is Conserved!

If mass is never created/destroyed, and it can be measured, then:

Key Point 3: Total mass of products = Total mass of reactants

Now Let’s Apply:

A student takes 30g of BaCl2 and reacts it with 25 g of LiOH.

BaCl2 + LiOH LiCl + Ba(OH)2

What is the total mass of the products formed?

Now Let’s Apply:

A student takes 30g of BaCl2 and reacts it with 25 g of LiOH.

BaCl2 + LiOH LiCl + Ba(OH)2

What is the total mass of the products formed?

55g.

Practice, Practice, Practice

• 45g of K3PO4 are combined with 25g of NaOH.

What is the total mass of products?

35g of MgSO4 are combined with 30g of KCl




What is the total mass of products? 70g









• 70g of BaCl combines with 50g of NaOH


253.4g of NaOH combines with 123.4g of LiCl











What is the total mass of products? 376.8g


• 70g of BaCl combines with 50g of NaOH and forms 60 g of BaOH.

• What is the mass of the NaCl that forms?

250g of NaOH combines with 125g of LiCl and forms 100 g of NaCl.

What is the mass of the LiOH that forms?


• 70g of BaCl combines with 50g of NaOH and forms 40 g of BaOH.

• What is the mass of the NaCl that forms? 80g

250g of NaOH combines with 150g of LiCl and forms 100 g of NaCl.

What is the mass of the LiOH that forms? 300g

Remastery quiz


Balancing equations RULES!

• When balancing equations, Never, Never, NEVER change subscripts, only coefficients!

But Ms. Hughes…

• What is a coefficient?

•GOOD QUESTION!

Coefficient

• A coefficient is a whole number in front of the compound, never in the middle!

• You multiply the coefficient to all the subscripts in the compound

2AlCl3

Do you get it?

• 3AlCl3

• How many atoms of each element do they have?

• ? Aluminum’s

• ? Chlorine’s

Practice

• 2AlCl3• 4H2O

• 6H2O2

• 5KCl

• 2Be3S2


H2 + O2 H2O

__H____O__

Write down elements.


H2 + O2 H2O

__H____O__

How many are there?


H2 + O2 H2O

_2_H_2___O__

How many are there?


H2 + O2 H2O

_2_H_2__2_O_1_

How many are there?

Is this chemical equation balanced? Defend you answer and how it relates to the Law of

Conservation of Mass.Mg(s) + O2(g) 2MgO


Conservation of Mass.Na(s) + O2(g) Na2O(s)


Conservation of Mass.2Al(s) + Cl2(g) Al2Cl3(s)


Conservation of Mass.Br2 + O2 2Br2O

Balancing Equations

1) Determine number of atoms for each element.

2) Pick an element that is not equal on both sides of the equation.

3) Add a coefficient in front of the formula with that

element and adjust your counts. 4) Continue adding coefficients to get the same

number of atoms of each element on each side.


H2 + O2 H2O

_2_H_2__2_O_1_

How many are there?


Try These:N2 + H2 NH3

P4O10 + H2O H3PO4 Ca3P2 + H2O Ca(OH)2 + PH3


Try These:N2 + 3H2 2NH3

P4O10 + H2O H3PO4 Ca3P2 + H2O Ca(OH)2 + PH3

Balancing with some hot sauce…

When balancing equations with polyatomic ions, keeping them together can make it easier!

What if you have some polyatomic ions?WHAAAAAAAAT will you do??

Work it out…

H3PO4 + ____ KOH ____ K3PO4 + ____ H2O

• Which polyatomics are we using?

– PO4 – phosphate

– OH – hydroxide

• Where is the OH on the other side?

– It’s okay – rewrite H2O as HOH

– Trust me!



P4O10 + 6H2O 4H3PO4 Ca3P2 + H2O Ca(OH)2 + PH3



P4O10 + 6H2O 4H3PO4 Ca3P2 + 6H2O

3Ca(OH)2 + 2PH3

Remastery quiz


Warm Up

1. Does breaking a bond absorb or release energy?

2. Does forming a bond absorb or release energy?

3. How is an exothermic reaction different from an endothermic reaction?

Why does the temperature change?!?

Key Point #1:

Breaking a bond requires energy.

Forming new bonds releases energy.

Unit for energy: kilojoules (kJ)

Endothermic

=

energy ABSORBED

energy goes IN

Exothermic

=

energy RELEASED

energy EXITS

Endo or Exo???

1. 2 HCl + 185 kJ H2 + Cl2

2. 4 NH3 + 5 O2 4 NO + 6 H2O + 1169 kJ

3. Cu + Cl2 CuCl2 + 220.1 kJ

4. H2O + C + 132 kJ CO2 + 2H2

Some Questions to ponder

The combustion of the hydrocarbon glucose (C6H12O6) produces carbon dioxide, water, and releases 2830 kJ.

Exo or Endo???

Some Questions to ponder

After absorbing 66.4 kJ of energy, 1 mole of nitrogen gas and 2 moles of oxygen gas react to form 2 moles of nitrogen monoxide.

Exo or Endo???

Remastery quiz


• Remember to look up the names of polyatomic ions

• Gases like oxygen, etc are O2

– “diatomic”

• + means “and”

• → means “yield”

States of Matter

• Products and reactants in chemical reactions are present in different states

• Solid (s)

• Liquid (l)

• Gas (g)

• Aqueous (aq)- dissolved in water

• Precipitate (ppt)- solid product of a reaction

Practice- what is formula equation?

Solid magnesium and aqueous Aluminum Chloride react to form an Aluminum

precipitate and aqueous Magnesium Chloride

Practice- what is the formula equation?

aqueous sodium chloride reacts with aqueous lead (II) nitrate to yield a lead (II) chloride precipitate and aqueous sodium

nitrate

• Solid Potassium metal and chlorine gas combine to form aqueous potassium chloride.

Aluminum and liquid hydrochloric acid (HCl) react to form Solid aluminum chloride and hydrogen gas.


Conservation of Mass.Mg(s) + O2(g) 2MgO


Conservation of Mass.Na(s) + O2(g) Na2O(s)


Conservation of Mass.2Al(s) + Cl2(g) Al2Cl3(s)


Conservation of Mass.Br2 + O2 2Br2O

Remastery quiz


Warm Up

1. When pressure increases, what happens to volume?

2. When temperature increases, what happens to volume?

Conclusions

• Pay attention

• Remember: CAUSE → EFFECT

• Lines intersecting on a graph means the values are equal at that point

• It’s all about relationships!

Conclusions

Incubation Temperature of Turtle Eggs Versus Sex of Hatchlings

Four groups of 25 eggs

Temperature

Number of Males

Number of Females

Eggs not hatched

Group 1 26 21 2 2

Group 2 28 13 11 1

Group 3 30 1 19 5

Group 4 32 1 20 4

Remastery quiz


Gases

• Particles are:– Spread apart– In constant motion– Very small– Exert force on each other

when collide– Exert force on container

when collide

– Which is the gas?

Volume

• Volume measures how much space matter takes up.

• The units of Volume are Liters (L)– 1 L = 1000 mL

Pressure

• Pressure describes how much force is applied over an area.– The more force, the more

pressure.– The more area, the less pressure

• Why doesn’t this person have a lot

of holes in their body?

Gas Pressure

• Gas Pressure is a measure of how much force the gas molecules hit the container with.

– If the gas molecules hit the container harder, what will happen to the pressure? • Answer in complete sentences

Units of Pressure

• Pressure is measured in many different units.

– Atmospheres (atm) – Kilopascals (kPa)– Millimeters of Mercury (mm Hg)– Torr (torr)

• 1 atm = 101.3 kPa = 760 mm Hg = 760 torr

Pressure and Volume

• Recall: – Pressure is related to the force on the gas molecules

in the container– Volume is how much space the gas takes up

• Imagine a balloon.– If the pressure on the gas molecules increases what

do you think will happen to the volume the gas molecules take up?• Explain your answer on the sheet in complete

sentences

Boyle’s Law

• Boyle’s Law relates gas pressure and gas volume

• Equation:

2211 VPVP

Initial Pressure Initial Volume Final Pressure Final Volume

*You can use any units, as long as they are on the same on each side

Temperature

• Temperature is a measure of how fast the molecules in a substance are moving.– The faster they move, the higher the temperature

• Temperature is measured in:– Degrees Fahrenheit (°F)

– Degrees Celsius (°C)

– Kelvin (K)

Charles’ Law

• Charles’ Law relates the temperature of a gas to the volume of a gas.

• The units for T must be Kelvin (K).– What could happen if the temperature was in C or F?

• The units for volume can change.

2

2

1

1

T

V

T

V

Initial Volume

Initial Temperature Final Temperature

Final Volume

Remastery quiz


Significant figures

• A way of keeping track of the precision of a measurement

Significant figures

• All measured digits + 1 guessed digit

What’s the measurement?

• Graduated cylinder- measure from the bottom of the curve

What’s the measurement?

• Triple beam balance- add three levels together

How many sig figs?

• Graduated cylinder- measure from the bottom of the curve

How many sig figs?

• Triple beam balance- add three levels together

How many sig figures?

• 400000

• .000034

• .00201

• 3402

• 60001

• 4032.00

Remastery quiz


Warm Up

1. What is the purpose of multiple trials?

2. Which of the following conducts electricity in water: NaCl or C2H3O2

Multiple Trials

• Doing an experiment multiple times or having multiple subjects

• Necessary to reduce error by taking the average

• Need a trial that has the control group (original form)

Remastery quiz


With addition of solute

• Boiling point increases

• Freezing point decreases

Why?

• Explain, in complete sentences, why people add salt to water to make the pasta cook faster.

• Explain, in complete sentences, why salt is added to roads when it snows.

BP and FP Change Equation

kmiT Change in temperature

constant

molality

Number of dissolved particles

kg

molm

kb for water is 0.51 °C/m

kf for water is -1.86 °C/m

An Example

• What is the boiling point of a 0.75 m MgF2 if water is the solvent?

Practice Questions

• Which of the following will increase the boiling point of solvent the most?– 1 m NaCl– 1 m C12H22O11

– 1 m CaCl2– 1 m Al2O3

– 1 m MgO

• What is the freezing point of a salt (NaCl) water solution with a molality of 3 m?

Question #1 Question #2

More Practice

• What is the molarity of a solution with 2.0 moles of CaCl2 in 4 L of H2O?

• What is the molality of a solution with 4.0 moles of CaCl2 in 6 L of H2O?

• What is the boiling point of a solution with 4 m CaCl2 in water?

Practice Quietly by yourself. Raise you hand if you have a question

Remastery quiz


Conductivity

• When ions are dissolved in water, they can conduct electricity– Because they can move charges in the liquid

• Why can’t ionic compounds conduct electricity while they are solids?

• Why can’t covalent compounds dissolved in water conduct electricity?

Review: ionic compound

A METAL + A NONMETAL

Why do some ionic compounds conduct better?

• More ions per volume of solution (concentration) means more charge is carried (better conduction)

• Ionic compounds that create more ions (higher concentration) when dissolved conduct electricity better

REMEMBER: Dissolution

• Dissolution is when an ionic compound dissolved into ions in a polar solvent.

– How many ion (not particles) will the following compounds make?

• NaCl 2

• CaCl2 3

• CH3OH none

Practice Problems

• Which of the following will conduct electricity?– Pure water– Salt water– A pile of salt– Sugar water– A pile of sugar

• In complete sentences, explain why gatorade and powerade can conduct electricity.

Question #1 Question #2

Practice

• NaCl• H2O• H2O with dissolved ions• C2H6O3• MgCl2• Strong electrolyte• Weak electrolyte• Solutions with high concentration of dissolved

ions

Remastery quiz


Documents

Warm Up Predict the products of the following 2 reactions: 1.NaCl + MgF2 → ? + ? 2.Calcium oxide and barium sulfide → ? and ?