REACTIONS Yr 9

1. Which of the following is a word equation?

Sodium oxide → sodium + oxygen

Sodium oxide decomposes to form sodium and oxygen

Na2O → Na + O2

2Na2O → 4Na + O2

2. In an exothermic reaction, heat is

Absorbed

Released

Destroyed

Conserved

3. What type of reaction is the following?
CH₄ + 2O₂ → CO₂ + 2H₂O

Synthesis

Decomposition

Single replacement

Double replacement

Combustion

4. Each of the substances to the left of the arrow in a chemical equation is a

Catalyst

Product

Reactant

Coefficient

5. In a combustion reaction, ______________ is always one of the reactants.

O

O2

CO2

H2O

6. What coefficients would balance the following equation?
Sr + H₂O → Sr(OH)₂ + H₂

1, 4, 2, 2

2, 4, 2, 4

1, 2, 1, 1

It is already balanced

7. In a combustion reaction between a hydrocarbon and oxygen, the products are always?

A synthesis reaction

Carbon dioxide and water

Oxygen

Hydrogen, carbon and oxygen

8. Which of the following is NOT an observable clue that a chemical reaction has occurred?

Release of a gas

Odor change

Precipitate formation

Mixing two reactants

9. What coefficients would be added to balance the following equation?
Fe + O₂ → Fe₂O₃

2, 3, 1

4, 3, 2

It is already balanced

You wouldn't add a coefficient you would just change the subscripts

10. In a chemical reaction, the total mass of the substances before the reaction compared to the total mass of the substances after the reaction is

Usually smaller

Usually greater

Equal

Sometimes greater, sometimes smaller

Reactions Yr 9

1. Which of the following is a word equation?

2.

What first name or nickname would you like us to use?

2. In an exothermic reaction, heat is

3. What type of reaction is the following?
CH₄ + 2O₂ → CO₂ + 2H₂O

4. Each of the substances to the left of the arrow in a chemical equation is a

5. In a combustion reaction, ______________ is always one of the reactants.

6. What coefficients would balance the following equation?
Sr + H₂O → Sr(OH)₂ + H₂

7. In a combustion reaction between a hydrocarbon and oxygen, the products are always?

8. Which of the following is NOT an observable clue that a chemical reaction has occurred?

9. What coefficients would be added to balance the following equation?
Fe + O₂ → Fe₂O₃

10. In a chemical reaction, the total mass of the substances before the reaction compared to the total mass of the substances after the reaction is

Reactions Yr 9

1. Which of the following is a word equation?

2.

What first name or nickname would you like us to use?

2. In an exothermic reaction, heat is

3. What type of reaction is the following?CH4 + 2O2 → CO2 + 2H2O

4. Each of the substances to the left of the arrow in a chemical equation is a

5. In a combustion reaction, ______________ is always one of the reactants.

6. What coefficients would balance the following equation?Sr + H2O → Sr(OH)2 + H2

7. In a combustion reaction between a hydrocarbon and oxygen, the products are always?

8. Which of the following is NOT an observable clue that a chemical reaction has occurred?

9. What coefficients would be added to balance the following equation?Fe + O2 → Fe2O3

10. In a chemical reaction, the total mass of the substances before the reaction compared to the total mass of the substances after the reaction is

3. What type of reaction is the following?
CH₄ + 2O₂ → CO₂ + 2H₂O

6. What coefficients would balance the following equation?
Sr + H₂O → Sr(OH)₂ + H₂

9. What coefficients would be added to balance the following equation?
Fe + O₂ → Fe₂O₃