Unit 9 Online quiz-Part 1 Multiple Choice

你有20分钟完成本次测试,祝你取得好成绩。
class
8-1
8-2
8-3
Name
    ____________
Burning fuels is an exothermic reaction. What is meant by the term exothermic? 
A.A gas is produced.
B. Energy is released.
C. Heat is absorbed.
D. The mass of the fuel decreases.
Which statement about chemical reactions is correct? 
A. Endothermic reactions show a temperature decrease because energy is absorbed from the surroundings.
B. Endothermic reactions show a temperature increase because energy is released into the surroundings.
C. Exothermic reactions show a temperature increase because energy is absorbed from the surroundings.
D. Exothermic reactions show a temperature decrease because energy is released into the surroundings.

Plant cells use energy from sunlight for photosynthesis. Which row describes and explains the energy change that occurs?

 

type of energy change

explanation

A

endothermic

less energy is released making bonds than is absorbed to break bonds

B

endothermic

more energy is released making bonds than is absorbed to break bonds

C

exothermic

less energy is released making bonds than is absorbed to break bonds

D

exothermic

more energy is released making bonds than is absorbed to break bonds

A.选项1
B.选项2
C.选项3
D.选项4
Which statements about exothermic and endothermic reactions are correct?

1 During an exothermic reaction, heat is given out.

2 The temperature of an endothermic reaction goes up because heat is taken in.

3 Burning methane in the air is an exothermic reaction.

A. 1, 2 and 3
B. 1 and 2 only
C. 1 and 3 only
D. 2 and 3 only
Which reaction is endothermic? 
A. neutralization of an acid by an alkali
B. reaction of hydrogen with oxygen
C. reaction of sodium with water
D. thermal decomposition of limestone
A diagram for the energy change during an exothermic reaction is shown.


For which reactions would this be an appropriate diagram?

1 CH 4 + 2O 2 → CO 2 + 2H 2 O

2 H 2 + O 2 → 2H 2 O

3 C + O 2 → CO 2

A. none of them
B. 1 and 2 only
C. 2 and 3 only
D. all of them
Equal volumes and concentrations of dilute hydrochloric acid and aqueous sodium hydroxide are mixed. The temperatures of the solutions are shown.


Which statement describes the reaction?

A. Energy is released and the products have less energy than the reactants.
B. Energy is released and the products have more energy than the reactants.
C. Energy is absorbed and the products have less energy than the reactants.
D. Energy is absorbed and the products have more energy than the reactants.
When blue copper (II) sulfate is heated, a white solid and water are formed. The white solid turns blue and gives out heat when water is added to it.

Which type of reaction and energy level diagram apply to the latter reaction?


A.选项1
B.选项2
C.选项3
D.选项4
Two elements, X and Y, react together to form a covalent molecule as shown. The reaction is exothermic.

X 2 (g) + Y 2 (g) → 2XY(g)

The bond energies are shown in the table.


A. +184 kJ / mol
B. –184 kJ / mol
C. +247 kJ / mol
D. –247 kJ / mol
The temperature of the water in two beakers, X and Y, is measured as 21.5 °C.

5 g of sodium chloride is dissolved in the water in beaker X. The temperature changes to 18.0 °C.

5 g of calcium oxide is dissolved in the water in beaker Y. The temperature changes to 29.4 °C.

Which types of process are occurring in beakers X and Y?


A.选项1
B.选项2
C.选项3
D.选项4
Ammonia is made by reacting nitrogen with hydrogen in the presence of an iron catalyst. The reaction is exothermic.

The equation for the reaction is shown.

N 2 + 3H 2 → 2NH 3

The bond energies are shown in the table.


What is the energy given out during this reaction? 

A. –4593kJ/mol
B. –1083kJ/mol
C. –959kJ/mol
D. –87kJ/mol
Which reaction is endothermic?
A. CaCO3 → CaO + CO2
B. CaO + 2HCl → CaCl2 + H2O
C. 2Ca + O2 → 2CaO
D. Ca + 2HCl → CaCl2 + H2
The equation for the reaction between hydrogen and chlorine is shown.

H 2 (g) + Cl 2 (g) → 2HCl (g)

The reaction is exothermic.

The bond energies are shown in the table.


A. –1536 kJ / mol
B. –184 kJ / mol
C. +184 kJ / mol
D. +246 kJ / mol
Hydrogen peroxide, H–O–O–H, decomposes to form water and oxygen. 

2H 2 O 2 (g) → 2H 2 O(g) + O 2 (g)

The bond energies are shown in the table. The reaction is exothermic.


A –346 kJ / mol
B –196 kJ / mol
C +196 kJ / mol
D +346 kJ / mol
Ethene reacts with hydrogen. The equation is shown.


The bond energies are shown in the table.


What is the energy change for the reaction?

A –560 kJ / mol
B –124 kJ / mol
C +486 kJ / mol
D +5496 kJ / mol

17题 | 被引用0次

模板修改
使用此模板创建