Week 1 - Recap Quiz

Last updated about 5 years ago

19 questions

1

In this lesson you will be using the information we have learnt so far to flex you scientific knowledge 

Can you impress Ms Bajulaiye ? 
Can you make her smile ?

Topics in Quiz - 
Exothermic and Endothermic Reactions
Temperature Changes x2
Reaction Profile
Bond Energy

In an exothermic reaction .....

energy is absorbed from the surroundings and the temperature increases

energy is released to the surroundings and the temperature of the surroundings increases

energy is absorbed from the surroundings and the temperature of the surroundings decreases

energy is released to the surroundings and the temperature of the surroundings decreases

In an endothermic reaction ......

energy is absorbed from the surroundings and the temperature increases

energy is released to the surroundings and the temperature of the surroundings increases

energy is absorbed from the surroundings and the temperature of the surroundings decreases

energy is released to the surroundings and the temperature of the surroundings decreases

When an exothemric reaction take place, the raction mixture gives out heat because ...

less energy is released when new bonds are formed than is taken in when existing bonds in the reactants are broken

energy is always absorbed in a chemical change which makes new substances

more energy is released when new bonds are formed than is taken in when existing bonds in the reactants are broken

energy is always released in a chemical change which makes new substances

Which of the following recation is exothermic ?

Photosysthesis 

Combustion 

Ethanoic acid + Sodium carbonate 

Ammonium nitrate + water

Energy change in a chemical reaction is represented by the symbol...

ΔE

H

ΔH

ΔT

ΔH is positive for what type of reactions?

Exothermic

Oxidation

Endothermic

Displacement 

Energy changes in chemical reactions are measured in...

Joules 

kJ

kJ/mol

kWh

Bond making is an

endothermic 

exothermic

eltothemric 

If a reaction is endothermic overall, what does this tell us about the bonds broken and made during the reaction?

There are equal amounts of energy required to break and make the bonds in the reaction

There is a lot of energy used for both making and breaking bonds

There is less energy used in breaking the bonds of the reactants than required to make the bonds of the products

There is more energy used in breaking the bonds of the reactants than required to make the bonds of the products

On an energy level diagram (reaction profile), the products of an exothermic reaction will be ...

higher than the reactants 

the same level as the recatants 

lower than the recatants 

ΔH is the energy change for the reaction. To calculate this...

add the reactants' energy to the products' energy

subtract the reactants' energy from the products' energy

divide the reactants' energy by the products' energy

subtract the products' energy from the reactants' energy

Thermal decomposition is...

an exothermic reaction

an endothermic reaction

an endothermic reaction

an energy rich reaction

Pick the correct combination for the correct information regarding bond energies.

Bond breaking - Exothermic - Takes in energy
Bond making - Endothermic - Gives out energy

Bond breaking - Endothermic - Takes in energy
Bond making - Exothermic - Gives out energy

Bond breaking - Endothermic - Gives out energy
Bond making - Exothermic - Takes in energy

Bond breaking - Exothermic - Gives out energy
Bond making - Endothermic - Takes in energy

The overall energy change in a chemcial reaction is -24kJ/mol. What does this tell us about the reaction?

endothermic 

temperature increased

exothermic 

temperature decreased 

The reaction profile for the course of a chemical reaction. Which of the following statements is TRUE?

The reaction is exothermic with an activation energy of 860 kJ/mol

The reaction is endothermic with 460 kJ/mol of heat taken in

The reaction is exothermic and 380 kJ/mol of heat energy is given out

The reaction is endothermic with an activation energy of 310 kJ/mol

When hydrogen fluoride is heated it breaks down into hydrogen and fluorine.
The equation can be written as: 2HF(g) ==> H2(g) + F2(g)
Use the bond energies shown below to calculate the energy change that takes place when 2 moles of hydrogen fluoride thermally decomposes in this way.

(Bond energies in kJ/mol: H-H = 440; F-F = 155; H-F = 560)

525 kJ given out

560 kJ taken in

525 kJ taken in

560 kJ given out

The reaction between hydrogen and chlorine to form hydrogen chloride can be written as:
H2(g) + Cl2(g) ===> 2HCl(g)
Use the bond energies shown to calculate the energy change that takes place when hydrogen chloride is formed according to the above equation.

(Bond energies in kJ/mol: H-H 435, Cl-Cl 245, H-Cl 430)

180 kJ given out 

250 kJ taken out 

125 kJ taken in 

90 kJ given out 

What is activation energy?

The minimum amount of energy needed for particles to collide.

The maximum amount of energy particles produce when they react.

The minimum amount of energy required for particles to collide and react

What must we remember to do with the ratio of moles in a reaction?

Ignore the number of moles

Multiply the bond energy by the number of moles

Divide the bond energy by the number of moles

In an exothermic reaction .....

energy is absorbed from the surroundings and the temperature increases

energy is released to the surroundings and the temperature of the surroundings increases

energy is absorbed from the surroundings and the temperature of the surroundings decreases

energy is released to the surroundings and the temperature of the surroundings decreases

In an endothermic reaction ......

energy is absorbed from the surroundings and the temperature increases

energy is released to the surroundings and the temperature of the surroundings increases

energy is absorbed from the surroundings and the temperature of the surroundings decreases

energy is released to the surroundings and the temperature of the surroundings decreases

When an exothemric reaction take place, the raction mixture gives out heat because ...

less energy is released when new bonds are formed than is taken in when existing bonds in the reactants are broken

energy is always absorbed in a chemical change which makes new substances

more energy is released when new bonds are formed than is taken in when existing bonds in the reactants are broken

energy is always released in a chemical change which makes new substances

Which of the following recation is exothermic ? 

Photosysthesis 

Combustion 

Ethanoic acid + Sodium carbonate 

Ammonium nitrate + water

Energy change in a chemical reaction is represented by the symbol...

ΔE

H

ΔH

ΔT

ΔH is positive for what type of reactions?

Exothermic

Oxidation

Endothermic

Displacement 

Energy changes in chemical reactions are measured in...

Joules 

kJ

kJ/mol

kWh

Bond making is an 

endothermic 

exothermic

eltothemric 

If a reaction is endothermic overall, what does this tell us about the bonds broken and made during the reaction?

There are equal amounts of energy required to break and make the bonds in the reaction

There is a lot of energy used for both making and breaking bonds

There is less energy used in breaking the bonds of the reactants than required to make the bonds of the products

There is more energy used in breaking the bonds of the reactants than required to make the bonds of the products

On an energy level diagram (reaction profile), the products of an exothermic reaction will be ...

higher than the reactants 

the same level as the recatants 

lower than the recatants 

ΔH is the energy change for the reaction. To calculate this...

add the reactants' energy to the products' energy

subtract the reactants' energy from the products' energy

divide the reactants' energy by the products' energy

subtract the products' energy from the reactants' energy

Thermal decomposition is...

an exothermic reaction

an endothermic reaction

an endothermic reaction

an energy rich reaction

Pick the correct combination for the correct information regarding bond energies.

Bond breaking - Exothermic - Takes in energy
Bond making - Endothermic - Gives out energy

Bond breaking - Endothermic - Takes in energy
Bond making - Exothermic - Gives out energy

Bond breaking - Endothermic - Gives out energy
Bond making - Exothermic - Takes in energy

Bond breaking - Exothermic - Gives out energy
Bond making - Endothermic - Takes in energy

The overall energy change in a chemcial reaction is -24kJ/mol. What does this tell us about the reaction?

endothermic 

temperature increased

exothermic 

temperature decreased 

The reaction profile for the course of a chemical reaction. Which of the following statements is TRUE?

The reaction is exothermic with an activation energy of 860 kJ/mol

The reaction is endothermic with 460 kJ/mol of heat taken in

The reaction is exothermic and 380 kJ/mol of heat energy is given out

The reaction is endothermic with an activation energy of 310 kJ/mol

When hydrogen fluoride is heated it breaks down into hydrogen and fluorine.

The equation can be written as: 2HF(g) ==> H2(g) + F2(g)

Use the bond energies shown below to calculate the energy change that takes place when 2 moles of hydrogen fluoride thermally decomposes in this way.

(Bond energies in kJ/mol: H-H = 440; F-F = 155; H-F = 560)

525 kJ given out

560 kJ taken in

525 kJ taken in

560 kJ given out

The reaction between hydrogen and chlorine to form hydrogen chloride can be written as:

H2(g) + Cl2(g) ===> 2HCl(g)

Use the bond energies shown to calculate the energy change that takes place when hydrogen chloride is formed according to the above equation. 

(Bond energies in kJ/mol: H-H 435, Cl-Cl 245, H-Cl 430)

180 kJ given out 

250 kJ taken out 

125 kJ taken in 

90 kJ given out 

What is activation energy?

The minimum amount of energy needed for particles to collide.

The maximum amount of energy particles produce when they react.

The minimum amount of energy required for particles to collide and react

What must we remember to do with the ratio of moles in a reaction?

Ignore the number of moles

Multiply the bond energy by the number of moles

Divide the bond energy by the number of moles