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IGCSE Chemistry Extended6.2.2—Catalyst increases the rate of aTopic Practice

6.2.2—Catalyst increases the rate of a

• State: a catalyst increases the rate of a reaction and is unchanged at the end of a reaction

Question 17

[Maximum number: 1]

Nitrogen, N2\mathrm{N}_{2}, and hydrogen, H2\mathrm{H}_{2}, can be converted into ammonia, NH3\mathrm{NH}_{3}, using a catalyst.
What is the purpose of the catalyst?

A

to increase the amount of ammonia produced

B

to increase the rate of reaction

C

to reduce the amount of reactants needed

D

to reduce the rate of reaction

Question 17

[Maximum number: 1]

The equation for the decomposition of hydrogen peroxide, H2O2\mathrm{H}_{2} \mathrm{O}_{2}, is shown.

2H2O2→2H2O+O22 \mathrm{H}_{2} \mathrm{O}_{2} \rightarrow 2 \mathrm{H}_{2} \mathrm{O}+\mathrm{O}_{2}

In an experiment, the total volume of oxygen produced is 100 cm3100 \mathrm{~cm}^{3}.
The experiment is repeated using 1.00 g of a solid catalyst. All other conditions remain the same.
Which row describes the total volume of oxygen and the mass of the catalyst at the end of the second experiment?

total volume of oxygen
/cm3/ \mathrm{cm}^{3}

mass of catalyst
/g

more than 100

less than 1.00

100

less than 1.00

100

1.00

more than 100

1.00

Question 3(c)(i)

[Maximum number: 2]

This question is about nitrogen and some of its compounds.

Some of the ammonia made by the Haber process is converted into nitric acid.

The first stage of this process is the oxidation of ammonia to make nitrogen monoxide.

4NH3( g)+5O2( g)⇌4NO( g)+6H2O( g)4 \mathrm{NH}_{3}(\mathrm{~g})+5 \mathrm{O}_{2}(\mathrm{~g}) \rightleftharpoons 4 \mathrm{NO}(\mathrm{~g})+6 \mathrm{H}_{2} \mathrm{O}(\mathrm{~g})

The process is carried out at 900∘C900^{\circ} \mathrm{C} and a pressure of 5 atmospheres using an alloy of platinum and rhodium as a catalyst.

The forward reaction is exothermic.

State the meaning of the term catalyst.

Question 4(b)(ii)

[Maximum number: 1]

Chlorine reacts with carbon monoxide to produce phosgene gas, COCl2( g)\mathrm{COCl}_{2}(\mathrm{~g}). A catalyst is used.

Cl2( g)+CO( g)⇌COCl2( g)\mathrm{Cl}_{2}(\mathrm{~g})+\mathrm{CO}(\mathrm{~g}) \rightleftharpoons \mathrm{COCl}_{2}(\mathrm{~g})

The reaction is exothermic.

State why a catalyst is used.

Question 3(b)(iii)

[Maximum number: 1]

Sulfur dioxide, SO2\mathrm{SO}_{2}, is used in the manufacture of sulfuric acid.

The next stage of the process is a reaction which can reach equilibrium.

The equation for this stage is shown.

2SO2( g)+O2( g)⇌2SO3( g)2 \mathrm{SO}_{2}(\mathrm{~g})+\mathrm{O}_{2}(\mathrm{~g}) \rightleftharpoons 2 \mathrm{SO}_{3}(\mathrm{~g})

Why is a catalyst used?

Question 4

[Maximum number: 3]

Oxygen is produced by the decomposition of aqueous hydrogen peroxide. Manganese(IV) oxide, MnO2\mathrm{MnO}_{2}, is a catalyst for this reaction.

Question 4(a)

(a)

State the meaning of the term catalyst.

[ 2 ]

Question 4(e)

(b)

State the effect on the mass of oxygen produced if the mass of powdered manganese(IV) oxide catalyst is increased.

[ 1 ]

Question 4

[Maximum number: 3]

Hydrogen peroxide, H2O2\mathrm{H}_{2} \mathrm{O}_{2}, decomposes into water and oxygen in the presence of a catalyst, manganese(IV) oxide.

2H2O2(aq)→2H2O(l)+O2( g)2 \mathrm{H}_{2} \mathrm{O}_{2}(\mathrm{aq}) \rightarrow 2 \mathrm{H}_{2} \mathrm{O}(\mathrm{l})+\mathrm{O}_{2}(\mathrm{~g})

Question 4(a)

(a)

What is meant by the term catalyst?

[ 2 ]

Question 4(c)(iv)

(b)

What would be the effect on the volume of oxygen produced if the mass of catalyst was increased?

[ 1 ]

Question 4(a)

[Maximum number: 2]

Hydrogen can be manufactured from methane by steam reforming.

CH4( g)+H2O( g)⇌CO( g)+3H2( g)\mathrm{CH}_{4}(\mathrm{~g})+\mathrm{H}_{2} \mathrm{O}(\mathrm{~g}) \rightleftharpoons \mathrm{CO}(\mathrm{~g})+3 \mathrm{H}_{2}(\mathrm{~g})

The reaction is carried out using a nickel catalyst at temperatures between 700∘C700^{\circ} \mathrm{C} and 1100∘C1100^{\circ} \mathrm{C} and using a pressure of one atmosphere.

The forward reaction is endothermic.

What is meant by the term catalyst?

Question 4(a)

[Maximum number: 2]

Ethanol is made industrially by the reaction of ethene with steam. The reaction occurs at a temperature of 300∘C300^{\circ} \mathrm{C} and a pressure of 60 atmospheres.

C2H4( g)+H2O( g)⇌C2H5OH( g)\mathrm{C}_{2} \mathrm{H}_{4}(\mathrm{~g})+\mathrm{H}_{2} \mathrm{O}(\mathrm{~g}) \rightleftharpoons \mathrm{C}_{2} \mathrm{H}_{5} \mathrm{OH}(\mathrm{~g})

A catalyst is used in this reaction.
The forward reaction is exothermic.

State what is meant by the term catalyst.

Question 5(a)(i)

[Maximum number: 2]

The table gives some chemical properties of transition elements and their compounds, and of Group I elements and their compounds.

Table

What is meant by the term catalyst?

0 selected