Paper 1 2019

Posljednje ažuriranje 11 days ago

(d) Ammonia is used to make hydrazine.

In the industrial process to manufacture ammonia, nitrogen and hydrogen are combined in the presence of an iron catalyst.

N_2 + 3H_2 \rightleftharpoons 2NH_3

Pieces of zinc react with copper sulfate solution. Zinc sulfate solution is colourless.

Zn(s) + CuSO4(aq) → ZnSO4(aq) + Cu(s)

The copper sulfate solution used has a concentration of 15.95 \, \text{g dm}^{-3}.

In another experiment, 0.043 \, \text{mol} of copper sulfate, \text{CuSO}_4, is used.

X and Y are solutions of two different acids. The concentration of acid in each solution, in mol dm-3, is the same. Solution X has a pH of 3.40 and solution Y has a pH of 4.40.

(a) Nitric acid can be titrated with a solution of ammonia.

In one stage of the production of nitric acid, nitrogen oxide, NO, is reacted with oxygen to make nitrogen dioxide, NO2.

\(2NO + O_2 \rightarrow 2NO_2\)

(c) In another stage in the production of nitric acid, ammonia is reacted with oxygen to form nitrogen oxide and water.

4\text{NH}_3(g) + 5\text{O}_2(g) \rightleftharpoons 4\text{NO}(g) + 6\text{H}_2\text{O}(g)

Paper 1 2019

Posljednje ažuriranje 11 days ago

Drugi mogući odgovor:

explode

dissolve

corrode

Drugi mogući odgovor:

alkali metal

transition metal

noble gas

(c) Some metal objects are electroplated.
State two reasons for electroplating a metal object.

To improve appearance
for decoration
to prevent corrosion
to make it harder
To make it more gansta

This is a valid reason
This is not a valid reason

Periodic table
Using the letters A, E, G, J, X and Z, give the letters of the two elements that are non-metals.

Periodic table
Give the letters of two elements in period 2. (NOTE THERE ARE IN FACT 3)

Periodic table
Give the letter of an element that normally forms an ion with a charge of +1 (GIVE BOTH)
.

Drugi mogući odgovor:

neutrons

protons

All atoms of element E in this sample contain

5 protons

5 neutrons

6 protons

6 neutrons

Element X has an atomic number of 18. State the electronic configuration of an atom of element X.

Drugi mogući odgovor:

0.25

A₂G

0.5

Drugi mogući odgovor:

relight

turn litmus white

go cloudy

explode

turn red litmus blue

Drugi mogući odgovor:

go cloudy

relight

turn red litmus blue

explode

turns white

Drugi mogući odgovor:

relight

go cloudy

turns white

explode

turn red litmus blue

Drugi mogući odgovor:

turns white

relight

explode

go cloudy

turn red litmus blue

Drugi mogući odgovor:

turn red litmus blue

relight

turns white

explode

go cloudy

Drugi mogući odgovor:

quadruple

double

triple

Molten lead bromide is electrolysed.
The products of this electrolysis are:

hydrogen and bromine

hydrogen and oxygen

lead and bromine

lead and oxygen

Drugi mogući odgovor:

are

insoluble

are not

soluble

Drugi mogući odgovor:

100

1.787

Drugi mogući odgovor:

5.450

expected

5.600

97.3

actual

The mass of solid left in the crucible is less than the theoretical mass of calcium oxide that should be obtained. A possible reason for this is that

some solid was lost from the crucible

the solid remaining absorbed some water from the air

some carbon dioxide remained in the crucible

the decomposition was incomplete

(d) (i) Calculate the relative formula mass of calcium carbonate, CaCO₃. (relative atomic masses: C = 12, O = 16, Ca = 40)

(ii) Calculate the atom economy for the formation of calcium oxide in this reaction.
CaCO_3 \rightarrow CaO + CO_2
You must show your working. (relative atomic masses: C = 12, O = 16, Ca = 40; relative formula mass: calcium oxide = 56)

An advantage of producing a metal by electrolysis is that:

electrolysis uses a large amount of electricity

the metal produced by electrolysis is very pure

electrolysis is a very cheap method of extraction

electrolysis is the only method of extracting unreactive metals

Drugi mogući odgovor:

steam

blue

colourless

white

water

Drugi mogući odgovor:

paler

decreased

hydrogen iodide

darker

iodine

hydrogen

(c) Calculate the number of atoms combined in one mole of copper iodide, CuI₂.
(Avogadro constant = 6.02 \times 10^{23})
______ x 10²⁴

When a metal corrodes

the metal reacts with nitrogen

the metal reacts with another metal

the metal element decomposes

the metal is oxidised

After a few days the two boiling tubes were examined. The results are shown in Figure 5.
boiling tube A: the appearance of the iron rod is unchanged
the magnesium has started to disappear
boiling tube B: a small amount of brown deposit has formed around the rod
Explain the results of this experiment.

Hydrazine, N_2H_4, reacts with oxygen.
N_2H_4 + O_2 \rightarrow N_2 + 2H_2O
A metal in water corrodes faster than an identical piece of metal in the same volume of water containing dissolved hydrazine. Use the information to explain how hydrazine slows corrosion.

(d) Ammonia is used to make hydrazine.

In the industrial process to manufacture ammonia, nitrogen and hydrogen are combined in the presence of an iron catalyst.

N_2 + 3H_2 \rightleftharpoons 2NH_3

State the name of the industrial process to manufacture ammonia.

Predict the effect that adding the catalyst has on the rate of attainment of equilibrium.

Predict the effect that adding the catalyst has on the equilibrium yield of ammonia.

Pieces of zinc react with copper sulfate solution. Zinc sulfate solution is colourless.

Zn(s) + CuSO4(aq) → ZnSO4(aq) + Cu(s)

Describe what you would see when an excess of zinc is added to copper sulfate solution and the mixture left until the reaction is complete. (2)

This reaction is described as a redox reaction.
Explain, in terms of electrons, which particles have been oxidised and which particles have been reduced in this reaction. (4)

The copper sulfate solution used has a concentration of 15.95 \, \text{g dm}^{-3}.

Calculate the number of moles of copper sulfate, \text{CuSO}_4, in 50.00 \, \text{cm}^3 of this solution. (relative atomic masses: \text{O} = 16, \text{S} = 32, \text{Cu} = 63.5)

number of moles of copper sulfate = ..................... mol

In another experiment, 0.043 \, \text{mol} of copper sulfate, \text{CuSO}_4, is used.

Calculate, to one decimal place, the minimum mass of zinc that must be added to react with all the copper sulfate. (relative atomic mass: \text{Zn} = 65)

mass = ..................... g

X and Y are solutions of two different acids. The concentration of acid in each solution, in mol dm-3, is the same. Solution X has a pH of 3.40 and solution Y has a pH of 4.40.

State what could be used to measure these pH values of 3.40 and 4.40.

What is the concentration of hydrogen ions in solution X compared with that in solution Y?

ten times lower

lower by a factor of 3.30/4.40

higher by a factor of 4.40/3.30

ten times higher

.....................................................................................................

(b) An experiment is planned to record the change in pH as a powdered base is added to 50 \, \text{cm}^3 dilute hydrochloric acid.

The method suggested is:

add dilute hydrochloric acid up to the 50 \, \text{cm}^3 mark on a beaker
add one spatula of the base and stir
measure the pH of the mixture
repeat steps 2 and 3 until the pH stops changing.

(i) State how you could change the method so that the amounts of dilute hydrochloric acid and of the base can be measured more accurately. (2)
dilute hydrochloric acid .......................................................................................................................
.....................................................................................................................................................................
base ..............................................................................................................................................................
.....................................................................................................................................................................

(ii) During the experiment the pH changes from 2 to 10. If phenolphthalein indicator is added at the beginning of the experiment, a colour change occurs as the base is added.
State the colour change that occurs. (1)

colour at start ..............................................................................................................................
colour at end ................................................................................................................................

(iii) Explain, in terms of the particles present, why the pH increases during the experiment. (2)
.....................................................................................................................................................................
.....................................................................................................................................................................
.....................................................................................................................................................................
.....................................................................................................................................................................

Some properties of four solids, A, B, C and D, are shown in Figure 6.

The solids, in no particular order, are copper carbonate, copper oxide, magnesium metal and sodium hydroxide.

A Colour of solid: black B Colour of solid: silver C Colour of solid: white D Colour of solid: green

Observation when solid is added to water

A: black solid remains
B: a few bubbles appear on surface of solid
C: solid dissolves and forms colourless solution
D: green solid remains

pH of mixture of solid added to water

A: 7
B: 8
C: 13
D: 7

Observation when solid is added to dilute sulfuric acid

A: on warming, solid disappears to form blue solution
B: effervescence, solid disappears to form colourless solution
C: solid disappears to form colourless solution
D: effervescence, solid disappears to form blue solution

Identify the solids A, B, C and D, explaining how the information in Figure 6 supports the identification of each solid.
(6)

(a) Nitric acid can be titrated with a solution of ammonia.

State the type of reaction occurring when nitric acid reacts with ammonia.

What salt is formed in this reaction?

ammonia nitric

ammonia nitrate

ammonium nitric

ammonium nitrate

In one stage of the production of nitric acid, nitrogen oxide, NO, is reacted with oxygen to make nitrogen dioxide, NO2.

\(2NO + O_2 \rightarrow 2NO_2\)

Calculate the minimum volume of air, measured at room temperature and pressure, required to react with 1000 g nitrogen oxide to form nitrogen dioxide.
Assume that the air contains 20% oxygen by volume. (relative atomic masses: N = 14, O = 16) 1 mol of gas occupies 24 dm3 at room temperature and pressure)

Volume of air = .......... dm3

(c) In another stage in the production of nitric acid, ammonia is reacted with oxygen to form nitrogen oxide and water.

4\text{NH}_3(g) + 5\text{O}_2(g) \rightleftharpoons 4\text{NO}(g) + 6\text{H}_2\text{O}(g)

Heat energy is given out when ammonia reacts with oxygen.

The conditions chosen for the reaction are:

excess air, rather than just the right amount
a pressure of 10 atm, rather than atmospheric pressure
a temperature of 900 °C, rather than room temperature

Paper 1 2019

Paper 1 2019

(c) Some metal objects are electroplated.State two reasons for electroplating a metal object.

(c) Some metal objects are electroplated.State two reasons for electroplating a metal object.

Periodic tableUsing the letters A, E, G, J, X and Z, give the letters of the two elements that are non-metals.

Periodic tableGive the letters of two elements in period 2. (NOTE THERE ARE IN FACT 3)

Periodic tableGive the letter of an element that normally forms an ion with a charge of +1 (GIVE BOTH).

All atoms of element E in this sample contain

Element X has an atomic number of 18. State the electronic configuration of an atom of element X.

Molten lead bromide is electrolysed.The products of this electrolysis are:

The mass of solid left in the crucible is less than the theoretical mass of calcium oxide that should be obtained. A possible reason for this is that

(d) (i) Calculate the relative formula mass of calcium carbonate, CaCO3. (relative atomic masses: C = 12, O = 16, Ca = 40)

(ii) Calculate the atom economy for the formation of calcium oxide in this reaction.CaCO_3 \rightarrow CaO + CO_2You must show your working. (relative atomic masses: C = 12, O = 16, Ca = 40; relative formula mass: calcium oxide = 56)

An advantage of producing a metal by electrolysis is that:

(c) Calculate the number of atoms combined in one mole of copper iodide, CuI2.(Avogadro constant = 6.02 \times 10^{23})______ x 1024

When a metal corrodes

After a few days the two boiling tubes were examined. The results are shown in Figure 5.boiling tube A: the appearance of the iron rod is unchangedthe magnesium has started to disappearboiling tube B: a small amount of brown deposit has formed around the rodExplain the results of this experiment.

Hydrazine, N_2H_4, reacts with oxygen.N_2H_4 + O_2 \rightarrow N_2 + 2H_2OA metal in water corrodes faster than an identical piece of metal in the same volume of water containing dissolved hydrazine. Use the information to explain how hydrazine slows corrosion.

State the name of the industrial process to manufacture ammonia.

Predict the effect that adding the catalyst has on the rate of attainment of equilibrium.

Predict the effect that adding the catalyst has on the equilibrium yield of ammonia.

Describe what you would see when an excess of zinc is added to copper sulfate solution and the mixture left until the reaction is complete. (2)

This reaction is described as a redox reaction.Explain, in terms of electrons, which particles have been oxidised and which particles have been reduced in this reaction. (4)

Calculate the number of moles of copper sulfate, \text{CuSO}_4, in 50.00 \, \text{cm}^3 of this solution. (relative atomic masses: \text{O} = 16, \text{S} = 32, \text{Cu} = 63.5)

number of moles of copper sulfate = ..................... mol

Calculate, to one decimal place, the minimum mass of zinc that must be added to react with all the copper sulfate. (relative atomic mass: \text{Zn} = 65)

mass = ..................... g

State what could be used to measure these pH values of 3.40 and 4.40.

What is the concentration of hydrogen ions in solution X compared with that in solution Y?

.....................................................................................................

.....................................................................................................

(ii) During the experiment the pH changes from 2 to 10. If phenolphthalein indicator is added at the beginning of the experiment, a colour change occurs as the base is added.State the colour change that occurs. (1)

colour at start ..............................................................................................................................colour at end ................................................................................................................................

Observation when solid is added to water

pH of mixture of solid added to water

Observation when solid is added to dilute sulfuric acid

Identify the solids A, B, C and D, explaining how the information in Figure 6 supports the identification of each solid.(6)

State the type of reaction occurring when nitric acid reacts with ammonia.

What salt is formed in this reaction?

Volume of air = .......... dm3

Explain the effect of the conditions chosen on the equilibrium yield of nitrogen oxide and on the rate of attainment of equilibrium.(6 marks)

(c) Some metal objects are electroplated.State two reasons for electroplating a metal object.

(c) Some metal objects are electroplated.State two reasons for electroplating a metal object.

Periodic tableUsing the letters A, E, G, J, X and Z, give the letters of the two elements that are non-metals.

Periodic tableGive the letters of two elements in period 2. (NOTE THERE ARE IN FACT 3)

Periodic tableGive the letter of an element that normally forms an ion with a charge of +1 (GIVE BOTH).

All atoms of element E in this sample contain

Element X has an atomic number of 18. State the electronic configuration of an atom of element X.

Molten lead bromide is electrolysed.The products of this electrolysis are:

The mass of solid left in the crucible is less than the theoretical mass of calcium oxide that should be obtained. A possible reason for this is that

(d) (i) Calculate the relative formula mass of calcium carbonate, CaCO3. (relative atomic masses: C = 12, O = 16, Ca = 40)

(ii) Calculate the atom economy for the formation of calcium oxide in this reaction.CaCO_3 \rightarrow CaO + CO_2You must show your working. (relative atomic masses: C = 12, O = 16, Ca = 40; relative formula mass: calcium oxide = 56)

An advantage of producing a metal by electrolysis is that:

(c) Calculate the number of atoms combined in one mole of copper iodide, CuI2.(Avogadro constant = 6.02 \times 10^{23})______ x 1024

When a metal corrodes

After a few days the two boiling tubes were examined. The results are shown in Figure 5.boiling tube A: the appearance of the iron rod is unchangedthe magnesium has started to disappearboiling tube B: a small amount of brown deposit has formed around the rodExplain the results of this experiment.

Hydrazine, N_2H_4, reacts with oxygen.N_2H_4 + O_2 \rightarrow N_2 + 2H_2OA metal in water corrodes faster than an identical piece of metal in the same volume of water containing dissolved hydrazine. Use the information to explain how hydrazine slows corrosion.

State the name of the industrial process to manufacture ammonia.

Predict the effect that adding the catalyst has on the rate of attainment of equilibrium.

Predict the effect that adding the catalyst has on the equilibrium yield of ammonia.

Describe what you would see when an excess of zinc is added to copper sulfate solution and the mixture left until the reaction is complete. (2)

This reaction is described as a redox reaction.Explain, in terms of electrons, which particles have been oxidised and which particles have been reduced in this reaction. (4)

Calculate the number of moles of copper sulfate, \text{CuSO}_4, in 50.00 \, \text{cm}^3 of this solution. (relative atomic masses: \text{O} = 16, \text{S} = 32, \text{Cu} = 63.5)

number of moles of copper sulfate = ..................... mol

Calculate, to one decimal place, the minimum mass of zinc that must be added to react with all the copper sulfate. (relative atomic mass: \text{Zn} = 65)

mass = ..................... g

State what could be used to measure these pH values of 3.40 and 4.40.

What is the concentration of hydrogen ions in solution X compared with that in solution Y?

.....................................................................................................

.....................................................................................................

(ii) During the experiment the pH changes from 2 to 10. If phenolphthalein indicator is added at the beginning of the experiment, a colour change occurs as the base is added.State the colour change that occurs. (1)

colour at start ..............................................................................................................................colour at end ................................................................................................................................

Observation when solid is added to water

pH of mixture of solid added to water

Observation when solid is added to dilute sulfuric acid

Identify the solids A, B, C and D, explaining how the information in Figure 6 supports the identification of each solid.(6)

State the type of reaction occurring when nitric acid reacts with ammonia.

What salt is formed in this reaction?

Volume of air = .......... dm3

Explain the effect of the conditions chosen on the equilibrium yield of nitrogen oxide and on the rate of attainment of equilibrium.(6 marks)

(c) Some metal objects are electroplated.
State two reasons for electroplating a metal object.

(c) Some metal objects are electroplated.
State two reasons for electroplating a metal object.

Periodic table
Using the letters A, E, G, J, X and Z, give the letters of the two elements that are non-metals.

Periodic table
Give the letters of two elements in period 2. (NOTE THERE ARE IN FACT 3)

Periodic table
Give the letter of an element that normally forms an ion with a charge of +1 (GIVE BOTH)
.

Molten lead bromide is electrolysed.
The products of this electrolysis are:

(d) (i) Calculate the relative formula mass of calcium carbonate, CaCO₃. (relative atomic masses: C = 12, O = 16, Ca = 40)

(ii) Calculate the atom economy for the formation of calcium oxide in this reaction.
CaCO_3 \rightarrow CaO + CO_2
You must show your working. (relative atomic masses: C = 12, O = 16, Ca = 40; relative formula mass: calcium oxide = 56)

(c) Calculate the number of atoms combined in one mole of copper iodide, CuI₂.
(Avogadro constant = 6.02 \times 10^{23})
______ x 10²⁴

Hydrazine, N_2H_4, reacts with oxygen.
N_2H_4 + O_2 \rightarrow N_2 + 2H_2O
A metal in water corrodes faster than an identical piece of metal in the same volume of water containing dissolved hydrazine. Use the information to explain how hydrazine slows corrosion.

This reaction is described as a redox reaction.
Explain, in terms of electrons, which particles have been oxidised and which particles have been reduced in this reaction. (4)

(ii) During the experiment the pH changes from 2 to 10. If phenolphthalein indicator is added at the beginning of the experiment, a colour change occurs as the base is added.
State the colour change that occurs. (1)

colour at start ..............................................................................................................................
colour at end ................................................................................................................................

Identify the solids A, B, C and D, explaining how the information in Figure 6 supports the identification of each solid.
(6)

Explain the effect of the conditions chosen on the equilibrium yield of nitrogen oxide and on the rate of attainment of equilibrium.
(6 marks)

(c) Some metal objects are electroplated.
State two reasons for electroplating a metal object.

(c) Some metal objects are electroplated.
State two reasons for electroplating a metal object.

Periodic table
Using the letters A, E, G, J, X and Z, give the letters of the two elements that are non-metals.

Periodic table
Give the letters of two elements in period 2. (NOTE THERE ARE IN FACT 3)

Periodic table
Give the letter of an element that normally forms an ion with a charge of +1 (GIVE BOTH)
.

Molten lead bromide is electrolysed.
The products of this electrolysis are:

(d) (i) Calculate the relative formula mass of calcium carbonate, CaCO₃. (relative atomic masses: C = 12, O = 16, Ca = 40)

(ii) Calculate the atom economy for the formation of calcium oxide in this reaction.
CaCO_3 \rightarrow CaO + CO_2
You must show your working. (relative atomic masses: C = 12, O = 16, Ca = 40; relative formula mass: calcium oxide = 56)

(c) Calculate the number of atoms combined in one mole of copper iodide, CuI₂.
(Avogadro constant = 6.02 \times 10^{23})
______ x 10²⁴

Hydrazine, N_2H_4, reacts with oxygen.
N_2H_4 + O_2 \rightarrow N_2 + 2H_2O
A metal in water corrodes faster than an identical piece of metal in the same volume of water containing dissolved hydrazine. Use the information to explain how hydrazine slows corrosion.

This reaction is described as a redox reaction.
Explain, in terms of electrons, which particles have been oxidised and which particles have been reduced in this reaction. (4)

(ii) During the experiment the pH changes from 2 to 10. If phenolphthalein indicator is added at the beginning of the experiment, a colour change occurs as the base is added.
State the colour change that occurs. (1)

colour at start ..............................................................................................................................
colour at end ................................................................................................................................

Identify the solids A, B, C and D, explaining how the information in Figure 6 supports the identification of each solid.
(6)

Explain the effect of the conditions chosen on the equilibrium yield of nitrogen oxide and on the rate of attainment of equilibrium.
(6 marks)