[Maximum number: 8]

A0.50 g sample of a Group 2 metal, M, was added to $40.0 \mathrm{~cm}^{3}$ of $1.00 \mathrm{~mol} \mathrm{dm}^{-3}$ hydrochloric acid (an excess).
equation 1

\mathbf{M}(\mathrm{s})+2 \mathrm{HCl}(\mathrm{aq}) \rightarrow \mathbf{M C l}_{2}(\mathrm{aq})+\mathrm{H}_{2}(\mathrm{~g})

(a)

Calculate the amount, in moles, of hydrochloric acid present in $40.0 \mathrm{~cm}^{3}$ of $1.00 \mathrm{moldm}^{-3} \mathrm{HCl}$ .
amount = mol

[ 1 ]

(b)

When the reaction had finished, the resulting solution was made up to $100 \mathrm{~cm}^{3}$ in a volumetric flask.

A $10.0 \mathrm{~cm}^{3}$ sample of the solution from the volumetric flask required $15.0 \mathrm{~cm}^{3}$ of $0.050 \mathrm{moldm}^{-3}$ sodium carbonate solution, $\mathrm{Na}_{2} \mathrm{CO}_{3}$ , for complete neutralisation of the remaining hydrochloric acid.

[ 7 ]

(i)

Calculate the amount, in moles, of sodium carbonate needed to react with the hydrochloric acid in the $10.0 \mathrm{~cm}^{3}$ sample from the volumetric flask.
amount = mol

[ 1 ]

(ii)

Calculate the amount, in moles, of hydrochloric acid in the $10.0 \mathrm{~cm}^{3}$ sample.
amount = mol

[ 1 ]

(iii)

Calculate the total amount, in moles, of hydrochloric acid remaining after the reaction shown in equation 1.
amount = mol

[ 1 ]

(iv)

Use your answers to (a) and (b)(iv) to calculate the amount, in moles, of hydrochloric acid that reacted with the 0.50 g sample of M.
amount = mol

[ 1 ]

(v)

Use your answer to (v) and equation 1 to calculate the amount, in moles, of M in the 0.50 g sample.
amount = mol

[ 1 ]

(vi)

Calculate the relative atomic mass, $A_{r}$ , of M and identify M.
$A_{r}$ of M=
identity of M=

[ 2 ]

[Maximum number: 5]

Some intercontinental jet airliners use kerosene as fuel. The formula of kerosene may be taken as $\mathrm{C}_{14} \mathrm{H}_{30}$ .

(a)

In this section, give your answers to one decimal place.

The flight path from Beijing to Paris is approximately 8195 km .
A typical intercontinental jet airliner burns 10.8 kg of kerosene for each kilometre covered.

[ 5 ]

(i)

Calculate the mass, in tonnes, of $\mathrm{C}_{14} \mathrm{H}_{30}$ burnt on a flight from Beijing to Paris. [1 tonne = 1000 kg ]

[ 1 ]

(ii)

Use your equation in (b) to calculate the mass, in tonnes, of $\mathrm{CO}_{2}$ produced during this flight.

Bicycles may be carried on commercial airliners. When carried on airliners, bicycles are placed in the luggage hold. This is a part of the aircraft which, in flight, will have different temperatures and air pressures from those at sea level.

This question concerns the change in pressure in an inflated bicycle tyre from when it is at sea level to when it is in the hold of an airliner in flight.

[ 4 ]

[Maximum number: 3]

The elements in Group 17 are known as the halogens.

(a)

The concentration of NaClO in bleach S is $x \mathrm{gdm}^{-3}$ .

NaClO reacts with $\mathrm{H}_{2} \mathrm{O}_{2}(\mathrm{aq})$ as shown.

\mathrm{H}_{2} \mathrm{O}_{2}(\mathrm{aq})+\mathrm{NaClO}(\mathrm{aq}) \rightarrow \mathrm{H}_{2} \mathrm{O}(\mathrm{l})+\mathrm{NaCl}(\mathrm{aq})+\mathrm{O}_{2}(\mathrm{~g})

A $5.00 \mathrm{~cm}^{3}$ sample of S completely reacts with $\mathrm{H}_{2} \mathrm{O}_{2}(\mathrm{aq})$ . The volume of $\mathrm{O}_{2}(\mathrm{~g})$ produced is $24.0 \mathrm{~cm}^{3}$ under room conditions.

Assume that only the NaClO in S reacts with $\mathrm{H}_{2} \mathrm{O}_{2}(\mathrm{aq})$ .
Calculate x. Show your working.

x=

$\mathrm{g} \mathrm{dm}^{-3}$

[ 3 ]

[Maximum number: 4]

Sulfides are compounds that contain sulfur but not oxygen.

(a)

The compound $\mathrm{As}_{2} \mathrm{~S}_{3}$ is a common mineral.

When $\mathrm{As}_{2} \mathrm{~S}_{3}$ is heated strongly in air, it forms a mixture of products, as shown.

2 \mathrm{As}_{2} \mathrm{~S}_{3}(\mathrm{~s})+9 \mathrm{O}_{2}(\mathrm{~g}) \rightarrow \mathrm{As}_{4} \mathrm{O}_{6}(\mathrm{~s})+6 \mathrm{SO}_{2}(\mathrm{~g})

[ 4 ]

(i)

A sample containing $0.198 \mathrm{~g} \mathrm{As}_{2} \mathrm{~S}_{3}$ is placed in $0.100 \mathrm{dm}^{3}$ of pure oxygen, an excess, in a reaction chamber connected to a gas syringe at room temperature.

The reactants are heated until no further change is observed. The products are then allowed to cool to room temperature.

Calculate the volume, in $\mathrm{dm}^{3}$ , of gas present at the end of the experiment.
The molar volume of gas is $24.0 \mathrm{dm}^{3} \mathrm{~mol}^{-1}$ under these conditions. Assume that the pressure is constant throughout the experiment.

Show your working.
volume of gas remaining = $\mathrm{dm}^{3}$

[ 4 ]

[Maximum number: 1]

In the Periodic Table, the p block contains elements whose outer electrons are found in the p subshell.

(a)

Sulfur-containing compounds, such as $\mathrm{C}_{2} \mathrm{H}_{5} \mathrm{SH}$ , are found in fossil fuels, and produce $\mathrm{SO}_{2}$ when they are burned.

[ 1 ]

(i)

Write the equation to show the complete combustion of $\mathrm{C}_{2} \mathrm{H}_{5} \mathrm{SH}$ .

[ 1 ]

(a)

Sodium chloride is traditionally added to a particular meat product. In response to the evidence that sodium chloride can lead to high blood pressure, the manufacturers have replaced the sodium chloride with a mixture of sodium and potassium chlorides. 100 g of the meat product usually contains about 2 g of the chloride mixture.
A particular meat product contains 1.10 g of sodium chloride and 0.90 g potassium chloride in 100 g .

[ 5 ]

(i)

Calculate the volume of $0.0200 \mathrm{~mol} \mathrm{dm}^{-3}$ silver nitrate solution that would be required if this titration were carried out on 100 g of the particular meat product described above.

[ 5 ]

[Maximum number: 1]

Which contains the largest number of hydrogen atoms?

A

0.10 mol of pentane

B

0.20 mol of but-2-ene

C

1.00 mol of hydrogen molecules

D

$6.02 \times 10^{23}$ hydrogen atoms

(a)

White phosphorus, $\mathrm{P}_{4}$ , is produced commercially by heating calcium phosphate(V) rock with a mixture of silica, $\mathrm{SiO}_{2}$ , and coke in an electric furnace at $1400^{\circ} \mathrm{C}$ . Calcium silicate, $\mathrm{CaSiO}_{3}$ , and carbon monoxide are the other products.

(i)

Balance the following equation which represents the overall process. $\mathrm{Ca}_{3}\left(\mathrm{PO}_{4}\right)_{2}+$ $\mathrm{SiO}_{2}+$ c → $\mathrm{P}_{4}+$ $\mathrm{CaSiO}_{3}+$ CO

When heated to $400^{\circ} \mathrm{C}$ in the absence of air, white phosphorus is changed into the red form of the element. The following table lists some of the properties of the two forms, which are known as allotropes.

(a)

The major source of sulfur for the manufacture of sulfuric acid by the Contact process is the de-sulfurisation of 'sour' natural gas. Many natural gas wells produce a mixture of volatile hydrocarbons (mainly $\mathrm{CH}_{4}$ and $\mathrm{C}_{2} \mathrm{H}_{6}$ ) together with up to 25 % hydrogen sulfide, $\mathrm{H}_{2} \mathrm{~S}$ .

(i)

Complete and balance the following equation showing the complete combustion of a gaseous mixture consisting of 2 mol of $\mathrm{CH}_{4}, 1 \mathrm{~mol}$ of $\mathrm{C}_{2} \mathrm{H}_{6}$ and 1 mol of $\mathrm{H}_{2} \mathrm{~S}$ .

2 \mathrm{CH}_{4}+\mathrm{C}_{2} \mathrm{H}_{6}+\mathrm{H}_{2} \mathrm{~S}+\ldots \rightarrow \mathrm{SO}_{2}+\ldots+

(ii)

If a sample of natural gas contains 5 % by volume of $\mathrm{H}_{2} \mathrm{~S}$ , calculate the mass of ethanolamine required to remove all the $\mathrm{H}_{2} \mathrm{~S}$ from a $1000 \mathrm{dm}^{3}$ sample of gas, measured under room conditions.

The $\mathrm{H}_{2} \mathrm{~S}$ can be recovered by warming the solution to $120^{\circ} \mathrm{C}$ , when the above reaction is reversed. The ethanolamine can then be recycled.

(a)

The iron(II) complex ferrous bisglycinate hydrochloride is sometimes prescribed, in capsule form, to treat iron deficiency or anaemia.
A capsule containing 500 mg of this iron(II) complex was dissolved in dilute $\mathrm{H}_{2} \mathrm{SO}_{4}$ and titrated with $0.0200 \mathrm{~mol} \mathrm{dm}^{-3} \mathrm{KMnO}_{4}$ .
$18.1 \mathrm{~cm}^{3}$ of $\mathrm{KMnO}_{4}$ solution were required to reach the end point.
The equation for the titration reaction is as follows.

5 \mathrm{Fe}^{2+}+\mathrm{MnO}_{4}^{-}+8 \mathrm{H}^{+} \rightarrow 5 \mathrm{Fe}^{3+}+\mathrm{Mn}^{2+}+4 \mathrm{H}_{2} \mathrm{O}

[ 4 ]

(i)

Calculate
- the number of moles of $\mathrm{Fe}^{2+}$ in the capsule,
- the mass of iron in the capsule,
- the molar mass of the iron(II) complex, assuming 1 mol of the complex contains 1 mol of iron.

[ 4 ]

Question 1

Question 1(a)

Question 1(b)

Question 1(b)(ii)

Question 1(b)(iii)

Question 1(b)(iv)

Question 1(b)(v)

Question 1(b)(vi)

Question 1(b)(vii)

Question 1

Question 1(c)

Question 1(c)(i)

Question 1(c)(ii)

Question 1

Question 1(e)

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Question 1(d)

Question 1(d)(i)

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Question 1(c)

Question 1(c)(i)

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Question 1(b)

Question 1(b)(iii)

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Question 1(b)

Question 1(b)(i)

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Question 1(b)

Question 1(b)(i)

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