AS & A Level Chemistry - 9701 Paper 1 2019 Winter Zone 2

The diagram shows a Boltzmann distribution of the energies of gaseous molecules and the activation energies, $E_a$, of a reaction with and without a catalyst.

Which statement about this distribution curve is correct?

In this question it should be assumed that $(NH_4)_2CO_3·H_2O(s)$ dissolves in water without causing an increase in volume.
Which mass of $(NH_4)_2CO_3·H_2O(s)$ should be added to 800 \text{cm}^3 of water to form a 0.100 \text{moldm}^{-3}$ solution of $NH_4^+$ ions?

The graph shows the successive ionisation energies of element X and element Y.
Both elements are in Period 3.

Which statement is correct?

Which statement about the electrons in a ground state carbon atom is correct?

In this question you should assume the vapour behaves as an ideal gas.
0.175g of a volatile liquid produces a vapour of volume $4.50 \times 10^{-5} \, \text{m}^3$ at $100^\circ \text{C}$ and pressure of $1.013 \times 10^5 \, \text{Pa}$.
What is the $M_r$ of the liquid?

Which reaction is endothermic?

Which equation correctly represents the standard enthalpy change of atomisation of the given element?

(NH$_4$)$_2$Cr$_2$O$_7$ decomposes when heated.
(NH$_4$)$_2$Cr$_2$O$_7$ $\rightarrow$ N$_2$ + 4H$_2$O + Cr$_2$O$_3$
Which element is oxidised and which element is reduced?

When lead(II) sulfide, PbS, is heated in air, sulfur dioxide and lead(II) oxide are formed. What is the equation for the reaction between PbS and oxygen?

The decomposition of SO$_3$(g) is a dynamic equilibrium.

2SO$_3$(g) ⇌ 2SO$_2$(g) + O$_2$(g)

What happens when the pressure of the system is increased?

Hydrated aluminium ions undergo the following reaction.
$$[Al(H_2O)_6]^{3+} \text{(aq)} + H_2O(l) \leftrightarrow [Al(H_2O)_5OH]^{2+} \text{(aq)} + H_3O^+ \text{(aq)}$$
Which statement about this reaction is correct?

Which diagram correctly shows the electronegativity of the elements Na, Mg, Al and Si plotted against their first ionisation energies?

Which statement about the compounds of Group 2 elements magnesium to barium is correct?

When equal volumes of saturated solutions of barium hydroxide and calcium hydroxide are mixed, a white precipitate, Y, forms. The mixture is filtered and carbon dioxide is bubbled through the filtrate, producing a second white precipitate, Z.
What are Y and Z?
[Table_1]

Chlorate(V) ions, $ClO_3^-$, are produced in the redox reaction between chlorine and hot aqueous sodium hydroxide. Oxidation numbers can be used to help balance the equation for this reaction.

$vCl_2(g) + wOH^-(aq) \rightarrow xCl^-(aq) + yClO_3^-(aq) + zH_2O(l)$

What are the values of $v$, $x$, and $y$ in the balanced equation?

The properties of chlorine, bromine and their compounds are compared.
Which property is \textbf{smaller} for chlorine than for bromine?

Solid sodium iodide reacts with concentrated sulfuric acid to form more than one product that contains sulfur.
What is the lowest oxidation number of sulfur in these products?

Which emission from an internal combustion engine contributes to the erosion of marble statues?

Ammonia, carbon dioxide and water react together to form ammonium carbonate.
Which statement about this reaction is correct?

Structural isomerism and stereoisomerism should be considered when answering this question.
How many isomers with the formula $\text{C}_5\text{H}_{10}$ have structures that involve $\pi$ bonding?

The diagram shows the skeletal formula of phenazine.
What is the empirical formula of phenazine?

An organic compound X reacts with hot, concentrated acidified potassium manganate(VII) solution to give a single carbon-containing product. What could be X?

1-chloro-2-methylbutane reacts with sodium cyanide in ethanol in a nucleophilic substitution reaction.
What is the most likely intermediate or transition state in this reaction?

Propan-1-ol can be reacted with acidified potassium dichromate(VI) to form propanoic acid, reaction 1, or propanal, reaction 2.



How can the reaction be carried out to ensure that reaction 2 occurs rather than reaction 1?

What is the smallest amount of oxygen molecules needed for the complete combustion of 40.0 g of methanol?

Compound X has stereoisomers and forms a precipitate when warmed with Fehling’s reagent. What could be the structure of compound X?

The diagram shows the structure of Y.
Two suggestions are made about Y.
1. Y can be oxidised by hot, acidified dichromate(VI) ions.
2. One mole of Y gives one mole of tri-iodomethane when it reacts with an excess of alkaline aqueous iodine.
Which suggestions are correct?

Esters can be prepared by the reaction of a carboxylic acid with an alcohol in the presence of concentrated sulfuric acid.
Which row gives the correct names of the reagents that would be suitable to prepare ester Z?

Compound Q can be hydrolysed by HCl(aq). The two products of this hydrolysis have the same empirical formula.
What could Q be?

Substance T was analysed and found to contain 62.07% carbon, 10.34% hydrogen and 27.59% oxygen.
The infra-red spectrum of substance T is shown.

Which substance could be T?

Which gaseous molecules are polar?
1 ammonia
2 hydrogen sulfide
3 boron trifluoride

A carbon monoxide molecule, CO, has three bonds between the carbon atom and the oxygen atom. Which features are present in one CO molecule?
1. two lone pairs of electrons
2. a co-ordinate (dative covalent) bond from oxygen to carbon
3. two $\pi$ bonds

Carbon can exist as allotropes which include graphite, diamond and a fullerene.
Which statements are correct?

1. All three allotropes contain covalent bonds.
2. All three allotropes are giant molecular.
3. All three allotropes have delocalised electrons.

The reaction pathway diagram for a reversible reaction is shown.

Which statements are correct?
1. The enthalpy change for the backward reaction is -20 kJ mol^-1.
2. The forward reaction is endothermic.
3. The activation energy for the forward reaction is +70 kJ mol^-1.

Silicon forms a tetrachloride, $\text{SiCl}_4$.
Which statements are correct?

1. In $\text{SiCl}_4$, the Si is $\delta^+$ and each Cl is $\delta^-$.
2. $\text{SiCl}_4$ is a liquid at room temperature.
3. $\text{SiCl}_4$ reacts with water to give an acidic solution and a precipitate.

Which statements about ammonia are correct?
1. An ammonia molecule has three bond pairs and one lone pair of electrons.
2. When ammonia is bubbled into water the pH of the solution increases.
3. Ammonia gas can be made by warming ammonium sulfate with aqueous hydrochloric acid.

Following fractional distillation of crude oil, which processes can be used to produce propene from larger hydrocarbon molecules?
1. cracking
2. reduction
3. polymerisation

Bromoethane undergoes nucleophilic substitution reactions.
Which statements are correct?
1. Bromoethane reacts with aqueous NaOH to make ethanol.
2. Bromoethane reacts with ethanolic NH₃ to make ethylamine.
3. Bromoethane reacts with ethanolic KCN to make ethanenitrile.

Which reagents, when used in excess, can convert Y into Z?
$$\text{CH}_3\text{CH(OH)CO}_2\text{H} \rightarrow \text{CH}_3\text{CH(OH)CO}_2\text{Na}$$
Y \hspace{2em} Z

Each of the compounds below is treated separately with an excess of NaBH$_4$.
The product of each reaction is then heated with an excess of concentrated H$_2$SO$_4$.
Which compounds give only one final product with the molecular formula C$_7$H$_{10}$?