Practice Paper 1A (HL IB Chemistry)

In which of the following species are the numbers of protons, neutrons and electrons all different?

There are six unpaired electrons in atoms of element Z. What could element Z be?

A compound of molar mass 92 g mol^-1 contains 12 g of carbon, 2 g of hydrogen and 32 g of oxygen. What is the molecular formula of the compound?

An experiment is conducted to calculate the M_r of an unknown gas of known mass.

Measurements of pressure, volume and temperature are taken during the experiment.

Which conditions of temperature and pressure would give the most accurate value of M_r?

What are the correct formulas for the following ions? 

Phosphine, PH₃, can react with a hydrogen ion, H⁺, to form the phosphonium ion.

Which type of bond is formed in this reaction?

Which of the following statements about 2-methylpropan-2-ol, CH₃C(CH₃)(OH)CH₃, are correct ? 

1. The structure contains 16 bonding pair of electrons
2. The O-C-C bond angle is 109.5 ^o
3. The total number of electrons is 32

CHCl₃ and Br₂ are both liquids at room temperature due to the existence of dipoles.

What dipoles are involved within CHCl₃ and Br₂?

What is the correct structure of the chlorite ion, ClO₂^- ?

Which of the following metals would have the highest melting point?

Which type of bonding can be described as ‘the electrostatic attraction between positive nuclei and electrons and occurs by the sharing of electrons’? 

Which statement correctly describes the trend in metallic radius in Group I elements
Na to Rb?

1. Increases moving down the group
2. Increases moving down due to the addition of electron shells
3. Decreases moving down due to increasing nuclear forces

Xylitol is an artificial sweetener used in toothpastes and chewing gum to improve their taste without impairing dental hygiene.

Which functional groups could be produced if Xylitol is oxidised under suitable conditions?

G and J are oxides of different Period 3 elements.

If one mole of J is added to water, the solution formed is neutralised by exactly one mole of G.

What could be the identities of G and J? 

An element is found in Group I of the Periodic Table, below lithium and sodium. From this information it is likely that the element is a metal with 

Which volume of oxygen measured at room temperature and pressure is needed for complete combustion of 0.1 mol of propane? (Molar volume = 24dm³ at rtp)

Which alcohol is not likely to have a fragment at m/e at 43 in its mass spectrum?

The mass spectra of three compounds A, B and C are shown below.

What evidence from the spectra of the three compounds A, B and C, suggests they could be isomers?

A student mixed 30.0 cm³ of 0.0250 mol dm^-3 potassium hydroxide solution with 30.0 cm³ of 0.0250 mol dm^-3 nitric acid. The temperature rose by 0.50 ^oC. Assume no heat was lost to the surroundings. 

The mixture had a specific heat capacity of 4.18 J g ^-1 K^-1. 

What is the molar enthalpy change for the reaction?

The first stage in the industrial production of nitric acid from ammonia can be represented by the following equation. 

4NH₃ (g) + 5O₂ (g) ⇌ 4NO (g) + 6H₂O (g) 

Using the following standard enthalpy change of formation data, what is the value of the standard enthalpy change, ΔH^θ, for this reaction?

Which process converts glucose to ethanol during the production of bioethanol? 

The equations below show the formation of sulfur oxides from sulfur and oxygen. 

S (s) + O₂ (g) → SO ₂(g)                    = –297 kJ mol^–1 

S (s) + 1½O₂ (g) →SO₃ (g)                = –395 kJ mol^–1 

What is the enthalpy change of reaction, ΔH^Θ, of 2SO₂ (g) + O₂ (g) → 2SO₃ (g) in kJ mol^–1?

Which of the following conditions will mean a reaction is never feasible?

A 2.27 dm³ sample of nitrogen gas, measured under standard conditions, reacted with a large excess volume of hydrogen gas to produce ammonia. Only 20.0% of the nitrogen gas reacted to produce ammonia.

What mass of ammonia was made?

Which of the following factors will not affect the value of the activation energy of a reaction?

1. The presence of a catalyst.
2. Changes in temperature.
3. Changes in the concentration of the reactants.

The distribution of molecular energies in a sample of a gas at a given temperature is shown by the Boltzmann distribution graph below.

If the temperature is increased, what will happen to the position of point X?

Which systems are correctly described? 

1. Matter and energy can be transferred across the boundary of an open system
2. Only matter can be transferred across the boundary of a closed system
3. Matter and energy cannot be transferred across the boundary of an isolated system

In a reaction between 1M hydrochloric acid and an excess of marble chips (calcium carbonate) the volume of gas produced was measured against time. This is shown on the dotted line in the graph below.

The experiment was repeated, but this time using the same volume of 2M hydrochloric acid. Which line on the graph represents this experiment?

Ethyne and hydrogen are formed from methane and a dynamic equilibrium is established.

2CH₄ (g)  ⇌   3H₂ (g) +   C₂H₂ (g)                                                 

What are the units for K_c?

The diagram shows a reaction pathway for an endothermic reaction.

Which arrow represents the activation energy for the forward reaction?

The typical reactions of dilute acids include them being able to react with

1. NaHCO₃
2. Mg
3. Cu

Some species may be classified as amphiprotic, some as amphoteric and some as both. Which of the following applies to HPO₄²⁻?

Oxidation numbers can be used to balance equations. Chlorine and hot aqueous sodium hydroxide react to produce chloride ions, chlorate ions and water. 

What are the values of the coefficients p, r and s in the equation?                                     

                     pCl₂(g) + qOH^-(aq)  →  rCl^-(aq) + sClO₃^-(aq) + tH₂O(l) 

The chemistry of the Group VII elements often involves redox processes.

Which of the following statements is correct?

Ethane reacts with bromine in the presence of ultraviolet light to form dibromoethane and hydrogen bromide.

The reaction proceeds via free radical substitution involving initiation, propagation and termination steps.

What is the minimum number of free radical mechanism steps to produce dibromoethane?

Which of these compounds would act as a nucleophile?

Isomers X and Y both react with HBr.

 A mixture of X and Y is reacted with HBr.

Which three structures represent three different possible products of this reaction?

Limonene is an oil formed in the peel of citrus fruits.

Which product is formed when an excess of bromine, Br₂(l), reacts with limonene at room temperature in the dark?

Which compound has an M_r of 84.18 and will react with HBr to give a product with an M_r of 165.09?