Chemistry SL Paper 2, May 2025, TZ3

Determine the molecular formula and the empirical formula of cresolphthalein.

Cresolphthalein is manufactured from 2-methylphenol, $\ce{CH3C6H4OH}$. State an equation that shows 2-methylphenol acting as a Brønsted–Lowry acid.

The kinetic molecular theory describes matter as particles in constant motion. State and explain two physical properties of a gas using this model.

An equilibrium mixture in a 25.0 $\mathrm{dm^3}$ reactor at 500 °C contains 15.0 mol $\ce{N2}$, 22.5 mol $\ce{H2}$ and 5.25 mol $\ce{NH3}$. Calculate the equilibrium constant, $K$, for the reaction.

The volume of the reactor containing the equilibrium mixture described in 3a is suddenly increased at constant temperature. Sketch, on the axes below, how the concentration of hydrogen changes with time until the new equilibrium is established.

State the IUPAC name of compound Y.

Calculate the percentage by mass of hydrogen in compound Y, giving your answer to four significant figures. Use section 7 of the data booklet.

Draw the structural formula of one structural isomer of compound Y.

Compound Y undergoes nucleophilic substitution with a hydroxide nucleophile. (i) Describe the movement of electron pairs during the reaction using curly arrows. (ii) Contrast homolytic and heterolytic fission of the C–Cl bond in compound Y. (iii) Explain,…

90.0 $\mathrm{cm^3}$ of buta-1,3-diene and 150.0 $\mathrm{cm^3}$ of hydrogen are mixed in a container at 450 K and 101 kPa and react to form butane only. Determine the maximum volume of butane that can be formed, measured at the same temperature and pressure.

Determine the total volume of gas present in the container at the end of the reaction described in 5a, under the same conditions of temperature and pressure.

Sodium ions are produced at the anode from the sodium atoms stored in the hard carbon. (i) State the half-equation for the reaction occurring at the anode while the battery discharges. (ii) The battery is rechargeable. Annotate the diagram below to show the…

Suggest why banks of sodium-ion batteries are often installed alongside wind turbines.

(i) State the electron configuration of a nitrogen atom. (ii) Draw the Lewis formula of ammonia. (iii) Deduce the electron domain geometry and the molecular geometry of the ammonia molecule. (iv) Explain why the ammonia molecule is polar.

Nitrogen dioxide reacts with rain water and oxygen to form nitric acid. (i) State an equation for this reaction, including state symbols. (ii) Explain, with reference to the oxidation states of two elements, why this is a redox reaction. (iii) Describe the…

Nitric acid can form hydrogen bonds with water. Annotate the structures below to show the formation of a hydrogen bond between a molecule of nitric acid and a molecule of water. Use a dotted line to represent the hydrogen bond.

Discuss the melting points in the table below in terms of the bonding and/or intermolecular forces present in each substance. Substance Melting point / K Silicon dioxide (quartz) 1986 Poly(propene) 433

(i) State the equation for the formation of glucose by photosynthesis. (ii) Outline two advantages of using biobutanol rather than petrol (gasoline) as a fuel for vehicles.

Calculate the rise in temperature of 400.0 $\mathrm{cm^3}$ of water heated by the complete combustion of 2.00 g of butan-1-ol, assuming that all the energy released is transferred to the water. Use sections 2 and 14 of the data booklet.