Year 12 Chemistry - Summary Quiz

How many protons are there in 6.0 g of nitrogen gas?

(Avogadro constant, L = 6.022 × 10²³ mol^–1)

• 1.3 × 10²³

• 9.0 × 10²³

• 1.8 × 10²⁴

• 3.6 × 10²⁴

The diagram shows how a property of Period 3 elements varies across the period.

What is the property?

• Atomic radius

• Electronegativity

• First ionisation energy

• Melting point

Which statement about barium sulfate is correct?

• It is soluble in water at a temperature of 100 °C.

• It is used in medicine because it does not dissolve in body fluids.

• It is a pale yellow solid.

• It reacts with acidified barium chloride solution.

Which statement is correct about the reaction between concentrated sulfuric acid and solid sodium bromide?

• Bromide ions are reduced.

• Hydrogen bromide and sulfur are formed.

• Sulfuric acid acts as an oxidising agent.

• Bromine and hydrogen sulfide are formed.

Which element has the highest first ionisation energy?

• Aluminium

• Phosphorus

• Silicon

• Sulfur

A solution of volume 500 cm³ contains 150 g of ammonia.

What is the concentration, in mol dm^–3, of ammonia in this solution? (Give answer to 3sf)

A student devised an experiment to find the concentration of sulfuric acid in a sample of battery acid.

• A measuring cylinder was used to transfer 10 cm³ of battery acid to a volumetric flask.

• Distilled water was added to the volumetric flask until the volume reached 250 cm³

• A 25.0 cm³ sample of diluted acid was transferred from the volumetric flask to a conical flask using a pipette.

• A few drops of methyl orange indicator were added to the acid in the conical flask before titrating the acid with sodium hydroxide.

• The titration was repeated five times but concordant results were not obtained.

(Note: Methyl orange is red in acid and yellow in alkali.)

Which suggestion would improve the chances of obtaining concordant titres?

• Invert the volumetric flask several times after adding the distilled water.

• Wash the pipette with distilled water between each titration.

• Add extra drops of indicator to the sample when nearing the end point in each titration.

• Use a more concentrated solution of sodium hydroxide in the burette.

A student has a 10 cm³ sample of 1.00 × 10^–2 moldm^–3 methanoic acid solution.

The student is asked to dilute the methanoic acid solution to a concentration of 2.00 × 10^–4 moldm^–3 by adding distilled water.

Which volume of water should be added?

• 200 cm³

• 490 cm³

• 500 cm³

• 510 cm³

Which molecule does not have a permanent dipole?

• CH₃Br

• CH₂Br₂

• CHBr₃

• CBr₄

Which is the MAJOR product of the reaction between 2-methylbut-2-ene and iodine monochloride (ICl)?

• A

• B

• C

• D