Physical and Inorganic 1

Which of the following contains the most chloride ions?

• 15 cm³ of 3.40 × 10⁻² mol dm⁻³ aluminium chloride solution

• 30 cm³ of 5.50 × 10⁻² mol dm⁻³ calcium chloride solution

• 40 cm3 of 2.30 × 10−2 mol dm−3 hydrochloric acid

• 45 cm³ of 2.20 × 10⁻² mol dm⁻³ sodium chloride solution

The maximum uncertainty when weighing 0.250 g on a balance was 0.001 g.

What is the percentage uncertainty?

• 4.0%

• 0.4%

• 0.8%

• 250%

Which species has the same number of electrons as the radical •CH₃?

• CH₂

• CH₃⁺

• CH₃⁻

• CH₄⁺

Line X in the diagram represents the volume (V) of gas formed with time (t) in a reaction between an excess of magnesium and aqueous sulfuric acid.

Which line represents the volume of hydrogen formed, at the same temperature and pressure, when the concentration of sulfuric acid has been halved?

• 
• 
• 
• 

Which of these species is not planar?

• HCHO

• CH₃⁺

• CH₃OH

• C₂H₄

Bromine exists as two isotopes ⁷⁹Br and ⁸¹Br, which are found in almost equal abundance.

Which of the statements is correct?

• The first ionisation energy of ⁷⁹Br is less than the first ionisation energy of ⁸¹Br

• The atomic radius of ⁷⁹Br is less than the atomic radius of ⁸¹Br

• The mass spectrum of C₃H₇Br has two molecular ion peaks at 122 and 124

• ⁷⁹Br is more reactive than ⁸¹Br

Which molecule does not have a permanent dipole?

• CH₃Cl

• CHCl₃

• CF₄

• CHCl₂F

The equation for the hydrogenation of ethyne is

C₂H₂ + 2H₂ ⟶ C₂H₆

The experimental yield is 65.0%.

What is the mass in grams of ethane that can be produced from 16.20 g of hydrogen?

• 42.53 g

• 78.98 g

• 121.5 g

• 527.7 g

What is the number of atoms in 0.0100 mol of NH₃?

(The Avogadro constant L = 6.022 × 10²³mol^-1)

• 6.02 × 10²⁵

• 1.20 × 10²³

• 1.81 × 10²²

• 2.41 × 10²²

What is the empirical formula of 4-hydroxypent-2-ene?

• C₅H₁₂O

• C₅H₁₀O

• CH₂O

• C₅H₉OH