Please check my answers for questions 7, 8, and 9.

Let's check your answers for questions 7, 8, and 9.

• 7.a.i) Name: 2-methylpropane ✅ Correct.

• 7.a.ii) Name: Butan-2-yne ❌ Incorrect. The longest carbon chain in $\text{CH}_3-\text{CH}_2-\text{C}\equiv\text{C}-\text{CH}_3$ has 5 carbon atoms, so the prefix should be "pent-". The correct name is Pent-2-yne.

• 7.b) Chemical test to distinguish between 2-methylpropane and pent-2-yne ✅ Correct. Your explanation is accurate.

• 8.a) Gay-Lussac's Law ✅ Correct. Your definition is accurate.

• 8.b) Volume of gas formed ✅ Correct. The volume of $\text{CO}_2$ formed is 20 cm$^3$.

• 9.a) Products formed when a candle burns in air ✅ Correct. The products are carbon dioxide and water.

• 9.b.i) Observation made in the combustion tube ✅ Correct. The silvery-white magnesium ribbon turns into a white solid.

• 9.b.ii) Name gas Y ✅ Correct. Gas Y is Hydrogen.