GCSE Chemistry 5 — Questions and Answers
Question 1: Which type of radiation is the most penetrating and requires thick lead or concrete to stop it?
- Alpha radiation
- Beta radiation
- Gamma radiation (Correct answer)
- Neutron radiation
Correct answer: Gamma radiation
Gamma radiation consists of high-energy electromagnetic waves with no mass or charge, making it the most penetrating type.
Question 2: What is produced when an alkene undergoes an addition reaction with hydrogen (hydrogenation)?
- An alcohol
- An alkane (Correct answer)
- A carboxylic acid
- An ester
Correct answer: An alkane
Hydrogenation of an alkene adds H2 across the double bond, converting it to a saturated alkane.
Question 3: Which of the following is a property of giant ionic lattices?
- They conduct electricity when solid
- They have low melting points
- They are soluble in non-polar solvents
- They conduct electricity when molten or dissolved in water (Correct answer)
Correct answer: They conduct electricity when molten or dissolved in water
Ionic compounds only conduct electricity when molten or dissolved because the ions are then free to move and carry charge.
Question 4: The Haber process produces ammonia from nitrogen and hydrogen. What are typical conditions used?
- 450°C, 200 atmospheres, iron catalyst (Correct answer)
- 100°C, 1 atmosphere, platinum catalyst
- 800°C, 50 atmospheres, vanadium oxide catalyst
- 250°C, 500 atmospheres, nickel catalyst
Correct answer: 450°C, 200 atmospheres, iron catalyst
The Haber process uses about 450°C, 200 atmospheres pressure, and an iron catalyst as a compromise between yield and reaction rate.
Question 5: Which functional group is present in carboxylic acids?
- −OH
- −COO−
- −COOH (Correct answer)
- −CHO
Correct answer: −COOH
Carboxylic acids contain the −COOH (carboxyl) group, which consists of a carbonyl and a hydroxyl group bonded to the same carbon.
Question 6: A student tests an unknown solution with universal indicator and it turns yellow. What does this indicate?
- The solution is strongly acidic (pH 1–2)
- The solution is weakly acidic (pH 5–6) (Correct answer)
- The solution is neutral (pH 7)
- The solution is weakly alkaline (pH 8–9)
Correct answer: The solution is weakly acidic (pH 5–6)
Yellow on a universal indicator corresponds to a weakly acidic solution with a pH of approximately 5–6.
Question 7: During the fractional distillation of crude oil, which fraction is collected at the lowest temperature?
- Bitumen
- Diesel
- Kerosene
- Refinery gases (Correct answer)
Correct answer: Refinery gases
Refinery gases (such as methane, ethane, propane) have the shortest carbon chains, lowest boiling points, and are collected at the top of the fractionating column at the lowest temperature.
GCSE Chemistry 5
Which type of radiation is the most penetrating and requires thick lead or concrete to stop it?