CIE iGCSE Co-Ordinated Science C12.4 Separation and purification Exam Style Questions Paper 1
Question
A mixture contains solid P dissolved in liquid Q.
Which process is used to obtain a pure sample of liquid Q from this mixture?
A crystallisation
B distillation
C evaporation
D paper chromatography
▶️Answer/Explanation
Ans : B
Question
A student adds excess copper oxide powder to warm dilute sulfuric acid.
Aqueous copper sulfate is formed.
Which method is used to remove the unreacted copper oxide?
A chromatography
B crystallisation
C distillation
D filtration
▶️Answer/Explanation
Ans : D
Question
An aqueous salt solution contains an insoluble impurity.
Which processes are used to obtain pure salt crystals?
(A) distillation then crystallisation
(B) distillation then chromatography
(C) filtration then crystallisation
(D) filtration then chromatography
▶️Answer/Explanation
Ans : C
Question
A sample of water contains two useful substances, insoluble chalk and a soluble salt.
Which two processes are used to individually separate the insoluble chalk from the soluble salt and from the water?
(A) distillation and chromatography
(B) distillation and crystallisation
(C) filtration and chromatography
(D) filtration and crystallisation
▶️Answer/Explanation
Ans: D
Question
Which method can be used to separate graphite from dilute nitric acid?
A. Chromatography
B. Crystallisation
C. Distillation
D. Filtration
▶️Answer/Explanation
Answer: D
Explanation: Filtration is used to separate insoluble solids (like graphite) from liquids (like dilute nitric acid). The solid remains on the filter paper, while the liquid passes through.
Question
A sample of water is contaminated with insoluble chalk and a soluble salt.
Which two processes are used to separate the water from the chalk and salt?
A. distillation and chromatography
B. distillation and crystallisation
C. filtration and chromatography
D. filtration and crystallisation
▶️Answer/Explanation
Answer: D. filtration and crystallisation
Explanation: Filtration is used to separate the insoluble chalk from the water, and crystallisation is used to separate the soluble salt from the water by evaporating the water and leaving the salt behind.
Question
An aqueous salt solution contains an insoluble impurity. Which processes are used to obtain pure salt crystals?
A) distillation then crystallisation
B) distillation then chromatography
C) filtration then crystallisation
D) filtration then chromatography
▶️Answer/Explanation
Answer: C) filtration then crystallisation
Explanation: Filtration is used to remove the insoluble impurity, and crystallisation is used to obtain pure salt crystals from the filtered solution.
Question
A mixture of solid sulfur and solid sodium chloride is added to water and stirred. Sulfur is insoluble in water. Sodium chloride is soluble in water. Which processes are used to obtain pure sodium chloride from the mixture?
A. distillation then chromatography
B. distillation then crystallisation
C. filtration then chromatography
D. filtration then crystallisation
▶️Answer/Explanation
Answer: D. filtration then crystallisation
Explanation: Filtration is used to separate the insoluble sulfur from the solution of sodium chloride. Crystallisation is then used to obtain pure sodium chloride by evaporating the water from the solution.
Question
How is copper sulfate separated from aqueous copper sulfate?
A. chromatography
B. crystallisation
C. filtration
D. fractional distillation
▶️Answer/Explanation
Answer: B. crystallisation
Explanation: Crystallisation is the process by which a solid is separated from a solution by evaporating the solvent, leaving behind the solid crystals. This method is commonly used to separate salts like copper sulfate from their aqueous solutions.