CSS - PMS - CCE - PCS - General Science
Basic Chemistry - Mixtures
Which mixture of metals is called an alloy?
A. A metallic mixture such as brass
B. Sodium chloride crystal
C. Distilled water
D. Pure oxygen
Correct Answer: A
Alloys are mixtures containing a metal and one or more other elements; brass is mainly copper and zinc.
CSS - PMS - CCE - PCS - General Science
Basic Chemistry - Mixtures
Does a mixture have a fixed composition?
A. Only if it is a gas
B. Only if it is colored
C. No
D. Yes, always
Correct Answer: C
The relative amounts of components in a mixture can vary.
CSS - PMS - CCE - PCS - General Science
Basic Chemistry - Mixtures
What property mainly allows evaporation to recover a dissolved solid from solution?
A. The solute is always magnetic
B. The solvent has no mass
C. The solvent is more volatile than the solute
D. The solute becomes an element
Correct Answer: C
Evaporation removes volatile solvent, leaving less volatile dissolved material behind.
CSS - PMS - CCE - PCS - General Science
Basic Chemistry - Mixtures
Which separation technique is widely used to separate colored components in inks?
A. Crystallization only
B. Magnetic separation
C. Chromatography
D. Sedimentation only
Correct Answer: C
Chromatography separates components based on differing affinities for stationary and mobile phases.
CSS - PMS - CCE - PCS - General Science
Basic Chemistry - Mixtures
How can iron filings be separated from sulfur powder before they react?
A. By adding more sulfur
B. Using a magnet
C. By melting both together
D. By electrolysis of air
Correct Answer: B
Iron is magnetic whereas sulfur is not.
CSS - PMS - CCE - PCS - General Science
Basic Chemistry - Mixtures
Which method is suitable for separating liquids with different boiling points?
A. Filtration
B. Decanting solids only
C. Magnetization only
D. Distillation
Correct Answer: D
Distillation separates substances based on volatility and boiling-point differences.
CSS - PMS - CCE - PCS - General Science
Basic Chemistry - Mixtures
Which method can separate an insoluble solid from a liquid?
A. Filtration
B. Chromatography only
C. Distillation only
D. Sublimation only
Correct Answer: A
Filtration traps insoluble solid particles while the liquid passes through.
CSS - PMS - CCE - PCS - General Science
Basic Chemistry - Mixtures
Which is an example of a heterogeneous mixture?
A. Oil and water
B. Sugar solution
C. Brass
D. Air
Correct Answer: A
Oil and water form separate phases and are not uniform.
CSS - PMS - CCE - PCS - General Science
Basic Chemistry - Mixtures
Which is an example of a homogeneous mixture?
A. Salt solution
B. Sand and iron filings
C. Granite
D. Oil and water
Correct Answer: A
A salt solution has uniform composition at the macroscopic scale.
CSS - PMS - CCE - PCS - General Science
Basic Chemistry - Mixtures
What is a mixture?
A. A compound with fixed bonding
B. A substance with only one atom type
C. A single element only
D. A physical combination of substances in which components retain their chemical identities
Correct Answer: D
Mixtures are formed physically and can often be separated by physical methods.