#1
Which of the following is not a pure substance?
Air
ExplanationAir is a mixture of gases, not a pure substance.
#2
What is the process of separating a mixture into its components using the difference in boiling points of substances?
Distillation
ExplanationDistillation utilizes differences in boiling points for component separation.
#3
What is the SI unit of temperature?
Kelvin
ExplanationKelvin is the standard unit of temperature in the International System of Units.
#4
Which of the following is an example of a physical change?
Boiling of water
ExplanationBoiling water is a physical change involving a state transition.
#5
What is the chemical symbol for gold?
Au
ExplanationAu is the chemical symbol for gold in the periodic table.
#6
Which of the following is an example of a homogeneous mixture?
Salad dressing
ExplanationSalad dressing is a homogeneous mixture with uniform composition.
#7
Which of the following is a chemical property of matter?
Reactivity
ExplanationReactivity is a characteristic of substances undergoing chemical changes.
#8
What is the principle behind chromatography?
Solubility differences
ExplanationChromatography separates based on substances' solubility variations.
#9
What is the technique used to separate a solid from a liquid using a filter paper?
Filtration
ExplanationFiltration employs filter paper to separate solid-liquid mixtures.
#10
Which of the following is a chemical change?
Rusting of iron
ExplanationRusting involves a chemical transformation of iron.
#11
What is the process of converting a solid directly into vapor without passing through the liquid state called?
Sublimation
ExplanationSublimation is the direct transition from solid to vapor.
#12
Which separation technique is commonly used in the purification of drinking water?
Filtration
ExplanationFiltration is widely used for drinking water purification.
#13
Which separation technique is based on the differences in the rate of movement of particles in a mobile phase through a stationary phase?
Chromatography
ExplanationChromatography relies on differential particle movement rates.
#14
What is the technique used to separate components of a mixture based on differences in their solubility in a solvent?
Crystallization
ExplanationCrystallization separates based on solubility variations.
#15
What is the process of converting a gas into a liquid called?
Condensation
ExplanationCondensation is the transformation of a gas into a liquid.
#16
What is the process of separating a mixture into its components by passing it through a medium that selectively retains certain particles?
Chromatography
ExplanationChromatography selectively retains particles during the separation process.
#17
What is the technique used to separate a mixture into its components based on differences in their boiling points?
Distillation
ExplanationDistillation exploits boiling point differences for component separation.