Q1. What type of change takes place when food we eat gets digested?
- Chemical change
- Reversible change
- Physical change
- Reversible chemical change
- Q2. Why do we separate ethyl alcohol and water by fractional distillation?
- The difference in the boiling point of the liquids is less than 30oC.
- Because water is a universal solvent.
- Because both of them are liquids.
- All of the above
- Q3. The separation of two immiscible liquids by a separating funnel depends upon
- The difference in their boiling points.
- The difference in their melting points.
- The difference in their colours.
- The difference in their densities.
- Q4. What is the principle behind the process of centrifugation?
- Lighter particles are forced to the bottom and denser particles stay at the top when spun rapidly.
- Denser particles are forced to the bottom and lighter particles stay at the top when spun rapidly.
- Particles are separated based on the difference in temperature.
- Particles are separated based on the difference in colour.
- Q5. In the fractional distillation of air, which component of air gets separated as dry ice?
- Hydrogen
- Oxygen
- Carbon dioxide
- Nitrogen
- Q6. Which of the following statements is correct about a chemical change?
- The chemical change is always accompanied with the liberation or absorption of energy.
- There is no change in weight of substance.
- No new products are formed.
- The change is temporary and reversible.
- Q7. Evaporation can be used to separate which type of mixture?
- Liquid-liquid mixture
- Liquid-gas mixture
- Gas-Solid mixture
- Liquid-solid mixture
- Q8. Why is ink not heated directly while separating coloured components from it?
- To save fuel used in burner.
- To prevent blackening of evaporating dish.
- To prevent breaking of evaporating dish.
- To avoid decomposition of dye components.
- Q9. Which of the following is an element?
- Water
- Tin
- Hydrogen sulphide
- Ammonia
- Q10. Which of the following will form a homogeneous mixture?
- Sand and water
- Oil and water
- Salt and water
- Chalk powder and water
Q11. Which of the following reactions involve a chemical change?- Freezing of water
- Weathering of rocks
- Ripening of fruits
- Copper metal drawn into wires
- Q12. 100 mL solution contains 3.5 g salt. The mass by volume percentage (m/v) of the solution is:
- 3.5 %
- 35 %
- 25 %
- 2.5 %
- Q13. During crystallisation, the clear solution obtained after filtration is heated till
- The colour of solution changes.
- A saturated solution is obtained.
- The volume of solution reduces to half.
- The solution starts boiling.
- Q14. From a chemical laboratory, which of the following is used for chromatographic technique?
- Funnel
- Filter paper
- Burner
- Wire gauze
- Q15. Which of the following substances will not dissolve in water?
- Carbon
- Sodium chloride
- Copper sulphate
- Sugar
- Q16. A mixture of iron dust and sulphur powder can be separated by
- Hand picking
- Dissolving sulphur in sulphuric acid
- Using a magnet
- Filtration
- Q17. What precaution should be taken while separating the coloured components of ink?
- Ink should not be heated directly.
- Ink should be heated directly at low temperature.
- Ink should be heated directly at high temperature.
- None of the above
- Q18. Which of the following methods can be used to separate a mixture of camphor and sugar?
- Sublimation
- Crystallisation
- Filtration
- Distillation
- Q19. Burning of a candle is an example of
- Physical change
- Chemical change
- Physical and chemical change
- Reversible change
- Q20. In cities, gutter water is filtered through
- Special water filters
- Metallic filters
- Sedimentation tank
- Coarse sand layer
- Q21. A solution in which no more solute can be dissolved at a given temperature is known as
- Dilute solution
- Unsaturated solution
- Saturated solution
- True solution
- Q22. The formation of water from oxygen and hydrogen is a _______ .
- Physical change
- Chemical change
- Reversible change
- Both Physical and Reversible change
- Q23. Which of the following substances does not undergo sublimation?
- Copper sulphate
- Naphthalene
- Ammonium chloride
- Camphor
- Q24. Which of the following will show Tyndall effect?
- Clouds
- Fog
- Sugar solution
- Both Clouds and Fog
- Q25. Which of the following statements is true about evaporation?
- Evaporation can be used to separate volatile component (solvent) from its non-volatile component (solute).
- Evaporation can be used to separate mixture of solids-solids.
- Evaporation is used to separate pigments from plants.
- Evaporation helps in separating liquid-liquid mixtures.
- Q26. Most paints are
- Emulsions
- Gels
- Sols
- Suspensions
- Q27. Which of the following statements is not true?
- The solubility of solids in liquids increases on increasing the temperature.
- The solubility of gases in liquids decreases on increasing the temperature.
- The solubility of gases in liquids increases on increasing the temperature.
- The solubility of solids in liquids remain unaffected by changes in pressure.
- Q28. Which of the following parameters of a substance does not alter during a physical change?
- Size
- State
- Mass
- Volume
- Q29. The components of crude petroleum get separated at different heights depending upon their _______ in the fractional distillation column.
- melting points
- boiling points
- colour
- density
- Q30. Which of the following involves physical change?
- Grinding
- Tearing
- Cutting
- All of the above
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