Ncert – class 9- science – Chapter 1 – Matter in Our Surroundings 1 Welcome to your Ncert - class 9- science - Chapter 1 – Matter in Our Surroundings 1 1. Match Column I with Column II and select the correct option from the codes given belowColumn IColumn II(a) Drying of clothes on a windy day(i) Time taken for evaporation increases(b) Liquefaction of gases(ii) Decreasing pressure and increasing temperature(c) Change in state of dry ice from solid to gas(iii) Increasing pressure and decreasing temperature(d) Less cooling effect of sweating in coastal areas(iv) Rate of evaporation increases a - (iv), b - (iii), c - (ii), d - (i) a - (iii), b - (iv), c - (ii), d - (i) a - (i), b - (ii), c - (iii), d - (iv) a - (iv), b - (iii), c - (i), d - (ii) None 2. Which of the following is the BEST indicator of the actual amount of water vapour in the air? Relative humidity Air temperature Dew point temperature Saturation vapour pressure None 3. Select the correct alternativeThe molecules can move freely anywhere in_____ state. solid liquid none of the above gaseous None 4. Which among the following have moderate intermolecular forces? Gases Equal in liquids and gases both Solids Liquids None 5. The molecules: in a liquid move within its boundary. in solid, liquid and gas move freely anywhere. in a gas move only within its boundary. in a solid move freely within its boundary. None 6. What is the effect on the chemical and physical properties of water when the temperature is changed? There is no effect on the chemical or physical properties of water when the temperature is changed. The chemical properties of water remain the same but the physical state changes with a temperature change. The chemical properties of water change with temperature change but physical properties remain the same. Both chemical and physical properties of water change with a temperature change. None 7. Latent heat is evolved during the transformation of liquids into solids. How will you explain this statements? None of the above Heat is absorbed and temperature increases Heat does not get absorbed nor released Heat is released and temperature decreases None 8. A fully inflated balloon goes higher in the atmosphere, so what will be the pressure outside and inside the balloon respectively. Increases, Remains constant Decreases, Remains constant Decreases, Increases Increases, Decreases None 9. The heat gained or lost during a change of state from solid to liquid or from liquid to solid is called the latent heat of ....... fusion freezing vaporisation condensation None 10. Which one of the following statement is correct ? Boiling is a bulk phenomenon, but evaporation is a surface phenomenon Both boiling and evaporation are bulk phenomena. Boiling is a surface phenomenon, but evaporation is a bulk phenomenon Both boiling and evaporation are surface phenomena. None 11. Identify the correct statement about gases: Gases have definite shapes. Gases can not be compressed easily. Gases occupy the entire space of the container. Gases can not flow. None 12. The temperature of melting ice remains constant for some time even if we continue to supply heat to the beaker. This is because of the heat energy ? is used to change the pressure on the particles is used to bring the particles of matter closer is used to overcome the forces of attraction between the particles is radiated out None 13. The process by which molecules undergo a spontaneous transition from the liquid phase to the gaseous phase is called as: evaporation freezing sublimation condensation None 14. Statement I : Evaporation causes cooling.Statement II: Particles of liquid absorb energy from the surrounding to regain the energy lost during evaporation. Both statements I and II are true, statement II is not the correct explanation for statement I. Both statements I and II are true, statement II is correct explanation for statement I. Statement I is false and statement II is true. Statement I is true and statement II is false. None 15. Which one of the following statement is correct in respect of fluids? Gases and liquid behave as fluids Only liquids behave as fluids Only gases behave as fluids Gases and solids behave as fluids None 16. Evaporation of a liquid takes place at: a fixed temperature higher than its boiling point. all temperatures. any temperature lower than its boiling point. a fixed temperature and pressure. None 17. Which of the following is a correct statement? The inter-particle force of attraction between the molecules in a liquid is either more or less when compared to solids. The inter-particle force of attraction between the molecules in a liquid is less when compared to solids. There is no inter-particle force of attraction between the molecules in a liquid. The inter-particle force of attraction between the molecules in a liquid is more when compared to solids. None 18. The percentage of para hydrogen in ordinary hydrogen increases when? None Pressure is increased and temperature is decreased Temperature is increased Temperature is lowered None 19. During change of state of matter, the temperature remains the same due to: lattice energy less supply of heat loss of heat latent heat None 20. Evaporative cooling is the phenomenon _____________. in which density of liquid changes none of these in which molecule of liquid with high kinetic energy evaporates quickly, leaving behind the particle of less kinetic energy in which molecule of liquid with low kinetic energy evaporates quickly, leaving behind the particle of high kinetic energy None Time's up Please Share This Share this content Opens in a new window Opens in a new window Opens in a new window Opens in a new window Opens in a new window Opens in a new window Opens in a new window Opens in a new window Opens in a new window Opens in a new window Leave a Reply Cancel replyCommentEnter your name or username to commentEnter your email address to commentEnter your website URL (optional) Save my name, email, and website in this browser for the next time I comment.
