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. During change of state of matter, the temperature remains the same due to: loss of heat latent heat lattice energy less supply of heat None 2. Evaporation of a liquid takes place at: any temperature lower than its boiling point. all temperatures. a fixed temperature higher than its boiling point. a fixed temperature and pressure. None 3. The process by which molecules undergo a spontaneous transition from the liquid phase to the gaseous phase is called as: evaporation sublimation condensation freezing None 4. The percentage of para hydrogen in ordinary hydrogen increases when? Pressure is increased and temperature is decreased Temperature is increased Temperature is lowered None None 5. Which among the following have moderate intermolecular forces? Solids Liquids Equal in liquids and gases both Gases None 6. 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 - (iv), b - (iii), c - (i), d - (ii) a - (i), b - (ii), c - (iii), d - (iv) None 7. The molecules: in a liquid move within its boundary. in solid, liquid and gas move freely anywhere. in a solid move freely within its boundary. in a gas move only within its boundary. None 8. Which one of the following statement is correct in respect of fluids? Only gases behave as fluids Gases and liquid behave as fluids Gases and solids behave as fluids Only liquids behave as fluids None 9. Latent heat is evolved during the transformation of liquids into solids. How will you explain this statements? Heat is released and temperature decreases Heat is absorbed and temperature increases None of the above Heat does not get absorbed nor released None 10. 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 Increases, Decreases Decreases, Increases None 11. 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 ....... condensation fusion freezing vaporisation None 12. Identify the correct statement about gases: Gases can not flow. Gases occupy the entire space of the container. Gases have definite shapes. Gases can not be compressed easily. None 13. What is the effect on the chemical and 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. There is no effect on the chemical or physical properties of water when the temperature is changed. 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 14. 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 bring the particles of matter closer is used to overcome the forces of attraction between the particles is used to change the pressure on the particles is radiated out None 15. Which one of the following statement is correct ? Boiling is a bulk phenomenon, but evaporation is a surface phenomenon Both boiling and evaporation are surface phenomena. Both boiling and evaporation are bulk phenomena. Boiling is a surface phenomenon, but evaporation is a bulk phenomenon None 16. Which of the following is the BEST indicator of the actual amount of water vapour in the air? Dew point temperature Air temperature Saturation vapour pressure Relative humidity None 17. Which of the following is a correct statement? The inter-particle force of attraction between the molecules in a liquid is more 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 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. None 18. Evaporative cooling is the phenomenon _____________. in which molecule of liquid with high kinetic energy evaporates quickly, leaving behind the particle of less kinetic energy none of these in which density of liquid changes in which molecule of liquid with low kinetic energy evaporates quickly, leaving behind the particle of high kinetic energy None 19. 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 correct explanation for statement I. Statement I is true and statement II is false. Both statements I and II are true, statement II is not the correct explanation for statement I. Statement I is false and statement II is true. None 20. Select the correct alternativeThe molecules can move freely anywhere in_____ state. gaseous liquid none of the above solid 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.
