1 (a) UNIQUE SIENE EMY Test (Unit 10-11) Name :... Paper: Physics ate :... lass: 1 Time llowed: 5Minutes Maximum Marks: 25 Theory Section: [Total 16 Marks] What do you understand by the term speccific latent heat of vaporisation? 1......[2] (b) In an experiment to find the specific latent heat of vaporisation of water, it took 4 500 J of energy to evaporate 15 g of water that was originally at 100. second experiment showed that 600 J of energy was lost to the atmosphere from the apparatus during the it took to evaporate 15 g of water. alculate the specific latent heat of vaporisation of water that would be obtained from this experiment. 2 specific latent heat = [] [Total:5] Fig.2.1 shows apparatus that a student uses to make an estimate of the specific heat capacity of iron. thermometer electrical heater iron block Fig. 2.1
2 (a) The power of the heater is known. State the four readings the student must take to find the specific heat capacity of iron. 1.... 2........ 4.... [4] (b) Write down an equation, in words or in symbols, that could be used to work out the specific heat capacity of iron from the readings in (a). [1] (c) (i) Explain why the value obtained with this apparatus is higher than the actual value....... [1] (ii) State one addition to the apparatus that would help to improve the accuracy of the value obtained....... [1] [Total:7] boiler contains 5 kg of water at 22. The specific heat capacity of water is 4200 J / (kg ). (i) alculate the thermal energy (heat) needed to raise the of the water from 22 to its boiling point. (ii) energy =...[2] The water in the boiler is heated with a 2600 W immersion heater. alculate the minimum for the heater to bring the water to its boiling point. =...[2] [Total:4]
1 MQ SETION: [Total 9 Marks] The table shows the melting points and boiling points of four substances. Which substance is a liquid at a room of 20 o? substance melting point / o boiling point / o 101 5 9 57 0 2100 27 1750 2 substance is heated at a steady rate. It changes from a solid to a liquid, and then to a gas. The graph shows how its changes with. R S Q P Which parts of the graph show a change of state taking place? P and R Q and R P and S Q and S The graph shows the change in of a material as it is heated. Which part on the graph shows when the material is boiling?
4 4 1kg of water and 1 kg of aluminium are heated to the same and then allowed to cool in a room. Why does the aluminium cool more quickly than the water? luminium contracts more than water. luminium does not evaporate but water does. luminium has a higher thermal capacity than water. luminium has a lower thermal capacity than water. 5 \ The graph shows how the of hot liquid wax changes with as the wax is allowed to cool. t which labelled point on the graph are both liquid wax and solid wax present? 6 0 0 sample of a solid is heated for 12 minutes and its noted every minute. The results are shown in the table. / min 0 1 2 4 5 6 7 8 9 10 11 12 / 11.5 16.1 22.1 1.0 1.1 1.1 1.1 1. 45.0 65.2 66.2 66. 66. How should the sample be described at the end of the 12 minutes? all solid in the process of melting all liquid in the process of boiling
5 7 student carries out an experiment to find the melting point of wax. The graph shows how the of the wax changes as it cools. / X melting point of wax Y Z 8 0 0 Which statement is correct? t X the drops more slowly than at Z. t Y all the wax is solid. t Y thermal energy is being given out by the wax. t Z the wax molecules are not moving. Ice is taken from a freezer and left in a room. The ice melts and eventually the water reaches room. Which energy transfers take place? energy transfer during melting energy transfer after melting from ice to room from water to room from ice to room from room to water from room to ice from room to water from room to ice from water to room 9 n ice-cube has a mass of 7.50 g. The ice-cube is at 0. Heat from the surroundings reaches the ice-cube at an average rate of 1.25J / s. How long does it take for all of the ice to melt? (specific latent heat of fusion of ice = J / g) 5.5 s 55.5 s 2000 s 120 s 5 MQ nswer Sheet 1 6 2 7 8 4 9