CHEM J-8 June Answer: THE REMAINDER OF THIS PAGE IS FOR ROUGH WORKING ONLY.

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1 CHEM J-8 June 2014 A 1.0 kg sample of copper metal is heated to C. The copper sample is immersed in a volume of water initially at 25.0 C. What volume of water is required so that the final temperature of the copper is 40.0 C? Show all working. Data: Specific heat capacity of Cu(s) is 0.39 J K 1 g 1. Specific heat capacity of H 2 O(l) is J K 1 g 1. The density of water is 1.0 g ml 1. 3 THE REMAINDER OF THIS PAGE IS FOR ROUGH WORKING ONLY.

2 CHEM N-9 November 2014 Lead shot was traditionally made by dropping molten lead into a tank of water. A piece of lead, initially at 327 C is dropped into ml of water raising its temperature from 25 to 35 C. What was the weight of the lead? Data: Specific heat capacity of Pb is J K 1 g 1 Specific heat capacity of H 2 O(l) is J K 1 g 1 The density of water is 1.0 g ml 1 2 THE REMAINDER OF THIS PAGE IS FOR ROUGH WORKING ONLY.

3 CHEM J-8 June L of water is heated to 95 o C and then solid copper, initially at 25 o C, is immersed in it. What mass of copper was added if the final temperature of the water was 84 o C? Show all working. Data: Specific heat capacity of Cu(s) is 0.39 J g 1 K 1. Specific heat capacity of H 2 O(l) is J g 1 K 1. The density of water is 1.0 g ml 1. 3

4 CHEM J-9 June 2012 A 2.5 kg block of aluminium is heated to 80.0 C and then placed into a thermally insulated water bath consisting of 10.0 L of water at 25.0 C. Calculate the final temperature of the water once equilibrium has been reached. Show all working. Data: Specific heat capacity of Al(s) is J g 1 K 1. Specific heat capacity of H 2 O(l) is J g 1 K 1. The density of water is 1 g ml 1. 3

5 CHEM N-10 November 2012 How many 2.0 L casks of wine and/or juices can be cooled on a hot Sydney day from 30 o C to a drinkable 10 o C with one 10.0 kg bag of ice taken from a freezer at 30 o C? Assume the specific heat of the wine and/or juice is the same as that of water, that the cardboard or plastic containers have negligible heat capacity, and that the density of the wine and juices is 1.0 g ml 1. Δ fus H(H 2 O) = 6.0 kj mol 1 ; C p (H 2 O(s)) = 2.2 J K 1 g 1 ; C p (H 2 O(l)) = 4.2 J K 1 g 1 6 What other assumption have you made in your calculation?

6 CHEM J-15 June 2010 Consider two blocks of steel: block A is 1.00 kg and block B is 600. g. Both blocks start from the same temperature and are heated so that 600. J flows into each of the blocks in the form of heat. What is the final difference in temperature, T A -T B, between block A and block B. The specific heat of steel is J g 1 K 1. Show all working. 2

7 CHEM N-7 November 2010 Water solutions of NaOH (100.0 ml, 2.0 M) and HCl (100.0 ml, 2.0 M), both at 24.6 C, were mixed together in a coffee cup calorimeter. The temperature of the solution rose to 38.0 C during the reaction process. Write a balanced ionic equation to describe the reaction in the calorimeter. 5 Is the process an endothermic or exothermic reaction? Assuming a perfect calorimeter, determine the standard enthalpy change for the neutralisation reaction. Assume the density of water is 1.00 g ml 1. The heat capacity of water is 4.18 J g 1 K 1. THE REMAINDER OF THIS PAGE IS FOR ROUGH WORKING ONLY. Page Total:

8 CHEM J-12 22/05(a) A radiator generates 150 J to heat up air inside a sealed container with volume of 2.00 L and initially at 25 C and atmospheric pressure. What will be the pressure inside the container after heating? Assume that air is composed of 80 % nitrogen and 20 % oxygen by volume. Specific heat capacities: N J K 1 mol 1 and O J K 1 mol 1 5 Pressure: If this heated air is injected into a balloon, it will rise. Use the ideal gas equation to explain why this happens.

9 CHEM J-6 June 2006 At room temperature and pressure (RTP), 1 mole of an ideal gas occupies L. Calculate the molar volume of the same ideal gas in the stratosphere, where the pressure is atm and the temperature is 200 K. 2 Two blocks of metal, as shown in the table below, are placed in intimate contact in an insulated environment. 4 Metal Iron Copper Mass (g) Initial T ( C) c (J g 1 K 1 ) In which direction will the heat flow? Write from Fe to Cu or from Cu to Fe. What is the final temperature of the system?

10 CHEM J-7 June 2005 Methane, CH 4, represents an increasingly important fuel. Write the balanced chemical equation for the combustion of methane. 4 Calculate the mass of CO 2 that would be produced by the combustion of 1.00 kg of methane. Calculate the volume of CO 2 produced at 0 C and 1 atm. In an inefficient combustion reaction some of the methane gas may escape into the atmosphere, thereby decreasing the amount of CO 2 produced. Would such a leakage lead to a greater or lesser enhancement of the Greenhouse Effect? Why?

11 CHEM N-7 November 2004 Two students determined the specific heat capacity of steel as follows. Student 1 poured 200 ml of recently boiled water into a styrofoam cup calorimeter and measured the temperature of the water to be 90.0 C. A steel teaspoon (25 g) at room temperature (20.0 C) was placed into the cup, where it was completely submerged. After equilibrium was presumably reached, the temperature was measured to be 88.7 C. Student 2 took the same cup and filled it with 200 ml of water at room temperature (20.0 C) and placed the same teaspoon from the freezer ( 40.0 C) into the cup. After equilibrium was presumably reached, the temperature recorded was 19.2 C. Determine the specific heat capacity of steel using the experimental data of each student. The specific heat capacity of water is J g 1 K 1. Assume the density of water is 1.00 g ml 1 at all temperatures. 5 Student 1: Student 2: Which student's value is more accurate? Give reasons for your answer.

Compiled by Rahul Arora What do you mean by corrosion? How can you prevent it?

Compiled by Rahul Arora What do you mean by corrosion? How can you prevent it? Rahul Arora 12. What do you mean by corrosion? How can you prevent it? 13. MnO2 + 4HCl MnCl2 + 2H2O + Cl2 In the above equation, name the compound which is oxidized and which is reduced? 14. Match the