What quantity of heat (in kJ) will be absorbed by a 33.1 g piece of aluminum (specific heat = 0.930 J/g °C) as it changes temperature from 23.0 °C to 67.0 °C?

Alloys When a 58.8-g piece of hot alloy is placed in125 g of cold water in a calorimeter, the temperature ofthe alloy decreases by 106.1°C, while the temperature ofthe water increases by 10.5°C. What is the specific heat ofthe alloy?

In a calorimetric experiment, 6.48 g of lithium hydroxide, LiOH, was dissolved in water. The temperature of the calorimeter rose from 25.00C to 36.66C. What is H for the solution process? LiOH(s)Li(aq)+OH(aq) The heat capacity of the calorimeter and its contents is 547 J/C.

Enthalpy a A 100.-g sample of water is placed in an insulated container and allowed to come to room temperature at 21C. To heat the water sample to 41C, how much heat must you add to it? b Consider the hypothetical reaction,2X(aq)+Y(l)X2Y(aq)being run in an insulated container that contains 100. g of solution. If the temperature of the solution changes from 21C to 31C, how much heat does the chemical reaction produce? How does this answer compare with that in part a? (You can assume that this solution is so dilute that it has the same heat capacity as pure water.) c If you wanted the temperature of 100. g of this solution to increase from 21C to 51C, how much heat would you have to add to it? (Try to answer this question without using a formula.) d If you had added 0.02 mol of X and 0.01 mol of Y to form the solution in part b, how many moles of X and Y would you need to bring about the temperature change described in part c. e Judging on the basis of your answers so far, what is the enthalpy of the reaction 2X(aq) + Y(l) X2Y(aq)?

When calcium carbonate, CaCO3 (the major constituent of limestone and seashells), is heated, it decomposes to calcium oxide (quicklime). CaCO3(s)CaO(s)+CO2(g);H=177.9kJ How much heat is required to decompose 21.3 g of calcium carbonate?

A 110.-g sample of copper (specific heat capacity = 0.20 J/C g) is heated to 82.4C and then placed in a container of water at 22.3C. The final temperature of the water and copper is 24.9C. What is the mass of the water in the container, assuming that all the heat lost by the copper is gained by the water?

If 125 J of heat energy is applied to a block of silver weighing 29.3 g, by how many degrees will the temperature of the silver increase? (See Table 10.1.)

You have two samples of different metals, metal A and metal B, each having the same mass. You heat both metals to 95C and then place each one into separate beakers containing the same quantity of water at 25C. a You measure the temperatures of the water in the two beakers when each metal has cooled by 10C and find that the temperature of the water with metal A is higher than the temperature of the water with metal B. Which metal has the greater specific heat? Explain. b After waiting a period of time, the temperature of the water in each beaker rises to a maximum value. In which beaker does the water temperature rise to the higher value, the one with metal A or the one with metal B? Explain.

A 0.470-g sample of magnesium reacts with 200 g dilute HCl in a coffee-cup calorimeter to form MgCl2(aq) and H2(g). The temperature increases by 10.9 C as the magnesium reacts. Assume that the mixture has the same specific heat as water and a mass of 200 g. (a) Calculate the enthalpy change for the reaction. Is the process exothermic or endothermic? (b) Write the chemical equation and evaluate H.

9.45 What happens to the temperature of a material as it undergoes an endothermic phase change? If heat is added, how can the temperature behave in this manner?