When a gas expands, 227 J of work is performed and 117 J of heat is transferred to the surroundings. In this example, the normal convention for sign indicate that ___. both work and heat are negative both work and heat are positive work is negative and heat is positive work is positive and heat is negative

A system gains 20.4 J of internal energy while doing 30.0 J of work.  Does heat enter or escape from the system?  How much heat?

17.0  J of heat is added to 10.00 g of gold, which is initially at 25°C.The heat capacity of gold is 25.41 J/(mol • °C).  What would be the final temperature of the gold?

10 A student heats 84.17 mL of water to 95.27°C using a hot plate. The heated water is added to a calorimeter containing 73.92 mL of cold water. The water temperature in the calorimeter rises from 2.15°C to 37.48°C. The specific heat capacity of water is 4.184 J and the density of water is g. °C 1.00 mL Assuming that heat was transferred from the hot water to the cold water and the calorimeter, determine the heat capacity of the calorimeter. J Heat capacity of calorimeter = °C

15.0  J of heat is added to 10.00 g of gold, which is initially at 25°C.The heat capacity of gold is 25.41 J/(mol • °C).  What would be the final temperature of the gold?

A house is built with a granite countertop. The heat capacity of the countertop is 156.0 kJ/°C. A hot pan of water is placed on the countertop, and 7500 J of heat energy is transferred into the countertop. By how much does the temperature of the countertop change?

A mixture of helium and hydrogen gas is compressed from a volume of 81.0 L to a volume of 70.0 L, while the pressure is held constant at 34.0 atm. Calculate the work done on the gas mixture. Be sure your answer has the correct sign (positive or negative) and the correct number of significant digits.

Calculate AEfor a chemical reaction that produces 432.0 kJ of heat but does no work on its surroundings. kJ

When a sample of titanium was supplied 1.00 kJ of energy, the temperature rose 103.5 °C. If the specific heat of titanium is 0.523 J/g · °C, what is the mass of the titanium sample?