Homework Answers

A 10kg block of aluminum (p=2700 kg/ m^3) is attached to a rope. Find the tension force in the rope if the block is in vacuum? What is the tension force in the rope if the block is in air (p=1.29 kg/m^3) and What is the tension force if the block is in water?

An unknown fluid, of mass 0.952 is ignited in a 4-liter bomb calorimeter. Both the liquid inside the calorimeter and the calorimeter itself increased in temperature by 3.914K. Previously, the same calorimeter was calibrated using 1.951 grams of benzoic acid and both the water and the calorimeter increased in temperature by 8.209K. Assume that the density of the water inside the calorimeter is not temperature-dependent. Heat of combustion for benzoic acid is 3226kJ per gram.

a.Find the heat of combustion of the fluid.

b.Which compound releases more heat, the unknown fluid or benzoic acid?

Suppose we have 2.0 g of ethyl alcohol at -50 degree celsius and we remove heat to it continuously. let us also assume that no heat is lost to the surroundings. How much heat is to be removed to convert this from liquid to solid at -120 degree celsius.