A.) Mothballs are composed primarily of the hydrocarbonnaphthalene (C10H8). When 1.025 g of naphthalene is burned in abomb calorimeter, the temperature rises from 24.25 ∘C to 32.33∘C.
Calculate the standard enthalpy of formation (ΔH∘f) fornitroglycerin. Express the change in energy in kilojoules per moleto three significant figures.
B.) The air within a piston equipped with a cylinder absorbs 575J of heat and expands from an initial volume of 0.12 L to a finalvolume of 0.83 L against an external pressure of 1.0 atm.
What is the change in internal energy of the air within thepiston?
C.) A 2.95 g lead weight, initially at 10.8 ∘C, is submerged in8.07 g of water at 51.9 ∘C in an insulated container. What is thefinal temperature of both the weight and the water at thermalequilibrium? Express the temperature in Celsiu
D.) Suppose that 24 g of each of the following substances isinitially at 26.0 ∘C. What is the final temperature of eachsubstance upon absorbing 2.40 kJ of heat?
gold
silver
aluminum
water
