Question

1.) Determine the enthalpy change when 62.0 g of steam at 135.0 oC is cooled to ice at –15.0 oC. Use the actual enthalpy and heat capacity values

2.) A heater in a hot water tank gives off 30,000 KJ per hour. The initial temperature of 450 kg of water in the tank is 18.0 oC. If the tank is heated for 90 minutes, determine the final temperature of the water.

3.) In general boiling and melting points increase with molar mass. Explain why water has such high melting and boiling pts (273 K and 373 K respectively), compared to other similarly sized molecules. For example: CH4 (91 K and 109 K) and H2S (187.5 K and 212.3 K).

Answer 1