Calculate the heat energy released when 14.2 g of liquid mercury at 25.00 °C is converted to solid mercury at its melting point. Constants for mercury at 1 atm heat capacity of Hg(1) melting point enthalpy of fusion. 28.0 J/(mol-K) 0.821 234.32 K 2.29 kJ/mol %p = kJ Incorrect Answer

If you want to convert 56.0 g ice (at 0 °C) to water at 75.0 °C, calculate how many grams of propane, C3H8, you would have to bum to supply the energy to melt the ice and then warm it to the final temperature (at 1 bar).

Sublimation is the phase change from solid to gas without going through a liquid phase. Solid CO2, called dry ice, is an example of one substance that sublimed. Use Hesss law to show that the enthalpy of sublimation, subH, is equal to fusH vapH.

Benzene, C6H6, is an organic liquid that freezes at 5.5 C (Figure 11.1) to form beautiful, feather-like crystals. How much energy is evolved as heat when 15.5 g of benzene freezes at 5.5 C? (The enthalpy of fusion of benzene is 9.95 kJ/mol.) If the 15.5-g sample is remelted, again at 5.5 C, what quantity of energy is required to convert it to a liquid?

1. Which of the following processes requires the largest input of energy as heat? raising the temperature of 100 g of water by 1.0 °C vaporization of 0.10 g of water at 100 °C melting 1.0 g of ice at 0 °C warming 1.0 g of ice from −50 °C to 0 °C (specific heat of ice = 2.06 J/g · K)

Which requires the absorption of a greater amount of heat—vaporizing 100.0 g of benzene or boiling 20.0 g of water? (Use Table 8.2.)

A 0.250-g chunk of sodium metal is cautiously dropped into a mixture of 50.0 g water and 50.0 g ice, both at 0C. The reaction is 2Na(s)+2H2O(l)2NaOH(aq)+H2(g)H=368kJ Assuming no heat loss to the surroundings, will the ice melt? Assuming the final mixture has a specific heat capacity of 4.18 J/gc, calculate the final temperature. The enthalpy of fusion for ice is 6.02 kJ/mol.

A student is asked to calculate the amount of heat involved in changing 10.0 g of liquid bromine at room temperature (22.5C) to vapor at 59.0C.To do this, one must use Tables 8.1 and 8.2 for information on the specific heat, boiling point, and heat of vaporization of bromine. In addition, the following step-wise process must be followed. (a) Calculate H for: Br2(l,22.5C)Br2(l,59.0C) (b) Calculate H for: Br2(l,59.0C)Br2(g,59.0C) (c) Using Hess's law, calculate H for: Br2(l,22.5C)Br2(g,59.0C)

Are changes in state physical or chemical changes? Explain. What type of forces must be overcome to melt or vaporize a substance (are these forces intramolecular or intermolecular)? Define the molar heat of fusion and molar heat of vaporization. Why is the molar heat of vaporization of water so much larger than its molar heat of fusion? Why does the boiling point of a liquid vary with altitude?

he enthalpy (H)of vaporization of water is about seven times larger than water’s enthalpy fusion(41kJ/molvs.6kJ/mol). What does this tell us about the relative similarities among the solid, liquid, and gaseous states of water?