Illustrated Guide to Home Chemistry Experiments

Chapter 15 Laboratory: Thermochemistry and Calorimetry 273

TABLE 15-1: Heat of solution—observed and calculated data

Solute Mass

Water

temperature

Solution

temperature

Temperature

difference

Calculated

heat of solution

A. Ammonium nitrate________.___ g________.__ °C________.__ °C(+/-) ________.__ °C(+/–) ________.___ kJ/mol

B. Sodium chloride________.___ g________.__ °C________.__ °C(+/-) ________.__ °C(+/–) ________.___ kJ/mol

C. Sodium hydroxide________.___ g________.__ °C________.__ °C(+/-) ________.__ °C(+/–) ________.___ kJ/mol

RQEWEvI UESTIOnS

q 1 : Using your experimental data, calculate the heats of solution for ammonium nitrate, sodium chloride, and sodium hydroxide.
Enter your calculated values in Table 15-1.

q: 2 Look up published values for the heats of solution of those three compounds on the Internet or in a printed reference. How
closely do the values that you obtained experimentally correspond to the published values? If your values are significantly different,
propose possible explanations.