A student investigates the enthalpy of solution, ΔHsoln for ammonium chloride, NH4Cl. In addition to the salt, the student has access to a calorimeter, a balance with a precision of ±0.1 g, and a thermometer with a precision of ±0.1°C. To measure ΔHsoln for NH4Cl, the student adds 904.0 g of water, initially at 31.0 °C to a calorimeter and adds 155 g of NH4Cl (s), stirring to dissolve. After the NH4Cl dissolves completely, the temperature of the solution is 90.0 °C. Assume the calorimeter was perfectly insulated and the specific heat of the solution was 4.2 J/(g·K). (a) Calculate the q for the dissolving of NH4Cl in water. Include units and proper sign in your answer. Show all work. (b) Calculate the ΔHsoln for NH4Cl, in kJ/molrxn. Include units and proper sign in your answer. Show all work. (c) Is the dissolving of NH4Cl endothermic or exothermic? Justify your answer.
A student investigates the enthalpy of solution, ΔHsoln for ammonium chloride, NH4Cl. In
addition to the salt, the student has access to a calorimeter, a balance with a precision of
±0.1 g, and a thermometer with a precision of ±0.1°C.
To measure ΔHsoln for NH4Cl, the student adds 904.0
g of water, initially at 31.0 °C to a calorimeter and adds 155 g of NH4Cl (s), stirring to dissolve. After the NH4Cl dissolves completely, the temperature of the solution is 90.0 °C. Assume the calorimeter was perfectly insulated and the specific heat of the
solution was 4.2 J/(g·K).
(a) Calculate the q for the dissolving of NH4Cl in water. Include units and proper sign in
your answer. Show all work.
(b) Calculate the ΔHsoln for NH4Cl, in kJ/molrxn. Include units and proper sign in your
answer. Show all work.
(c) Is the dissolving of NH4Cl endothermic or exothermic? Justify your answer.
Trending now
This is a popular solution!
Step by step
Solved in 4 steps
