# Problem: Potassium nitrate, KNO3, has a molar mass of 101.1 g/mol. In a constant-pressure calorimeter, 32.3 g of KNO3 is dissolved in 243 g of water at 23.00 °C.KNO3(s)+H2O(aq) →  KOH(aq)+HNO3(aq)The temperature of the resulting solution decreases to 17.90 °C. Assume the resulting solution has the same specific heat as water, 4.184 J/(g·°C), and that there is negligible heat loss to the surroundings.1. How much heat was released by the solution?2. What is the enthalpy of the reaction?

###### FREE Expert Solution
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###### FREE Expert Solution

Calculate the amount of heat released in the reaction

• Since no heat is lost to the surroundings: qsystem = 0

The heat (q) of the solution can be calculated using:

Where

m is the mass of the solution

c is the specific heat of water (4.1801 J/g-k)

∆T is the change in temperature (Tfinal - Tinitial)

87% (113 ratings)
###### Problem Details

Potassium nitrate, KNO3, has a molar mass of 101.1 g/mol. In a constant-pressure calorimeter, 32.3 g of KNO3 is dissolved in 243 g of water at 23.00 °C.

KNO3(s)+H2O(aq) →  KOH(aq)+HNO3(aq)

The temperature of the resulting solution decreases to 17.90 °C. Assume the resulting solution has the same specific heat as water, 4.184 J/(g·°C), and that there is negligible heat loss to the surroundings.

1. How much heat was released by the solution?

2. What is the enthalpy of the reaction?

What scientific concept do you need to know in order to solve this problem?

Our tutors have indicated that to solve this problem you will need to apply the Thermochemical Equations concept. You can view video lessons to learn Thermochemical Equations Or if you need more Thermochemical Equations practice, you can also practice Thermochemical Equations practice problems .

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