Question

Calculate the heat of hydration of copper (II) sulfate pentahydrate given that 5.00 g of the hydrate was dissolved in 100.0 mL of water at 25°C, and the resulting solution temperature increased from 25°C to 30°C. The molar mass of copper (II) sulfate pentahydrate is 249.685 g/mol and the specific heat capacity of water is 4.184 J/g°C.

Answer 1

First, we need to calculate the moles of copper  II  sulfate pentahydrate that were dissolved:moles = mass / molar massmoles = 5.00 g / 249.685 g/molmoles = 0.02003 molNext, we need to calculate the heat absorbed by the water:q = mass x specific heat capacity x change in temperatureq = 100.0 g x 4.184 J/gC x  30C - 25C q = 100.0 g x 4.184 J/gC x 5Cq = 2092 JNow, we can calculate the heat of hydration per mole of copper  II  sulfate pentahydrate:heat of hydration = q / molesheat of hydration = 2092 J / 0.02003 molheat of hydration = 104,450 J/molThe heat of hydration of copper  II  sulfate pentahydrate is approximately 104,450 J/mol.