A coffee cup calorimeter initially contains 140.g water at 22.7°C. 4.7g of a salt is added to the water and, after the salt dissolves, the final temperature is 28.0°C. Calculate the heat for the dissolving of the salt. Assume that the specific heat capacity of the solution is 4.2 J/g°C and that no heat is transferred to the surroundings or the calorimeter.

3220 J of heat released

Explanation:

-qcal = (144.7g total)(4.2 J/g degrees C)(5.3 C)

in the given question, the partial pressure is calculated by using the ideal gas equation, that is, pv = nrt

here, p is pressure, v is volume = 25 l, n is number of moles = 0.0104 moles, r is gas constant = -0.0821 l.atm / mol.k

t is temperature = 273 k

p = nrt / v

p = (0.0104 mol × 0.0821 l.atm / mol.k × 273 k) / 25 l

= 0.0093 atm