If a 375 ml sample of water was cooled from 37.5 degree C to 0 degree C, how muc
ID: 515203 • Letter: I
Question
If a 375 ml sample of water was cooled from 37.5 degree C to 0 degree C, how much heat was lost (in joules)? A 150.0 mL sample of a 1.50 M solution of CuSO_4 is mixed with a 150.0 ml sample of 300 M KOH in a coffer cup calorimeter. The temperature of both solutions and the calorimeter was 25.2 degree C before mixing and 31.3 degree C after mixing. The heat capacity of the calorimeter is 24.2 J/K. Calculate the for this reaction in units of kJ/mol of copper (II) hydroxide. Assume the solution is dilute enough that the specific heat and density of the solution is the same as that of water.Explanation / Answer
(1)
Given that,
Volume of water = 375 mL
Initial temperature, t1 = 37.50C
final temperature, t2 = 0.000C
Change in teperature, t2-t1 = 0.00 - 37.5 = - 37.5 0C
Specific heat of water, s = 4.184 J/g.0C
It is known that density of water = 1 g/mL
So, amss of water, m = 375 g.
Therefore, heat change = mass * specific heat * cahnge in temperature
q = 375 * 4.184 * (-37.5)
q = - 58837.5 J
q = heat lost by water = - 58.8 kJ