How much heat, in kilojoules (kJ), is required to raise the temperature of 2.50kg Hg(l) from -20.0 to -6.0C? Assume a density of 13.6g/ml and a molar heat capacity of 28.0 J mol -1 C -1 for Hg(l).

Please helpppppp .... thanks in advance

4 answers

Through out the temperature range, Hg remains as liquid.
Recall that heat released or absorbed is given by
Q = m*c*(T2 - T1)
where
m = mass
c = specific heat
T = temperature
Note that molar mass of Hg is 200.6 g/mol.
Substituting,
Q = (250000 / 200.6)*(28.0)*(-6 -(-20))
Q = ?

Now solve for Q. The units are in J, so divide by 1000 to convert to kJ.

Hope this helps :3
*sorry, my conversion of 2.5 kg to g is wrong. The equation should be
Q = (2500 / 200.6)*(28.0)*(-6 -(-20))
How much heat is required to raise the temperature of a 2.0 kg of water (specific heat = 1.0 cal/g°C) from 5.0°C to 100.0°C?
Why the density of Hg is given here in above question
-from Pakistan