Question #23703

1 Answer
Apr 1, 2015

Heat lost equals heat gained.
The hot metal transfers heat to the cooler water until both temperatures are equal. The equation for heat gained or lost is
Q = mcΔT. Q is the heat, m is the mass, c is the specific heat capacity, and ΔT is the change in temperature.
In the case of the metal mass, Q is lost. Water gains the heat. So:
36.835 g x c x (100-29)°C = 30 g x 4.186 J/g°C x (29.0-22.1)°C
The metal's specific heat capacity is 0.331 J/g°C.

 To convert this to a molar form you will need to identify the metal, most likely using the specific heat value. However, I haven't been able to find a metal that matches this value. The closest elements I found are arsenic, germanium, and selenium. 
 Convert one gram of the element to a molar amount. ( **For example**, 1 g of Na would be 1/22.99 = 0.0435 mol Na.) Substitute the amount you determine for your sample into the specific heat value and calculate the value of 0.331/(# of mol).  If the metal were sodium (it isn't), you would have 0.331J/0.0435 mol °C = 7.61 J/mol°C.