For the first question, we will use the calorimetry formula, which is:
Q = mcΔT
We have:
Q = is heat, 27.0 J
m = is mass, 250.0 g
ΔT = is the change in temperature, which will be, Final T - Initial T (15 - 10 = 5°C)
Now we add these values to the formula:
27.0 J = 250.0 g * c * 5°C
27.0 = 1250c
c = 0.0216 J/g°C, this is the specific heat for this metal
For the second question, we will again use the same calorimetry formula, but now we are going to look for the mass:
Q = mcΔT
We have:
Q = 5000 J
m = ?
c = 2.03 J/g°C
ΔT = 30 - 15 = 15°C
Now we add these values to the formula:
5000 J = m * 2.03 J/g°C * 15°C
5000 J = 30.45m
m = 164.2 grams, this is the mass for this question