Question

6) How much heat energy in J) is required to rise the temperature of 250 g plate of pure aluminum "Al” from 25 °C to 55 °C. (Cp,m of Al = 24.35 JK' mol'']

Answer 1

The amount of heat required to raise the temperature of a substance from T1 to T2 is calculated by the formula-

q = m * C * ΔT

• Where q = amount of heat required
• m = mass of that substance taken
• C = Specific heat of that substance
• ΔT = Change in temp = T2 - T1

Or if our Specific heat has the formula including the unit mo, then the mass of the substance should be converted into mols. And

• q = n * C * ΔT

where n = mols of substance

Now in our question, we are given with the information associated with Aluminum

here m = mass of Al taken =  250 g

• Then mols of Al taken = mass / molar mass of Al
• = 250 g / 27 g/mol
• = 9.259 mols

Again given C = 24.35 J/ K mol

• ΔT = T2 - T1 = 55 °C - 25 °C = 30 °C
• = 30 + 273 = 303 K

Now putting these values

• q = n * C * ΔT
• = 9.259 mols * 24.35 J/ K mol * 303 K
• = 68,313.36 J

So the total heat required is 68,313.36 J