Calculate the number of kilojoules to warm 125 g of iron from 23.5°c to 78.0°c.

3065.63 J = 3.066 kJ.

Explanation:

Q = m.c.ΔT,

where, Q is the amount of heat needed to warm Fe (Q = ??? J).

m is the mass of Fe (m = 125.0 g).

c is the specific heat capacity of Fe (c = 0.45 J/g.°C).  

ΔT is the difference in T (ΔT = final temperature - initial temperature = 78.0°C - 23.5°C = 54.5°C).

∴ Q = m.c.ΔT = (125.0 g)(0.45 J/g.°C)(54.5°C) = 3065.63 J = 3.066 kJ.

answer; ///(d) the correct answer is double or triple

a compound is a molecule made of atoms from different elements.

a. by the combination of an unlimited number of elements