A 175 g piece of iron and a 175 g piece

of aluminum are placed in a hot water

bath so that they are warmed to 99.7/C.

The metal samples are removed and

cooled to 21.5/C. Which sample

undergoes the greater heat change?

(Al; -12.3 kJ Fe; - 6.08 kJ)

please help

Answer : The sample undergoes the greater heat change is, aluminum.

Explanation :

Specific heat capacity : It is defined as the amount of heat absorbed by one gram of a substance to raise its temperature by one degree Celsius.

Formula used for specific heat capacity :

where,

C = specific heat capacity

m = mass of a substance

q = heat required

= change in temperature of substance

As we know that the heat change is directly proportional to the specific heat capacity  at constant temperature and mass that means higher the specific heat capacity, the higher will be the heat change and vice-versa.

The specific heat capacity  of iron and aluminum is, 0.449 J/g.°C and 0.903 J/g.°C respectively.

From this we conclude that the specific heat capacity of aluminum is greater than iron. So, aluminium sample undergoes the greater heat change.

Hence, the sample undergoes the greater heat change is, aluminum.

atomic mass = 39

number of neutrons = 20

number of protons= 19

electronic configuration = 1s2 2s2 2p6 3s2 3p6 4s1

the number of electron in first shell = 2

number of electrons in n=3 shell = 8