Question

A mass of stainless steel spoon is $0.04kg$ and specific heat is $0.50kJ/kg \times ^\circ C.$
Then calculate the heat which is required to raise the temperature $20^\circ C$ to $50^\circ C$ of the spoon.
A. $200J$
B. $400J$
C. $600J$
D. $800J$
E. $1,000J$

Answer 1

Heat required is the product of mass, specific heat and the raise in temperature. Use this formula and the given information to solve this question.

Complete step by step answer:
Heat required to raise the temperature of a body is given by the product of mass, specific heat and the rise in temperature. i.e.
$Q = ms\Delta T$
Where,
$\Delta T$ is the change in temperature
$Q$ is the amount of heat absorbed or released
$m$ is mass of the body
$s$ is specific heat of the body.
It is given in the question that,
Mass of the stainless spoon is $m = 0.04kg$
Its specific heat is $s = 0.50kJ/kg \times {}^0C = 500J/kg{}^0C$
And the change in temperature is given by $\Delta T = 50^\circ C - 20^\circ C = 30^\circ C$
now, by substituting these values in the formula, we get
$Q = ms\Delta T$
$= 0.04 \times 500 \times 30$
$\Rightarrow Q = 600J$
Thus, the heat required is $600J$ to rise the temperature from $20^\circ C$ to $50^\circ C$

Therefore, from the above explanation the correct option is (C) $600J$.

Note: Specific heat capacity is defined as the amount of heat required to raise the temperature of 1 kilogram of a substance by 1 kelvin. The SI unit of specific heat capacity is $Jk{g^{ - 1}}{K^{ - 1}}$
In this question, we converted the specific heat into joules from kilojoules to convert it into SI units. But we didn’t convert ${}^0C$ into Kelvin. Ideally, we should have done that. But since, in this question, the rise in temperature was also given in ${}^0C$ the solution didn’t change.