Question

how much heat is needed to change the temperature of 3 grams of gold (c = 0.129 $\frac{j}{g^{circ}c}$) from 21°c to 363°c? the answer is expressed to the nearest whole number. 121 joules 132 joules 140 joules 149 joules

Explanation:

Step1: Identify the formula

The formula for heat $Q = mc\Delta T$, where $m$ is mass, $c$ is specific - heat capacity, and $\Delta T$ is change in temperature.

Step2: Calculate the change in temperature

$\Delta T=T_2 - T_1=363^{\circ}C - 21^{\circ}C = 342^{\circ}C$

Step3: Identify given values

$m = 3g$ and $c=0.129\frac{J}{g^{\circ}C}$

Step4: Substitute values into formula

$Q=mc\Delta T=3g\times0.129\frac{J}{g^{\circ}C}\times342^{\circ}C$
$Q = 3\times0.129\times342J$
$Q=3\times44 = 132J$ (rounded to the nearest whole number)

Answer:

132 joules