Question

copper metal has a specific heat of 0.385 j/g·°c. calculate the amount of heat required to raise the temperature of a 22.8 g sample of copper from 20.0 °c to 875 °c. 1.22 kj 10.5 kj 7.51 kj 1.97 kj 329 kj

Explanation:

Step1: Calculate the temperature change

The formula for temperature change $\Delta T$ is $\Delta T=T_{final}-T_{initial}$.
Given $T_{initial} = 20.0\ ^{\circ}C$ and $T_{final}=875\ ^{\circ}C$, so $\Delta T=875 - 20.0=855\ ^{\circ}C$.

Step2: Use the heat - transfer formula

The heat - transfer formula is $q = mc\Delta T$, where $m$ is the mass, $c$ is the specific heat capacity, and $\Delta T$ is the temperature change.
Given $m = 22.8\ g$, $c=0.385\ J/g\cdot^{\circ}C$, and $\Delta T = 855\ ^{\circ}C$.
Substitute the values into the formula: $q=(22.8\ g)\times(0.385\ J/g\cdot^{\circ}C)\times(855\ ^{\circ}C)$.
First, calculate $(22.8\times0.385)=8.778$.
Then, $q = 8.778\times855\ J$.
$q=7505.19\ J$.

Step3: Convert joules to kilojoules

Since $1\ kJ = 1000\ J$, then $q=\frac{7505.19\ J}{1000}=7.50519\ kJ\approx7.51\ kJ$.

Answer:

7.51 kJ