Question

What amount of heat is required to increase the temperature of 75.0 grams of gold from 150°C to 250°C? The specific heat of gold is 0.13 J/g°C.
A.
750 joules
B.
980 joules
C.
1300 joules
D.
1500 joules
E.
2500 joules

Answer 1

To find the amount of heat required to increase the temperature of gold, we can use the formula:

\[ Q = mc\Delta T \]

where:
- \( Q \) is the heat absorbed or released (in joules),
- \( m \) is the mass (in grams),
- \( c \) is the specific heat capacity (in J/g°C),
- \( \Delta T \) is the change in temperature (in °C).

Given:
- \( m = 75.0 \) grams,
- \( c = 0.13 \) J/g°C,
- Initial temperature \( T_i = 150°C \),
- Final temperature \( T_f = 250°C \).

First, we calculate the change in temperature:

\[ \Delta T = T_f - T_i = 250°C - 150°C = 100°C \]

Now we can substitute the values into the equation:

\[ Q = (75.0 \, \text{g}) \times (0.13 \, \text{J/g°C}) \times (100 \, \text{°C}) \]

Calculating \( Q \):

\[ Q = 75.0 \times 0.13 \times 100 \]

\[ Q = 75.0 \times 13 \]

\[ Q = 975 \, \text{J} \]

Since none of the options exactly match our calculation, but 980 joules (option B) is the closest.

Therefore, the answer is:
**B. 980 joules**.