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The specific heat capacity of liquid mercury is 0.14 J/g-K. How many joules of heat are needed to raise the temperature of 5.00 g of mercury from 36.0 °C to 75.0 °C?

A.78 J
B.27 J
C.7.2 x 10⁻⁴
D.1.5 J
E. 1.4 x 10³

1 Answer

5 votes

Final answer:

To find the joules of heat needed to raise the temperature of mercury, use the formula Q = m × c × ΔT. The calculation yields 27.3 J, so the correct answer is 27 J. Option B is correct.

Step-by-step explanation:

To calculate the amount of heat required to raise the temperature of a given mass of a substance, we'll use the formula:

Q = m × c × ΔT

Where:

Q is the heat in joules (J)

m is the mass of the substance in grams (g)

c is the specific heat capacity of the substance in J/g-K

ΔT is the change in temperature in degrees Celsius (°C)

For our problem: the mass (m) is 5.00 g of mercury, the specific heat capacity (c) is 0.14 J/g-K, and the change in temperature (ΔT) is 75.0 °C - 36.0 °C which equals 39.0 °C. Plugging these values into our formula:

Q = 5.00 g × 0.14 J/g-K × 39.0 °C

Q = 27.3 J

Therefore, the correct answer is B.27 J.

To calculate the amount of heat needed, we can use the equation:

q = m * c * ΔT

Where q is the heat energy, m is the mass, c is the specific heat capacity, and ΔT is the change in temperature.

Given:

Mass of mercury (m) = 5.00 g

Specific heat capacity of mercury (c) = 0.14 J/g-K

Change in temperature (ΔT) = (75.0 °C - 36.0 °C) = 39.0 °C

Substituting these values into the equation, we have:

q = 5.00 g * 0.14 J/g-K * 39.0 °C

q = 27.3 J

Therefore, the correct answer is B. 27 J.

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