Question

Calculate the energy required to heat 0.80 kg of iron from -2.3 °C to 13.0 °C. Assume the specific heat capacity of iron

under these conditions is 0.449 J•g
Round your answer to 2 significant digits.

Answer 1

To calculate the energy required to heat a substance, you can use the formula:

Energy (Q) = mass (m) x specific heat capacity (c) x change in temperature (ΔT)

Where:

• Q is the energy in joules (J).
• m is the mass in kilograms (kg).
• c is the specific heat capacity in joules per gram per degree Celsius (J/g°C).
• ΔT is the change in temperature in degrees Celsius (°C).

Given:

• Mass (m) = 0.80 kg
• Specific heat capacity (c) = 0.449 J/g°C
• Change in temperature (ΔT) = (final temperature - initial temperature) = (13.0°C - (-2.3°C)) = 15.3°C

Now, convert the specific heat capacity from J/g°C to J/kg°C (since the mass is given in kilograms):

1 g = 0.001 kg, so 0.449 J/g°C = 0.449 * 0.001 J/kg°C = 0.000449 J/kg°C

Now, you can calculate the energy required:

Q = 0.80 kg x 0.000449 J/kg°C x 15.3°C

Q ≈ 0.00548 J

Rounded to 2 significant digits, the energy required to heat 0.80 kg of iron from -2.3°C to 13.0°C is approximately 0.0055 J.

Answer 2

Step-by-step explanation:

To calculate the energy required to heat an object, we use the formula:

Q = m * c * ΔT

where Q is the energy required, m is the mass of the object, c is the specific heat capacity, and ΔT is the change in temperature.

In this case, the mass of the iron is 0.80 kg, the specific heat capacity is 0.449 J/g•°C, and the change in temperature is (13.0 °C) - (-2.3 °C) = 15.3 °C.

Now we can substitute these values into the formula:

Q = (0.80 kg) * (0.449 J/g•°C) * (15.3 °C) = 2.4 x 10^3 J.

Rounding to 2 significant digits, the energy required is 2.4 x 10^3 J.