Final answer:
To find the energy released as a 5.5 gram sample of iron cools from 52°C to 22°C, the specific heat of iron (0.449 J/g°C) is multiplied by the mass and the temperature change, resulting in 73.9 J after rounding to the nearest tenth of a joule.
Step-by-step explanation:
To calculate the energy released as a 5.5 gram sample of iron cools from 52°C to 22°C, we use the formula q = mcΔT, where q is the heat energy in joules, m is the mass of the sample in grams, c is the specific heat capacity of iron, and ΔT is the change in temperature. The specific heat capacity (c) of iron is given in several of the exercises as 0.449 J/g°C or 0.451 J/g°C. We will use the former, 0.449 J/g°C, for this calculation since that value appears more frequently in the provided exercises. The change in temperature (ΔT) is 52°C - 22°C = 30°C.
Substituting the values into the formula we get:
q = (5.5 g) × (0.449 J/g°C) × (30°C)
Thus, the calculation is:
q = 5.5 × 0.449 × 30
q = 73.935 J
After rounding to the nearest tenth of a joule, the energy released is 73.9 J.