Question

For a process at constant pressure, 1.24 × 104 calories of heat are released. this quantity of heat is equivalent to

a) 5.18 × 104 joules
b) 5.18 × 103 joules
c) 1.24 × 107 joules
d) 1.24 × 106 joules

Answer 1

To convert the given heat from calories to joules, we multiply 1.24 × 10⁴ calories by the conversion factor 4.184 J/cal, which results in 5.18 × 10⁴ joules, making option (a) the correct answer.

Step-by-step explanation:

The student asked about converting a quantity of heat from calories to joules for a process occurring at constant pressure. To do this, we use the conversion factor: 1 calorie = 4.184 joules. The given quantity of heat is 1.24 × 10⁴ calories, and we calculate its equivalent in joules by multiplying by the conversion factor.

1.24 × 10⁴ cal × 4.184 J/cal = 5.18816 × 10⁴ J

After rounding to three significant figures, the equivalent quantity of heat in joules is 5.18 × 10⁴ joules (Option a).