Question 4.sp.1: A reaction releases 421 kJ of energy. How many kilocalories ...

[1] Identify the original quantity and the desired quantity.

421 kJ                  ? kcal
original quantity           desired quantity

[2] Write out the conversion factors.
• Choose the conversion factor that places the unwanted unit, kilojoules, in the denominator so that the units cancel.

[3] Set up and solve the problem.
• Multiply the original quantity by the conversion factor to obtain the desired quantity.