Answer
Calculate the required heat.
$$Q = cm \Delta T$$
$$=\frac{1 cal}{g \cdot ^{\circ}C}(50000 g)(20^{\circ}C ) = 1000000 cal = 1000 kcal$$
Now convert to joules.
$$1000000 cal \frac{4.19 J}{1 cal} = 4190 kJ$$
Work Step by Step
The conversion factor is on page 289.
