Question

A chemical reaction requires 31.39 kJ. How many kilocalories does this correspond to?

Answer 1

7.502 kilo calories

Step-by-step explanation:

We are given;

• Quantity of heat, Q as 31.39 kJ

We are required to convert it to kilo calories

First, we convert it to Joules

1 kJ = 1000 J

Therefore;

31.39 kJ will be equivalent to 31390 Joules

Second we convert Joules to calories using a suitable conversion factor

The suitable conversion factor is 4.184 J/Cal

Thus;

31390 Joules will be equivalent to;

= 31390 J ÷ 4.184 J/Cal

= 7502.39 Cal

Third, we convert calories to kilo calories

1 kCal = 1000 cal

Therefore;

7502. 39 Cal will be equivalent to;

= 7502.39 ÷ 1000

= 7.50239

=7.502 kilo calories

Hence, 31.39 kJ will correspond to 7.502 kilo calories