Achemical reaction requires 31.39 kj. how many kilocalories does this correspond to?

7.502 kilo calories

We are given;

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

the ideal gas law equation is as follows

pv = nrt

where p - pressure

v - volume

n - number of moles

r - universal gas constant

t - temperature

so if the pressure, volume and temperature are already known

we are left with n and r

since r is the universal gas constant that has a known fixed value then r too is known

so we are left with 'n'

once we know temperature volume and pressure

we can find the number of moles of gas present using the ideal gas law equation

this is not my own answer, this is an answer for the same question by the user blahblahmali. i do not claim ownership of this account.