Question

Calculate the heat evolved when 496 g of white phosphorus $P_4$ burns in air according to equation
$P_4\left(s\right)+5O_2\left(g\right)\to P_4{O}_{10}\left(s\right)$ $\Delta H=-3013kJ/mol$

• A. $60226kJ$
• B. $12052kJ$
• C. $1252kJ$
• D. $3052kJ$

Answer 1

The correct option is B $12052kJ$

Number of moles of $P_4$ = $\frac{496}{124}$ = 4 mol
As per the reaction, heat evolved for 1 mole of $P_4$ consumed = $3013$ kJ
So heat evolved for 4 moles of $P_4$ = $4\times 3013$ kJ
$12052$ kJ