Question

Calculate the heat evolved when 248 g of white phosphorus $P_4$ burns in air according to equation
$P_4\left(s\right)+5O_2\left(g\right)\to P_4{O}_{10}\left(s\right)$ $\Delta H=-3013kJ/mole$

• A. $4266$ kJ
• B. $9026$ kJ
• C. $3013$ kJ
• D. $6026$ kJ

Answer 1

The correct option is D $6026$ kJ

Number of moles of $P_4$ = $\frac{248}{124}$ = 2 mol
As per the reaction, heat evolved for 1 mole of $P_4$ consumed = $3013$ kJ
So heat evolved for 2 moles of $P_4$ = $2\times 3013$ kJ
$6026$ kJ