How much energy is required to decompose 800 g of pcl3, according to the reaction below? the molar mass of pcl3 is 137.32 g/mol and may be useful. 4 pcl3 (g) → p4 (s) + 6 cl2 (g) δh∘rxn = + 1207 kj how much energy is required to decompose 800 of, according to the reaction below? the molar mass of is 137.32 and may be useful. 4 (g) (s) + 6 (g) = + 1207 1.76*103 kj 4.53*103 kj 2.31*103 kj 6.72*103 kj 5.90*103 kj?

First, we have to get the no. of moles of PCl3:

no. of moles of PCl3 = mass/molar mass of PCl3

when we have mass = 800 g & molar mass of PCl3 = 137.32 g / mol

so by substitution:

no. of moles of PCl3 = 800 g / 137.32 g/mol

= 5.83 mol

from the balanced equation:

4PCl3 (g) → P4 (s) + 6Cl (g) ΔH = + 1207 KJ

we can see that 4 mol of PCl3 need 1207 KJ to be decomposed

So 5.83mol of PCl3 need X KJ?

∴energy required = 1207 KJ * 5.83 mol / 4 mol

=1.76*10^3 KJ