[thermodynamics]

∆h_rxn = -670kj

45.8 g

Step-by-step explanation:

M_r: 34.08

         2H₂S + SO₂ ⇌ 3S + 2H₂O ; ΔH°r =  -670 kJ

1. Calculate the moles of H₂S

Treat the heat as if it were a product in the equation. Then use the molar ratio (2 mol H₂S/670 kJ) in the usual way.

Moles of H₂S = 450 kJ × 2 mol H₂S/670 kJ = 1.343 mol H₂S

2. Calculate the mass of H₂S

Mass of H₂S = 1.343 mol H₂S × (34.08 g H₂S/1 mol H₂S) = 45.8 g H₂S

You need 45.8 g of H₂S to produce 450 kJ of energy.

what are the two models

explanation:

c. because step up transformer steps up the input voltage i.e increases the input voltage  

the number of turns are greater on the secondary side of step up transformer  

transformer does not handle dc current