∆H ° rxn =-2855.56 kJ
<h3>Further explanation</h3>
Given
ΔHf CO₂ = -393.5 kJ/mol
ΔHf H₂O = -241.82 kJ/mol
ΔHf C₂H₆ = - 84.68 kJ/mol
Reaction
2C2H6(g) + 7O2(g) -> 4CO2(g) + 6H2O(g)
Required
ΔHrxn=
Solution
<em>∆H ° rxn = ∑n ∆Hf ° (product) - ∑n ∆Hf ° (reactants) </em>
∆H ° rxn = (4.-393.5+6.-241.82)-(2.-84.68)
∆H ° rxn = (-1574-1450.92)-(-169.36)
∆H ° rxn =-3024.92+169.36
∆H ° rxn =-2855.56 kJ
Molarity of solution = 1.6 M
<h3>Further explanation</h3>
Given
40 g NaOH
6 L solution
Required
Steps to solve the problem of molarity
Solution
No additional information about the question.
If you want to make the solution above, then we just need to put the existing NaOH (40 g) into 6 L of water, then do the stirring (in a warm temperature above the hot plate will speed up the NaOH dissolving process)
But if you want to know the molarity of a solution, then
- 1. we calculate the moles of NaOH

MW(molecular weight) of NaOH=
Ar Na+ Ar O + Ar H
23 + 16 + 1 = 40 g/mol
so mol NaOH :


Answer:
15g
Explanation:
The equation for the reaction is given below:
CaO + SO2 —> CaSO3
Molar Mass of CaO = 40 + 16 = 56g/mol
Molar Mass of CaSO3 = 40 + 32 + (16x3) = 40 + 32 + 48 = 120g/mol
From the equation,
56g of CaO produced 120g of CaSO3.
Therefore, 7g of CaO will produce = (7 x 120)/56 = 15g of CaSO3
Therefore, 15g of CaSO3 is produce