Answer:
ΔH°rxn = -827.5 kJ
Explanation:
Let's consider the following balanced equation.
2 PbS(s) + 3 O₂(g) → 2 PbO(s) + 2 SO₂(g)
We can calculate the standard enthalpy of reaction (ΔH°rxn) from the standard enthalpies of formation (ΔH°f) using the following expression.
ΔH°rxn = [2 mol × ΔH°f(PbO(s)) + 2 mol × ΔH°f(SO₂(g)
)] - [2 mol × ΔH°f(PbS(s)) + 3 mol × ΔH°f(O₂(g)
)]
ΔH°rxn = [2 mol × ΔH°f(PbO(s)) + 2 mol × ΔH°f(SO₂(g)
)] - [2 mol × ΔH°f(PbS(s)) + 3 mol × ΔH°f(O₂(g)
)]
ΔH°rxn = [2 mol × (-217.32 kJ/mol) + 2 mol × (-296.83)] - [2 mol × (-100.4) + 3 mol × 0 kJ/mol]
ΔH°rxn = -827.5 kJ
Molarity is a measure of a solution's concentration calculation by getting the ratio of the number of moles of solute to the total volume of solution. This has a unit of M or molar, equivalent to mole/L.
It is more important and meaningful to know the molarity rather than if the solution is dilute or concentrated because molarity gives the QUANTITATIVE approach of knowing the concentration while the second one only gives us the QUALITATIVE description of the solution. Hence, we are able to calculate for other unknown parameters if we have the molarity known.
Answer:
Answer C
Explanation:
Heat is used to turn the solid ice into liquid water
Those are both correct! great job, keep up the good work (-:
