Answer:
m(H₂O) = 97,2 g.n(H₂O) = m(H₂O) ÷ M(H₂O).n(H₂O) = 97,2 g ÷ 18
Explanation:
It's like saying that if 1 meter is equal to 100 cm,
or
You can base the answers from the chart
The answer is (3). The number of Sr is the same so if the compound has the smallest gram formula mass, it has the highest percent composition by mass of strontium. So the answer is (3).
When highly electronegative element like oxygen is directly attached to less electronegative element like hydrogen the electrons from less electronegative elements are attracted toward the highly electronegative element, making the less electronegative element deficient in electron density (partial positive) and a partial negative charge on more electronegative element is created. In such situation the intermolecular forces formed are dipole-dipole interactions or hydrogen bond interaction like in HF.
Answer:
ΔH°r = -1562 kJ
Explanation:
Let's consider the following combustion.
C₂H₆(g) + 7/2 O₂(g) ⇒ 2 CO₂(g) + 3 H₂O(l)
We can calculate the standard heat of reaction (ΔH°r) using the following expression:
ΔH°r = ∑np × ΔH°f(p) - ∑nr × ΔH°f(r)
where,
ni are the moles of reactants and products
ΔH°f(i) are the standard heats of formation of reactants and products
The standard heat of formation of simple substances in their most stable state is zero. That means that ΔH°f(O₂(g)) = 0
ΔH°r = ∑np × ΔH°f(p) - ∑nr × ΔH°f(r)
ΔH°r = [2 mol × ΔH°f(CO₂) + 3 mol × ΔH°f(H₂O)] - [1 mol × ΔH°f(C₂H₆) + 7/2 mol × ΔH°f(O₂)]
ΔH°r = [2 mol × (-394.0 kJ/mol) + 3 mol × (-286.0 kJ/mol)] - [1 mol × (-84.00 kJ/mol) + 7/2 mol × 0]
ΔH°r = -1562 kJ
