Answer:
Percent yield of alum is 38.6%
Explanation:
Find attached calculations for detailed explanation.
Answer:
0.4
Explanation:
Given data:
Number of moles of SrCl₂ consumed = ?
Mass of ZnCl₂ produced = 54 g
Solution:
Chemical equation:
ZnSO₄ + SrCl₂ → SrSO₄ + ZnCl₂
Number of moles of ZnCl₂:
Number of moles = mass/ molar mass
Number of moles = 54 g/136.3 g/mol
Number of moles = 0.4 mol
Now we will compare the moles of ZnCl₂ with SrCl₂ from balance chemical equation.
ZnCl₂ : SrCl₂
1 : 1
0.4 : 0.4
Thus when 54 g of ZnCl₂ produced 0.4 moles of SrCl₂ react.
Answer:
90.3 kJ/mol
Explanation:
Let's consider the following thermochemical equation.
2 NO(g) + O₂(g) → 2 NO₂(g) ∆H°rxn = –114.2 kJ
We can find the standard enthalpy of formation for NO using the following expression.
∆H°rxn = 2 mol × ΔH°f(NO₂(g)) - 2 mol × ΔH°f(NO(g)) - 1 mol × ΔH°f(O₂(g))
∆H°rxn = 2 mol × ΔH°f(NO₂(g)) - 2 mol × ΔH°f(NO(g)) - 1 mol × 0 kJ/mol
∆H°rxn = 2 mol × ΔH°f(NO₂(g)) - 2 mol × ΔH°f(NO(g))
ΔH°f(NO(g)) = (2 mol × ΔH°f(NO₂(g)) - ∆H°rxn) / 2 mol
ΔH°f(NO(g)) = (2 mol × 33.2 kJ/mol + 114.2 kJ) / 2 mol
ΔH°f(NO(g)) = 90.3 kJ/mol
Answer:
When excess of carbon dioxide is passed in lime water, calcium carbonate is converted to calcium bicarbonate which is soluble, hence the milkiness due to calcium carbonate disappears.
Explanation:
Ca(OH)2+CO2 → CaCO3 (Milkiness) ↓+H2O
CaCO3+H2O+CO2 → Ca(HCO3)2 (soluble)
I got that pH=3.65 using the fact that Ka=[H⁺][A⁻]/[HA] at equilibrium. In the ice table, I stands for initial, C stands for change, and E stands for equilibrium.
I hope this helps. Let me know if anything is unclear.
