Answer:
86% is the percent yield of the reaction
Explanation:
Percent yield is defined as 100 times the ratio of actual yield / theoretical yield.
Based on the reaction:
2Na + Cl₂ → 2NaCl
The theoretical yield is 0.50 moles because 0.50 mol of Na are added in the beginning. As 0.43 moles are produced, actual yield is 0.43 mol. And percent yield is:
0.43mol / 0.50mol * 100 =
<h3>86% is the percent yield of the reaction</h3>
1500 cm^3 ; 1 mL equals 1 cm^3
Answer:
- <em>The vapor pressure of the solution at 25°C is </em><u><em>23.6 mmHg</em></u>
Explanation:
<u>1) Data:</u>
- Mass of solute, sucroese, m₁ = 40.0 g
- Mass of solvent, water, m₂ = 250. g
- Vapor pressure of solution, p = ?
- Vapor pressure of pure water, p⁰ = 23.76 mm Hg
<u>2) Principles and formulae:</u>
- Raoult's law states that the vapor pressure of a solution is equal to the mole fraction of the solvent times the vapor pressure of the pure liquid.
p = X p⁰
<u>3) Solution:</u>
a) <u>Mole fraction of the solvent (water)</u>
- X = number of moles of solvent / number of moles of solution
- number of moles of solvent, n₁ = mass in grams / molar mass
n₁ = 250. g / 18.015 g/mol = 13.88 moles
- number of moles of solute, n₂ = mass in grams / molar mass
n₂ = 40.0 g / 342,3 g/mol = 0.12 moles
- total number of moles, n₁ + n₂ = 13.88 moles + 0.12 moles = 14.0 moles
- moles fraction of water, X = 13.88 moles / 14.0 moles = 0.99
b) <u>Vapor pressure of the solution</u>:
- p = p⁰ X = 23.76 mmHg × 0.99 = 23.56 mm Hg
Rounding to three significant figures: 23.6 mm Hg.
Answer:
28 g
Explanation:
The chemical equation of the reaction is given below:
CaCO₃ (s) ⇒ CaO (s) + O₂ (g)
From the chemical equation, 1 mole of CaCO₃ produces 1 mole of CaO.
So, we find the number of moles,n of CaCO₃ in 50 g from
n = m/M where n = number of moles of CaCO₃, m = mass of CaCO₃ and M = molar mass of CaCO₃ = 40 g/mol + 12 g/mol + 3 × 16 g/mol = 52 g/mol + 48 g/mol = 100 g/mol
So, n = m/M
= 50 g/100 g/mol
= 0.5 mol
Since From the chemical equation, 1 mole of CaCO₃ produces 1 mole of CaO, then 0.5 × 1 mole of CaCO₃ produces 0.5 × 1 mole of CaO, which is 0.5 mole of CaCO₃ produces 0.5 mole of CaO.
So, we have 0.5 mol of CaO.
We find the mass of CaO from
n =m'/M' where n = number of moles of CaO = 0.5, m' = mass of CaO and M' = molar mass of CaO = 40 g/mol + 16 g/mol = 56 g/mol
So, m' = nM'
= 0.5 mol × 56 g/mol
= 28 g