Answer:
87.15%
Explanation:
To find percent yield, we can use this simple equation
[tex]\frac{Actual}{Theoretical} *100[/tex]
Where "Actual" is the amount in grams actually collected from the reaction, and "Theoretical" is, well, the theoretical amount that should have been produced.
They give us these values, so to find the percent yield, just plug the numbers in.
[tex]\frac{30.85}{35.40} *100\\\\ =87.15[/tex]
So, the percent yield is 87.15%
An easy trick to remember how to do this is just to divide the smaller number by the bigger number and move the decimal back two places. If you have a percent yield greater than 100%, something is wrong in the reaction.
To determine the concentration of a sodium thiosulfate solution as in this experiment, a student pipetted 25.0 mL of 0.0100 M potassium iodate (KIO3) solution into a 125 mL Erlernmeyer flask. Potassium iodide and sulfuric acid were added as in this experiment. The titration needed 15.21 mL of the sodium thiosulfate to reach the end point. What is the concentration of the sodium thiosulfate solution
Answer:
0.0986M is the concentration of the Na₂S₂O₃ solution
Explanation:
Potassium iodate, KIO₃, reacts with sodium thiosulfate, Na₂S₂O₃, as follows:
KIO₃ + 6Na₂S₂O₃ +5KI + 3H₂SO₄ → 3H₂O + 3K₂SO₄ + 3Na₂S₄O₆ + 6NaI
To solve this question we must find the moles of sodium thiosulfate that reacts as follows:
Moles KIO₃:
0.0250L * (0.0100mol / L) = 2.5x10⁻⁴moles KIO₃
Moles Na₂S₂O₃:
2.5x10⁻⁴moles KIO₃ * (6mol Na₂S₂O₃ / 1mol KIO₃) = 1.5x10⁻³ moles Na₂S₂O₃
Molar concentration:
1.5x10⁻³ moles Na₂S₂O₃ / 0.01521L =
0.0986M is the concentration of the Na₂S₂O₃ solution2 moles KCl + 3 moles O2 → 2moles KCIO3
Calculate the number of particles of each substance based on the number of moles from the balanced equation
Answer:
KCl ⇒ 1.205x10²⁴ molecules
O₂ ⇒ 1.807x10²⁴ molecules
KClO₃ ⇒ 1.205x10²⁴ molecules
Explanation:
In order to calculate the number of particles from the number of moles, we have to use Avogadro's number, which states the number of particles in one mol:
In 1 mol there are 6.023x10²³ particles (ions, molecules or atoms).So now we multiply the number of moles of each substance by Avogadro's number:
KCl ⇒ 2 mol * 6.023x10²³ molecules/mol = 1.205x10²⁴ moleculesO₂ ⇒ 3 mol * 6.023x10²³ molecules/mol = 1.807x10²⁴ moleculesKClO₃ ⇒ 2 mol * 6.023x10²³ molecules/mol = 1.205x10²⁴ moleculesConsider the Fischer ester synthesis of methyl benzoate from benzoic acid and methanol in the presence of sulfuric acid as a catalyst. A reaction was performed in which 3.8 g of benzoic acid was reacted with excess methanol to make 2.0 g of methyl benzoate. Calculate the theoretical yield and percent yield for this reaction.
Answer:
48.8%
Explanation:
The reaction has a 1:1 mole ratio so;
Number of moles of benzoic acid reacted = mass/molar mass = 3.8 g/122.12 g/mol = 0.03 moles
So;
0.03 moles of methyl benzoate is formed in the reaction
Mass of methyl benzoate formed = 0.03 moles * 136.15 g/mol = 4.1 g
percent yield = actual yield/theoretical yield * 100/1
percent yield = 2.0 g/4.1 g * 100 = 48.8%