Percentage Yield = (Actual Yield ÷ Theoretical Yield) × 100
The Actual Yield is given in the question as 21.2 g of NaCl. However, in order to find the theoretical yield, you have to write a balanced equation and use the mole ratio to calculate the mass of NaCl that would be produced.
Balanced Equation: CuCl + NaNO₃ → NaCl + CuNO₃
Moles of CuCl = Mass of CuCl ÷ Molar Mass of CuCl
= 31.0 g ÷ (63.5 + 35.5)g/mol
= 0.31 mol
the mole ratio of CuCl to NaCl is 1 : 1,
∴ if moles of CuCl = 0.31 mol,
then moles of NaCl = 0.31 mol
Now, Mass of NaCl = Moles of NaCl × Molar Mass of NaCl
= 0.31 mol × (23 + 35.5) g/mol
= 18.32 g
⇒ the THEORETICAL Yield of NaCl, in this case, is 18.32 g.
Now, since Percentage Yield = (Actual Yield ÷ Theoretical Yield) × 100
⇒ Percentage Yield of NaCl = (21.2g ÷ 18.32g) × 100
= 115.7 %
NOTE: Typically, the percentage yield of a reaction is less than 100%, however in a case where the mass of the substance is weighed with impurities, then that mass may be in excess of 100% as seen here.
i believe the answer is A (((:
Answer:
<h3>The answer is 4.65 moles</h3>
Explanation:
To find the number of moles given it's number of entities we use the formula
where n is the number of moles
N is the number of entities
L is the Avogadro's constant which is
6.02 × 10²³ entities
From the question
N = 2.8 × 10²⁴ atoms of Cl2
So we have
We have the final answer as
<h3>4.65 moles</h3>
Hope this helps you
The
correct answer is A. In the combined gas law, if the volume is decreased and
the pressure is constant, then the temperature decreases.
<span>P1V1/
T1 = P2V2 / T2</span>
<span>Assume
the volume decrease by half; V2 = V1/2</span>
<span>P1V1/
T1 = P2V1 /2 T2</span>
<span>Cancelling
terms,</span>
<span>1/T1
= 1/2 T2</span>
T2
= T1/2
<span>Thus,
the temperature decreased.</span>
