Respuesta :
Answer : The mass of benzoin is, 8.58 grams.
Explanation :
First we have to calculate the moles of benzil.
[tex]\text{Moles of benzil}=\frac{\text{Mass of benzil}}{\text{Molar mass of benzil}}[/tex]
Molar mass of benzil = 210.23 g/mol
[tex]\text{Moles of benzil}=\frac{10g}{210.23g/mol}=0.0476mol[/tex]
Now we have to calculate the moles of benzoin.
The balanced chemical reaction is:
[tex](C_6H_5CO)_2+NaBH_4\rightarrow C_{14}H_{12}O_2+BH_3+NaOH[/tex]
From the balanced chemical reaction we conclude that,
As, 1 mole of benzil react to give 1 mole of benzoin
So, 0.0476 mole of benzil react to give 0.0476 mole of benzoin
Now we have to calculate the mass of benzoin.
[tex]\text{Mass of benzoin}=\text{Moles of benzoin}\times \text{Molar mass of benzoin}[/tex]
Molar mass of benzoin = 212.24 g/mol
[tex]\text{Mass of benzoin}=0.0476mol\times 212.24g/mol=10.1g[/tex]
Theoretical yield of benzoin = 10.1 g
Now we have to calculate the experimental mass of benzoin.
[tex]\% \text{ yield of reaction}=\frac{\text{ Experimental yield of benzoin}}{\text{ Theoretical yield of benzoin}}\times 100[/tex]
[tex]\text{Experimental yield of benzoin}=\frac{85}{100}\times 10.1g=8.58g[/tex]
Therefore, the mass of benzoin is, 8.58 grams.
