Respuesta :
Answer: The percentage by mass of NaCl in the mixture is 38.5 %
Explanation:
To calculate the mass percentage of element in compound, we use the equation:
[tex]\text{Mass percent of element}=\frac{\text{Mass of element}}{\text{Mass of compound}}\times 100[/tex] .......(1)
- For NaCl:
Mass of sodium element = 23 g
Mass of NaCl = 58.5 g
Putting values in equation 1, we get:
[tex]\text{Mass percent of sodium element}=\frac{23g}{58.5g}\times 100=39.32\%[/tex]
Mass fraction of sodium metal in NaCl = 0.3932
- For [tex]NaNO_3[/tex] :
Mass of sodium element = 23 g
Mass of [tex]NaNO_3[/tex] = 85 g
Putting values in equation 1, we get:
[tex]\text{Mass percent of sodium element}=\frac{23g}{85g}\times 100=27.1\%[/tex]
Mass fraction of sodium metal in sodium nitrate = 0.271
Let us assume the mass fraction of NaCl in the mixture is 'x'
So, the mass fraction of [tex]NaNO_3[/tex] in the mixture will be '(1-x)'
We are given:
Percent by mass of Na in the mixture = 31.8 %
Mass fraction of Na in the mixture = 0.318
Evaluating the mass fraction of NaCl in the mixture:
[tex][(x\times 0.3932)+((1-x)\times 0.271)]=0.318[/tex]
x = 0.385
Percent by mass of NaCl in the mixture will be = [tex](0.385\times 100)=38.5\%[/tex]
Hence, the percentage by mass of NaCl in the mixture is 38.5 %
