Respuesta :
Answer:
0.18 %
Explanation:
Considering:
[tex]Molarity=\frac{Moles\ of\ solute}{Volume\ of\ the\ solution}[/tex]
Or,
[tex]Moles =Molarity \times {Volume\ of\ the\ solution}[/tex]
Given :
For [tex]Cr_2O_7^{2-}[/tex] :
Molarity = 0.05961 M
Volume = 35.46 mL
The conversion of mL to L is shown below:
1 mL = 10⁻³ L
Thus, volume = 35.46×10⁻³ L
Thus, moles of [tex]Cr_2O_7^{2-}[/tex] :
[tex]Moles=0.05961 \times {35.46\times 10^{-3}}\ moles[/tex]
Moles of [tex]Cr_2O_7^{2-}[/tex] = 0.002114 moles
According to the given reaction:
[tex]16H^+_{(aq)}+2Cr_2O_7^{2-}_{(aq)}+C_2H_5OH_{(aq)}\rightarrow 4Cr^{3+}_{(aq)}+2CO_2_{(g)}+11H_2O_{(l)}[/tex]
2 moles of [tex]Cr_2O_7^{2-}[/tex] react with 1 mole of alcohol
Thus,
0.002114 moles of [tex]Cr_2O_7^{2-}[/tex] react with 1/2*0.002114 mole of alcohol
Moles of alcohol = 0.001057 moles
Molar mass of ethanol = 46.07 g/mol
Mass = Moles * Molar mass = 0.001057 * 46.07 g = 0.048696 g
Mass of plasma = 26.60 g
Mass Percent is the percentage by the mass of compound present in the mixture.
[tex]Mass\ \%=\frac{Mass_{ethanol}}{Total\ mass\ of\ plasma}\times 100[/tex]
[tex]Mass\ \%=\frac{0.048696}{26.60}\times 100=0.18\ \%[/tex]
