Question

In: Chemistry

A 15.86 g mixture of sugar (C12H22O11) and table salt (NaCl) is dissolved in 145 g...

A 15.86 g mixture of sugar (C12H22O11) and table salt (NaCl) is dissolved in 145 g of water. The freezing point of the solution was measured as -4.45 °C. Calculate the mass percent of sugar in the mixture.

Solutions

Expert Solution

let n1 be no. of mol of sugar
and n2 be no. of mol of NaCl

i for sugar is 1
i for NaCl is 2
Kf for water = 1.86 oC/m
use,
(delta Tf) = Kf*{(n1 + 2*n2)/(mass of water in kg)}
0 - (-4.45) = 1.86*{(n1+2*n2)/0.145}
4.45 = 1.86*{(n1+2*n2)/0.145}
0.645 = 1.86*(n1+2*n2)
n1+2*n2 = 0.347

let mass of Sugar be x
then, mass of NaCl = 15.86-x

molar mass of Sugar(m1) = 342 g/mol
molar mass of NaCl(m2) = 58.5 g/mol

use,
(mass of sugar)/m1 + 2*(mass of salt)/m2 = 0.347
x/342 + 2*(15.86-x)/58.5 = 0.347
58.5*x + 10848.2 - 684*x = 6942.4
-625.5*x = -3905.8
x = 6.2 g

so,
mass of sugar = x
= 6.2 g

mass % of sugar = {(mass of sugar)/(mass of mixture)}*100
= (6.2/15.86)*100
= 39.1 %

Answer: 39.1%


Related Solutions

A 19.04 g mixture of sugar (C12H22O11) and table salt (NaCl) is dissolved in 233 g...
A 19.04 g mixture of sugar (C12H22O11) and table salt (NaCl) is dissolved in 233 g of water. The freezing point of the solution was measured as -3.58 °C. Calculate the mass percent of sugar in the mixture. A list of Kf values can be found here.
A 13.13 g mixture of sugar (C12H22O11) and table salt (NaCl) is dissolved in 253 g...
A 13.13 g mixture of sugar (C12H22O11) and table salt (NaCl) is dissolved in 253 g of water. The freezing point of the solution was measured as -2.41 °C. Calculate the mass percent of sugar in the mixture. Solvent Formula Kf value* (°C/m) Normal freezing point (°C) Kb value (°C/m) Normal boiling point (°C) water H2O 1.86 0.00 0.512 100.00
A 19.57 g mixture of sugar (C12H22O11) and table salt (NaCl) is dissolved in 223 g...
A 19.57 g mixture of sugar (C12H22O11) and table salt (NaCl) is dissolved in 223 g of water. The freezing point of the solution was measured as -3.85 °C. Calculate the mass percent of sugar in the mixture. A list of Kf values can be found here.
Table salt, NaCl(s), and sugar, C12H22O11(s), are accidentally mixed. A 3.50-g sample is burned, and 2.10...
Table salt, NaCl(s), and sugar, C12H22O11(s), are accidentally mixed. A 3.50-g sample is burned, and 2.10 g of CO2(g) is produced. What was the mass percentage of the table salt in the mixture?
Table salt, NaCl(s), and sugar, C12H22O11(s), are accidentally mixed. A 6.00-g sample is burned, and 2.80...
Table salt, NaCl(s), and sugar, C12H22O11(s), are accidentally mixed. A 6.00-g sample is burned, and 2.80 g of CO2(g) is produced. What was the mass percentage of the table salt in the mixture?
11.35 g (about one tablespoon) of table sugar (sucrose, C12H22O11) is dissolved in 242.9 mL of...
11.35 g (about one tablespoon) of table sugar (sucrose, C12H22O11) is dissolved in 242.9 mL of water (density 0.997 g/mL). The final volume is 250.0 mL (about one cup). 1.Calculate the molarity of sucrose in this solution. 2.Calculate the molality of sucrose in this solution. 3.Calculate the mass percent of sucrose in this solution.
When 13.56 g (about one tablespoon) of table sugar (sucrose, C12H22O11) is dissolved in 241.5 mL...
When 13.56 g (about one tablespoon) of table sugar (sucrose, C12H22O11) is dissolved in 241.5 mL of water (density 0.997 g/mL), the final volume is 250.0 mL (about one cup). 1)What is the mass percent of the table sugar? 2)What is the molarity of the table sugar? 3)What is the molality of the table sugar?
When 13.63 g (about one tablespoon) of table sugar (sucrose, C12H22O11) is dissolved in 241.5 mL...
When 13.63 g (about one tablespoon) of table sugar (sucrose, C12H22O11) is dissolved in 241.5 mL of water (density 0.997 g/mL), the final volume is 250.0 mL (about one cup). Part A What is the mass percent of the table sugar? Express your answer to three significant figures. % SubmitMy AnswersGive Up Part B What is the molarity of the table sugar? Express your answer to three significant figures. M SubmitMy AnswersGive Up Part C What is the molality of...
A 0.9140 g sample of a mixture of NaCl and KCl is dissolved in water, and...
A 0.9140 g sample of a mixture of NaCl and KCl is dissolved in water, and the solution is then treated with an excess of AgNO3 to yield 1.943 g of AgCl. Calculate the percent by mass of each compound in the mixture.
A 0.9000 g sample of a mixture of NaCl and KCl is dissolved in water, and...
A 0.9000 g sample of a mixture of NaCl and KCl is dissolved in water, and the solution is then treated with an excess of AgNO3 to yield 1.923 g of AgCl. Calculate the percent by mass of each compound in the mixture. ____% mass of NaCl ____% mass of KCl
ADVERTISEMENT
ADVERTISEMENT
ADVERTISEMENT