1. How many grams of NaNO3 would you add to 500 g of H2O in order to prepare a s
ID: 786229 • Letter: 1
Question
1. How many grams of NaNO3 would you add to 500 g of H2O in order to prepare a solution that is 0.500 molal in NaNO3
2. Calculate the freezing point of a solution containing 1.25 g of benzene in 100 g of chloroform.
3. A solution containing 0.750 g of an unknown substance in 30.0 g of cyclohexane was found to freeze at 3.1 C. What is the molar mss of the unlown substance?
4. Describe an experiment to determine the molal freezing point depression constant (Kf) for a solvent of your choice.
Please explain your answers. I really appreciate it.
Explanation / Answer
1)
m(solvent)= 500 g
= 0.5 kg
use:
number of mol,
n = Molality * mass of solvent in Kg
= (0.5 mol/Kg)*(0.5 Kg)
= 0.25 mol
Molar mass of NaNO3,
MM = 1*MM(Na) + 1*MM(N) + 3*MM(O)
= 1*22.99 + 1*14.01 + 3*16.0
= 85 g/mol
use:
mass of NaNO3,
m = number of mol * molar mass
= 0.25 mol * 85 g/mol
= 21.25 g
Answer: 21.2 g
Only 1 question at a time please
Related Questions
Navigate
Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.