Ask question

Ask question

All categories

3 years ago

6

What is the boiling point of a 0.75-molal solution of a non-volatile non-electrolyte solute in water? Kb for water = 0.52 degree

s C/ molal.
99.61 °C
100.0 °C
100.39 °C
101.44 °C

2 answers:

Tom [10]3 years ago

4 0

The answer is C. I just did this assignment

AVprozaik [17]3 years ago

3 0

Take the molality and multiply it by the Kb
0.75 × 0.52 = 0.39 C

then add the boiling pt to the 0.39
100 + 0.39 = 100.39 C

You might be interested in

Question 3) A 1.00 L buffer solution is 0.250 M in HF and 0.250 M in LiF. Calculate the pH of the solution after the addition of

Masja [62]

The pH of the solution after adding 0.150 moles of solid LiF is 3.84

<u>Explanation:</u>

We have the chemical equation,

HF (aq)+NaOH(aq)->NaF(aq)+H2O

To find how many moles have been used in this

c= n/V=> n= c.V

nHF=0.250 M⋅1.5 L=0.375 moles HF

Simillarly

nF=0.250 M⋅1.5 L=0.375 moles F

nHF=0.375 moles - 0.250 moles=0.125 moles

nF=0.375 moles+0.250 moles=0.625 moles

[HF]=0.125 moles/1.5 L=0.0834 M

[F−]=0.625 moles/1.5 L=0.4167 M

To determine the problem using the Henderson - Hasselbalch equation

pH=pKa+log ([conjugate base/[weak acid])

Find the value of Ka

pKa=−log(Ka)

pH=−log(Ka) +log([F−]/[HF]

pH= -log(3.5 x 10 ^4)+log(0.4167 M/0.0834 M)

pH=-log(3.5 x 10 ^4)+log(4.996)

pH= -4.54+0.698

pH=-(-3.84)

pH=3.84

The pH of the solution after adding 0.150 moles of solid LiF is 3.84

5 0

3 years ago

The force of gravity always pulls ____

damaskus [11]

Down...
and if you were wondering, the earth pushes back

6 0

3 years ago

What fraction of a sample of 6832ge, whose half-life is about 9 months, will remain after 2.9 yr ?

Viefleur [7K]

<span>The half-life of 9 months is 0.75 years. 2.0 years is 2.0/0.75 = 2.67 half-lives. Each half-life represents a reduction in the amount remaining by a factor of two, so: A(t)/A(0) = 2^(-t/h) where A(t) = amount at time t h = half-life in some unit t = elapsed time in the same unit A(t)/A(0) = 2^(-2.67) = 0.157 15.7% of the original amount will remain after 2.0 years. This is pretty easy one to solve. I was happy doing it.</span>

4 0

3 years ago

What substances were found in the innermost regions (within about the inner 0.3 au) of the solar system before planets began to

coldgirl [10]

The answer would be Rocks, metals, hydrogen compounds, hydrogen and helium, all in gaseous form.

5 0

3 years ago

What is true about the slope of a line if an object is moving back towards the starting point?

alina1380 [7]

I think its positive if its not im sorry :((

7 0

3 years ago