Question 5 of 5

Determine the molality of a solution of methanol dissolved in ethanol for which the mole fraction of methanol is 0.135. Give you

Alja [10]

Answer: The molality of the solution is 0.11 m

Explanation:

We are given:

Mole fraction of methanol = 0.135

This means that 0.135 moles of methanol is present in 1 mole of a solution

Moles of ethanol = 1 - 0.135 = 0.865 moles

To calculate the mass for given number of moles, we use the equation:

$\text{Number of moles}=\frac{\text{Given mass}}{\text{Molar mass}}$

Moles of ethanol = 0.865 moles

Molar mass of ethanol = 46 g/mol

$0.865mol=\frac{\text{Mass of ethanol}}{46g/mol}\\\\\text{Mass of ethanol}=(0.865mol\times 46g/mol}=39.79g$

To calculate the molality of solution, we use the equation:

$Molality=\frac{m_{solute}\times 1000}{M_{solute}\times W_{solvent}\text{ (in grams)}}$

Where,

$m_{solute}$ = Given mass of solute (methanol) = 0.135 g

$M_{solute}$ = Molar mass of solute (methanol) = 32 g/mol

$W_{solvent}$ = Mass of solvent (ethanol) = 39.79 g

Putting values in above equation, we get:

$\text{Molality of methanol}=\frac{0.135\times 1000}{32\times 39.79}\\\\\text{Molality of methanol}=0.106m\approx 0.11m$

Hence, the molality of the solution is 0.11 m

6 0

3 years ago

What is the name of the ionic compound Csmc010-1.jpgS? cesium sulfur cesium sulfide dicesium sulfur dicesium sulfide

nika2105 [10]

Answer is: cesium sulfide.
Formula for ionic compound is: Cs₂S.
Ionic compound electrically neutral, cesium has charge +1 (2· (+1) = +2) and sulfur has charge -2.
Cesium sulfide is whide powder, soluble in water, pyrophoric in dry air, reductant.

5 0

3 years ago

Read 2 more answers

OMG PLEASE HELP!! THIS IS IMPORTANT!!

bogdanovich [222]

Answer:

The cell membrane is protective layer surrounding a cell.

5 0

2 years ago

Read 2 more answers

What is the mass percentage of carbon in 5.000 G of sucrose

Crank

17) 8.4 / 20 x 100

18) 20 . 0.5150

19) 6,50% because (as you said) the law of definite proportions states that regardless of the amount, a compound is always composed of the same elements in the same proportion by mass

3 0

3 years ago

Read 2 more answers

Nitrogen gas is more abundant in our atmosphere than oxygen! However, nitrogen needs to be converted into different forms to be

Pavlova-9 [17]

Explanation:

(A)role of nittogen fixing bacteria

=Nitrogen-fixing bacteria, microorganisms capable of transforming atmospheric nitrogen into fixed nitrogen (inorganic compounds usable by plants). More than 90 percent of all nitrogen fixation is effected by these organisms, which thus play an important role in the nitrogen cycle.

B)role of nitrifying bacteria

=Nitrifying bacteria convert the most reduced form of soil nitrogen, ammonia, into its most oxidized form, nitrate. In itself, this is important for soil ecosystem function, in controlling losses of soil nitrogen through leaching and denitrification of nitrate.

C)role of denitrifying bacteria

=Denitrifying bacteria converts nitrates back to nitrogen gas.

4 0

3 years ago