Which element has an atomic number of 6? lithium boron carbon oxygen

What is the mole fraction of each component in a solution made by mixing 300 g of ethanol(C2H5OH) and 500 g of water?

Snowcat [4.5K]

Answer:

The mole fraction of ethanol and water in the solution are 0.19 and 0.81 respectively.

Explanation:

The Molar Fraction is a way of measuring the concentration that expresses the proportion in which a substance is found with respect to the total moles of the solution, which are calculated by adding the moles of solute (s) and solvent.

It is calculated by dividing the number of moles of one of the components by the total number of moles of the solution.

The sum of all the molar fractions of the substances present in a solution is equal to 1.

So, the expression to calculate the mole fraction is:

$Molar fraction (Xi)=\frac{moles of sudstance}{total moles of the solution}$

Being the molar mass of the compounds:

Ethanol 46 $\frac{g}{mol}$

Water 18 $\frac{g}{mol}$

the number of moles that represent the mass quantities is calculated as:

Moles of ethanol: 300 grams* $\frac{1 mol}{46 grams}$ = 6.52 moles
Moles of water: 500 grams* $\frac{1 mol}{18 grams}$ = 27.78 moles

So the total moles in solution are 6.52 moles + 27.78 moles = 34.3 moles

The mole fraction of ethanol in the solution is calculated as:

$mole fraction of ethanol=x_{ethanol} =\frac{6.52 moles}{34.3 moles}$

$x_{ethanol} =0.19$

The mole fraction of water in the solution is calculated as:

$mole fraction of water=x_{water} =\frac{27.78 moles}{34.3 moles}$

$x_{water} =0.81$

Then:

$x_{water} +x_{ethanol} = 0.81 + 0.19$

$x_{water} +x_{ethanol} =1$

The mole fraction of ethanol and water in the solution are 0.19 and 0.81 respectively.

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8 0

3 years ago

How much heat energy in megajoules is neede to convert 7kilograms of ice at negative 9 degrees to water at 0 degrees celsius

den301095 [7]

Heat_1: Get the ice to 0 degrees

Convert 7 kg to grams

7 kg [1000 grams / 1 kg] = 7000 grams

Heat needed to get the the ice from - 9 to 0

deltat = 0 - -9 = 9 degrees

m = 7000 grams

c = 2.1 joules/gram

Heat_1 = m*c*deltat

Heat_1 = 7000 * 2.1 * 9

Heat_1 = 132,300 joules

Heat_2: Melt the ice.

There is no temperature change. The formula is 333 j/gram

Formula: H = mass * constant

H = 7000 g * 333 J / gram

H = 2331000 joules

Heat_3: Total amount of Joules needed.

2331000 + 132300 = 2 463 300 joules

Convert to Megajoules

2 463 300 joules * 1 megajoule / 1000000 = 2.63 megajoules.

8 0

3 years ago

Which best describes what happens when a neutral atom becomes a positive

defon

Answer: the answer is b

Explanation:

8 0

3 years ago

What will determine the number of moles of hydronium in an aqueous solution of a strong monoprotic acid?.

marin [14]

Answer:

What will determine the number of moles of hydronium in an aqueous solution of a strong monoprotic acid? The amount of acid that was added.

Explanation:

3 0

2 years ago

The overall flow of energy through an ecosystem is from

Alik [6]

Answer:

So, I don't know if this is 100% correct, but, I believe it's B.photosynthetic organisms to herbivores to carnivores and decomposers. I'm so sorry if it's wrong!

Explanation: looked all over go ogle.

Have a good morning, afternoon, or night!

~Dreamer1331~

*please mark brainliest when possible, if correct, and if you feel I deserve it, Thank you!*

7 0

3 years ago