When given percents for an empirical formula problem, first consider all the percents as grams.

58.82% carbon —> 58.82 g carbon
27.45% nitrogen —> 27.45 g nitrogen
13.73% hydrogen —> 13.73 g hydrogen

Then convert the grams of all the elements to moles, based on their molar masses.

Carbon - 58.82 g / 12.01 g/mol = 4.898 mol carbon

Nitrogen - 27.45 g / 14.01 g/mol = 1.959 mol nitrogen

Hydrogen - 13.73 g / 1.008 g/mol = 13.62 mol hydrogen

Then divide all of the mole numbers by the smallest number of moles, which is in this case, the 1.959 mol of nitrogen.

Carbon - 4.898 / 1.959 = 2.5

Nitrogen - 1.959 / 1.959 = 1

Hydrogen - 13.62 / 1.959 = 7

You want whole numbers for all of your mole numbers, so multiply all of them by 2, since 2.5 isn’t a whole number.

Final answer: C5N2H14

4 0

3 years ago

The vapor pressure of pure benzene is 750.0 torr and the vapor pressure of toluene is 300.0 torr at a certain temperature. You m

kow [346]

Answer:

Mole fraction of benzene in pure solution is 0.4472

Explanation:

Vapor pressure of pure benzene= 750 torr

Vapor pressure of pure toulene= 300 torr

Mole fraction of benzene in vapor= 0.669

1/P=Xa/Pa+ Xb/Pb

Where

Xa = mole fraction of A in water

Xb = mole fraction of B in water

P= Total pressure

Pa= total vapor pressure of pure A

Pb = total vapor pressure of pure B

Xa+Xb=1

Let A be benzene and B be toulene

We have Xa=0.669 and Xb= 0.331

1/P= 0.669/750 + 0.331/300

1/P= 0.000892/torr + 0.001103/torr

1/P=0.001995/torr

P= 501.25torr

We have P= Pa+ Pb

Where Pa= XaPa0

And Pb=XbPb0

Where

Xa= mole fraction of A in solution

Xb= mole fraction of B in solution

Now, substitute the data into the formula

501.25torr=Xa750torr + (1- Xa) 300 torr

Xa450torr + 300torr

Xa(450torr)= 201.25torr

Xa= 0.4472

Therefore, mole fraction of benzene in pure solution is 0.4472

7 0

3 years ago

What is the main source of energy for the water cycle.

viktelen [127]

Answer:

The main source of energy is the sun. The sun has a big part in the water cycle because it turns the water into water vapor. This cause the water cycle to start over again once it rains. Therefore, making the sun ne of the biggest parts in the water cycle.

7 0

2 years ago