# How many moles of molecules are in a mass of 26.8 g of xe at stp?

## Answers

0.204580152 moles is 26.8 xe

6.03 moles.

1 molecule of butane contains 4 carbon atoms and ten hydrogen atoms.

The molar mass is 4 times the atomic mass of carbon, 12 g/mol, plus 10 times the atomic weight of hydrogen, 1 g/mol.

Molar mass = 4 * 12 g/mol + 10 * 1 g/mol = 58 g/mol.

This means that 1 mole of butane has a mass of 58 g.

To figure out how many moles are in a sample of butane, divide the mass of sample in grams by 58 grams

Number of moles in sample = 350 g / 58 g/mol = 6.03 moles.

[tex]m=525g\\ M=169,07\frac{g}{mol}\\\\ n=\frac{525g}{169,07\frac{g}{mol}}\approx3,11mol[/tex]

molecules

Explanation:

Data Given:

mass of aspartame = 10 g

molecules of aspartame = ?

Solution

First we calculate no. of moles of 10 g aspartame

For which mole formula will be used

no. of moles = mass in grams / molar mass . . . . . . .(1)

Formula of aspartame:

C₁₄H₁₈N₂O₅

So,

The molar mass of aspartame (C₁₄H₁₈N₂O₅) will be

molar mass of C₁₄H₁₈N₂O₅ = 14(12) + 18(1) + 2(14) +5(16)

molar mass of C₁₄H₁₈N₂O₅ = 168 + 18+ 28 + 80

molar mass of C₁₄H₁₈N₂O₅ = 294 g/mol

put values in equation 1

no. of moles = 10 g / 294 g/mol

no. of moles = 0.034 mol

now we will calculate no. of molecules

Formula will be used

no. of moles = no. of molecules / Avogadro's number

Rearrange the above equation:

no. of molecules = no. of moles x Avogadro's number . . . . . (2)

Where

Avogadro's number = 6.022 x 10²³

Put values in equation 2

no. of molecules =0.034 mol x 6.022 x 10²³ (molecules/mol)

no. of molecules = 2.0475 x 10²²

So,

There are 2.0475 x 10²² molecules are in 10 grams of aspartame that is 0.034 moles of aspartame.

So, in turn its 0.034 moles of molecules are in 10 g of aspartame.

0.3504 mol of CF₂Cl₂.

Explanation:

We need to know the molar mass of CF₂Cl₂ to find out the moles

Molar mass of C = 12 g/mol

Molar mass of F = 19 g/mol

Molar mass of Cl = 35.45 g/mol

Molar mass of CF₂Cl₂ = 12 + 19 . 2 + 35.45 . 2 =120.9 g/mol

Now we determine the moles of our mass

42.37 g . 1 mol / 120.9 g = 0.3504 mol

Number of molecules = 23.9 × 10²³ molecules

Number of moles = 3.97 mol

Explanation:

Mass of HNO₃ = 250 g

Number of moles = ?

Number of molecules = ?

Solution:

Number of moles = mass / molar mass

Number of moles = 250 g/63 g/mol

Number of moles = 3.97 mol

Number of molecules:

The given problem will solve by using Avogadro number.

It is the number of atoms , ions and molecules in one gram atom of element, one gram molecules of compound and one gram ions of a substance.

The number 6.022 × 10²³ is called Avogadro number.

For example,

18 g of water = 1 mole = 6.022 × 10²³ molecules of water

1.008 g of hydrogen = 1 mole = 6.022 × 10²³ atoms of hydrogen

For 250 g of HNO₃:

250 g/ 63 g/mol = 3.97 mole

3.97 × 6.022 × 10²³ molecules = 23.9 × 10²³ molecules

Answer is: there is 0,592 moles of CF₂Cl₂.

m(CF₂Cl₂) = 71,66 g.

n(CF₂Cl₂) = m(CF₂Cl₂) ÷ M(CF₂Cl₂).

n(CF₂Cl₂) = 71,66 g ÷ 120,91 g/mol.

n(CF₂Cl₂) = 0,592 mol.

M - molar mass substance.

m - mass of substance.

n - amount of substance.

First you find the molar mass of the formula.

3C: 36.03g + 8H:8.08g + N: 14.01g + 5O: 80g + P: 30.97g = 169.09g

Then do the mole ratio (304.3g)x(1mole/169.09g) = 1.800 moles

First, is to solve the molar mass of the herbicide, with a formula

C3H8NO5P

C3 = 12 ( 3 ) = 36

H8 = 1 ( 8 ) = 8

N = 14

O5 = 16 ( 5 ) = 80

P = 31

so in total the molar mass of C3H8NO5P is 36 + 8 + 14 + 80 + 31 = 169 g/mol

number of moles = 783.5 g ( 1 mol / 169 g)

number of moles = 4.64 mol C3H8NO5P

From the periodic table:

molecular mass of carbon = 12 grams

molecular mass of fluorine = 18.99 grams

molecular mass of chlorine = 35.5 grams

Therefore:

one mole of CF2Cl2 = 12 + 2(18.99) + 2(35.5) = 120.98 grams

Therefore, we can use cross multiplication to find the number of moles in 79.34 grams as follows:

mass = (79.34 x 1) / 120.98 = 0.6558 moles

Now, one mole contains 6.022 x 10^23 molecules, therefore:

number of molecules in 0.65548 moles = 0.6558 x 6.022 x 10^23

= 3.949 x 10^23 molecules