Question

The molecular formula of Allicin, The compound responsible for the characteristics smell of garlic, is C6H 10 OS2. A) what is the molar mass of a Allicin?B) how many moles of allicin are present in 4.20 mg of the substance?C) how many molecules of Allicin are in 4.20 mg of the substance?D) how many C atoms are present in 4.20 mg of allicin?

Answer 1

1) Molar mass of Allicin.

1.1- Write the formula.

`C_6H_(10)OS_2`

1.2- Look for the molar mass of each element in the formula.

C: 12.011 g/mol

H: 1.008 g/mol

O: 15.999 g/mol

S: 32.06 g/mol

1.3- Count how many atoms are there in the formula.

C: 6

H: 10

O: 1

S: 2

1.4- Set the equation.

`TheMolarMass=(6*C)+(10*H)+(1*O)+(2*S)`

Plug in the known values.

`TheMolarMass=(6*12.011\text{ }g/mol)+(10*1.008\text{ }g/mol)+(1*15.999\text{ }g/mol)+(2*32.06\text{ }g/mol)`
`MM=72.066\text{ }g/mol+10.08\text{ }g/mol+15.999\text{ }g/mol+64.12\text{ }g/mol`
`MM=162.265\text{ }g/mol`

The molar mass (MM) of Allicin (C6H10OS2) is 162.265 g/mol.

2) Moles of Allicin in the sample.

Allicin sample: 4.20 mg

The molar mass of Allicin (C6H10OS2) is 162.265 g/mol.

2.1- Convert mg to g.

1g = 1000 mg

`g=4.20\text{ }mg*\frac{1\text{ }g}{1000\text{ }mg}=0.00420\text{ }g`

2.2- Convert grams to moles.

The molar mass of Allicin (C6H10OS2) is 162.265 g/mol.

Allicin sample: 0.00420 g

`mol\text{ }C_6H_(10)OS_2=0.00420\text{ }g\text{ }C_6H_(10)OS_2*\frac{1\text{ }mol\text{ }C_6H_(10)OS_2}{162.265\text{ }g\text{ }C_6H_(10)OS_2}=0.00002588\text{ }mol\text{ }C_6H_(10)OS_2`

There are 0.00002588 moles of Allicin (C6H10OS2) in 4.20 mg of substance.

The result can also be expressed as 2.588*10^(-5) mol.

3) Molecules of Allicin in the sample.

The Avogadro's number is 6.022*10^(23).

1 mol C6H10OS2 = 6.022*10^(23) molecules C6H10OS2

Allicin sample: 0.00002588 mol.

`molecules\text{ }of\text{ }C_6H_(10)OS_2=0.00002588\text{ }mol\text{ }C_6H_(10)OS_2*\frac{6.022*10^(23)\text{ }molecules}{1\text{ }mol\text{ }C_6H_(10)OS_2}=1.558*10^(19)\text{ }molecules\text{ }of\text{ }C_6H_(10)OS_2`

There are 1.558*10^(19) molecules in the sample.

4) C atoms in the sample of Allicin.

The ratio of carbon in one molecule of Allicin is 6 C atoms: 1 molecule of Allicin.

Allicin sample: 1.558*10^(19) molecules C6H10OS2.

`C\text{ }atoms=1.588*10^(19)\text{ }molecules*\frac{6\text{ }C\text{ }atoms}{1\text{ }molecule\text{ }C_6H_(10)OS_2}=9.35*10^(19)\text{ }C\text{ }atoms.`

There are 9.35*10^(19) C atoms in the sample.