Question

Ibuprofen is an anti-inflammatory with the formula C13H18O2.

Part A:

How many grams of ibuprofen are in 0.570 mole?

Express your answer using three significant figures.

Part B:

How many moles of carbon are in 15.0 g of ibuprofen?

Express your answer using three significant figures.

Part C:

How many moles of ibuprofen contain 1.18×10²³ atoms of carbon?

Express your answer using three significant figures.

Answer 1

A)

Molar mass of C13H18O2,

MM = 13*MM(C) + 18*MM(H) + 2*MM(O)

= 13*12.01 + 18*1.008 + 2*16.0

= 206.274 g/mol

use:

mass of C13H18O2,

m = number of mol * molar mass

= 0.57 mol * 2.063*10^2 g/mol

= 118 g

Answer: 118 g

B)

Molar mass of C13H18O2,

MM = 13*MM(C) + 18*MM(H) + 2*MM(O)

= 13*12.01 + 18*1.008 + 2*16.0

= 206.274 g/mol

mass(C13H18O2)= 15.00 g

use:

number of mol of C13H18O2,

n = mass of C13H18O2/molar mass of C13H18O2

=(15 g)/(2.063*10^2 g/mol)

= 7.272*10^-2 mol

This is number of moles of C13H18O2

one mole of C13H18O2 contains 13 mole of C

use:

number of moles of C = 13 * number of moles of C13H18O2

= 13 * 7.272*10^-2

= 0.9453

Answer: 0.945 mol

C)

Number of moles of C = number of atoms / Avogadro’s number

= (1.18*10^23)/(6.022*10^23)

= 0.196 mol

1 mol of C13H18O2 has 13 moles of c

so,

moles of C = moles of C13H18O2 / 13

= 0.0151 mol

Answer: 0.0151 mol