Question

Find the number of ibuprofen molecules in a tablet containing 200.0 mg of ibuprofen (c13h18o2). express the amount to four significant figures.

Answer 1

$\boxed{5.8383\times 10^{20} \text{ molecules}}$ of ibuprofen present in tablet that contains 200.0 mg of ibuprofen.

Further Explanation:

The formula to calculate moles of ibuprofen is as follows:

$\text{Moles of ibuprofen}=\dfrac{\text{Mass of ibuprofen}}{\text{Molar mass of ibuprofen}}$                   ...... (1)

Mass of ibuprofen is to be converted from mg to g. The conversion factor for this is as follows:

$\text{1 mg}=10^{-3}\text{ g}$

Therefore mass of ibuprofen can be calculated as follows:

$\begin{aligned}\text{Mass of ibuprofen}&=(\text{200.0 mg})\left (\dfrac{10^{-3}\text{ g}}{1\text{ mg}}\right)\\&=0.2000\text{ g} \end{aligned}$

The mass of ibuprofen is 0.2000 g.

The molar mass of ibuprofen is 206.29 g/mol.

Substitute 0.2000 g for mass of ibuprofen and 206.29 g/mol for molar mass of ibuprofen in equation (1).

$\begin{aligned}\text{Moles of ibuprofen}&=\dfrac{\text{0.2000 g}}{\text{206.29 g/mol}}\\&=\text{0.0009695 mol}\end{aligned}$

Avogadro's law states that one mole of substance has $6.022\times10^{23}$ molecules. Therefore molecules of ibuprofen that are present in 0.0009695 moles of ibuprofen can be calculated as follows:

$\begin{aligned}\text{Molecules of ibuprofen}&=(\text{0.0009695 mol})\left(\dfrac{6.022\times10^{23}\text{ molecules}}{\text{1 mol}}\right)\\&={5.8383\times10^{20}\text{ molecules}\end{aligned}$

Therefore ${5.8383\times 10^{20} \text{ molecules}}$ of ibuprofen are contained in a tablet that has 200.0 mg of ibuprofen in it.

Learn more:

1. How many moles of Cl are present in 8 moles of $\text{CCl}_4$ ? brainly.com/question/3064603

2. Calculate the moles of ions in HCl solution: brainly.com/question/5950133

Answer details:

Grade: Senior School

Subject: Chemistry

Chapter: Mole concept

Keywords: ibuprofen, 200.0 mg, 0.2000 g, Avogadro's law, moles, molecules, 5.8383*10^20 molecules, mass of ibuprofen, molar mass of ibuprofen, 6.022*10^23 molecules, mg, g, conversion factor, mass, molar mass, 206.29 g/mol, 0.0009695 moles, tablet, formula, 10^-3 g, 1 mg.

Answer 2

First let us calculate for the molar mass of ibuprofen:

Molar mass = 13 * 12 g/mol + 18 * 1 g/mol + 2 * 16 g/mol

Molar mass = 206 g/mol = 206 mg / mmol

 

Calculating for the number of moles:

moles = 200 mg / (206 mg / mmol)

moles = 0.971 mmol = 9.71 x 10^-4 moles

 

Using the Avogadros number, we calculate the number of molecules of ibuprofen:

Molecules = 9.71 x 10^-4 moles * (6.022 x 10^23 molecules / moles)

Molecules = 5.85 x 10^20 molecules