Question

A sample of crude oil contains 3.09 mM naphthalene, 10.0 mM methylnaphthalene, 23.2 mM dimethylnaphthalene, and 14.4 mM trimethylnaphthalene. What is the total number of moles of all naphthalene compounds combined in 100.0 mL of the oil

Answer 1

Answer: 0.00507 moles

Explanation:

Molarity of a solution is defined as the number of moles of solute dissolved per liter of the solution.

$Molarity=\frac{n\times 1000}{V_s}$

where,

n = moles of solute

$V_s$ = volume of solution in ml

1. moles of napthalene = $\frac{3.09\times 0.001\times 100.0}{100}=0.000309moles$

2. moles of methyl napthalene = $\frac{10.0\times 0.001\times 100.0}{1000}=0.001mole$

3. moles of dimethyl napthalene = $\frac{23.2\times 0.001\times 100.0}{1000}=0.00232moles$

4. moles of trimethyl napthalene = $\frac{14.4\times 0.001\times 100.0}{1000}=0.00144moles$

Thus total moles of all naphthalene compounds combined is (0.000309+0.001+0.00232+0.00144) = 0.00507.