Question

A solution is composed of 1.15 mL of diethyl ether (C4H10O, density=0.7134 g/mL) dissolved in 78.85 mL of dichloromethane (CH2Cl2, density=1.3266 g/mL). What is the molarity of the solution?

Answer 1

Answer:

Molarityof the solution is 0.1375 M.

Explanation:

We will first find the number of moles of diethyl ether (C4H10O)  by finding its molar mass and measured mass.

Molar mass of diethyl ether (C4H10O) = 74.12 g.

Now, volume of diethyl ether (C4H10O) = 1.15 mL and its density = 0.7134 g/mL.

Therefore,  measured mass of diethyl ether (C4H10O) = volume x  density = 1.15 mL x 0.7134 g/mL = 0.82 g.

Now, number of moles of diethyl ether (C4H10O) = $\dfrac{Measured \ mass}{ Molar\ mass}$$= \frac{0.82\ g}{74.12\ g}$

= 0.011 Moles.

Volume of the solution = volume of diethyl ether + volume of dichloromethane = 1.15 mL + 78.85 mL = 80 mL.

Now, molarity of the solution = Number of moles of diethyl ether / Volume of the solution( in  mL) x 1000 =  $\dfrac {0.011}{80}\times 1000 = 0.1375\ M$