Question

A solution is made by mixing 20.0 mL of toluene C6H5CH3d=0867gmL with 140.0 mL of benzene C6H6d=0874gmL. Assuming that the volumes add upon mixing, the molarity (M) and molality (m) of the toluene are...

______ M and

______ m.

I need help. :(

Answer 1

1. Use:
mass = (volume)*(density), or
grams = (milliliters)(grams/ml)
to calculate the mass (grams) of each compound.
2. Find the molar mass of toluene.
3. Divide the mass (grams) of toluene by the molar mass of toluene to convert grams to moles.
4. Convert the grams of benzene to kilograms.
5. molality = (moles toluene)/(kgs of benzene)

Answer 2

To find the <b>molarity</b>,
1. Convert the 140 mLs of benzene to liters
2. Molarity = (moles of toluene) / (liters of benzene)

NOTE: This is a continuation of the previous answer (finding the molality). Refer to steps 2 and 3.