What mass of water must be used to dissolve 20.0 grams of ethanol,C2H5OH,to prepare a 0.0500 molal solution of ethanol

Answer 1

To prepare a 0.0500 molal solution of ethanol, we need to dissolve 0.0500 moles of ethanol in 1 kg of water.

The molar mass of ethanol, C2H5OH, is 46.07 g/mol.

So, 0.0500 moles of ethanol will weigh:
0.0500 mol x 46.07 g/mol = 2.3035 g

To dissolve 20.0 grams of ethanol, we need to use the following proportion:

2.3035 g ethanol / x grams water = 0.0500 mol/kg

Solving for x, we get:

x = 45.85 g water

So, we need 45.85 grams of water to dissolve 20.0 grams of ethanol and prepare a 0.0500 molal solution of ethanol.