A solution made from ethanol and water is 1.75 molar (M) in ethanol. How many grams of ethanol are contained per 250 grams of water?

There are 20.15g of ethanol in 250g of water in a 1.75M solution of ethanol. To solve this problem, we first need to calculate how many moles of ethanol are in 250g based on the molarity. You can set up a stoichiometry ratio like this:

250g water (1.75 mole ethanol / 1000g water) = 0.43 mole ethanol

So, there are 0.43 mole of ethanol in 250g of water. But, how do we calculate the mass? To do this, we need to set up another stoichiometry ratio using the molar mass of ethanol. To calculate the molar mass of ethanol, we sum the molecular weight of each of the atoms in it. Ethanol has the molecular formula C2H5OH, so there are two carbon atoms, six hydrogen atoms and one oxygen atom. We can calculate the molar mass of ethanol as follows:

Carbon: 2 * 12.01g/mol

Hydrogen: 6 * 1.007g/mol

Oxygen: 15.999g/mol

So, the total molar mass for ethanol is 46.07g/mol

Now, we can convert the moles we calculated for ethanol in 250g of water to grams.

0.43 moles ethanol (46.07g / 1 mol) = 20.15g ethanol