Question

A solution contains 225 g of glucose, `C_6H_12O_6`, dissolved in enough water to make 0.825 L of solution. What is the molarity of the solution?

Answer 1

`"1.51 M"`

Explanation:

In order to find the molarity of a solution, we use the following equation:

The volume of the given solution has the proper units, but the amount of solute does not. We are given the mass of glucose, not the number of moles. In order to find the number of moles of glucose, you would divide the given mass by the molecular weight of glucose, which is `"180.16 g/mol"`.

`"moles of glucose" = (225 cancel("g"))/(180.16 cancel("g")/"mol") = "1.25 mol"`

Now all we have to do is divide that value by the volume to obtain the molarity like so:

`"molarity" = "1.25 mol" / "0.825 L" = "1.51 molar"`

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