Question

A 1 M solution of glucose is 180 g of glucose in a 1 liter solution. If you wanted to make a solution of 0.2 M glucose, how many grams of glucose would you need?

Answer 1

36 g

Step-by-step explanation:

Data provided in the question:

A 1 M solution of glucose = 180 g of glucose in a 1 liter solution

i.e Mass of solute = 180 g

Now,

Molarity = [ Number of moles of solute ] ÷ [ Volume Solution in liters ]

also,

Number of moles of solute =
`\frac{\text{Mass of solute}}{\text{Molar Mass of solute}}`

Thus,

1 M =
`\frac{\frac{180\ g}{\text{Molar mass}}}{1\ \L}`

or

Molar mass = 180 g

Therefore,

For molarity = 0.2 M

we have for per liter of solution

0.2 M =
`\frac{\frac{\text{Mass of glucose}}{180}}{1\ \L}`

or

Molar glucose = 0.2 × 180

= 36 g