Determine the mass in grams of sucrose that must be added to 26 g of water to make a 1.15 m solution. Enter your answer to 2 decimal places.

10.23 grams of sucrose should be added.

Explanation:

1.15 m means molality (moles of solute in 1kg of solvent)

1.15 moles of sucrose are contained in 1 kg of solvent (1000 g)

Let's determine the moles in our mass of solvent.

Firstly we convert the g to kg → 26 g. 1kg/1000g = 0.026 kg

m. mass (kg) = 1.15 mol/kg. 0.026kg → 0.0299 moles.

Finally we convert the moles to mass (mol. molar mass)

0.0299 mol. 342.3 g/mol = 10.23 g

The mass of sucrose is 10.23 grams

Explanation:

Step 1: Data given

Mass of water = 26 grams = 0.026 kg (=solvent)

Molality = 1.15 m

Step 2: Calculate moles sucrose

molality = moles sucrose / mass water

1.15 = moles sucrose / 0.026 kg

moles sucrose = 1.15 * 0.026

moles sucrose = 0.0299 moles

Step 3: Calculate mass of sucrose

mass sucrose = moles sucrose * molar mass sucrose

mass sucrose = 0.0299 moles * 342.3 g/mol

mass sucrose = 10.23 grams

The mass of sucrose is 10.23 grams