Question

you need to make 300ml of a 1m stock solution of lactose molecular weight =342 how many grams of lactose do you need for your solution

Answer 1

To prepare 300ml of a 1M stock solution of lactose, you need 102.6 grams of lactose, calculated by multiplying the molarity (1M), the volume (0.3L), and the molecular weight of lactose (342 g/mol).

Step-by-step explanation:

To make 300ml of a 1M stock solution of lactose, you'll need to calculate the amount of lactose required using its molar mass.

The molecular weight of lactose is 342 g/mol.

Since 1 mole of lactose equals 342 grams, for a 1M solution, you need 342 grams of lactose per liter of solution.

However, because you only need 300ml (0.3 liters), you multiply 342 g/mol by 0.3 L to find the mass of lactose needed.

Amount of lactose = Molarity (M) × Volume (L) × Molecular weight (g/mol)
Amount of lactose = 1 M × 0.3 L × 342 g/mol

= 102.6 grams of lactose.