Question

What is the molality of the solution if 2.82g of glucose dissolved in 30g of water?

Answer 1

ANSWER :

Given :

▪ Weight of glucose = 2.82g

▪ Weight if water = 30g

To Find :

▪ Molality of the solution.

Definition :

✏ Molality is defined as the ratio of moles of solute to the weight of solvent (in kg).

✏ Unit : mole/kg

✏ Sign : m

Mathematically,

☞ m = w/(Mw × w')

• m denotes molality
• w denotes weight of solute
• Mw denotes molecular weight of solute
• w' denotes weight of solvent (in kg)

✒ Solute : Glucose

✒ Solvent : Water

✴ Molecular weight of Glucose = 180g/mol

Calculation :

→ m = 2.82×1000/(180×30)

→ m = 2820/540

→ m = 0.52 mole/kg

Answer 2

$\rule{200}3$

$\huge\tt{GIVEN:}$

• 2.82g of glucose is dissovled in 30g of water.

$\rule{200}3$

$\huge\tt{TO~FIND:}$

• The motarily of that solution.

$\rule{200}3$

$\huge\tt{CONCEPT~USED:}$

• Motarily is the ratio of moles of solute to the weight of the solvent.

The formula used is m = w/(Me × w')

• Where, m = molarity, w = weight of solute, Me = molecular weight of solute , w' = weight of solvent in kg. Also, the unit of mole is mole/kg
• Here, Solute is glucose and the solvent is water, And molecular weight of glucose is 180g/mol

$\rule{200}3$

$\huge\tt{SOLUTION:}$

so, putting the values here,

m = 2.82 × 100/ (180 × 30)

m = 2820/ 540

m = 0.52 mole/kg

$\rule{200}3$