Molarity is defined as

• the number of moles of solute dissolved in 1 dm³ of the solution

• the number of moles of solute dissolved in 1 kg of solvent

• the number of moles of solute dissolved in 1 dm³ of the solvent

• the number of moles of solute dissolved in 100 ml of the solvent

The molality of solution containing 15.20 g of urea, (molar mass = 60) dissolved in 150 g of water is

• 1.689 mol kg^-1

• 0.1689 mol kg^-1

• 0.5922 mo kg^-1

• 0.2533 mol kg^-1

For which among the following equimolar aqueous solutions Van't Hoff factor has the lowest value?

• Aluminium chloride

• Potassium sulphate

• Ammonium chloride

• Urea

The molality of the 3M solution of methanol if the density of the solution is 0.9 g cm^-3 is

• 3.73

• 3.0

• 3.33

• 3.1

10 g of MgCO₃ decomposes on heating to 0.1 mole CO₂ and 4 g MgO. The percent purity of MgCO₃ is

• 24%

• 44%

• 84%

• 74%

The compound Na₂CO₃ . x H₂O has 50% H₂O by mass. The value of "x" is

• 4

• 5

• 6

• 8

The volume of oxygen liberated at STP from 15 mL of 20 volume H₂O₂ is

• 100 mL

• 200 mL

• 300 mL

• 400 mL

Calculate the molality of a solution that contains 51.2 g of naphthalene (C₁₀H₈) in 500 mL of carbon tetrachloride. The density of CCl₄ is 1.60 g/mL

• 0.250 m

• 0.500 m

• 0.750 m

• 0.840 m

When 2.46 gm of a hydrated salt (MSO₄xH₂O) is completely dehydrated, 1.20 gm of anhydrous salt is obtained. If the molecular weight of anhydrous salt is 120 gm mol^-1, what is the value of x?

• 2

• 7

• 4

• 6

70.

An organic compound contains 90% carbon and 10% hydrogen by mass. Its empirical formula is

• C₂H₄

• C₃H₆

• C₃H₈

• C₃H₄