How much time (in hours) would it take to distribute one Avogadro number of wheat grains, if 10²⁰ grains are distributed each second?

• 0.1673

• 1.673

• 16.73

• 167.3

At 25°C, at 5% aqueous solution of glucose (molecular weight = 180g mol^-1) is isotonic with a 2% aqueous solution containing and unknown solute. What is the molecular weight of the unknown solute?

• 60

• 80

• 72

• 63

73.

200 mL of water is added to a 500 mL of 0.2 M solution. What is the molarity of this diluted solution?

• 0.5010M

• 0.2897M

• 0.7093

• 0.1428

When 200 mL of aqueous solution of HCl (pH = 2) is mixed with 300 mL of an aqueous solution of NaOH (pH = 12) the pH of the resulting mixture is

• 10

• 2.7

• 4.0

• 11.3

The percentage of an element M is 53 in its oxide of molecular formula M₂O₃. Its atomic mass is about

• 45

• 9

• 27

• 36

The pH of a solution obtained by mixing 50 mL of 1 N HCl and 30 mL of 1 N NaOH is [log 2.5 = 0.3979]

• 12.042

• 0.6021

• 0.3979

• 3.979

How much of sulphur is present in an organic compound, if 0.53 g of the compound gave 1.158 g of BaSO₄ on analysis ? 

• 10%

• 20%

• 30%

• 15%

Law of multiple proportions is illustrated by one of the following pairs :

• N₂O and NO

• H₂S and SO₂

• NH₃ and Na₂O

• BeO and BeCl₂

Avogadro's hypothesis states that :

• the ideal gas consists of a large number of small particles called molecules

• under the same conditions of temperature and pressure equal volumes of gases contain the same number of molecules

• volume of a definite quantity of gas at constant pressure is directly proportional to absolute temperature

• a given mass of gas at constant pressure is directly proportional to absolute temperature

If 117 gm NaCl is dissolved in 1000 g of water the concentration of the solution is said to be :

• 2 molar

• 2 molal

• 1 normal

• 1 molal