In acid medium, Zn reduces nitrate ion to NH${}_4^{+}$ ion according to the reaction,

Zn + NO${}_3^{-}$→ Zn²⁺ + NH${}_4^{+}$ + H₂O (unbalanced).

How many moles of HCl are required to reduce half a mole of NaNO₃ completely ? Assume the availability of sufficient Zn.

• 5

• 4

• 3

• 2

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 relative lowering of vapour pressure of a dilute aqueous solution containing non-volatile solute is 0.0125. The molality of the solution is about

• 0.70

• 0.50

• 0.90

• 0.80

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

0.1 mole of a carbohydrate with empirical formula CH₂O contains 1 g of hydrogen. What is its molecular formula?

• C₂H₄O₂

• C₅H₁₀O₅

• C₃H₆O₃

• C₆H₁₂O₆

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%

347.

Commercial 11.2 volume H₂O₂ solution has a molarity of :

• 1.0

• 0.5

• 11.2

• 1.12

100 g CaCO₃ is treated with 1 L of 1N HCl. What would be the weight of CO₂ liberated after the completion of the reaction ?

• 55 g

• 11 g

• 22 g

• 33 g

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