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KMnO₄ reacts with oxalic acid according to the equation:

2MnO4− + 5C2O42− + 16H+ → 2Mn2+ + 10CO2 + 8H2O 20 mL of 0.1 M KMnO4 will react with? A. 20 mL of 0.25 M oxalic acid B. 20... View Article

Find the equivalent weight of KMnO₄ which is in an alka condition and for which the reaction occurs as follows:

2KMnO4 + 2KOH ⟶ 2K2MnO4 + H2O + O A. 31.6 B. 52.7 C. 49 D. 158 Solution: (D) Equivalent mass of KMnO4 = Molecular Weight / No of... View Article

The enthalpy of combustion of methane at 25 ^∘C is 890 kJ. The heat liberated when 3.2 g of methane is burnt in the air is:

A. 445 kJ B. 278 kJ C. -890kJ D. 178 kJ Solution: (D) Number of moles of methane burnt = 3.2 / 16 = 0.2 Enthalpy of combustion of 1... View Article

The volume of oxygen necessary for the complete combustion of 20 litre of propane is:

A. 40 litre B. 60 litre C. 80 litre D. 100 litre Solution: (D) C3H8 + 5O2 → 3CO2 + 4H2O From the equation: 1 volume of C3H8... View Article

When 10 g of 90% pure limestone is heated completely, the volume (in litres) of CO₂ is liberated at STP is:

A. 22.4 B. 2.24 C. 20.6 D. 2.016 Solution: (D) As per the questions the sample of limestone is only 90 % pure. Thus, 100 g limestone... View Article

2g of a mixture of CO and CO₂ on reaction with excess I₂O₅ produced 2.54 g of I₂. What would be the mass % of CO₂ in the original mixture?

A. 60 B. 30 C. 70 D. 35 Solution: (B) 5CO + I2O5 → 5 CO2 + I2 1 mol of I2 = 1 mol of I2O5 = 5 mol of CO Hence, mol of CO = 5... View Article

Air contains 20% O₂ by volume. How many cc of air will be required for oxidation of 100 cc of acetylene?

A. 500 cc B. 1064 cc C. 212.8 cc D. 1250 cc Solution: (D) Writing the reaction down, 2C2H2 + 5O2 → 4CO2 + 2H2O 2 moles of C2H2... View Article

The decomposition of a certain mass of CaCO3 gave 11.2 dm³ of CO₂ gas at STP. The mass of KOH required to completely neutralise the gas is:

A. 56 g B. 28 g C. 42 g D. 20 g Solution: (B) Weight of 11.2 dm3 of CO2 gas at STP = 44 / 2 KOH + CO2 → KHCO3 56g 44g KOH... View Article

The stoichiometry of the following reaction is:

K2S2O8(aq) + 2KI(aq) → 2K2SO4(aq) + I2(aq) A. 2 : 2 B. 1 : 1 C. 1 : 2 D. 2 : 1 Solution: (C) Generally, the stoichiometry of a... View Article

1 mole of methyl amine on reaction with nitrous acid gives at NTP

A. 1.0 L of nitrogen B. 22.4 L of nitrogen C. 11.2 L of nitrogen D. 5.6 L of nitrogen Solution: (B) The reaction: CH3−NH2 +... View Article

Sodium nitrate on reduction with Zn in presence of NaOH solution produces NH₃ Mass of sodium nitrate absorbing 1 mole of electron will be:

A. 7.750 B. 10.625 C. 8.000 D. 9.875 Solution: (B) Lets look at the following reaction: Zn + 2OH− ⟶ ZnO22− + 2H+ +... View Article

The ratio of amounts of H₂S needed to precipitate all the metal ions from 100mL of 1MAgNO₃ and 100mL of 1MCuSO₄ will be:

A. 1:1 B. 1:2 C. 2:1 D. None of these Solution: (B) 100 mL of 1 M AgNO3 = 0.1 mol AgNO3 100 mL of 1 M CuSO4 = 0.1 mol CuSO4 2AgNO3... View Article

Match the following Column I and Column II.

A. A - 4, B - 1, C - 2, D - 3 B. A - 5, B - 1, C - 2, D - 3 C. A - 4, B - 1, C -3, D - 2 D. A - 1, B - 4, C - 2, D - 3 Solution: (A) -... View Article

Acidified KMnO₄ oxidizes oxalic acid to CO₂. What is the volume (in litre) of 10⁻⁴MKMnO₄ required to completely oxidize 0.5litre of 10⁻²M oxalic acid in acid medium?

A. 125 B. 1250 C. 200 D. 20 Solution: (D)... View Article

Excess of carbon dioxide is passed through 50 mL of 0.5 M calcium hydroxide solution. After the completion of the reaction, the solution was evaporated to dryness. The solid calcium carbonate was completely neutralised with 0.1N Hydrochloric acid. The volume of Hydrochloric acid required is: (At. mass of calcium = 40)

A. 500 cm3 B. 400 cm3 C. 300 cm3 D. 200 cm3 Solution: (A) Let us find the volume of hydrochloric acid. No. of millimoles of Ca(OH)2 =... View Article

An aqueous solution containing 6.5gm of NaCl of 90% purity was subjected to electrolysis. After the complete electrolysis, the solution was evaporated to get solid NaOH. The volume of 1M acetic acid required to neutralise NaOH obtained above is:

A. 100 cm3 B. 200 cm3 C. 1000 cm3 D. 2000 cm3 Solution: (A) Let us calculate the weight of pure NaCl = 6.5 × 0.9 = 5.85 g No.... View Article

A mixture of CaCl2 and NaCl weighing 4.44g is treated with sodium carbonate solution to precipitate all the calcium ions as calcium carbonate. The calcium carbonate so obtained is heated strongly to get 0.56g of CaO. The percentage of NaCl in the mixture is:

(Atomic mass of Ca=40) A. 30.6 B. 75 C. 69.4 D. 25 Solution: (B) Weight of CaO = 0.56 g 0.56 g of CaO contains 0.40 g of calcium... View Article

Stoichiometric ratio of sodiumdihydrogen orthophosphate and sodium hydrogen orthophosphate required for synthesis of Na5P3O10 is:

A. 1.5:3 B. 3:1.5 C. 1:1 D. 2:3 Solution: (A)... View Article

The mass of potassium dichromate crystals required to oxidise 750 cm³ of 0.6 M Mohr’s salt solution is: (Given molar mass potassium dichromate = 294, Mohr’s salt = 392)

A. 0.45 g B. 22.05 g C. 2.2 g D. 0.49 g Solution: (B) Mohr's salt is FeSO4.(NH4)2S04.6H20 Only oxidisable part Fe2+ is;... View Article

5 moles of Ba(OH)₂ are treated with excess of CO₂. How much Ba(OH₂) will be formed?

A. 39.4 g B. 197 g C. 591 g D. 985g Solution: (D) Ba(OH)2 + CO2 → BaCO3 + H2O Given, 5 moles of barium hydroxide reacts with... View Article