On reduction with CO, 200 kg of iron ore (Fe₂O₃) containing 20% impurities gives iron. The amount of iron produced will be-

1. 84 kg

2. 200 kg

3. 56 kg

4. 112 kg

At STP the moles of oxygen atoms in 2.8 L of CO₂ gas is:-

1. 0.125

2. 0.25

3. 0.5

4. 1

Identify the incorrect statement among the following:

1. 1 mol N^-3 ions have 10 mole electrons

2. 1 mol O^-2 ions have  6.023 x 10²² electrons

3. 1 mol CH₄ has 10 mole protons

4. 1 mol water has 10 mole protons

Mass of sucrose C₁₂H₂₂O₁₁ produced by mixing 84 gm of carbon, 12gm of hydrogen and 56L. O₂ at 1atm & 273 K according to give reaction, is C(s) + H₂(g) +O₂(g) $\to$ C₁₂H₂₂O₁₁ (s)

1. 138.5

2. 155.5

3. 172.5

4. 199.4

A mixture contains Na₂CO₃ and NaHCO₃ and wt. of mixture is 10gm. Mixture on heating liberates 56ml of CO₂ at S.T.P, wt of Na₂CO₃ in mixture is

1. 9.58 gm

2. 5 gm

3. 7.5 gm

4. 8 gm

How many moles of KMnO₄ are needed to oxidize a mixture of 1 mole of each FeSO₄ & FeC₂O₄ in acidic medium

1. $\frac{4}{5}$

2. $\frac{5}{4}$

3. $\frac{3}{4}$

4. $\frac{5}{3}$

1.0 mol of Fe reacts completely with 0.65 mol of O₂ to give a mixture of only FeO and Fe₂O₃. The mole ratio of ferrous oxide to ferric oxide is

(1) 2 : 2

(2) 4 : 3

(3) 1 : 2

(4) 2 : 7

The percentage of copper in a copper(II) salt can be determined by using a thiosulphate titration. 0.305 gm of a copper(II) salt was dissolved in water and added to, an excess of potassium iodide solution liberating iodine according to the following equation 2Cu² (aq) + 4I^– (aq) $\stackrel{}{\rightleftharpoons }$ 2CuI(s) + I₂(aq) The iodine liberated required 24.5cm³ of a 0.100 mole dm^-3 solution of sodium thiosulphate 2S₂O₃^2- (aq) + I₂(aq) $\underset{}{\overset{}{\to }}$ 2I^– (aq) + S₄O₆^2- (aq) the percentage of copper, by mass in the copper(ll) salt is. [Atomic mass of copper = 63.5]

1. 64.2

2. 51.0

3 48.4

4. 25.5

Oxygen contains 90% O¹⁶ and 10% O¹⁸. Its atomic mass is

(1) 17.4

(2) 16.2

(3) 16.5

(4) 17

The total number of electrons present in 1.6 gm. of methane is [IIT 1976; Roorkee 1985; CPMT 1987, 92]

(1) 6.02 × 10²³

(2) 6.02 × 10²²

(3) 6.02 × 10²¹

(4) 4.02 × 10²⁰