The maximum number of atoms is present in which of the following -

1. 1 g of Mg(s) 2. 1 g of O2 (g)
3. 1 g of Li(s) 4. 1 g of Ag(s)

Subtopic:  Moles, Atoms & Electrons |
 79%
Level 2: 60%+
NEET - 2020
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One mole of carbon atom weights 12 g, the number of atoms in it is equal to:
(Mass of carbon – 12 is 1.9926×10-23 g)

1. 1.2×1023

2. 6.022×1022

3. 12×1022

4. 6.022×1023

Subtopic:  Moles, Atoms & Electrons |
 80%
Level 1: 80%+
NEET - 2020
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The density of a 2 M aqueous solution of NaOH is 1.28 g/cm3. The molality of the solution is: 
[molecular mass of NaOH = 40 g mol-1]

1. 1.20 m 2. 1.56 m
3. 1.67 m 4. 1.32 m
Subtopic:  Concentration Based Problem |
 73%
Level 2: 60%+
NEET - 2019
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An organic compound contains 80 % (by wt.) carbon and the remaining percentage of hydrogen. The empirical formula of this compound is:
[Atomic wt. of C is 12, H is 1] 
1. CH3
2. CH4
3. CH
4. CH2

Subtopic:  Empirical & Molecular Formula |
 75%
Level 2: 60%+
NEET - 2021
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To produce 20 moles of ammonia via Haber's process, how many moles of hydrogen molecules are required?

1. 40 mol 2. 10 mol
3. 20 mol 4. 30 mol
Subtopic:  Limiting Reagent | Equation Based Problem |
 81%
Level 1: 80%+
NEET - 2019
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Calculate the mass of 95% pure CaCO3 that will be required to neutralize 50 mL of 0.5 M HCl solution according to the following reaction.
CaCO3(s) + 2HCl(aq) → CaCl2(aq) + CO2(g) + 2H2O(l)
[Calculate up to the second place of decimal point]
1. 9.50 g 2. 1.25 g
3. 1.32 g 4. 3.65 g
Subtopic:  Equation Based Problem |
 55%
Level 3: 35%-60%
NEET - 2022
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Match List-I with List-II:

List-I
(Quantities)
List-II
(Corresponding Values)
(a) 4.48 litres of O2 at STP (i) 0.2 mole
(b) 12.022 × 1022 molecules of H2O (ii) 12.044 × 1023
molecules
(c) 96 g of O2 (iii) 6.4 g
(d) 88 g of CO2 (iv) 67.2 litres at STP
(Given - Molar volume of a gas at STP - 22.4 L)
Choose the correct answer from the options given below:
(a) (b) (c) (d)
1. (i) (iii) (iv) (ii)
2. (iii) (i) (iv) (ii)
3. (iv) (i) (ii) (iii)
4. (iii) (i) (ii) (iv)
Subtopic:  Moles, Atoms & Electrons |
 50%
Level 3: 35%-60%
NEET - 2022
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The mass of a 2.5 mL solution (the density of the solution is 2.15 g/mL) in the correct significant figures is:
1. 5375 × 10–3 g 2. 5.4 g
3. 5.38 g 4. 53.75 g
Subtopic:  Introduction |
 73%
Level 2: 60%+
NEET - 2022
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What fraction of Fe exists as Fe(III) in Fe0.96O?
(Consider Fe0.96 to be made up of Fe(II) and Fe(III) only)
1.  \(\dfrac{1}{12}\)
2.  \(0.08\)
3.  \(\dfrac{1}{16}\)
4.  \(\dfrac{1}{20}\)
Subtopic:  Moles, Atoms & Electrons |
Level 3: 35%-60%
NEET - 2022
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The mass of CO2 produced by heating 20 g of 20% pure limestone, as per the equation given below, is:\(\mathrm{CaCO}_3(\mathrm{~s}) \xrightarrow{\text { heat }} \mathrm{CaO}(s)+\mathrm{CO}_2(\mathrm{~g})\)
1. 1.32 g  2. 1.12 g 
3. 1.76 g  4. 2.64 g
Subtopic:  Equation Based Problem |
 75%
Level 2: 60%+
NEET - 2023
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