Q. No.When \(1 \text{ dm}^3\) of \(\text{CO}_2\) gas is passed over hot coke, the volume of gaseous mixture after complete reaction at STP becomes \(1.4 \text{ dm}^3\). The composition of the gaseous mixture at STP is :
| 1. | \(0.6 \text{ dm}^3\) of \(\text{CO},\) \(0.8 \text{ dm}^3\) of \(\text{CO}_2\) |
| 2. | \(0.8 \text{ dm}^3\) of \(\text{CO},\) \(0.8 \text{ dm}^3\) of \(\text{CO}_2\) |
| 3. | \(0.8 \text{ dm}^3\) of \(\text{CO},\) \(0.6 \text{ dm}^3\) of \(\text{CO}_2\) |
| 4. | \(0.6 \text{ dm}^3\) of \(\text{CO},\) \(0.4 \text{ dm}^3\) of \(\text{CO}_2\) |
Subtopic: Moles, Atoms & Electrons | Concentration Based Problem |
Level 3: 35%-60%
NEET - 2026
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The number of hydrogen atoms present in 5.4 g of urea is :
(Given : Molar mass of urea : 60 g mol-1, NA : 6.022 × 1023 particles mol-1)
1. 2.168 × 1023
2. 2.168 × 1022
3. 1.084 × 1022
4. 1.084 × 1023
(Given : Molar mass of urea : 60 g mol-1, NA : 6.022 × 1023 particles mol-1)
1. 2.168 × 1023
2. 2.168 × 1022
3. 1.084 × 1022
4. 1.084 × 1023
Subtopic: Moles, Atoms & Electrons |
57%
Level 3: 35%-60%
NEET - 2026
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The numbers 17.0145 and 21.0235 were rounded to three figures after the decimal point. The resulting numbers, respectively, are:
| 1. | 17.015 and 21.024 |
| 2. | 17.014 and 21.023 |
| 3. | 17.015 and 21.023 |
| 4. | 17.014 and 21.024 |
Subtopic: Moles, Atoms & Electrons |
63%
Level 2: 60%+
NEET - 2026
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Consider the following data of compounds:
Which of the following represents a correct set of compounds having an equal number of atoms?
| A. | \(212 ~g ~\text{of}~Na_2CO_3 (s) \text{[molar mass}=106 ~g]\) |
| B. | \(~248 g ~\text{of}~ {Na}_2 \mathrm{O}({s}) [\text{molar mass} =62 \mathrm{~g} ]\) |
| C. | \(240 g ~\text{of} ~NaOH (s)~ [\text{molar mass} =40 \mathrm{~g} \) |
| D. | \( 12 g~ \text{of}~ \mathrm{H}_2(\mathrm{~g})[ \text{molar mass} =2 \mathrm{~g}].\) |
| E. | \( 220 g~ \text{of} ~\mathrm{CO}_2(\mathrm{~g})[\text{ molar mass }=44 \mathrm{~g}]\) |
| 1. | B, C, and D only | 2. | B, D, and E only |
| 3. | A, B, and C only | 4. | A, B, and D only |
Subtopic: Moles, Atoms & Electrons |
51%
Level 3: 35%-60%
NEET - 2025
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Which of the following contains the highest number of helium atoms?
1. 4 u of helium
2. 4 g of helium
3. 2.27 L of helium at STP
4. 4 mol of helium
1. 4 u of helium
2. 4 g of helium
3. 2.27 L of helium at STP
4. 4 mol of helium
Subtopic: Moles, Atoms & Electrons |
76%
Level 2: 60%+
NEET - 2024
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1.0 g of \(H_2\) has same number of molecules as in:
| 1. | 14 g of \(N_2\) | 2. | 18 g of \(H_2O\) |
| 3. | 16 g of CO | 4. | 28 g of \(N_2\) |
Subtopic: Moles, Atoms & Electrons |
80%
Level 1: 80%+
NEET - 2024
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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 |
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 |
Level 3: 35%-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. \(\dfrac{1}{20}\)
(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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Which of the following contains the maximum number of atoms ?
| 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 atoms has a mass of 12 g. Determine the number of atoms present in this sample:
(Given: Mass of \(C^{12}\) is )
| 1. | 2. | ||
| 3. | 4. |
Subtopic: Moles, Atoms & Electrons |
81%
Level 1: 80%+
NEET - 2020
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