Mark the species among the following that contains the highest number of atoms.
1. 4 g He
2. 46 g Na
3. 0.40 g Ca
4. 12 g He
Match the following:
COLUMN I | COLUMN II |
A. 88 g of CO2 | 1. 0.25 mol |
B. 6.022×1023 molecules of H2O | 2. 2 mol |
C. 5.6 L of O2 at STP | 3. 3 mol |
D. 96 g of O2 | 4. 1 mol |
A | B | C | D | |
1. | 2 | 4 | 1 | 3 |
2. | 1 | 2 | 3 | 4 |
3. | 1 | 4 | 3 | 2 |
4. | 4 | 1 | 3 | 2 |
Given below are two statements:
Assertion (A): | One atomic mass unit is defined as one-twelfth of the mass of one carbon-12 atom. |
Reason (R): | The carbon-12 isotope is the most abundant isotope of carbon and has been chosen as the standard. |
1. | Both (A) and (R) are true and (R) is the correct explanation of (A). |
2. | Both (A) and (R) are true but (R) is not the correct explanation of (A). |
3. | (A) is true but (R) is false. |
4. | (A) is false but (R) is true. |
Assertion (A): | The combustion of 16 g of methane gives 18 g of water. |
Reason (R): | In the combustion of methane, water is one of the products. |
1. | Both (A) and (R) are True and (R) is the correct explanation of (A). |
2. | Both (A) and (R) are True but (R) is not the correct explanation of (A). |
3. | (A) is True but (R) is False. |
4. | (A) is False but (R) is True. |
One mole of oxygen gas at STP is equal to:
(a) | 6 .022× 1023 molecules of oxygen |
(b) | 6.022 × 1023 atoms of oxygen |
(c) | 16 g of oxygen molecule |
(d) | 32 g of oxygen |
1. (a) and (b)
2. (a) and (c)
3. (a) and (d)
4. (c) and (d)
Which of the following pairs have the same number of atoms?
(a) | 16 g of O2(g) and 4 g of H2(g) |
(b) | 16 g of O2 and 44 g of CO2 |
(c) | 28 g of N2 and 32 g of O2 |
(d) | 12 g of C(s) and 23 g of Na(s) |
1. (a), (b)
2. (b), (c)
3. (c), (d)
4. (b), (d)
16 g of oxygen has the same number of molecules as in:
(a) 16 g of CO
(b) 28 g of N2
(c) 14 g of N2
(d) 1.0 g of H2
1. (a), (b)
2. (b), (c)
3. (c), (d)
4. (b), (d)
(a) 16 g of gas
(b) 22.7 L of gas
(c) dioxygen molecules
(d) 11.2 L of gas
The incorrect statements regarding 1 mole of dioxygen gas at STP from the above four statements are:
1. (a, b, c)
2. (a, b, d)
3. (b, c, d)
4. (a, c, d)