The mass of one 12C atom in g is:
1. 1.393 x 10-23
2. 1.993 x 10-23
3. 1.773 x 10-23
4. 1.593 x 10-23
The number of significant figures present in the answer of the following calculations [(i), (ii), (iii)] are respectively -
1. | 0 . 02856 × 298 . 15 × 0 . 112 / 5785 |
2. | 5 × 5.364 |
3. | 0.0125 + 0.7864 + 0.0215 |
1. | 4, 4, 3 | 2. | 3, 3, 4 |
3. | 4, 3, 4 | 4. | 3, 4, 4 |
The molar mass of naturally occurring Argon isotopes is:
Isotope | Isotopic molar mass | Abundance |
36-Ar | 35.96755 g mol–1 | 0.337% |
38-Ar | 37.96272 g mol–1 | 0.063% |
40-Ar | 39.9624 g mol–1 | 99.600% |
1. | 49.99947 g mol-1 | 2. | 39.99947 g mol-1 |
3. | 35.59947 g mol-1 | 4. | 45.59947 g mol-1 |
The highest number of atoms is present in -
1. 52 moles of Ar
2. 52 u of He
3. 52 g of He.
4. All of the above have the same number of atoms
Burning a small sample of welding gas (constituted of C and H only) in oxygen gives 3.38 g carbon dioxide, 0.690 g of water, and no other products. A volume of 10.0 L (measured at STP) of this welding gas is found to weigh 11.6 g. Molecular formula of welding gas would be:
1. C2H2
2. C2H6
3. CH
4. C2H4
The mass of CaCO3 required to react completely with 25 mL of 0.75 M HCl according to the given reaction would be:
CaCO3(s) + HCl(aq) ➡ CaCl2(aq) + CO2(g) + H2O(l)
1. 0.36 g
2. 0.09 g
3. 0.96 g
4. 0.66 g
Amount of HCl that would react with 5.0 g of manganese dioxide, as per the
given reaction will be:
4HCl(aq) + MnO2(s) ➡ 2H2O(l) + MnCl2(aq) + Cl2(2)
1. 4.8 g
2. 6.4 g
3. 2.8 g
4. 8.4 g
List I | List II | ||
a. | Micro | i. | m |
b. | Mega | ii. | m |
c. | Giga | iii. | m |
d. | Femto | iv. | m |
a | b | c | d | |
1. | i | iv | iii | ii |
2. | iii | iv | ii | i |
3. | ii | iii | iv | i |
4. | i | iii | iv | ii |
The numbers 234,000 and 6.0012 can be represented in scientific notation as:
1.
2. 0.234 and
3.
4. 2.34 and 6.0012
The number of significant figures in the numbers 5005, 500.0, and 126,000 are, respectively:
1. | 2, 4, and 3 | 2. | 4, 1, and 3 |
3. | 4, 4, and 6 | 4. | 4, 4, and 3 |