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 |
0.50 mol Na2CO3 and 0.50 M Na2CO3 are different because:
1. | Both have different amounts of Na2CO3. |
2. | 0.50 mol is the number of moles and 0.50 M is the molarity. |
3. | 0.50 mol Na2CO3 will generate more ions. |
4. | None of the above. |
Round up the following number into three significant figures:
i. 10.4107 ii. 0.04597 respectively are
1. | 10.4, 0.0460 | 2. | 10.41, 0.046 |
3. | 10.0, 0.04 | 4. | 10.4, 0.0467 |
The following data was obtained when dinitrogen and dioxygen react together to form different compounds:
Mass of dinitrogen | Mass of dioxygen | |
i. | 14 g | 16 g |
ii. | 14 g | 32 g |
iii. | 28 g | 32 g |
iv. | 28 g | 80 g |
The law of chemical combination applicable to the above experimental data is:
1. Law of reciprocal proportions
2. Law of multiple proportions
3. Law of constant composition
4. None of these.
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