Which of the following combinations illustrates the law of reciprocal proportions?
1.
2.
3.
4.
The formula of an acid is The mass of 0.0242 moles of the acid is 1.657 g.
The atomic weight of X is:
| 1. | 35.5 | 2. | 28.1 |
| 3. | 128 | 4. | 19.0 |
A 6.85 g sample of the hydrates is dried in an oven to give 3.13 g of anhydrous . The value of x is -
(Atomic weights : Sr=87.60, O=16.0, H=1.0)
1. 8
2. 12
3. 10
4. 6
A solution of Na2S2O3 is standardized iodometrically against 0.167 g of KBrO3. This process requires 50 mL of the solution. What is the normality of the Na2S2O3?
1. 0.2 N
2. 0.12 N
3. 0.72 N
4. 0.02 N
The evolved due to complete conversion of N from 1.12 g sample of protein was absorbed in 45 mL of 0.4 N . The excess acid required 20 mL of 0.1 N . The % N in the sample is:
1. 8
2. 16
3. 20
4. 25
Rearrange the following (I to IV) in the order of increasing masses:
(I) 0.5 mole of O3
(II) 0.5 gm atom of oxygen
(III) 3.0111023 molecules of O2
(IV) 5.6 liter of CO2 at STP
| 1. | II<IV<III<I | 2. | II<I<IV<III |
| 3. | IV<II<III<I | 4. | I<II<III<IV |
The density of dry air containing only and is 1.15 g/L at 740 mm and 300 K. What is the percentage
composition of by weight in the air?
| 1. | 78.00% | 2. | 75.50% |
| 3. | 70.02% | 4. | 72.75% |
The vapour density of a mixture containing and is 27.6. The mole fraction of in the mixture is:
1. 0.1
2. 0.2
3. 0.5
4. 0.8
How much volume of 75% alcohol by weight (d=0.80 g/cm³) is required to prepare 150 cm³ of 30% alcohol by weight (density = 0.90 g/cm³)?
| 1. | 67.5 mL | 2. | 56.25 mL |
| 3. | 44.44 mL | 4. | None of the above |
The average atomic mass of magnesium is 24.31 a.m.u. Magnesium consists of three isotopes: \(^{24}Mg\), \(^{25}Mg \), and \(^{26}Mg\). The mole percentage of \(^{24}Mg\) is 79%, and the remaining 21% is a mixture of \(^{25}Mg \) and \(^{26}Mg\).
Calculate the mole percentage of \(^{26}Mg\).
1. 10 %
2. 11 %
3. 15 %
4. 16 %
Calculate the % of free in oleum (a solution of in ) that is labelled 109% .
1. 40
2. 30
3. 50
4. None
Suppose two elements X and Y combine to form two compounds and when 0.05 mole of weighs 5 g while 3.0111023 molecules of weighs 85 g. The atomic masses of x and y are respectively:
1. 20, 30
2. 30, 40
3. 40, 30
4. 80, 60
100 mL of 10% NaOH (w/V) is added to 100 mL of 10% HCl (w/V). The resultant solution becomes:
1. Alkaline
2. Strongly alkaline
3. Acidic
4. Neutral
1.44 gram of titanium (At. wt. =48) reacted with excess of and produce x gram of non-stoichiometric compound Ti1.44 O
1. 2
2. 1.77
3. 1.44
4. None of the above
2Fe(NO₃)₃ + 3Na₂CO₃ → Fe₂(CO₃)₃ + 6NaNO₃
2.5 moles of Fe(NO₃)₃ are allowed to react with 3.6 moles of Na₂CO₃. If the actual amount of NaNO₃ produced is 6.3 moles, calculate the percentage yield of the reaction.A 6.0 g impure sample of sodium chloride is dissolved in water and reacted with excess silver nitrate solution. If 14.0 g of silver chloride is formed, determine the percentage purity of NaCl in the sample.
1. 95%
2. 85%
3. 75%
4. 65%
25.4 g of and 14.2 g of are made to react completely to yield a mixture of ICI and ICI3. The mole of ICI and ICI3 formed, is respectively -
1. 0.5, 0.2
2. 0.1, 0.1
3. 0.1, 0.3
4. 0.3, 0.4
The vapour density of a mixture containing \(NO_{2}\) and \(N_{2} O_{4}\) is 38.3. The mole of \(NO_{2}\) in a 100 g mixture is:
[Vapour density = (Molar mass / 2)]
1. 0.437
2. 0.347
3. 0.557
4. 0.663
The average molar mass of the mixture of and present in the mole ratio of a:b is
20 g mol-1. When the mole ratio is reversed, the molar mass of the mixture will be:
| 1. | 24 gram | 2. | 42 gram |
| 3. | 20 gram | 4. | 15 gram |
| 1. | 2 |
| 2. | 3 |
| 3. | 4 |
| 4. | 5 |
The vapour density of a volatile chloride of a metal is 95 and the specific heat of the metal is 0.13 cal/g. The equivalent mass of the metal will be:
1. 6 g
2. 12 g
3. 18 g
4. 24 g