Concentrated nitric acid is 70% HNO3. The amount of concentrated nitric acid solution that should be used to prepare 250 mL of 2.0 M HNO3 would be:
1. 90.0 g conc. HNO3
2. 70.0 g conc. HNO3
3. 54.0 g conc. HNO3
4. 45.0 g conc. HNO3
The mole fraction of the solute in a 1.00 molal aqueous solution is:
1. | 0.00177 | 2. | 0.0344 |
3. | 0.0177 | 4. | 0.1770 |
6.02x1020 molecules of urea are present in 100mL of its solution. The concentration of the solution is:
1. | 0.02M | 2. | 0.01M |
3. | 0.001M | 4. | 0.1M |
Which of The following has a maximum number of molecules?
1. 7g N2
2. 2g H2
3. 16g NO2
4. 16g O2
Calculate the number of moles of oxygen in 1L of air containing 21% oxygen by volume, under standard conditions.
1. 0.0093 mole
2. 2.10 moles
3. 0.186 mole
4. 0.21 mole
How much oxygen gas (O2) at standard temperature (0°C) and pressure (1 atm) is required to completely combust 1 liter of propane gas (C3H8) under the same conditions?
1. | 7L | 2. | 6L |
3. | 5L | 4. | 10L |
1 g of magnesium is burnt with 0.56g of oxygen in a closed vessel. The left-out reactant and its quantity are
(At. weight of Mg = 24, O=16)
1. | Mg, 0.16g | 2. | O2, 0.16g |
3. | Mg, 0.44g | 4. | O2, 0.28g |
Percentage of Se in peroxidase anhydrase enzyme is 0.5% by weight (at. weight = 78.4), then minimum molecular weight of peroxidase anhydrase enzyme is
1. 1.568 x 103
2. 15.68
3. 2.168 x 104
4. 1.568 x 104
Assuming fully decomposed, the volume of CO2 released at STP on heating 9.85g of BaCO3 [at. mass of Ba = 137] will be
1. 1.12L
2. 0.84L
3. 2.24L
4. 4.96L
The total number of valence electrons in 4.2g of ion is (NA is the Avogadro's number)
1. 2.1NA
2. 4.2NA
3. 1.6NA
4. 3.2NA