General
✓✗If the atomic mass unit were defined as one-sixth of the mass of a carbon-12 atom instead of one-twelfth, the molecular mass of water on this scale would be
- 18 u
- 3 u
- 36 u
- 9 u
General
✓✗Molality is defined as the number of moles of solute per
- litre of solvent
- kilogram of solution
- litre of solution
- kilogram of solvent
General
✓✗How many litres of air at STP (21% oxygen by volume) are required for complete combustion of 1 mol of propane?
- 112 L
- 533 L
- 107 L
- 224 L
General
✓✗The volume of 0.1 M HCl required to react completely with 1.0 g of a mixture of equal masses of Na2CO3 and NaHCO3 is about (Na = 23, C = 12, O = 16, H = 1)
- 154 mL
- 77 mL
- 200 mL
- 100 mL
General
✓✗What volume of ammonia is formed when 15 L of hydrogen reacts completely with excess nitrogen, all volumes measured at the same temperature and pressure?
- 30 L
- 10 L
- 15 L
- 5 L
General
✓✗The number of molecules in 4.4 g of CO2 is
- 6.022 × 1022
- 1.204 × 1023
- 3.011 × 1022
- 6.022 × 1023
General
✓✗The specific volume of a cylindrical virus particle is 6.02 × 10−2 cm3 g−1, and its radius and length are 7 Å and 10 Å respectively. If NA = 6.02 × 1023 mol−1, the molar mass of the virus is
- 1.54 × 104 kg mol−1
- 3.08 × 104 kg mol−1
- 15.4 kg mol−1
- 3.08 × 103 kg mol−1
General
✓✗Which of the following can be separated into its components by physical methods?
- Water
- A mixture of salt and sand
- Carbon dioxide
- Sodium chloride
General
✓✗The smallest particle of a substance that can exist independently and shows all its properties is
- a nucleus
- a molecule
- an electron
- an atom
General
✓✗A sample of a compound always contains the same elements in the same proportion by mass, yet two different compounds can contain the same two elements. Which pair of laws together accounts for both observations?
- Gay-Lussac's law and law of conservation of mass
- Law of multiple proportions and Avogadro's law
- Law of conservation of mass and Avogadro's law
- Law of definite proportions and law of multiple proportions
General
✓✗One litre of hard water contains 12.00 mg of Mg2+. The number of milli-equivalents of washing soda required to remove its hardness is
- 1 × 10−3
- 1
- 12.16 × 10−3
- 12.16
General
✓✗In Haber process 30 litres of dihydrogen and 30 litres of dinitrogen were taken for reaction which yielded only 50% of the expected product. What will be the composition of gaseous mixture under the aforesaid condition in the end?
- 20 litres ammonia, 20 litres nitrogen, 20 litres hydrogen
- 10 litres ammonia, 25 litres nitrogen, 15 litres hydrogen
- 20 litres ammonia, 10 litres nitrogen, 30 litres hydrogen
- 20 litres ammonia, 25 litres nitrogen, 15 litres hydrogen
General
✓✗The number of electrons in 1.6 g of CH4 is approximately
- 1 × 1023
- 6 × 1023
- 6 × 1022
- 3 × 1023
General
✓✗The volume occupied by 8.8 g of CO2 at STP is
- 4.48 L
- 8.96 L
- 22.4 L
- 2.24 L
General
✓✗How many moles of lead(II) chloride will be formed from a reaction between 6.5 g of PbO and 3.2 g of HCl?
- 0.011
- 0.029
- 0.333
- 0.044