The number of moles of oxygen in 1 L of air containing 21 % oxygen by volume, under standard conditions, is
0.0093 mole
2.10 moles
0.186 mole
0.21 mole
Which law says that when two elements combine separately with a definite mass of a third element, then the ratio of their masses in which they do so is either the same or some whole number multiple of the ratio in which they combine with each other ?
Law of conservation of mass
Law of multiple proportion
Law of reciprocal proportions
Law of constant composition.
One litre hard water contains 12.00 mg Mg2+ . Milliequivalents of washing soda required to remove its hardness is
1
12.16
1 x 10 -3
12.16 x 10 -3
The percentage weight of Zn in white vitriol [ZnSO4 . 7 H2O] is approximately equal to (Zn = 65, S = 32, O = 16 and H = 1 )
33.65%
32.56%
23.65%
22.65%
0.24 g of a volatile gas, upon vaporisation, gives 45 mL vapour at NTP. What will be the vapour density of the substance?(Density of H2 = 0.089)
95.93
59.93
95.39
5.993
10 g of hydrogen and 64 g of oxygen were filled in a steel vessel and exploded. Amount of water produced in this reaction will be
2 moles
3 moles
4 moles
1 mole
The total number of valence electrons in 4.2 g of ion is (NA is the Avogadro's number)
2.1 NA
4.2 NA
1.6 NA
3.2 NA
In Haber process 30 L of dihydrogen and 30 L 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 L ammonia, 10 L nitrogen, 30 L hydrogen
20 L ammonia, 25 L nitrogen, 15 L hydrogen
20 L ammonia, 20 L nitrogen, 20 L hydrogen
10 L ammonia, 25 L nitrogen, 15 L hydrogen
How many moles of lead (II) chloride will be formed from a reaction between 6.5 g of PbO and 3.2 g of HCI ?
0.044
0.333
0.011
0.029
The number of moles of KMnO4 that will be needed to react with one mole of sulphite ion in acidic solution is
4/5
2/5
3/5
