WorksheetsBasic Principles of Chemistry
Total questions: 45
Worksheet time: 23mins
Suppose the elements X and Y combine to form two compounds XY2 and X3Y2. When 0.1 mole of XY2 weights 10 g and 0.05 mole of X3Y2 weights 9g, the atomic weights of X and Y are
40,50
60,40
20,30
30,20
If Avogadro number NA, is changed from 6.022 x 1023 mole -1 to 6.022 x 1020 mole-1 this would change
The definition of mass in units of grams
The mass of one mole of carbon
The ratio of chemical species to eash other in a balanced equation
The ratio of elements to each other in a compounds
- g of a magnesium carbonate sample decomposes on heating to give carbon dioxide and 8.0 gmagnesium oxide. What will be the percentage purity of masnesium carbonate in the sample? (Atomic weight of Mg = 24)
75
96
60
84
What is the mass of precipitate formed when 50mL of 16.9% solution of AgNO3 is mixed with 50 mL of 5.8% NaCl solution? (Ag = 107.8, N = 14, O = 16, Na + 23, Cl = 35.5)
28 g
3.5 g
7 g
14 g
The number of water molecules is maximum in
18 molecules water
1.8 g of water
18 g of water
18 moles of water
When 22.4L of H2(g) is mixed with 11.2 L of Cl2(g), each at STP, the moles of HCl(g) formed is equal to
1 mole of HCI (g)
2 moles of HCl (g)
0.5 mole of HCl (g)
1.5 moles of HCl (g)
1.0 g of magnesium is burnt with 0.56 g of oxygen in a closed vessel. Which reactant is left in excess and how much?
(At. weight of Mg = 24, O = 16)
Mg, 0.16 g
02, 0.16 g
Mg, 0.44 g
O2, 0.28 g
How many grams of concerntrated nitric acid solution should be used to prepare 250 mL of 2.0 M HNO3? The concerntrated acid is 70% HNO3.
45.0 g conc. HNO3
90.0 g conc. HNO3
70.0 g conc. HNO3
54.0 g conc. HNO3
6.02 x 1020 molecules of urea are present in 100 mL of its solution. The concentration of solution is
0.02 M
0.01 M
0.001 M
0.1 M
The number of atoms in 0.1 mole of a triatomic gas is (NA = 6.023 x 1023 mole-1)
6.026 x 1022
1.806 x 1023
3.600 x 1023
1.800 x 1022
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
Volume occupied by one molecule of water (density = 1 g cm-3) is
9.0 x 10-23 cm3
6.023 x 10-23 cm3
3.0 x 10-23 cm3
5.5 x 10-23 cm3
What volume of oxygen gas (O2) measured at 0oC and 1 atm, is needed to burn completely 1L of propane gas (C3H8) measured under the same conditions?
7L
6L
5L
10L
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?
0.044
0.333
0.011
0.029
Number of moles of MnO-4 required to oxidise one mole of ferrous oxalate completely in acidic medium will be
0.6 mole
0.4 mole
7.5 mole
0.2 mole
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
1
3/5
An element, X has the following isotopic composition:
200 X : 90%, 199 X : 8.0%, 202 X : 2.0%
The weighted average atomic mass of the naturally occurring element X is closest to
201 u
202 u
199 u
200 u
The number of moles of KMnO4 reduced by one mole of KI in alkaline medium is
one fifth
five
one
two
The mass of carbon anode consumed (giving only carbon dioxide) in the production of 270 kg of aliminium metal from bauxite by the Hall process is (at. mass of Al = 27)
180 kg
270 kg
540 kg
90 kg
The maximum number of molecules are present in
15 L of H2 gas at STP
5 L o fN2 gas at STP
0.5 g of H2 gas
10 g of O2 gas
In Haber process 30L of dihydrogen and 30L 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
Which has maximum number of molecules?
7 g N2
2 g H2
16 g NO2
16 g O2
Specifc volume of cylindrical virus particle is 6.02 x 10-2 cc/g, whose radius and length are 7Å and 10Å respectively.
If NA = 6.023 X 1023 , find molecular weight of virus.
15.4 kg/mol
1.54 x 104 kg/mol
3.08 x 104 kg/mol
3.08 x 103 kg/mol
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
1.568x 103
15.68
2.168x 104
1.568x 104
Assuming fully decomposed, the volume of CO2 released at STP on heating 9.85 g of BaCO3 ( at. mass of Ba = 137) will be
1.12 L
0.84 L
2.24 L
4.96 L
The number of atoms in 4.25 g of NH3 is approximately
4 x 1023
2 x 1023
1 x 1023
6 x 1023
In the reaction,
4NH3 (g) + 5O2 (g) → 4NO(g) + 6H2O(1)
When 1 mole of ammonia and 1 mole of O2 are made to react to completion, then
1.0 mole of H2O is produced
1.0 mole of NO will be produced
all the oxygen will be consumed
all the ammonia will be consumed
Haemoglobin contains 0.33% of iron by weight. The molecular weight of haemoglobin is approximately 67200 g. The number of iron atoms (at. weight of Fe is 56) present in one molecule of haemoglobin are
1
6
4
2
The number of significant figures for the three numbers 161 cm, 0.161 cm, 0.0161 cm are
3,4 and 5 respectivley
3,4 and 4 respectivley
3,3 and 4 respectivley
3,3 and 3 respectivley
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
Liquid benzene (C6H6) burns in oxygen according to the equation,
2C6H6(1) + 15O2(g) → 12CO2(g) + 6H2O(g)
How many litres of O2 at STP are needed to complete the combustion of 39 g of liquid benzene? (Mol. weight of O2 = 32, C6H6 = 78)
74 L
11.2 L
22.4 L
84 L
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
The percentage weight of Zn in white vitriol [ZnsO4 . 7H2O] is approximately equal to
(at. mass of Zn = 65, S = 32, O = 16 and H = 1)
33.65%
32.56%
23.65%
22.65%
The total number of valence electrons in 4.2 g of N−3 ion is (NA is the Avogadro's number)
2.1 NA
4.2 NA
1.6 NA
3.2 NA
In the final answer of the expression
(29.2 − 20.2) (1.79 x 105) / 1.37
the number of significant figures is
1
2
3
4
The number of gram molecules of oxygen in 6.02 x 1024 CO molecules is
10 g molecules
5 g molecules
1 g molecules
0.5 g molecules
The number of oxygen atoms in 4.4 g of CO2 is
1.2 x 1023
6 x 1022
6 x 1023
12 x 1023
Boron has two stable isotopes, 10B (19%) and 11B (81%). Calculate average atomic weight of boron in the periodic table.
10.8
10.2
11.2
10.0
The molecular weight of O2 and SO2 are 32 and 64 respectively. At 15oC and 150 mmHg pressure, 1L of O2 contains 'N' molecules. The number of molecules in 2L of SO2 under the same conditions of temperature and pressure will be
N/2
N
2 N
4 N
Ratio of Cp and Cv of a gas 'X' is 1:4. The number of atoms of the gas 'X' present in 11.2 L of it at NTP will be
6.02 x 1023
1.2 x 1023
3.01 x 1023
2.01 x 1023
A metal oxide has the formula Z2O3. It can be reduced by hydrogen to give free metal and water. 0.1596 g of the metal oxide requires 6 mg of hydrogen for complete reduction. The atomic weight of the metal is
27.9
159.6
79.8
55.8
What is the weight of oxygen required for the complete combustion of 2.8 kg of ethylene?
2.8 kg
6.4 kg
9.6 kg
96 kg
One litre hard water contains 12.00 mg Mg2+. Miliequivalents of washing soda required to remove its hardness is1
1
12.16
1 x 10-3
12.16 x 10-3
1 cc N2O at NTP contains
1.8 / 224 x 1022 atoms
6.02 / 22400 x 1023 molecules
1.32 / 224 x 1023 electrons
All of the above
At STP, the density of CCl4 vapour in g/L will be nearest to
6.87
3.42
10.26
4.57
