A gaseous mixture contains oxygen and nitrogen in the ratio of 1:4 by weight. Therefore, the ratio of their number of molecules is
1:4
1:8
7:32
3:16
The total number of electrons in one molecule of carbon dioxide is
22
44
66
88
The largest number of molecules is in
36 g of water
28 g of CO
46 g of ethyl alcohol
54 g of nitrogen pentaoxide (N2O5 )
When the same amount of zinc is treated separately with excess of sulphuric acid and excess of sodium hydroxide, the ratio of volumes of hydrogen evolved is
1:1
1:2
2:1
9:4
Which has maximum number of molecules?
7 g of N2
2 g of H2
16 g of NO2
16 g of O2
2.6 g of a mixture of calcium carbonate and magnesium carbonate is strongly heated to constant mass 1.3 g. The atomic weights of calcium and magnesium are 40 and 24 respectively. State which of the following masses expresses the mass of calcium carbonate in the original mixture?
980 mg
400 mg
1.75 g
0.74 g
If 0.44 g of a colourless oxide of nitrogen occupies 224 mL at 1520 mm Hg and 273 degree Celcius ,then the compound is
N2O
NO2
NO4
N2O2
The ratio of masses of oxygen and nitrogen and a particular gaseous mixture is 1:4. The ratio of number of their molecule is
1:4
7:32
1:8
3:16
2.76 g of silver carbonate on being strongly heating yields a residue weighing
2.16 g
2.48 g
2.32 g
2.64 g
4.0 g of caustic soda (mol. mass 40) contains same number of sodium ions as per presen in :
10.6 g of Na2CO3 (mol. mass 106)
58.5 g of NaCI (formula mass 58.5)
100 mL of 0.5 M Na2SO4 (formula mass 14)
1 g equivalent of Na2NO3 (mol. mass 85)
0.1 g of a metal on reaction with dil acid gave 34.2 mL hydrogen gas at N.T.P. The equivalent weight of the metal is :
32.7
48.6
64.2
16.3
74.5 g of a metal chloride contains 35.5 g of chlorine. The equivalent weight of the metal is:
19.5
35.5
39.0
78.0
The chloride of a metal (M) contains 65.5% of chlorine. 100 mL. of the vapour of the chloride of the metal at N.T.P. weights 0.72 g. The molecular formula of the metal chloride is:
MCI
MCl2
MCl3
MCl4
The oxide of an element possesses the formula M2O3 . If the equivalent weight of the metal is 9, then the atomic weight of the metal will be :
9
18
27
none of these
What volume of hydrogen gas at 273 K and 1 atm pressure will be consumed in obtaining 21.6 g of elemental boron (atomic mass = 10.8 g) from the reduction of boron trichloride by hydrogen ?
Upto which element, the Law of Octavees was found to be applicable.
Oxygen
Calcium
Cobalt
Potassium
In Mendeleev’s Periodic Table, gaps were left for the elements to be discovered later. Which of the following elements found a place in the Periodic Table later?
Oxygen
Chlorine
Silicon
Gemanium
At the time of Mendeleev, the number of elements known was
65
63
64
62
The arrangement of elements in the Modem Periodic Table is based on their
increasing atomic mass in the period
increasing atomic number in the horizontal rows
increasing atomic number in the vertical columns
increasing atomic mass in the group
Where would you locate the element with electronic configuration 2, 8 in the Modern Periodic Table?
Group 8
Group 18
Group 2
Group-10
Element ‘X’ forms a chloride with the formula XCl2, which is a solid with high melting point. X would most likely be in the same group of the periodic table as:
Si
Mg
Al
Na
Which of these belong to the same period? Element A B C Atomic number 2 10 5
A, B
B, C
C, A
A, B and C
Pick out the chemically most reactive elements from the given triads. Li, Na, K F, Cl, Br
Li and F
Li and Br
K and F
K and Br
Which among the following elements has the largest atomic radii?
Na
Mg
K
Al
Which of the following elements does not lose electron easily?
Na
F
Mg
Al
Chlorine (17) belongs to which group and period
17,3
17,4
16, 4
16, 3
Which of the following elements will form an acidic oxide?
An element with atomic number 7
An element with atomic number 3
An element with atomic number 12
An element with atomic number 19
The element with atomic number 14 is hard and forms acidic oxide and a covalent halide. to which of the following categories does the element belongs?
Metal
Metalloid
Non-metal
Non
An element 'X' belong to third period and second group of the modern Periodic table. (a) Write its electronic configuration. (b) is it a metal or non-metal?
(a) 2,8,2 (b) Metal
(a) 2,8,1 (b) Metal
(a) 2,8,2 (b) Non-Metal
(a) 2,8,1 (b) Non-Metal
The elements A, B and C belong to groups 1, 14 and 17 respectively of the Periodic Table. Which two elements will form ionic compounds?
A and B
A and C
B and C
None
An element X from group 2 of the Periodic Table reacts with Y from group 17 to form a compound. Give the formula of the compound.
XY2
XY
X2Y
(XY)2
An element ‘A’ belongs to the third period and group 16 of the Periodic Table. Find out the valency of A.