A 100% pure sample of a divalent metal carbonate weighing 2 g on complete thermal decomposition releases 448 cc of carbon dioxide at STP. The equivalent mass of the metal is
40
20
28
12
B.
20
Let the metal be M, so the formula of its carbonate is MCO3.
Molar mass of MCO3 = x + 12 + 3 × 16
= (x + 60) g/ mol
(Let atomic mass of M be x)
448 cc (448 mL) CO2 is produced from carbonate = 2gm.
22400cc CO2 will be obtained from carbonate
= = 100 gm
100 = x + 60
x = 100 - 60 = 40 g/mol
Eq. wt. of metal = = 20 g equiv-1
The ratio of the frequency corresponding to the third line in Lyman series of hydrogen atomic spectrum to that of the first line in Balmer series of Li2+ spectrum is
The incorrectly matched pair, among the following is-
BrF5 - Trigonal bipyramidal
SF4 - See-saw
ClF3 - T-shape
NH3 - Trigonal pyramidal
Molecules/ ions and their magnetic properties are given below-
Molecule/ Ion | Magnetic Property |
i. C6H6 | 1. Antiferromagnetic |
ii. CrO2 | 2. Ferrimagentic |
iii. MnO | 3. Ferromagnetic |
iv. Fe3O4 | 4. Paramagnetic |
v. Fe3+ | 5. Diamagnetic |
The correctly matched pairs in the above is
i - 5; ii - 3; iii - 2; iv - 1; v - 4
i - 3; ii - 5; iii - 1; iv - 4; v - 2
i - 5; ii - 3; iii - 1; iv - 2; v - 4
i - 5; ii - 3; iii - 1; iv - 4; v - 2