Some Basic Concepts of Chemistry · Question 1

An oxide of iron contains 69.9% iron, its empirical formula, is: (Given : Molar mass of Fe and O are 56 and 16 g mol-1 respectively.)

1. FeO
2. Fe2O3
3. Fe3O4
4. FeO3

Which of the following contain the same number of atoms? (Given : Molar mass in g mol-1 of H, He, O and S are 1, 4, 16 and 32 respectively) Choose the correct answer from the options given below :

1. A and B only
2. B and C only
3. C and D only
4. A, C and E only

How many grams of residue is obtained by heating 2.76 g of silver carbonate? (Given : Molar mass of C, O and Ag are 12, 16 and 108 g mol-1 respectively)

1. 1.08 g
2. 2.16 g
3. 3.24 g
4. 4.32 g

What volume of hydrogen gas at STP would be liberated by action of 50 mL of H2SO4 of 50% purity (density = 1.3 g mL-1) on 20 g of zinc? Given : Molar mass of H, O, S, Zn are 1, 16, 32, 65 g mol-1 respectively.

1. 5.824 L
2. 7.428 L
3. 6.892 L
4. 8.375 L

Number of moles and number of molecules in 1.4187 L of SO2 at STP respectively are

1. 0.1266; 3.812 1022
2. 0.0633; 3.812 1022
3. 0.1266; 7.6238 1022
4. 0.0633; 7.6238 1022

The correct order of total number of atoms present in (A) 2 moles of cyclohexane (B) 684 g of sucrose (C) 90.8 L of dihydrogen at STP is :

1. C > A > B
2. C > B > A
3. B > C > A
4. B > A > C

The mass of iron converted into Fe3O4 by the action of 18 g of steam is : (Given : Molar mass of H, O and Fe are 1, 16 and 56 g mol-1 respectively) Assume iron is present in excess :

1. 2.1 g
2. 4.2 g
3. 21 g
4. 42 g

The ratio of mass percentage (w/w) of C : H in a hydrocarbon is 12 : 1. It has two carbon atoms. The weight (in g) of CO2(g) formed when 3.38 g of this hydrocarbon is completely burnt in oxygen is : (Given : Molar mass in g mol-1 C : 12, H : 1, O : 16)

1. 5.68
2. 11.44
3. 22.74
4. 17.05

For the given reaction; CaCO3 + 2HCl CaCl2 + H2O + CO2 If 90 g CaCO3 is added to 300 mL of HCl which contains 38.55% HCl by mass and has density 1.13 g mL-1, then which of the following option is correct? Given molar mass of H, Cl, Ca and O are 1, 35.5, 40 and 16 g mol-1 respectively.

1. 64.97 g of HCl remains unreacted
2. 60.32 g of HCl remains unreacted
3. 32.85 g of CaCO3 remains unreacted
4. 97.30 g of HCl reacted

A student has planned to prepare acetanilide from aniline using acetic anhydride. The student has started from 9.3 g of aniline. However, the student has managed to obtain 11 g of dry acetanilide. The % yield of this reaction is :-

1. 59.5\%
2. 72.5\%
3. 97.5\%
4. 81.5\%