Some Basic Concepts of Chemistry · Question 23

Among 10-9 g (each) of the following elements, which one will have the highest number of atoms? Element: Pb, Po, Pr and Pt

1. Pr
2. Pt
3. Po
4. Pb

Mass of magnesium required to produce 220 mL of hydrogen gas at STP on reaction with excess of dil. HCl is Given: Molar mass of Mg is 24 g mol-1.

1. 0.24 mg
2. 235.7 g
3. 2.444 g
4. 236 mg

10 mL of 2 M NaOH solution is added to 20 mL of 1 M HCl solution kept in a beaker. Now, 10 mL of this mixture is poured into a volumetric flask of 100 mL containing 2 moles of HCl and made the volume up to the mark with distilled water. The solution in this flask is :

1. 0.2 M NaCl solution
2. 20 M HCl solution
3. Neutral solution
4. 10 M HCl solution

X g of nitrobenzene on nitration gave 4.2 g of m-dinitrobenzene. X = g. (nearest integer) [Given : molar mass (in g mol-1) C : 12, H : 1, O : 16, N : 14]

CaCO3(s)+2HCl(aq) CaCl2(aq)+CO2(g)+H2O(l) Consider the above reaction, what mass of CaCl2 will be formed if 250 mL of 0.76 M HCl reacts with 1000 g of CaCO3 ? (Given : Molar mass of Ca, C, O, H and Cl are 40, 12, 16, 1 and 35.5 g mol-1, respectively)

1. 3.908 g
2. 2.636 g
3. 10.545 g
4. 5.272 g

On complete combustion 1.0 g of an organic compound (X) gave 1.46 g of CO2 and 0.567 g of H2O. The empirical formula mass of compound (X) is g. (Given molar mass in g mol-1 C : 12, H : 1, O : 16)

1. 60
2. 45
3. 30
4. 15

0.1 mol of the following given antiviral compound (P) will weigh 10-1 g (nearest integer). [figure] (Given : molar mass in g mol-1 H : 1, C : 12, N : 14, O : 16, F : 19, I : 127)

'x' g of NaCl is added to water in a beaker with a lid. The temperature of the system is raised from 1 C to 25 C. Which out of the following plots, is best suited for the change in the molarity (M) of the solution with respect to temperature? [Consider the solubility of NaCl remains unchanged over the temperature range]

1. [figure]
2. [figure]
3. [figure]
4. [figure]

Choose the correct statements. Choose the correct answer from the options given below :

1. (B), (C) and (D) Only
2. (A), (B) and (C) Only
3. (C), (D) and (E) Only
4. (A), (D) and (E) Only

The molarity of a 70\% (mass/mass) aqueous solution of a monobasic acid (X) is 10-1 M (Nearest integer) [Given: Density of aqueous solution of (X) is 1.25 g mL-1 Molar mass of the acid is 70 g mol-1]