x mg of pure HCl was used to make an aqueous solution. 25.0 mL of 0.1 M Ba(OH)2 solution is used when the HCl solution was titrated against it. The numerical value of x is 10-1. (Nearest integer) Given : Molar mass of HCl and Ba(OH)2 are 36.5 and 171.0 g mol-1 respectively.
Some Basic Concepts of Chemistry
Previous year questions with solutions · 2025 – 2026
Year-wise statistics questions · papers · average per paper · weightage
| Year | Questions | Papers | Avg / paper | Weightage |
|---|---|---|---|---|
| 2026 | 18 | 19 | 0.95 | 3.79% ↓33.1% |
| 2025 | 17 | 12 | 1.4 | 5.67% |
20 mL of sodium iodide solution gave 4.74 g silver iodide when treated with excess of silver nitrate solution. The molarity of the sodium iodide solution is M. (Nearest Integer value) (Given : Na = 23, I = 127, Ag = 108, N = 14, O = 16 g mol-1)
Thyroxine, the hormone, has the structure given below [figure] The percentage of iodine in thyroxine is %. (nearest integer) (Given molar mass in g mol-1 C : 12, H : 1, O : 16, N : 14, I : 127)
Butane reacts with oxygen to produce carbon dioxide and water following the equation given below. C4H10(g) + 132O2(g) 4CO2(g) + 5H2O(l) If 174.0 kg of butane is mixed with 320.0 kg of O2, the volume of water formed in liters is . (Nearest integer) [Given : (a) Molar mass of C, H, O are 12, 1, 16 g mol-1 respectively, (b) Density of water = 1 g mL-1]
Fortification of food with iron is done using FeSO4 7H2O. The mass in grams of the FeSO4 7H2O required to achieve 12 ppm of iron in 150 kg of wheat is (Nearest integer) [Given: Molar mass of Fe, S and O respectively are 56, 32 and 16 g mol-1]
The amount of calcium oxide produced on heating 150 kg limestone (75% pure) is kg. (Nearest integer) Given: Molar mass (in g mol-1) of Ca-40, O-16, C-12
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]
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)
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]
Quantitative analysis of an organic compound (X) shows following % composition. C : 14.5\% Cl : 64.46\% H : 1.8\% Empirical formula mass of the compound (X) is 10-1 (Given molar mass in g mol-1 of C : 12, H : 1, O : 16, Cl : 35.5)