Some Basic Concepts of Chemistry
Class 11 · Chemistry · 36 Questions
Calculate the molar mass of the following: (i) H₂O (ii) CO₂ (iii) CH₄
Calculate the mass per cent of different elements present in sodium sulphate (Na₂SO₄).
Determine the empirical formula of an oxide of iron, which has 69.9% iron and 30.1% dioxygen by mass.
Calculate the amount of carbon dioxide that could be produced when (i) 1 mole of carbon is burnt in air. (ii) 1 mole of carbon is burnt in 16 g of dioxygen. (iii) 2 moles of carbon are burnt in 16 g of dioxygen.
Calculate the mass of sodium acetate (CH₃COONa) required to make 500 mL of 0.375 molar aqueous solution. Molar mass of sodium acetate is 82.0245 g mol⁻¹.
Calculate the concentration of nitric acid in moles per litre in a sample which has a density, 1.41 g mL⁻¹ and the mass per cent of nitric acid in it being 69%.
How much copper can be obtained from 100 g of copper sulphate (CuSO₄)?
Determine the molecular formula of an oxide of iron, in which the mass per cent of iron and oxygen are 69.9 and 30.1, respectively.
Calculate the atomic mass (average) of chlorine using the following data:
% Natural Abundance Molar Mass ³⁵Cl 75.77 34.9689 ³⁷Cl 24.23 36.9659
In three moles of ethane (C₂H₆), calculate the following: (i) Number of moles of carbon atoms. (ii) Number of moles of hydrogen atoms. (iii) Number of molecules of ethane.
What is the concentration of sugar (C₁₂H₂₂O₁₁) in mol L⁻¹ if its 20 g are dissolved in enough water to make a final volume up to 2L?
If the density of methanol is 0.793 kg L⁻¹, what is its volume needed for making 2.5 L of its 0.25 M solution?
Pressure is determined as force per unit area of the surface. The SI unit of pressure, pascal is as shown below: 1 Pa = 1 N m⁻² If mass of air at sea level is 1034 g cm⁻², calculate the pressure in pascal.
What is the SI unit of mass? How is it defined?
Match the following prefixes with their multiples: (i) micro 10⁶ (ii) deca 10⁹ (iii) mega 10⁻⁶ (iv) giga 10⁻¹⁵ (v) femto 10
What do you mean by significant figures?
A sample of drinking water was found to be severely contaminated with chloroform, CHCl₃, supposed to be carcinogenic in nature. The level of contamination was 15 ppm (by mass). (i) Express this in per cent by mass. (ii) Determine the molality of chloroform in the water sample.
Express the following in the scientific notation: (i) 0.0048 (ii) 234,000 (iii) 8008 (iv) 500.0 (v) 6.0012
How many significant figures are present in the following? (i) 0.0025 (ii) 208 (iii) 5005
Round up the following upto three significant figures: (i) 34.216 (ii) 10.4107 (iii) 0.04597 (iv) 2808