1.Some Basic Concepts of chemistry
Qno.1. Choose the most correct option A. A sample of pure water, whatever the source always contains ......................... by mass of oxygen and 11.1 % by mass of hydrogen. a. 88.9 b. 18 c. 80 d. 16 B. Which of the following compounds can NOT demonstrate the law of multiple proportions? a. NO, NO₂ b. CO, CO₂ c. H₂O, H₂O₂ d. Na₂S, NaF C. Which of the following temperature will read the same value on Celsius and Fahrenheit scales? a. -40° b. +40° c. -80° d. -20° D. SI unit of the quantity electric current is ......................... a. Volt b. Ampere c. Candela d. Newton E. In the reaction N₂ + 3H₂ → 2NH₃ the ratio by volume of N₂, H₂ and NH₃ is 1 : 3 : 2. This illustrates the law of a. definite proportion b. reciprocal proportion c. multiple proportion d. gaseous volumes F. Which of the following has the maximum number of molecules? a. 7 g N₂ b. 2 g H₂ c. 8 g O₂ d. 20 g NO₂ G. How many g of H₂O are present in 0.25 mol of it? a. 4.5 b. 18 c. 0.25 d. 5.4 H. The number of m...