Quantrex Quantrex AcademyJEE · NEET · NDA PYQs with solutions Open app
NTA Abhyas JEE Main2020ChemistrySome Basic Concepts of ChemistryPractice

A complex of cobalt with ammonia is analyzed for determining its formula, by titrating it against a strandarized acid as follows : Co NH 3 x Cl y aq + HCl → NH 4 + aq + Co y + + aq + Cl − aq A 1.8 g complex required 20.00 mL 1.54 M HCl to reach the equivalence point. Also, if the reaction mixture at equivalence point is treated with excess of AgNO 3 solution, 7.735 g of AgCl precipitate was produced. What is the form

Options

  1. ACo NH 3 4 Cl 3
  2. BCo NH 4 4 Cl 3
  3. CCo NH 3 3 Cl 4
  4. DCo NH 4 3 Cl 4

Correct answer

A. Co NH 3 4 Cl 3

Step-by-step solution

Co ( NH 3 ) x Cl y 1 .8 M + xHCL 1 .8 M → x NH 4 + aq + Co y + + ( x + y ) Cl - 1 .8 ( x + r ) M 1 . 8 x M = 2 0 × 1 . 5 4 × 1 0 - 3 = 3 0 . 8 × 1 0 - 3 ........(I) 1 · 8 x + y M = 7 . 7 3 5 1 4 3 . 5 = 5 3 . 9 × 1 0 - 3 ........(II) II I ⇒ 5 3 . 9 × 1 0 - 3 3 0 . 8 × 1 0 - 3 = 1 . 7 5 = x + y x = 1 + y x y x = 0 . 7 5 Substituting in (I) ⇒ 1 . 8 x 5 9 + 1 7 x + 3 5 . 5 × 0 . 7 5 x = 3 0 . 8 × 1 0 - 3 ∴ x = 3.98 = 4 ∴ y = 3

Practice Some Basic Concepts of Chemistry on Quantrex Academy →

More from Some Basic Concepts of Chemistry

Match List-I with List-II. List-I Mass of substance List-II Number of atoms A. 1.8 mg water I. 2 10⁻⁴ N_A B. 9.8 mg sulphuric acid II. 1.5 10⁻⁴ N_A C. 1.8 mg carbon III. 3 10⁻⁴ N_A 2026Which 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) A. 2 g of O₂ gas B. 4 g of SO₂ gas C. 2026An 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.) 2026What 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, 2026How 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) 2026The 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: 2026Number of moles and number of molecules in 1.4187 L of SO₂ at STP respectively are: 2026The 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 b 2026 Full Some Basic Concepts of Chemistry list All NTA Abhyas JEE Main PYQs