JEE MainChemistrySolid State
A sample of cuprous sulfide is found to be non-stoichiometric with the empirical formula Cu_ 1.8 S . Because of this metal deficiency, the crystal contains both Cu⁺ and Cu²⁺ ions to maintain electrical neutrality. What is the percentage of copper ions that exist in the +2 oxidation state?
Options
- A20.00 %
- B11.11 %
- C88.89 %
- D10.00 %
Correct answer
B. 11.11 %
Step-by-step solution
Let the number of S²⁻ ions in the formula be 1 . The total negative charge provided by the sulfide ion is 2 . According to the empirical formula Cu_ 1.8 S , the total number of copper ions is 1.8 . Let the number of Cu²⁺ ions be x and the number of Cu⁺ ions be y . Total number of copper ions: x + y = 1.8 To maintain electrical neutrality, the total positive charge must equal the total negative charge: 2x + 1y = 2 Subtracting the first equation from the second equation gives: (2x + y) - (x + y) = 2 - 1.8 x = 0.2 The