Exams › JEE Main › Chemistry

The equation which is balanced and represents correct product(s) is:

1. Li2O + 2KCl → 2LiCl + K2O
2. [CoCl(NH3)5] + 5H+ → Co2+ + 5NH4+ + Cl−
3. [Mg(H2O)6]2+ + (EDTA)4− —excess NaOH→ [Mg(EDTA)]2− + 6H2O
4. CuSO4 + 4KCN → K2[Cu(CN)4] + K2SO4

Correct answer: [Mg(H2O)6]2+ + (EDTA)4− —excess NaOH→ [Mg(EDTA)]2− + 6H2O

Solution

[Mg(H2O)6]^2+ + (EDTA)^4- -> [Mg(EDTA)]^2- + 6H2O is correctly balanced in mass and charge (-2 = -2) and is a genuine complexometric reaction. The Li2O/KCl swap does not occur, the [CoCl(NH3)5] equation is charge-unbalanced, and CuSO4 + KCN gives Cu(I) as K3[Cu(CN)4], not K2[Cu(CN)4].

Related JEE Main Chemistry questions

• When sodium hydroxide is introduced into an aqueous Zn2+ solution, a white precipitate forms, and this precipitate dissolves when more NaOH is added. In such a solution, zinc is present in the:
• When excess ammonia is added to a copper sulphate solution, a deep blue colour appears because of the formation of which species?
• In the nitroprusside ion, iron and NO are present as Fe2+ and NO+ instead of Fe3+ and NO. These two formulations can be distinguished by
• In the brown ring test for nitrite and nitrate ions, the characteristic brown ring is produced because a complex ion is formed with which formula?
• What is the spin-only magnetic moment, expressed in Bohr magnetons (μB), for Ni2+ in aqueous solution? (Atomic number of Ni = 28)
• Silver chloride dissolves in aqueous ammonium hydroxide because it leads to the formation of which species?

⚔️ Practice JEE Main Chemistry free + battle 1v1 →