JEE Main 2022 · 28 July · evening · Single correct · +4 / −1
Statement I : An alloy of lithium and magnesium is used to make aircraft plates.
Statement II : The magnesium ions are important for cell-membrane integrity.
In the light the above statements, choose the correct answer from the options given below :
- (a) Both Statement I and Statement II are true
- (b) Both Statement I and Statement II are false
- (c) Statement I is true but Statement II is false
- (d) Statement I is false but Statement II is true
Answer and solution
Answer (b) Both Statement I and Statement II are false
Solution
Chemistry ma’am · 3 steps
Each statement swaps one word from NCERT: armour plates, not aircraft; calcium, not magnesium.
- Statement I. Lithium forms useful alloys, and each use goes with a specific partner. With magnesium it makes armour plates, and with aluminium it makes aircraft parts. So a Li–Mg alloy for aircraft plates is false.
- Statement II. Cell-membrane integrity is a job of Ca²⁺ ions, along with neuromuscular function and blood clotting. Mg²⁺ ions do other work: they are the cofactor for enzymes that use ATP, and magnesium sits at the centre of chlorophyll. So Statement II is false.
Statement What it says What is actually true Verdict I Li–Mg alloy for aircraft plates Li–Mg gives armour plates; Li–Al gives aircraft parts False II Mg²⁺ for cell-membrane integrity Ca²⁺ for membrane integrity; Mg²⁺ for ATP enzymes and chlorophyll False - So. Both statements are false, which is option (b).
The idea to keep. Match each element to its exact use. Li–Mg gives armour plates, Li–Al gives aircraft parts. Ca²⁺ keeps membranes intact; Mg²⁺ serves ATP enzymes and chlorophyll.
Answer from the NTA final answer key. Solution by PrepWiser.