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5 moles of AB_2 weigh 125× 10^-3 kg and 10 moles of A_2 B_2 weigh 300× 10^-3 kg . The molar mass of A (M_A) in kg mol^-1 are:

JEE Main 2019 — Chemistry Physical Chemistry

2019mcqmedium

555 moles of AB2A{B}_{2}AB2​ weigh 125×10−3kg125\times {10}^{-3} kg125×10−3kg and 101010 moles of A2B2{A}_{2}{B}_{2}A2​B2​ weigh 300×10−3kg300\times {10}^{-3} kg300×10−3kg . The molar mass of A (MA)({M}_{A})(MA​) in kgmol−1kg {mol}^{-1}kgmol−1 are:

Official previous-year question

Held on 12 Apr 2019 · Verified 6 Jul 2026.

Options

  1. A

    MA=5×10−3{M}_{A}=5\times {10}^{-3}MA​=5×10−3 and MB=10×10−3{M}_{B}=10\times {10}^{-3}MB​=10×10−3

  2. B

    MA=25×10−3{M}_{A}=25\times {10}^{-3}MA​=25×10−3 and MB=50×10−3{M}_{B}=50\times {10}^{-3}MB​=50×10−3

  3. C

    MA=50×10−3{M}_{A}=50\times {10}^{-3}MA​=50×10−3 and MB=25×10−3{M}_{B}=25\times {10}^{-3}MB​=25×10−3

  4. D

    MA=10×10−3{M}_{A}=10\times {10}^{-3}MA​=10×10−3 and MB=5×10−3{M}_{B}=5\times {10}^{-3}MB​=5×10−3

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