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JEE Main 4 August 2021, Shift 2, Chemistry Q51

Question 51 of 90 in this shift, Chemistry question 21 of 30, Section B.

The amount of potassium chlorate (

\mathrm{KClO_3}

) that needs to be completely decomposed in order to liberate 40

\mathrm{dm^3}

of oxygen gas at STP is ________ g. (Nearest integer) [Atomic Masses : K = 39.0 u; Cl = 35.5 u; O = 16.0 u, R = 0.0831 L bar

\mathrm{mol^{-1}\ K^{-1}}

Assume oxygen is an ideal gas at STP; at STP molar volume of an ideal gas is 22.7 L

\mathrm{mol^{-1}}

]

Official answer

144

NTA final key.

Same idea in other shifts