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Question
A gas cylinder contain 12 × 1024 molecules of oxygen gas
If Avogadro's number is 6 × 1023,
calculate :
(i) The mass of oxygen present in the cylinder.
(ii) The volume of oxygen at STP present in the Cylinder[O=16]
Solution
1 mole oxygen molecule = 6.022 x 1023 molecules.
19.93 moles of Oxygen molecule = 12 x 1024 molecules
Number moles of O2 = `"Mass of O"_2/"Molar mass of CO"_2`
Mass of O2 = 32 x 19.93 = 637.76g
(ii) 6.022 x 1023 molecules occupies 22.4L
12 x 1024 molecules occupies = `[12 xx 10^24 xx 22.4]/[6.022 xx 10^23]`
= 446.36L volume.
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