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# Chemistry question gas volumes watch

1. 0.625 g of a gas occupied 500 cm3 at RTP.
Which row in the table is correct?
Gas
A N2
B CO
C NO
D O2
2. n= v/24
n=0.5/24
n=0.0208333
m=0.625g
n=m/Mr
Mr= m/n
Mr= 0.625/0.0208
Mr= 30.04808
Now:
Mr (N2) 14x12= 28
Mr (CO) 12+16= 28
Mr (NO) 14+16= 30
Mr (O2) 16x2=32

Therefore the one that matches is NO (of Mr 30) (answer C)
3. Hope it helped xx

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Updated: January 6, 2017
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