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1. Some basic concept of chemistry — Chemistry STD 11 Science — Question

Gujarat BoardEnglish MediumSTD 11 ScienceChemistry1. Some basic concept of chemistry1 Mark
MCQ
The number of molecules and moles in $2.8375$ litres of $O _2$ at STP are respectively
  • A
    $7.527 \times 10^{22}$ and $0.250\,mol$
  • B
    $1.505 \times 10^{23}$ and $0.250\,mol$
  • C
    $7.527 \times 10^{23}$ and $0.125\,mol$
  • ✓
    $7.527 \times 10^{22}$ and $0.125\,mol$
✓

Answer

Correct option: D.
$7.527 \times 10^{22}$ and $0.125\,mol$
d
Number of moles of $O _2=\frac{2.8375}{22.7}=0.125$

Number of molecules $=0.125\,N _{ A }$

$=7.525 \times 10^{22}$

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