Home › Tamil Nadu SSLC (Class 10) › Chemistry › Atoms and Molecules › How many moles of oxygen gas are present in 5.6 …
How many moles of oxygen gas are present in 5.6 litre of oxygen measured at STP?
A0.10 mole
B0.25 mole
C0.50 mole
D1.00 mole
Answer & Solution
Correct answer: B. 0.25 mole
1. Number of moles $= \dfrac{\text{volume at STP}}{\text{molar volume}}$.
2. $= \dfrac{5.6}{22.4}$.
3. $= 0.25$ mole of oxygen.
Using 11.2 litre as molar volume would wrongly give 0.5 mole, but molar volume at STP is 22.4 litre.
_Source: Samacheer Kalvi (TN SCERT) Class 10 Science, Unit 7 Atoms and Molecules "Solved Problems", p.106_
Related questions
Calculate the mass percentage of sulphur in sulphuric acid, H2SO4. (Atomic masses: H = 1, How many atoms of oxygen are present in 5 moles of CO2? (NA = 6.023 x 10^23)Calculate the gram molecular mass of calcium phosphate, Ca3(PO4)2. (Atomic masses: Ca = 40What volume at STP is occupied by 2.5 mole of CO2 gas? (Molar volume = 22.4 litre)How many molecules of water are present in 54 g of H2O? (Molecular mass of H2O = 18, NA = Calculate the number of molecules present in 11.2 litre of CO2 measured at STP. (NA = 6.02Boron occurs as B-10 (20% abundance) and B-11 (80% abundance). Calculate its average atomiAmong the following, which sample has the smallest mass?