Conversion of the above-mentioned molecules into moles is as follows:
(a) Given: Mass of oxygen gas=12g
Molar mass of oxygen gas = 2 Mass of Oxygen = 2 x 16 = 32g
Number of moles = Mass given / molar mass of oxygen gas = 12/32 = 0.375 moles
(b) Given: Mass of water = 20g
Molar mass of water = 2 x Mass of Hydrogen + Mass of Oxygen = 2 x 1 + 16 = 18g
Number of moles = Mass given / molar mass of water
= 20/18 = 1.11 moles
(c) Given: Mass of carbon dioxide = 22g
Molar mass of carbon dioxide = Mass of C + 2 x Mass of Oxygen = 12 + 2x 16 = 12+32=44g
Number of moles = Mass given/ molar mass of carbon dioxide = 22/44 = 0.5 moles
Answered by Shivani Kumari | 1 year agoCalculate the number of aluminium ions present in 0.051g of aluminium oxide.
(Hint: The mass of an ion is the same as that of an atom of the same element. Atomic mass of Al = 27u)
Calculate the number of molecules of sulphur (S8) present in 16g of solid sulphur.
What is the mass of:
(a) 0.2 mole of oxygen atoms?
(b) 0.5 mole of water molecules?
What is the mass of -
(a) 1 mole of nitrogen atoms?
(b) 4 moles of aluminium atoms((Atomic mass of aluminium =27)?
(c) 10 moles of sodium sulphite (Na2SO3)?
Calculate the molar mass of the following substances.
(a) Ethyne, C2H2
(b) Sulphur molecule, S8
(c) Phosphorus molecule, P4 (Atomic mass of phosphorus =31)
(d) Hydrochloric acid, HCl
(e) Nitric acid, HNO3