What are polyatomic ions? Give examples.
Polyatomic ions are ions that contain more than one atom, but they behave as a single unit,
Example: CO32-, H2PO4 -
Calculate 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?
Convert into mole.
(a) 12g of oxygen gas
(b) 20g of water
(c) 22g of carbon dioxide
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)?