a. What is atomicity? Name One diatomic molecule. b. Calculate the formula unit mass of Caso4.2H2O
Answers
a. ATOMICITY IS DEFINED AS THE TOTAL NUMBER OF ATOMS THAT CONSTITUTE A MOLECULE. FOR EXAMPLE, EACH MOLECULE OF OXYGEN IS COMPOSED OF TWO OXYGEN ATOMS. SO ATOMICITY OF OXYGEN IS 2.IN OLDER CONTEXTS, THE TERM ATOMICITY IS SOMETIMES USED IN THE SAME SENSE AS
VALENCY.
THE ONLY CHEMICAL ELEMENTS THAT FORM STABLE HOMONUCLEAR DIATOMIC MOLECULES AT STANDARD TEMPERATURE AND PRESSURE (STP) (OR TYPICAL LABORATORY CONDITIONS OF 1 BAR AND 25 °C) ARE THE GASES HYDROGEN (H2), NITROGEN (N2), OXYGEN (O2), FLUORINE (F2), AND CHLORINE (CL2).
b. Formula unit mass of CaSO4.2H2O
= (Number Calcium atoms x atomic mass of Calcium) + (Number Sulphur atoms x atomic mass of sulphur) + (Number Oxygen atoms x atomic mass of Oxygen) + (Number Water molecules x Molecular mass of water molecule)
=(1×40)+(1×32)+(4×16)+(2×18)
=40+32+64+36
=172
Formula unit mass of gypsum = 172
Explanation:
atomicity is the total no. of atom constituting an molecule
diatomic molecule: oxygen