Mole Concept Flashcards
Define moles if weight of the compound is given.
Moles = Weight/Molecular Mass
Define moles if entities of the compound is given.
Moles = Entities(atoms, molecules, ions)/Avagadro’s Number(NA)
Define moles if volume at stp given.
Moles = Volumes(litres)/22.4
Percentage composition of element is
(Atomic Weight of element*No. of atoms *100)/ Molecular Weight of Compounds
Calculate the percentage composition of all the elements in CaCO3
Ca- 40%, C- 12%, O- 48%
Absolute density of solids and liquid
Mass/Volume
Relative density of solids and liquid
Density of substance/ Density of H2O at 4°C
Absolute density of gases
From the ideal gas equation, density = PM/RT
Relative density of gases
The density of a gas w.r.t another gas at constant temperature and pressure
Vapour density of gases
The density of a gas w.r.t H2 gas at constant temperature and pressure
Calculate the relative density of CH4 w.r.t O2
1/2
Average Atomic Weight formula
(% abundance* At. wt.1 + % abundance*At. wt2)/100
Mean Molar Mass Formula
(n1M1 + n2M2)/ n1 + n2
For reaction 2A+ B→ A2B. 5 moles of A are reacted with 10 moles of B. Hence the limiting reagent and the moles of A2B formed are:
A, 2.5
C3H8 + 5O2 → 3CO2 + 4H2O
If 2.5 moles of C3H8 are present, then how many moles of CO2 are formed using the stoichiometry method?
7.5 moles of CO2 are formed
What is the relation between empirical and molecular formulas?
M.F. = (E.F.)n, where n = MFW/EFW
Define molarity(M).
Molarity is the ratio of moles of solute and volume of solution in litre.
Define molality(m)
Molality is the ratio of moles of solute and weight of solvent in kg.
Define mole fraction
(Number of moles of A)/ (Number of moles of A+ number of moles of B)
