Advertisements
Advertisements
Question
Explain the term:
Mole
Advertisements
Solution
The mole is a unit of measurement for the amount of substance. Moles give us a consistent method to convert between atoms/molecules and grams.
The mathematical expression for calculating moles is expressed as:
moles = mass / molar mass
We can express moles in terms of molecular mass, number of atoms/molecules and in terms of volume.
- 1 mole of a pure substance has a mass in grams equal to its molecular mass.
- 1 mole contains the same number of particles as there are in 12g of carbon-12 atoms. This number is called Avogadro’s number and is equal to 6.023 × 1023 particles.1 mole of a gas occupies a volume of: 22.4 litres at S.T.P.
For example: 1 mole of sodium atom has mass 23 g. It contains 6.023 × 1023 atoms and occupies 22.4 litres of volume at S.T.P.
RELATED QUESTIONS
How many moles of calcium carbonate (CaCO3) are present in 10 g of the substance ? (Ca = 40 u ; C = 12 u ; O = 16 u)
Calculate the mass in grams of 0.17 mole of hydrogen sulphide, H2S. (Atomic masses : H = 1 u, S = 32 u)
The relative atomic mass of Cl atom is 35.5 a.m.u. Explain this statement.
Fill in the blank
One gram atom of an element contains ______ atoms.
The equation for the burning of octane is:
\[\ce{2C8H18 + 25O2 -> 16CO2 + 18H2O}\]
How many moles of carbon dioxide are produced when one mole of octane burns?
Find the number of molecules in 73 g of HCl.
How many grams of Al are present in 0.2 mole of it?
The difference in the mass of 100 moles each of sodium atoms and sodium ions is 5.48002 g. Compute the mass of an electron.
Cinnabar (HgS) is a prominent ore of mercury. How many grams of mercury are present in 225 g of pure HgS? Molar mass of Hg and S are 200.6 g mol–1 and 32 g mol–1 respectively.
The visible universe is estimated to contain 1022 stars. How many moles of stars are present in the visible universe?
