Advertisements
Advertisements
Question
Explain with examples what is meant by a 'mole' of a substance.
Solution
A mole is the quantity of a substance whose mass in grams is equal in magnitude to the molecular mass of that substance in Daltons. Thus, the molecular mass of oxygen is 32 u, and therefore 32g oxygen is 1 mole of oxygen. The molecular mass of water is 18u. Therefore, 18g of water makes 1 mole of water.
1 mole of a compound is the mass of that substance in grams equal in magnitude to its molecular mass. The SI unit is mol.
Number of moles of substances (n) = `"Mass of substance in grams"/"Molecular mass of substance"`
APPEARS IN
RELATED QUESTIONS
What is the mass of 0.5 mole of water molecules?
Calculate the percentage of water of crystallization in CuSO4.5H2O
(H = 1, O = 16, S = 32, Cu = 64)
What is the mass of 0.2 mole of oxygen atoms ?
How many moles of calcium carbonate (CaCO3) are present in 10 g of the substance ? (Ca = 40 u ; C = 12 u ; O = 16 u)
If 16 g of oxygen contains 1 mole of oxygen atoms, calculate the mass of one atom of oxygen.
Which of the following pair of elements represents a mole ratio of 1 : 1 ?
Prove the Following :
One mole of any gas contains th e same number of molecules.
The relative atomic mass of Cl atom is 35.5 a.m.u. Explain this statement.
Explain the term : Gram atom
Calculate the weight of one molecule of oxygen .
[Avogadro's number = 6 x 1023, O = 16 ]
Define or explain the term:
Molar volume
Define or explain the term:
Mole
How many grams of Al are present in 0.2 mole of it?
Calculate the mass of 0.1 mole of the following:
CaCl2
(Ca = 40, Na=23, Mg =24, S=32, C = 12, Cl = 35.5, O=16, H=1)
What mass of Ca will contain the same number of atoms as are present in 3.2 g of S?
If phosphorus is considered to contain P4 molecules, then calculate the number of moles in 100g of phosphorus?
N2 + 3H2 → 2NH3
(The atomic mass of nitrogen is 14, and that of hydrogen is 1)
1 mole of nitrogen (______ g) +
3 moles of hydrogen (______ g) →
2 moles of ammonia (______ g)
Calculate the number of moles in 27g of Al.
How many grams are there in the following?
4 moles of the phosphorous molecule, P4
Deduce the number of molecules of the following compound in the given quantity.
8.8g carbon dioxide
