Can I get general formulas for solving numericals of this chapter??

CBSE Class 11-science Answered

Can I get general formulas for solving numericals of this chapter??

Asked by polpriyanshu | 13 Apr, 2015, 08:46: AM

Expert Answer

One mole is the amount of a substance that contains as many particles or entities as there are atoms in exactly 12 g (or 0.012 kg) of ¹²C.
Following relations given below can be summarized as
- One mole of atoms = atoms = Gram atomic mass of an element.
- One mole of molecules = molecules = Gram molecular mass of a substance.

The concentration of a solution can be expressed in any of the following ways: Mass per cent, mole fraction, molarity and molality.

Molarity is the number of moles of solute in per liter of solution. Unit is moles per liter.

Molecular formula shows the exact number of different types of atoms present in a molecule of a compound.
If the mass per cent of various elements present in a compound is known, then its empirical formula can be determined.
Where, n is a simple number and may have values 1, 2, 3….
Following steps should be followed to determine empirical formula of the compound:
- Step 1: Conversion of mass per cent of various elements into grams.
- Step 2: Convert mass obtained in step 1 into number of moles.
- Step 3: Divide the mole value obtained in step 2 by the smallest mole value (out of the mole value of various elements calculated).
- Step 4: In case the ratios are not whole numbers, they may be converted into whole numbers by multiplying by a suitable coefficient.
- Step 5: Write empirical formula by mentioning the numbers after writing the symbols of respective elements.'

Answered by Hanisha Vyas | 13 Apr, 2015, 12:16: PM