TEST YOURSELF 1.6 Chemistry 9th Chapter 1

TEST YOURSELF 1.6

(1)            Which term is used to represent the mass of 1 mole of molecules of a substance?

Gram molecular mass is used to represent the mass of 1 mole of molecules of a substance.

(2)            How many atoms are present in one gram atomic mass of a substance?

6.02*10²³ atoms are present in one gram atomic mass of a substance. Because one gram means that atomic mass of a substance expressed in grams.

(3)            Explain the relationship between mass and mole of a substance.

The relationship between mass and mole of a substance is given as following :

Mass of a substance = No of moles * Molar mass

(4)            Find out the mass of 3 moles of oxygen atoms?

No of moles of oxygen = 3 mol

               Molar mass of oxygen atom = 16 g mol^-1

               Mass of oxygen atom = No of moles * Molar mass

               Mass of oxygen atom = 3*16

                                       = 48 grams

(5)             How many molecules of water are present in half mole of water?

      No of moles of water = ½ mol

      Number of water molecules = ?

      Number of water molecules = No of moles * N_A

      Number of water molecules = ½ * 6.02*10²³

                                                          =3.01 * 10²³ molecules