Question

Fill in the following blanks (a) 1 mole contains ...................... atoms, molecules or ions of a substance.
(b) A mole represents an ..................... number of particles of a substance.
(c) 60 g of carbon element are ................... moles of carbon atoms.
(d) 0.5 mole of calcium element has a mass of ......................
(e) 64 g of oxygen gas contains ....................... moles of oxygen atoms.

Answer 1

Answer:

1. 1 mole contains 6.02X10^23
2. a mole represents avogadro no.
3. 5 moles of carbon atom
4. mass=0.5X40=20
5. 4 moles of oxygen

Answer 2

Explanation:

(a) 1 mole contains $6.022 \times 10^{23}$atoms, molecules or ions of a substance.

(b) A mole represents the Avogadro number of particles of a substance.

(c) 60g of carbon element are 5 moles of carbon atoms.

(d) 0.5 moles of calcium element have a mass of 20g.

(e) 64g of oxygen contain 4 moles of oxygen atoms.

$6.022 \times 10^{23}$is also called Avogadro’s constant or Avogadro’s number. $6.022 \times 10^{23}$ is equal to one mole of molecules, atoms or ions.