Question

Define one mole. Convert into mole.

(a) 20 g of water (b) 22 g of carbon dioxide.

( Atomic mass of H= 1u, C= 12u, O= 16u)​

Answer 1

Answer:

MOLE

Mole, also spelled mol, in chemistry, a standard scientific unit for measuring large quantities of very small entities such as atoms, molecules, or other specified particles.

formula

Mole = given mass ➗ molecular mass.

Calculation

a) 20 g of water

:- Required mole = 20 ÷ 32 = 0.625 mole

B) 22 g of carbon dioxide.

:- Required mole =22 ÷ 44 = 0.5 mole.

Answer 2

Explanation:

The mole is a unit of measurement for amount of substance. It is defined as the amount of any chemical substance that contains as many elementary entities e.g.atoms, molecules, ions, electrons or photons like atoms present in 12 gm of pure carbon with relative atomic mass 12. It has the unit symbol mol. The number of molecules in a mole is defined such that the mass of one mole of a substance expressed in grams is equal to mean molecular mass of the substance.

(a) Molar mass of Water =H 2O=2+16=18 g/mol

So, 1 mole of water weighs = 18 g

which implies, 18g of water = 1 mole

Therefore, 20g of water =20/18=1.11 mole

(b) Molar mass of 1 mole of CO 2 = Molar mass of C +2 x Molar mass of O = 12 + 32 = 44.

⟹ 44 gm of CO 2= 1 mole of CO 2

So, 22 gm of CO 2= 22/44 moles of CO 2= 0.5 moles of CO 2