Question

1. Put a circle around the Lewis Acids and a Box around the Lewis Bases:

Ca²⁺                 S^2-               OH^-                      Fe³⁺                      I^-

	pH	pOH	[H+], M	[OH-], M	Is it acidic, basic or a neutral soln?
2.	2.6
3.		3.4
4.			3.2 x 10-9
5.				4.7 x 10-3
6.			1 x 10-7

Answer 1

1)Lewis acid: A substance which accept electron pairs from other substances is called Lewis acid.

2)To accept electron pairs a Lewis acid must contain vacant orbitals.

3)List of Lewis acids among the given species:

Ca+2,Fe+3, H+

4)Lewis base:A substance which donate electron pairs to other substances is called Lewis base.

5)To donate electron pairs a Lewis base must contain lone pairs of electrons.

6)List of Lewis bases among the given species:

S-2, OH-1

7)For a solution if

PH = 7 it is neutral

PH < 7 it is acidic

PH >7 it is basic

8)Given PH  value 2.6 < 7 is acidic

Given POH value 3.4

its PH = 14- POH  = 14 - 3.4 = 10.6 >7 hence it is basic

9)For a solutin if [H+]

> 10-7   it is acidic

< 10-7 it is basic

= 10-7   it is neutral.

8) Given [H+] =3.2* 10-9  < 10-7  hence it is basic

[H+] =1* 10-7 it is neutral.

[OH-] =4.7* 10-3  for this [H+] is in the order of 10-11 < 10-7 hence it is basic.