Acid & Base

Properties

100

Define Acid and Alkali 

Acid: A substance that ionize when it DISSOLVE IN WATER and IONIZES to HYDROGEN ION OR HYDROXIDE ION 

Alkali: is a BASE that is DISSOLVE IN WATER and IONIZES to HYDROXIDE ION

200

Which of the following is the base? Why do you say so?
A. Apple juice 

B. Milk 

C. Potassium Oxide 

D. Soft drinks

Potassium Oxide because a base is a substance that react with water to form salt and water. 

K₂O + H₂O → K⁺OH^- + H₂

300

Which of the following is a diproctic acid? 

A. Ethanoic Acid

B. Phosphoric acid

C. Sulphuric acid

D. Hydrochloric acid 

sulphuric acid because it ionize 2 Hydrogen ions. it is a weak acid for the reaction is reversible 

H₂SO₄ → H⁺ + HSO₄^-

HSO₄^- ⇄ H⁺ + HSO₄^-2

400

When a neutral solution is tested using Methyl orange, what colour is formed?

Yellow

500

Properties of alkali

1. bitter

2. pH value > 7

3. corrosive 

4. slippery 

pH Value

100

If the pH of a solution is 4.0, what is the pOH?

pH=-log[H⁺]

pOH=-log[OH^-]

pH+pOH=14

pOH=14-4.0

pOH=10

200

Sulphuric acid has a [H⁺] of 1.7 x 10^-2 M. Its pH is?

H₂SO₂  → H⁺ + HSO₄^-

pH=-log[H⁺]

pH= -log (1.7 x 10^-2)

pH = 1.77

300

What is the pH of a solution with [H⁺]=1.24 x 10^-2

pH=- log [H⁺]

pH= - log [1.24 x 10^-2]

pH=1.91

400

Why water is neutral?

Because water can ionizes the same number of moles of hydrogen ion and hydroxide ion. 

500

Determine the molarity of lithium hydroxide solution LiOH with pH value 12.0

LiOH → Li⁺ + OH^-

given the pH for hyroxide ion is 12.0, hence we need to find the the pOH for hydroxide ion.

pH + pOH = 14.0

12.0 + pOH = 14.0

pOH = 14.0-12.0

       = 2.0

pOH = - log [OH^-]

  2.0 = - log [OH^-]   

log [OH^-] = -2.0

[OH^-] = 10^-2

         = 0.01 mol dm^-3

Therefore, the molarity of LiOH = 0.01 mol dm^-3 

 

Strength

100

What completely ionizes in solution?

Strong acids and strong alkalis 

200

An acid that does not break apart completely.
Range from 4-7 on the pH scale. 

What is me?

weak acid

300

Completely dissociates in water to form OH- ions.

Strong alkali

400

What is type of acid that ionises completely in water to produce a high concentration of hydrogen ions, H+.

Strong acid

500

Ammonia and potassium hydroxide have same concentration, but why ammonia have a lower pH value?

Because ammonia...

is weak base that ionise partially in water to produce low concentration hydroxide ion

NH₃ + H₂O ⇄ NH₄⁺ + OH^-

KOH → K⁺ + OH^-

common acid

100

What is the name for this compound? 

HI

Hydroiodic acid 

200

What is the name for this compound? 

H₃PO₄

Phosphoric acid 

300

Write the chemical formula for nitrous acid

HNO₂

400

What is the name for this compound? 

C₂H₂O₄

Oxalic acid

500

Write the chemical formula for chlorous acid

HCIO₂