Chapter 4-Acids And Redox

Question 1

Strong acid

Answer 1

Releases all its hydrogen atoms into solution as H+ ions and COMPLETELY DISASSOCIATES in aq solution

Question 2

Weak acid

Answer 2

Only releases a small proportion of its available hydrogen atoms into solution as H+ ions
A weak acid partially dissociates in aq solution

Question 3

What is a base?

Answer 3

A base neutralizes an acid to form a salt

Question 4

Give examples of common bases

Answer 4

Metal oxides metal carbonates and alkali’s

Question 5

What is an alkali?

Answer 5

A soluble base produces hydroxide ions (OH-) when added to water

Question 6

What does the +aq represent?

Answer 6

That an excess of water is present

Question 7

What occurs in the neutralisation of an acid?

Answer 7

H+ (aq) ions react with a base to form a salt and neutral water and the hydrogen in the acid is replaced by a metal or NH4

Question 8

Give the reaction for the neutralisation of an acid by a metal voice or hydroxide

Answer 8

Acid+metal oxide/hydroxide= salt + water

Question 9

Neutralisation of an acid with an alkali reaction?

Answer 9

Acid + alkali= salt + water

Question 10

What is the equation for the neutralisation of acids by metal carbonates?

Answer 10

Acid+ metal carbonate= salt + water + CO2 (g)

Question 11

Why is the oxidation number always zero for elements?

Answer 11

In a pure element, any bonding is to atoms of the same element. Oxidation number only apparent in bonding to different elements

Question 12

What is the oxidation number of 0?

Answer 12

-2

Question 13

Ox. No. F?

Answer 13

-1

Question 14

Ox. No. H in metal hydrides?

Answer 14

-1

Question 15

Ox no. 0 in peroxide’s?

Answer 15

-1

Question 16

Ox. No. Of 0 bonded to F?

Answer 16

+2

Question 17

What are redox reactions?

Answer 17

Reactions that involve reduction and oxidation.

Question 18

What is reduction in terms of electrons?

Answer 18

Reduction is the gain of electrons

Question 19

What is oxidation in terms of electrons?

Answer 19

Oxidation is the loss of electrons

Question 20

What is reduction in terms of ox. No.?

Answer 20

Reduction is a decrease in ox. No.

Question 21

What is oxidation in terms of ox. No.?

Answer 21

Oxidation is an increase in oxidation number

Question 22

What is classified as a base?

Answer 22

Metal oxides, metal hydroxides and ammonia

Question 23

what are the 3 common bases ?

Answer 23

metal oxides, metal carbonates, alkali’s

Question 24

what are 3 alkali’s and why are they considered to bebases?

Answer 24

KOH , NaOH, NH3

they are proton acceptors

Question 25

Dissociation of sulfuric acid why is it different to normal acids?

Answer 25

• H2SO4 is a strong acid but only for one of the two H atoms donated to water.
  1st stage ; H2SO4 releases 1 H+ and forms HSO4^-
  2nd stage; HSO4^- partially dissociates (therefore it is a weak acid) to form H+ and SO4^2-

Question 26

charge of each ion in phosphoric acid

Answer 26

H3PO4 ;
PO4 3-
3H +

Question 27

wat is a buffer solution?

Answer 27

a solution of a weak acid and conj base that minimises change when a small amount of acid/alkali are added.