1.1 Formulae and Equations

Question 1

What is the formulae of Ammonium?

Answer 1

NH4+

Question 2

What is the formulae of hydrogen carbonate?

Answer 2

HCO3-

Question 3

What is hydroxide?

Answer 3

OH-

Question 4

What is nitrate?

Answer 4

NO3-

Question 5

What is carbonate?

Answer 5

CO3 2-

Question 6

What is sulfate?

Answer 6

SO4 2-

Question 7

What is phosphate?

Answer 7

P04 3-

Question 8

What does ‘Oxidation number’ mean?

Answer 8

It’s the number of electrons that need to be added to or subtracted from an element to make it neutral.

Question 9

What are the rules of giving oxidation numbers?

Answer 9

1. The oxidation of an uncombined element is 0.
2. The sum of the oxidation number in a compound is 0.
   In an ion the sum equals the overall charge.
3. In compounds the oxidation number of group 1 metals is +1 and in group 2 metals is +2.
4. The oxidation number of oxygen is -2 in compounds except with fluorine or in peroxides.
5. The oxidation number of hydrogen is +1 in compounds except in metal hydrides.
6. In chemical species with atoms of more than one element, the most electronegative element is given the oxidation number.