C4.1

Question 1

Define relative atomic mass, Ar.

Answer 1

the average mass of naturally occurring atoms of an element on a scale where the (12)C atom has a mass of
exactly 12 units

Question 2

Define relative molecular mass, Mr

Answer 2

the sum of the relative atomic masses (will be used for ionic compounds)

Question 3

relative molecular mass =

Answer 3

relative formula mass (same thing)

Question 4

rules for naming compounds

Answer 4

1. element that is furthest to the left comes first in the name (often these are metals), the name of this element DOES NOT CHANGE
2. If there are two elements in the compound, then the second element will change its name ending to “-ide”
3. If there are 3 elements in the compound and one of them is oxygen then the compound name will end in “-ate” or “-ite” (this represents the oxygen)

Question 5

memorize the groups and valencies in periodic table

Answer 5

group : valency
1 = 1
2 = 2
3 = 3
4 = 4
5 = 3
6 = 2
7 = 1
8/0 = 0

Question 6

SVSDF?

Answer 6

Symbol
Valency
Swap
Divide
Formula

Question 7

What does the human numeral indicate?

Answer 7

the valency

ex. colbalt (II) = valency 2 for cobalt

Question 8

write the roman numerals for numbers up to 6

Answer 8

I, II, III, IV, V, VI

Question 9

write the radical, formula, and valency for
hydroxide

Answer 9

radical: OH(-)
formula: OH
valency: 1

Question 10

write the radical, formula, and valency for
hydrogen carbonate

Answer 10

radical: HCO(3)(-)
formula: HCO(3)
valency: 1

Question 11

write the radical, formula, and valency for
nitrate

Answer 11

radical: NO(3)(-1)
formula: HCO(3)
valency: 1

Question 12

write the radical, formula, and valency for
ammonium

Answer 12

radical: NH(4)(+)
formula: NH(4)
valency: 1

Question 13

write the radical, formula, and valency for
carbonate

Answer 13

radical: CO(3)(2(-)
formula: CO(3)
valency: 2

Question 14

write the radical, formula, and valency for
sulfate

Answer 14

radical: SO(4)(2)(-)
formula: SO(4)
valency: 2

Question 15

write the radical, formula, and valency for
phosphate

Answer 15

radical: PO(4)(3)(-)
formula: PO(4)
valency: 3

Question 16

rule for ionic formulae?

Answer 16

the first element will be positive (+), second will be negative (-)

Question 17

where to find relative atomic mass?

Answer 17

on the periodic table! easy!

Question 18

how to find relative molecular mass?

Answer 18

using molecular formula mass, but still noted as Mr

add the relative atomic masses of the elements found (in periodic table). if there is two of the same element than multiply. ex. CO(2) = 12 + (2x16) = 44