1.4 Chemical Formulae Flashcards
1
Q
What is valency?
A
Valency is combining power. It is indicated by:
* Prefix (di… tri… tetra… etc.)
* group
* roman numeral (iron (III))
2
Q
What are the suffixes and what do they mean?
A
- -ide: only 2 things in the compound/molecule (sodium chloride - NaCl)
- -ite/ate: contains 3 things including oxygen (calcium carbonate - CaCO3)
3
Q
How do you work out a formula?
A
- Symbol - C S
- Valency - 4 2
- Swap - 2 4
- Simplify - 1 2
- Formula - CS2 (Carbon Sulphide)
For ions containing more than one atom, their formula & valency is shown in the data book.
4
Q
What is GFM?
A
GFM (gram formula mass) is the mass of one mole of the molecule.
5
Q
How do you work out the GFM of Na2CO3?
A
Na=2x23=46
C=1x12=12
O=3x16=48
46+12+48=106g
6
Q
What are the state symbols?
A
Solid - s
Liquid - l
Gas - g
Aqueous - aq
7
Q
What is an ionic formula?
A
A chemical formula showing the charges on each ion
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The positive and negative charges shown in an ionic formula should always balance
8
Q
What is a group ion?
A
An ion containing more than one type of atom
9
Q
A