Chemistry Flashcards
What is an ionic compound?
Result when atoms transfer electrons and occur between metal elements and non-metal elements.
M + NM
What are covalent compounds?
Result when atoms share electrons. Covalent compunds occure between non-metal and non-metal elemtns,
NM + NM
What is the naming rule for ionic compounds
M + NM
Ionic compound are always listed with the metal element first and the non-mental eleven second (ie. NaCl)
With ionic compunds we simpy read out the names of the two elemetns (poitive/metal ion first, negative/non-metal ion second) and change the ending of the sedon element to “ide”
Also, with ionice compounds we can ignore the rations (numbers) that are in the formulat (we don’t have to make any changed to the name)
Al2O3 = aluminum chloride
Ionic compounds with “multivalent” metals
Some metals do have more than on ion charge – for example Iron can be Fe2 or Fe3 – this is called multivalent.
So when it reacts with Oxygen (O-2) you can end up with compounds with different formulas (FeO vs. Fe2O3)., They also have totally different properties (colour, state, etc. Therefore you can’t call them both “iron oxide”
To tell the difference between the different compounds, you simply put the ion charge that was ‘used’ (as a Roman numeral) directly into the name
What is a polyatomic ion?
When some ionic compounds are disolved in water, the form separate ions. However, not all ions are made up of only one element. Polyatomic ions are groups of atoms that tend to stay together and carry and overall change (Like an ion)
What happens during a chemical reaction?
- Bonds are broken
- New bonds are made
- Or both can happen
What is an exothermic reactions?
- Produces energy
- “EXO” means “outside”
- “THERM” means “hot”
- Energy is the product (right side of the equation)
- Examples – burning, explosions, bombardier beetle
What is an endothermic reactions?
- Absorbs energy
- “ENDO” means “inside”
- “THERM” means “heat”
- Energy is a reactant (left side of the equation)
- Examples – cooking, cold pack
What are diatomic molecules?
They are the only elements that exists in pairs when not reacted with something `
- like to be in buddies – always two together
H O F Br I N Cl
What are examples of diatomic molecules?
H2, O2, F2, Br2, I2, N2, Cl2
synthesis reactions.
-sythesis is a combination of two or more subsences to form compound.
-It has the genaral form:A+B->AB
Example:the formation of water is a sythisis reaction:
2H2 (g) +O2 (g) ->2H2O
-Two small things come together to make a bigger compound
Decompostion reactions
> Decompistion is the opposite of synthesis.
One substance breaks down to form two or more simpiler substences. – bigger compound is broken down into smaller components
These reactions have the genaral form:AB->A+B
Exsample:the decompostion of water, producing hydrodgen and oxygen.
2H2O (I) ->2H2 (g) +O2 (g)
Double replacement reaction
> Double replacements ocur when the elaments in diffrent compounds replace each other or exchange places.
The genaral form: AB+XY->AY+XB
FeCl2+K2S->FeS+2KCl
(square dancing)
Single replacement reaction
> single replacement reactions occur when one element is replaced by another in a compound
These have the genaral formula A+BC->AC+B
2Al (s) +Fe2O3 (s) ->2Fe (I) +Al2O3 (s)
- welders melt metal parts to fuse together
(tagging out in soccer games)
Neutralization reactions
> neutralization reactions are a special type of double replacement reaction in which an acid and a base react.
The result of the reations is the formation of a salt and water
the genaral form is:AB+XY->AY+XB
or H2O
Acid +Base->Salt +Water
HOH
Acid start with “H” in their formula
Bases always contain “OH”
