Unit 2: Chemical Reactions Flashcards
(21 cards)
Catalyst
A substance that speeds up the rate of a reaction without causing permanent change.
Enzyme
A molecule found within a biological system that increases the speed of a chemical reaction.
Combustion Reaction
The reaction of a substance with oxygen, producing one or more oxides, heat, and light.
What 3 things from the “Fire Triangle” are nessesary for a combustion reaction?
1) Fuel (hydrocarbon)
2) Oxygen to burn it with
3) Something to ignite the reaction (Spark)
What is the general word equation for combustion?
Hydrocarbon + Oxygen→ Carbon Dioxide + Water
*CARBON DIOXIDE AND WATER ARE ALWAYS THE PRODUCTS OF COMBUSTION*
Incomplete Combustion
Something that occurs when there is not enough oxygen present in the reaction.
What are the pros and cons of incomplete combustion?
Good: Bright yellow flames used in candles
Bad: Porduces elemental carbon (soot) and toxic carbon monoxide (CO)
What are 3 dangers of carbon monoxide?
1) A toxic gas with no colour or smell
2) Binds to oxygen binding sites in the blood, the longer its breathed in the fewer binding sites are availible to carry the blood
3) Symptoms include headache to suffocation
Solubility
A measure of the extent to which a solute dissolves in a solvent at a given temperature and pressure.
What is the “Solubility Table” used for? How do you use it?
We use the table to predict the solubilty in water of an ionic compound in a double displacement reaction.
To use: Look for the second element (non-metal) on the chart and find it’s compounded element. The chart will say whether it is soluable or has low solubility (Solid).
What are the 5 steps to solving a solubility problem?
Step 1: Identify the type of reaction and its products
Step 2) Look up solubility of the products
Step 3) Indicate states of reactants and products
Step 4) Write the chemical equation
Step 5) Balance the equation
*LOW SOLUBILITY MEANS SOLID*
What happens if there is no precipitate formed in a solubility reaction?
There was no reaction.
Total Ionic Equation
A chemical equation that illustrates all soluable (aq) ionic compounds in their ionic form.
Spectator Ions
Ions present in the products and reactants of the equation. They cancel eachother and when rewritten it is called a net ionic equation.
Net Ionic Equation
An equation that only show the ions that were involved in the chemical reaction.
A re-writtten equation without spectator ions.
What are the 3 clues that tell us a reaction is proceeding?
1) A precipitiate is formed
2) A gas is produced
3) The solution becomes neutral
How does a double displacement reaction sometimes occur in 2 steps?
When a double displacement reaction produces 2 products one of them spontaneously demcomposes to produce a gas.
Neutralization
The process of making a neutral solution by combining an acid (H) with a base (OH). A water and a salt will result.
What are 2 ways neutralization is used in everyday life?
1) They’re used to treat acid or base spills
2) Milk of Magnesia: a medicine that neutralizes stomach acid
What is the “Activity Series”?
A ranking of metal elements according to reactivity.
It increases going from bottom to top.
How does the activity series work?
In a single displacement reaction one element can displace element below it but not above it on the activity series. The farther appart two elements are, the more likely the displacement will occur. The less reactive element appears as a solid.
Example: Ni is above Ag therefore they would switch in a reaction.
