Chemical Reactions Flashcards
Catalytic decomposition
Reactions that involve the breaking down of a chemical substance using another chemical - a catalyst
Precipitation reaction
Where two ionic solutions are mixed and an insoluble solid (precipitate) forms
Covalent bonding
The sharing of electrons between non-metals to gain a full outer shell
Combination reactions
Where two elements react to produce a single, more complex compound
Ionic bonding
The transfer of valence electrons between atoms to create an ion
Solubility
How much of a substance appears to dissolve in a solvent
Catalyst
A substance that is not used up in a reaction but takes part - it speeds up the rate of reaction by providing an alternate pathway for the reaction to occur with lower activation energy
Precipitate
A solid that forms and sinks to the bottom of a solution
Decomposition Reaction
When a compound breaks down into its component elements or simpler molecules. Two kinds –> thermal –> catalytic
Thermal decomposition
Reactions involving the break down of a chemical substance using strong heat
Observations
Describe what the reactant looked like, what the product looked like (colour, appearance) and what happened during the reaction
Spectator ion
An ion that does not take part in a chemical reaction. It remains unchanged and is left out of ionic equations
Aqueous
In water
What is cobalt chloride paper used for?
A test to prove the presence of water. It turns from blue to pink in the presence of water. (CoCl2)
What is limewater used for?
A test to prove the presence of carbon dioxide gas. It turns from clear to milky. (Ca(OH)2)
Metal hydroxide -> thermal decomposition reaction
= metal oxide + water
Metal carbonate -> thermal decomposition reaction
= metal oxide + carbon dioxide
Metal hydrogen carbonate ->thermal decomposition reaction
= metal carbonate + carbon dioxide + water
Hydrogen peroxide catalytic decomposition reaction
= oxygen gas + water
Why does a precipitate form?
A precipitate will form if it is insoluble. If a compound is insoluble, it means that the attractions between the ions in the fixed 3D lattice are greater than the attraction between the ions and solvent molecules.
Covalent compound are made of
nonmetal and nonmetal
Catalytic decomposition of hydrogen peroxide requires ______________
manganese dioxide
Catalytic decomposition of hydrogen peroxide
2H202 -> 2H2O + 02 (with help of manganese dioxide catalyst, MnO2)
What do metals react with to form ionic compounds?
Non-metals (ie copper +oxygen=copper oxide)
What happens when a metal and non-metal react to form an ionic compound?
Metal atoms transfer electrons to non-metal atoms and form ions. Metal becomes cations. Non-metals become negative ions
What is the attraction between negative and positive atoms called?
Electrostatic - this is why ionic solids have high melting and boiling points as it takes lots of energy to break the forces.
What do non-metals and non-metals react to form?
Covalent compounds
What is a covalent compound?
A non-metal and non-metal that share electrons to form molecules. Very weak intermolecular between molecules, strong between atoms
All reactions need what to occur?
Heat
Ionic equations in precipitate reactions only involve what?
The precipitate and what it forms - everything else is left out
Copper oxide colour
Black
Calcium oxide colour
White
What is the glowing splint test?
Proves the presence of O2 gas by relighting.
What is the squeaky pop test>
A lit splint proves the presence of H2 gas by making a popping noise.
