C4-Chemical Changes Flashcards
Metal+oxygen —> ?
Metal oxides
Oxidation is the … of oxygen
Gain
Metals form…ions
Positive
Displacement reaction
A reaction in which a more reactive element takes the place of a less reactive element.
Ionic equation
An ionic equation is one that shows only those ions or atoms that change.
Ions or atoms that don’t change in a chemical reaction are called…
Spectator ions
Acids dissolved in water have a pH value of…
Less than 7, acids are proton H+ ion donors
Acid + metal —>
Salt + hydrogen
Hydrochloric acid
HCl -1
Sulfuric acid
H₂SO₄
Nitric acid
HNO₃ +1
Redox reaction
When both oxidation and reduction occur
How are soluble salts made?
By reacting acids with solid insoluble substances, such as metals, metal oxides, hydroxides or carbonates.
Acid + base —>
Salt + water
Alkalis
Have a pH value more than 7
Acid + alkali —>
Salt + water
Acid + metal carbonate —>
Salt + water + carbon dioxide
Unit of concentration
Moles per decimetre cubed
Strong acids are … ionised in an aqueous solution
Completely
Weak acid is … ionised in an aqueous solution
Partially
As the pH decreases by one unit, the hydrogen ion concentration of the solution…
Increases by a factor of 10
Electrolysis
Breaks down ionic compounds (salts) into their elements using electricity.
Cations
Positive ions
Anions
Negative ions
Anode
Positive electrode
Cathode
Negative electrode
At the cathode the ion of the …
Least reactive electron will be discharged.
At the anode if a … is present that will be discharged over anything else.
Halide
Ore
An ore is a material containing enough metal for it to be economically worth extraction.
Quantative data
Measured empirically
Qualitative data
Data collected by observation
