Chemical Changes Flashcards
What pH value are 9, 2, 7 and 6?
Alkali, acid, neutral and acidic.
What type of reagent could be used to show that an acid or base has been completely neutralised?
Universal indicator or a pH probe.
What is a strong acid?
What proportion of the acid molecules ionise in the water.
Write a balanced equation for the reaction between hydrochloric acid and sodium carbonate?
hydrochloric acid + sodium carbonate –> sodium chloride + water + carbon dioxide
Is zinc more or less reactive than iron?
More reactive.
What is the reactivity series?
A list that ranks metals in order of reactivity:
Very reactive - Potassium, Sodium, Lithium then Calcium.
Fairly reactive - Magnesium, Carbon, Zinc then Iron.
Not very reactive - Hydrogen then Copper.
What is the general word equation for the reaction of a metal with an acid?
Acid + Metal –> Salt + Hydrogen
What products form in the oxidation of magnesium by oxygen?
Magnesium oxide.
Explain how you decide whether a metal can be extracted from its oxide by reduction with carbon.
The position of a metal in the reactivity series.
Definition of oxidation.
Gain of oxygen.
In a displacement reaction, does the metal atom get reduced or oxidised?
Oxidised.
During electrolysis, which electrode are the positive ions attracted to?
The cathode.
Why can ionic solids not undergo electrolysis?
The ions are in fixed positions and can’t move.
Do ions get reduced or oxidised at the anode?
Oxidised.
