Fichas
Unit 5: Section 2: Period 3 and Redox Equilibria
Fichas del conjunto (21)
- 1What solution is produced from the reaction of sodium with water?A strong alkaline solution (pH 12-14)
- 2What solution is formed when magnesium reacts with water?A weak alkaline solution (pH 9-10)
- 3What are the oxides formed when period 3 elements react with oxygen?Na₂O
MgO
Al₂O₃
SiO₂
P₄O₁₀
SO₂ - 4Which 2 period 3 elements react slowly with air?Aluminium and Silicon
- 5What colours are the flames for the reactions of Na, Mg, P and S in air?Na→ Yellow
Mg→ Brilliant white
P→ Brilliant white
S→ Blue - 6Which oxides form alkaline solutions?Sodium oxide and magnesium oxide.
- 7Which oxides form acidic solutions?Silicon oxide, phosphorus oxide and sulfur oxide.
- 8What does amphoteric mean?Can act as an acid or a base.
- 9Which oxide is amphoteric?Aluminium oxide
- 10What is an oxidising agent?-Accepts electrons
-Becomes reduced - 11What is a reducing agent?-Donates electrons
-Becomes oxidised - 12What oxidation state do uncombined elements have?0
- 13What oxidation state do elements bonded to identical elements have? E.g. O₂0
- 14What is the oxidation state of combined oxygen usually?-2
- 15What is the oxidation state of oxygen in peroxides?-1
- 16When does the oxidation state increase?When an electron is lost.
- 17What is the standard electrode potential of a half-cell?The voltage measured under standard conditions when the half-cell is connected to a standard hydrogen electrode.
- 18What is a selection pressure?An environmental factor that confers greater chances of survival to reproductive age on some members of the population.
E.g. predation - 19What are isolating mechanisms?Things that may prevent a population from freely interbreeding.
- 20What are some isolating mechanisms?-Geographic barriers e.g. a mountain range.
-Seasonal barriers e.g. climate change.
-Reproductive barriers e.g. courtship behaviours vary. - 21What effect do isolating mechanisms have on a population?-Leaves 2 sub-populations.
-Different alleles will be eliminated/increased.
-Eventually they will become different species and no longer able to interbreed.