Period 3 Flashcards
How does sodium react with water?
It reacts vigorously with cold water to form sodium hydroxide and hydrogen gas.
How does magnesium react with water?
- It reacts slowly with cold water to form magnesium hydroxide.
- It reacts much faster with steam to form magnesium oxide and hydrogen gas.
Why does magnesium form a weakly alkaline solution when it reacts with water?
This is because magnesium hydroxide is not very soluble in water so few hydroxide ions are produced.
What is sodium’s reaction with oxygen?
It reacts vigorously and burns with a yellow flame.
What is magnesium’s reaction with oxygen?
It reacts vigorously and burns with a bright white flame.
What is aluminium’s reaction with water?
Al2O3
What is silicon’s reaction to oxygen?
It reacts slowly.
What is phosphorous’ reaction with oxygen?
It spontaneously combusts and burns with a bright white flame.
What is sulfur’s reaction with oxygen?
It burns with a blue flame and produces an acidic choking gas.
Why does sodium oxide have a lower melting point compared to magnesium oxide?
The sodium ions are larger and have a less positive charge compared to the magnesium ions so the electrostatic forces of attraction between the ions, in the giant ionic lattice, are weaker and need less energy to break.
Why does the melting point decrease between magnesium oxide and aluminum oxide?
The aluminium oxide is partially covalent because the electronegativity between aluminium and oxygen isn’t that different and this causes a decrease in the melting points.
Why is the melting point of silicon dioxide the highest out of the non-metal oxides?
It is a macromolecular structure and the structure is held together by strong covalent bonds that need a lot of energy to break compared to the other non-metal oxides that are only held together by weaker van der Waals forces that need less energy to break.
How does sodium oxide react with water?
It produces an alkali solution of sodium hydroxide.
How does magnesium oxide react with water?
It produces an alkali solution of magnesium hydroxide.
Why does aluminium oxide and silicon dioxide not react with water?
Silicon dioxide is insoluble in water because the covalent bonds that hold the structure together need a lot of energy to break. Aluminium is also insoluble in water because it is partially ionic and covalent.
