Chemical Periodicity

State one property of aluminium oxide that explains why an aluminium object does not react with cold water until the aluminium oxide layer is removed.

Write an equation, with state symbols, for the reaction of aluminium oxide with an excess of $\text{NaOH(aq)}$.

Name one other Period 3 element that also produces bubbles of gas when added to cold water.

Aluminium nitrate is a white soluble salt. On heating aluminium nitrate, thermal decomposition occurs and a brown gas is seen.

State the formula of the salt of another element in Period 3 which also decomposes on heating to produce a brown gas.

State the maximum oxidation number of aluminium and of phosphorus in these solid chloride salts.

maximum oxidation number of aluminium .............................................

maximum oxidation number of phosphorus ..........................................

State why the maximum oxidation number of aluminium is different from that of phosphorus.

Write an equation for the reaction of solid phosphorus chloride and excess water.

Name the type of reaction that occurs when aluminium chloride is added to water.

Explain why the solution produced after aluminium chloride is added to water has a pH of 1–2.

explanation

explanation

explanation

Identify one of these six oxides that has no reaction at all with water.

Suggest the identities of D and G.

hydrochloric acid,

sodium hydroxide.

Write an equation for the formation of an acidic solution when GO₂ dissolves in water.

Give the formula of the oxide formed when each element is heated in air. One has been completed for you.

Describe what you would see when sodium and sulfur are each heated separately in air and give an equation for each reaction.

Place the symbols of the elements in (a)(i) in the appropriate row of the table to indicate this behaviour.

State the bonding present in acidic and basic oxides.

Write equations for the reaction of aluminium oxide with each of hydrochloric acid, $\text{HCl}$, and sodium hydroxide, $\text{NaOH}$.

Using these terms only, complete the table to describe the oxides of the elements of the third period of the Periodic Table sodium to sulfur.

Give the names of two elements from sodium to chlorine which form more than one oxide.

Describe, as fully as you can, what you would see when a piece of sodium is reacted with water.

Write an equation for the reaction of sodium with water.

Explain the trend shown in the atomic radii of the Period 3 elements Na to Cl.

Explain why there is a large difference in the ionic radii of Al and P.

Complete Table 2.1.

State why there is no data given in row B for $\text{Al}_2\text{O}_3$ and $\text{SiO}_2$.

Write an equation for the reaction of $\text{Na}_2\text{O}$ with dilute hydrochloric acid.

Construct an equation for the reaction of $\text{Al}_2\text{O}_3$ with a base to form $\text{NaAlO}_2$.

Sulfur forms a number of chlorides which are liquid at room temperature.

Which other element of the third period forms a chloride which is liquid at room temperature?

Name one element of the third period which burns in chlorine with a coloured flame.

Aluminium chloride may be produced by passing a stream of chlorine over heated aluminium powder in a long hard-glass tube.

State two observations you could make during this reaction.

Write a balanced equation, with state symbols, for this reaction of aluminium with chlorine.

No chloride of argon has ever been produced.

Suggest a reason for this.

Complete the table below, stating how the chlorides of Na, Al, and Si behave when mixed with water. In the first column use only the terms ‘dissolve’ or ‘react’.

What type of reaction takes place between a chloride and water?

A Period 3 oxide produces a solution with a pH greater than 10 when it is added to water.
State the formula of the oxide.

$\text{P}_4\text{O}_{10}$ is added to an excess of aqueous $\text{NaOH}$.
Write an equation to describe the reaction.

Identify the oxide from Table 2.1 that contains the element with the highest oxidation number.

State why $\text{ZnO}$ is described as a Brønsted–Lowry base when it is added to $\text{H}_2\text{SO}_4(\text{aq})$.

State the formula of the aluminium‑containing species produced when $\text{Al}_2\text{O}_3$ reacts with $\text{NaOH}(\text{aq})$.

State the formula of the aluminium‑containing salt produced when $\text{Al}_2\text{O}_3$ reacts with $\text{H}_2\text{SO}_4(\text{aq})$.

Chlorine is very reactive and will form compounds by direct combination with many elements.

Describe what you would see when chlorine is passed over separate heated samples of sodium and phosphorus.
In each case write an equation for the reaction.

sodium

phosphorus

Magnesium chloride, $\text{MgCl}_2$, and silicon tetrachloride, $\text{SiCl}_4$, each dissolve in or react with water.

Suggest the approximate pH of the solution formed in each case.

$\text{MgCl}_2$: .................................

$\text{SiCl}_4$: .................................

Explain, with the aid of an equation, the difference between the two values.