EduNinjaThe elements phosphorus, sulfur and chlorine are in Period 3 of the Periodic Table.
Table 1.1 shows some properties of the elements P to Cl .
The first ionisation energy of S is not shown.
Table 1.1
A student does three tests on separate samples of NaCl(aq).
Complete Table 1.2 with the observations the student makes in each test.
Table 1.2
Copper is a transition element and has atomic number 29.
Ethane-1,2-diamine is a useful reagent in organic chemistry.
Explain how the amino groups in ethane-1,2-diamine allow the molecule to act as a Brønsted-Lowry base.
Write an equation for the reaction of ethane-1,2-diamine with an excess of hydrochloric acid.
Silicon tetrachloride, , is formed when silicon reacts with chlorine under suitable conditions. It is a colourless liquid with a low boiling point.
reacts with water to produce an acidic solution.
A sample of 0.8505 g of is added to of water. All of the soluble acidic product is dissolved in the water.
Calculate the pH of the solution obtained.
Sodium oxide, , is a white crystalline solid with a high melting point.
When sodium oxide reacts with water an alkaline solution is obtained.
Explain why the solution obtained is alkaline. You should use the Brønsted-Lowry theory of acids and bases in your answer.
Sulfides are compounds that contain sulfur but not oxygen.
Hydrogen sulfide gas, , is slightly soluble in water. It acts as a weak acid in aqueous solution.
State the meaning of weak acid.
The compound is a common mineral.
When is heated strongly in air, it forms a mixture of products, as shown.
can be removed from the air by reacting it with NaOH(aq).
Construct an equation for the reaction of with NaOH(aq). Include state symbols.
In 1814, Sir Humphrey Davy and Michael Faraday collected samples of a flammable gas, A, from the ground near Florence in Italy.
They analysed A which they found to be a hydrocarbon. Further experiments were then carried out to determine the molecular formula of A.
When of A was mixed at room temperature with of oxygen (an excess) and exploded, of gas remained after cooling the apparatus to room temperature and pressure.
When this of gas was shaken with an excess of aqueous potassium hydroxide, of gas still remained.
The combustion of A produced a gas that reacted with the KOH(aq).
What is the identity of this gas?
Two Period 3 elements react with an excess of oxygen at room pressure.
The solutions made in column 3 of Table 1.2 are mixed together. Name the type of reaction that occurs.
The iron(II) complex ferrous bisglycinate hydrochloride is sometimes prescribed, in capsule form, to treat iron deficiency or anaemia.
A capsule containing 500 mg of this iron(II) complex was dissolved in dilute and titrated with .
of solution were required to reach the end point.
The equation for the titration reaction is as follows.
Describe how you would recognise the end point of this titration.
Species such as and are examples of molecular ions.
is a Brønsted-Lowry acid.
Define Brønsted-Lowry acid.
When is heated with NaOH(aq), a pungent gas is produced.
Write an ionic equation for this reaction.
Hydrogen iodide, HI, is a colourless gas at room temperature.
In the laboratory, HI(aq) can be formed in a two-step process.
step
step
and HI(aq) are both strong Brønsted-Lowry acids.
Give the meaning of the term strong Brønsted-Lowry acid.