Chemistry
Study the information given in the table below and answer the questions that follow. (Note- the letters do not represent the actual symbols of the elements)
| Element | Electronic configuration | Ionisation energy kjmol-1 |
|---|---|---|
| X | 2,2 | 900 |
| Y | 2,8,2 | 738 |
| Z | 2,8,8,2 | 590 |
(a) Explain why element X has highest ionisation energy.
(b) To which period does Z belong?
(c) Draw the electron dot structure of the compound formed between Z and oxygen.
Answer
(a) Element X has the highest ionisation energy because it has the smallest atomic size, fewer electron shells, and its valence electrons experience a stronger attraction to the nucleus.
(b) Z has the configuration of 2,8,8,2, electrons occupying K,L,M and N shells. Hence, Z belongs to Period 4.
(c) The electron dot structure of the compound formed between Z and oxygen is shown below:
Related Questions
An element X combines with oxygen to form an oxide X2O3. This oxide is a good conductor of electricity and can be reduced to its metal only by electrolysis.
(a) Write the equation for the reaction formed when the oxide (X2O3) combines with hydrochloric acid.
(b) How many valence electrons are present in the outermost shell of X?
(c) Will element X undergo oxidation or reduction?
Observe the reactions given below and answer the following questions:
(a) Identify compound P.
(b) Give the chemical formula of Z.
(c) Write the reaction taking place between the identified compound P and sulphuric acid.
(d) Name compound Y.
A student prepared a Potassium sulphite solution in the lab and added few drops of barium nitrate solution to it. He observed a white precipitate being formed in the test tube. On addition of dilute hydrochloric acid to the white precipitate and mixing it, he observed that the precipitate disappeared.
(a) Name the white precipitate.
(b) Write a balanced chemical equation for the reaction between dilute hydrochloric acid and the white precipitate.
(c) Name the gas evolved in the above reaction.
The empirical formula of a hydrocarbon is C2H3. The hydrocarbon has a relative molecular mass of 54. (At wt: H = 1, C = 12)
(a) What is the molecular formula of the hydrocarbon?
(b) Draw the structural formula of the hydrocarbon.
(c) Give the general formula of the hydrocarbon.