22 Silicon(IV) oxide is a covalently bonded compound.
Which statements are correct?
1
2
Silicon atoms form four single bonds in silicon(IV) oxide.
Oxygen atoms form two double bonds in silicon(IV) oxide.
Silicon(IV) oxide has a high melting point.
Silicon(IV) oxide contains one silicon atom and four oxygen atoms.
3
4
с
D
2 and 3 only
3 and 4 only
B
1 and 3 only
1 and 2 only
А
А

Oxygen atoms form two double bonds in silicon(IV) oxide.

Silicon(IV) oxide has a high melting point.

Explanation:

Silicon dioxide is structurally analogous to carbon dioxide in the sense that it also contains two oxygen atoms that are double bonded to silicon the central atom in the molecule.

Silicon dioxide has a very high melting point of about 1710 degrees centigrade because of its large macromolecular structure which requires much energy to break such intermolecular interactions.

substituting a hydrogen atom with a halogen in a hydrocarbon:

- the single bond remains single. a is wrong.

- the bond with hydrogen is as strong as with a halogen. c is wrong

- a hydrocarbon is saturated if there is no double bond. we do not know that so d is wrong.

- carbon will always have four valence electrons. e is wrong.

by elimination, the correct answer is b. the boiling point of the new compound increases.