Level 3 YR 1- unit 1 Principles and application of science- chemistry

Question 1

1. Hydrocarbons are molecules which are made of hydrogen and carbon only.
   The bonding between atoms of hydrogen and carbon is covalent.
   (a) (i) State what is meant by the term covalent bond.

Answer 1

Clue: Please explain what is meant by covalent bond. write answer in your book

Question 2

Methane is a hydrocarbon and has the molecular formula CH4.
Draw a dot-and-cross diagram for a molecule of methane.
Show outer electrons only.

Answer 2

Clue: Dot and cross diagram of covalent bond in methane

Question 3

The melting point of methane is –182 °C.

Explain, in terms of intermolecular forces, the melting point of methane.

Answer 3

Clue: Low MP and BP

Please use ‘induced dipole induced dipole bond
weak forces

Question 4

(a) A phosphorus atom contains 15 electrons.
Complete the electronic configuration for a phosphorus atom.

1s2 2s2 2p6 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Answer 4

Please check the electronic configuration chat given by Kwabena

Question 5

Calcium is a metal.
Word equations for two reactions of calcium are shown.
calcium + oxygen → calcium oxide
calcium + hydrochloric acid → calcium chloride + hydrogen
(a) Complete the word equation for the reaction of calcium with sulfuric acid.

calcium + sulfuric acid → . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
(b) Write the balanced equation for the reaction of calcium, Ca, with oxygen.
(
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
(c) The equation for the reaction of dilute hydrochloric acid with calcium is
Ca + 2HCl → CaCl2 + H2
Calculate the maximum mass of calcium chloride produced by reacting 8.02 grams
of calcium with excess hydrochloric acid.
relative atomic mass: Ca = 40.1
relative formula mass: CaCl2 = 111.1
Show your working.

Answer 5

Complete equation, metal react with acid to produce salt and hydrogen

Question 6

Manganese, Mn, is a metal.
It has a metallic structure.
(a) Explain why metals are malleable.

Answer 6

Explain: they can be bent an shaped without breaking. This is because they consist of layers of atoms

Question 7

KMnO4 is a useful compound of manganese.

Calculate the relative formula mass for KMnO4

Answer 7

Clue: Find the Masses of each atom from the periodic table and add together

Question 8

Manganese and zinc are both metals in the d block of the periodic table.
Table 1 shows some information about manganese and zinc.
metal short electronic configuration common oxidation states
manganese [Ar] 3d5 4s2 +2, +4, +7
zinc [Ar] 3d10 4s2 +2
Table 1
Discuss why manganese is classified as a transition metal, but zinc is not.

Answer 8

Research this information and write in your book