Hint

SOLUTION:

Metals above hydrogen in the activity series can displace or
replace hydrogen present in water (H2O) example of such
metals are Ca, K, Na etc. But the metals below hydrogen in the
activity series cannot replace hydrogen in the activity series
example of such metals are Cu Hg.

Hint

SOLUTION:

P 6 = 2, 4

Q 11 = 2, 8, 1

R 15 = 2, 8, 5

S 17 = 2, 8, 7

Given the above is the electronic arrangement of PQRS
elements, Q will form an electrovalent bond with S. Without
argument, D is the answer because electrovalency involves
the transfer of electron. Already, Q is 11 with electronic
configuration of 2, 8, 1, i.e. having 1 valence electron which is
ready to be lost by the atom of element Q, also, S is 17, with
electronic configuration of 2, 8, 7. There the 7 valence electron
of S attracts that only 1 electron to attain a stable octet
structure.

Hint

SOLUTION:

Ethyl benzene is used to manufacture styrene, which is used in
the production of latex, synthetic rubber and polystyrene,
which is used mainly in food packaging. Phenol and its
derivatives are used to make aspirin, antiseptics, explosives,
plastics, and dyes used in textiles and food.

Hint

In electro-valency the oxidation number of the participating
metal remains constant

Hint

SOLUTION:

Ionic Radius vs. Atomic Radius Metals – the atomic radius of a
metal is generally larger than the ionic radius of the same
element. Why? Generally, metals loose electrons to achieve
the octet. This creates a larger positive charge in the nucleus
than the negative charge in the electron cloud, causing the
electron cloud to be drawn a little closer to the nucleus as an
ion. Non-metals – the atomic radius of a non-metal is generally
smaller than the ionic radius of the same element. Why?
Generally, non-metals loose electrons to achieve the octet.
This creates a larger negative charge in the electron cloud
than positive charge in the nucleus, causing the electron cloud
to ‘puff out’ a little bit as an ion. Cations (or anions) of different
elements are said to be **isoelectronic** if they both have the
same electronic configuration e.g. K+ and Ca 2+ For
isoelectronic cations, the more positive the ionic charge, the
smaller the ionic radius. For isoelectronic anions, the more
negative the ionic charge, the larger the ionic radius. ubc.ca

Hint

SOLUTION:

Calcium trioxocarbonate (IV) = CaCO

Percentage of Oxygen = × 100%

3

Molar mass of 3O
Molar mass ofCaCO3

Percentage of Oxygen = x 100%

Percentage of Oxygen = x 100%

Percentage of Oxygen = 48%

Hint

SOLUTION:

Bronze is an alloy consisting primarily of copper, commonly
with about 12% tin and often with the addition of other metals
(such as aluminium, manganese, nickel or zinc) and
sometimes non-metals or metalloids such as arsenic,
phosphorus or silicon.

Hint

SOLUTION:

Molecular mass = Vapour Density x 2

Vapour Density = 49g/mol

Hint

SOLUTION:

N + 3H ⇔ 2NH In the Haber process, the forward
reaction is exothermic and the backward reaction is
endothermic. If the temperature is decreased, the yield from

(3×16)
(40+12+48)
48
100

Molecular Mass

2

98
2

2(g) 2(g) 3(g)

the exothermic direction is increased i.e. the forward reaction
is increased.

Hint

SOLUTION:

Formula for enthalpy change: ΔH = ΔU + Pex(ΔV)

The enthalpy change is zero because both terms on the right
are zero in free expansion of an ideal gas.

There is no external pressure in a free expansion, so P (ex) =
0. And the internal energy change, ΔU of free expansion in a
closed system is zero since no inter molecular forces have to
be overcome. The temperature remains constant and no heat
is absorbed or released.

Hint

SOLUTION:

Sweat consists primarily of water and electrolytes. The primary
electrolytes contained in sweat are sodium and chloride.
Potassium, urea, lactate, amino acids, bicarbonate and
calcium are also found.

Hint

SOLUTION:

Alkanones (also known as ketones) have the general formula
R2CO

Hint

SOLUTION:

The periodic number table is arranged in order of atoms
increasing atomic number

Hint

SOLUTION:

Image result for chemical composition of
claywww.researchgate.net Between the five main minerals
found in clay, kaolinite is the most common. Kaolinite holds the
chemical composition Al2Si2O5(OH)4 and is an aluminum
silicate material with a low “shrink-swell” capacity. It is a soft,
white mineral but is often colored orange or red by iron oxide
found in the soil
Clay minerals are hydrous aluminium phyllosilicates,
sometimes with variable amounts of iron, magnesium, alkali
metals, alkaline earths, and other cations found on or near
some planetary surfaces.

Hint

SOLUTION:

In petrochemistry, petroleum geology and organic chemistry,
cracking is the process whereby complex organic molecules
such as kerogens or long-chain hydrocarbons are broken
down into simpler molecules such as light hydrocarbons, by
the breaking of carbon-carbon bonds in the precursors.
Wikipedia

Hint

SOLUTION:

In the periodic table, elements are arranged according to their
atomic number (that is, proton number).

In the periodic table, electronegativity increase from left to right
while atomic radius increases down the group