Aluminium is used in the manufacture or aircraft because it
Is hard and brittle
Is light and resists corrosion
Has high density and conducts electricity
Is malleable and ductile
Correct answer is B
No explanation has been provided for this answer.
Metals can be stretched into wires because they are
Ductile
Good conductors
Lustrous
Malleable
Correct answer is A
No explanation has been provided for this answer.
The mass of potassium hydroxide required to make 300.ocm3 of 0.4 moldm-3 solution is {KOH = 56.0}
26.88g
13.44g
6.72g
3.36g
Correct answer is C
300cm3 of 0.4moldm3
1000cm3 contains 0.4mole
300cm3 will contain \(\frac{300 \times 0.4}{1000}\)
= 0.12mole
Number of moles = \(\frac{Mass}{\text {Molecular mass}}\)
Mass = number of moles x m.mass
= 0.12 x 56 = 6.72g
Chemicals that are produced in small quantities and with very degree of purity are
Bulk chemicals
Fine chemicals
Heavy chemicals
Light chemicals
Correct answer is B
No explanation has been provided for this answer.
The boiling points of HF, H2O and NH3 increase in the order of
NH3
H2O < HF
HF < NH3 < H2O
NH3 < HF < H2O
Correct answer is D
Ammonia = -33.34°C; Hydrogen fluoride = 19.5°C; Water = 100°C