In which of the following is the entropy change positive?
Thermal dissociation of ammonium chloride
Reaction between an acid and a base
Addition of concentrated acid to water
Dissolution of sodium metal in water
Correct answer is A
Thermal dissociation of ammonium chloride is an endothermic reaction as heat is absorbed for a positive entropy, with more products than reactants.
0.2 g
1.8 g
5.4 g
14.2 g
Correct answer is B
Q = It = 10 x 1930 ( given)
27g → 3F( since aluminum is trivalent)
27g → 3 x 96500
x → 19300
x = \(\frac{27 \times 19300}{3 \times 96500}\)
x = 1.8g
Iron can be protected from corrosion by coating the surface with?
gold
silver
copper
zinc
Correct answer is D
No explanation has been provided for this answer.
The IUPAC nomenclature of the compound LiAlH4 is?
lithiumtetrahydridoaluminate (III)
aluminium tetrahydrido lithium
tetrahydrido lithium aluminate (III)
lithium aluminium hydride
Correct answer is A
No explanation has been provided for this answer.
HNO3(aq)
H2O(l)
PH3(g)
AgNO3(aq)
Correct answer is C
Phosphorus(iii)hydride is a strong reducing agent which reduces solution of silver or copper(ii)salts to the metals or phosphides.