lowering the pressure of the reaction
increasing the surface area of the reactant
increase the rate of the reaction
lowering the energy barrier of the reaction
Correct answer is C
- The presence of MnO2 increase the rate of the reaction by providing a new reaction path / making more particles possess kinetic energy greater then the activation energy.
If a reaction is exothermic and there is a great disorder, it means that?
the reaction is static
the reaction is in a state of equilibrium
there will be a large increase in free energy
there will be a large decrease in free energy
Correct answer is D
If a reaction is exothermic and there is a great disorder for a spontaneous reaction to occur, a large decrease in free energy is evident.
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.