SURFACE CHEMISTRY QUIZ-5
Dear Readers,
IIT JEE exam which consists of JEE Main and JEE Advanced is one of the most important entrance exams for engineering aspirants. The exam is held for candidates who are aspiring to pursue a career in the field of engineering and technical studies.
Chemistry is important because everything you do is chemistry! Even your body is made of chemicals. Chemical reactions occur when you breathe, eat, or just sit there reading. All matter is made of chemicals, so the importance of chemistry is that it's the study of everything..
Q1. Statement 1: Thermal decomposition of KClO_3 (s) in presence of MnO_2 (s) is an example of homogeneous catalysis.
Statement 2: A homogeneous catalysis involves phase P=1.
Solution
(b). Heterogeneous system has P ≥2 S+S has P=2.
(b). Heterogeneous system has P ≥2 S+S has P=2.
Q2. Statement 1: ZSM – 5 is used as a catalyst in petrochemical industries.
Statement 2: Zeolites are three dimensional network silicates in which some silicon atoms are replaced by aluminium atoms.
Statement 2: Zeolites are three dimensional network silicates in which some silicon atoms are replaced by aluminium atoms.
Solution
(b). ZSM-5 converts alcohols directly into gasoline (petrol) by dehydrating them so that a mixture of hydrocarbons is formed.
(b). ZSM-5 converts alcohols directly into gasoline (petrol) by dehydrating them so that a mixture of hydrocarbons is formed.
Q3.Statement 1: Hard water consumes more soap.
Statement 2: The ion responsible for cleansing action is precipitated out by Ca^(2+) or Mg^(2+) ion.
Solution
(c) 2RCOONa+Ca^(2+)⟶ (RCOO)2Ca+2Na^+
(c) 2RCOONa+Ca^(2+)⟶ (RCOO)2Ca+2Na^+
Q4. Statement 1: Aqueous gold colloidal solution is red in colour.
Statement 2: The colour arises due to scattering of light by colloidal gold particles.
Solution
(a). The colour of colloidal solution depends upon the wavelength of light scattered by the dispersed particles which in turn depends upon size and nature of particles. Finest gold colloidal solution is red, as the size increase it become purple, blue and finally yellow.
(a). The colour of colloidal solution depends upon the wavelength of light scattered by the dispersed particles which in turn depends upon size and nature of particles. Finest gold colloidal solution is red, as the size increase it become purple, blue and finally yellow.
Q5.Statement 1: Activity of an enzyme is pH dependent
Statement 2: Change in pH affects the solubility of the enzyme in water
Solution
(c). With change in pH, the extent of protonation of the bases changes.
(c). With change in pH, the extent of protonation of the bases changes.
Q6. Statement 1: Now-a-days term catalyst means specifically a substance that accelerates the reaction.
Statement 2: The terms inhibitor is commonly used for substances which retards the rate of reaction.
Solution
(d). Both are different facts but true.
(d). Both are different facts but true.
Q7.Statement 1: The effectiveness of catalyst has found more applications in solid catalyst and gaseous reactant systems.
Statement 2: A large number of industrial preparations are based on this type of reactions.
Solution
(c). Explanation is correct reason for statement.
(c). Explanation is correct reason for statement.
Q8.Statement 1: The charge on lyophobic particles is responsible for their nature to exist as sol.
Statement 2: It is the formation of thin layer around sol particles which is responsible for stability of lyophilic sols.
Solution
(d). Both are different facts but true.
(d). Both are different facts but true.
Q9.Statement 1: Oxidation of Na2SO3 is not caused by air but in presence of Na3 AsO3 both undergo oxidation simultaneously.
Statement 2: Neither Na2SO3 nor Na3AsO3 is oxidised by air.
Solution
(a). It is called induced oxidation.
(a). It is called induced oxidation.
Q10. Statement 1: Langmuir adsorption is a single-layer phenomenon.
Statement 2: It is due to van der Waals forces.
Statement 2: It is due to van der Waals forces.
Solution
(c). The single layer formed may be due to van der Waals adsorption or chemisorption.
(c). The single layer formed may be due to van der Waals adsorption or chemisorption.
