- Accepts proton
- Donates proton
- Is having incomplete octet
- Donates electrons
- c
2025
All Solved Current and Past Papers of 2025 are included in this section of ETEST Academy’s Website. All MCQs of Year 2025 are solved with short detailed answers. ETEST Academy updates this portion of Past Papers 2025 on daily basis.
Which of the following statement is not correct for a galvanic cell?
- Reduction occur cathode
- Oxidation occur at cathode
- Electron flow from cathode to anode
- Both A and B
- a
-
Oxidation occurs at anode.
Electron flow from anode to cathode.
SCUBA is a breathing apparatus which contains:
- 50% Nitrogen and 50% Oxygen
- 96% Helium and 4% Oxygen
- 96% Oxygen and 4% Helium
- 78% Nitrogen and 21% Oxygen
- b
-
SCUBA stands for Self Contained Underwater Breathing Apparatus. It is used for breathing underwater.
Pure mixture of 50% both is dangerous.
Normal ratio of both is not used for deep depth.
Maximum Helium as 96% is used in deep dive to prevent from Nitrogen Narcosis.
Too much Oxygen is dangerous.
Ionic product of (Kw) of water will increase if:
- H plus ion are added
- OH negative ions are added
- Temperature increased
- Pressure increase
- c
-
Kw is ionic product of water.
Kw tells us about strength of water in making H+ and OH-.
H+ makes water acidic and HO- makes water basic.
Pure water has equal amount of H+ and HO-.
Lead storage battery is a/an:
- Dry cell
- Electrolytic cell
- Voltaic cell
- Daniel solution
- c
-
An electrochemical cell that converts chemical energy into electrical energy by a spontaneous redox reaction.
Lead storage battery works on spontaneous redox reactions.
Voltaic cell is also called Galvanic cell.
Which of the following enthalpy is always positive?
- Enthalpy of combustion
- Enthalpy of solution
- Enthalpy of reaction
- Enthalpy of atomization
- d
-
Enthalpy of combustion releases heat and exothermic.
Enthalpy of solution can be positive or negative depends on the substance.
Enthalpy of reaction it also be negative or positive.
Enthalpy of atomization is always positive because energy is required to break bonds and form free atoms.
Total energy of system is called:
- Potential Energy
- Electrical Energy
- Internal Energy
- Kinetic Energy
- c
-
Potential energy is due to position.
Electric energy is due to electric current.
Total energy of system consist of K.E and P.E which is called Internal Energy.
Kinetic energy is due to motion.
Metal used for galvanization is:
- Mg
- Fe
- Cu
- Zn
- d
-
Zinc protects iron / steel from rusting by forming a protective coating.
What is the molarity of solution containing urea in 500 cm3 of solution?
- 1.5 molar
- 2.0 molar
- 1 molar
- 0.5 molar
- c
Unit of rate constant k is:
- dm3M-1
- dm3M-1
- dm3M-1S-1
- M-1S-1
- d
-
The unit of rate constant k depends on the order of the reaction.