- 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.
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 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.
Galvanic cell which cannot be recharge are called:
- Secondary cell
- Diffuse cell
- Tertiary cell
- Primary cell
- d
-
Primary cell in not rechargeable. It is also called Galvanic cell.
Secondary cell is rechargeable. It is also known as Accumulator.
Distillation under reduced pressure:
- Steam distillation
- Fraction distillation
- Destructive distillation
- Vacuum distillation
- d
-
مثال کے طور پر جب ہم پانی کو اُبالتے ہیں تو پانی 100 سینٹی گریڈ پر اُبلتا ہے۔
پانی کے اُبلنے کے دوران پانی پر ہوا کا دباؤ / پریشر ہوتا ہے۔اگر ہم پانی کے اوپر سے ہوا کے دباؤ کو ویکیوم پمپ کی مدد سے کم کر دیں تو یہی پانی 100 سینٹی گریڈ کی بجائے کم درجہ حرارت پر بھی آسانی سے اُبل سکے گا
Example of salt of strong acid and weak base is:
- Na2CO3
- NaCl
- NH4Cl
- KCl
- a
-
In Na₂CO₃, NaOH is strong base and H₂CO₃ is weak acid.
In NaCl, Na is strong acid and Cl is strong base.
In NH₄Cl, HCl is strong acid and NH₄OH is weak base.
In KCl, K is strong acid and Cl is strong base.
Select a pair of compounds which are isomorphic in nature.
- NaCl and ZnO
- NaCl and MgO
- KNO3 and MgO
- ZnO and CaCO3
- b
-
Isomorphous compounds are those that have the same crystal structure.
NaCl is chemical formula of Sodium Chloride.
MgO is chemical formula of Magnesium Oxide.