One Liner Mcqs of Chemistry

Here you will find the most frequent questions of Chemistry which are asked in competitive exams. Moreover, This is smart study series keeping in view the importance of time.

However you don’t have to look for the options. You have to just read the most frequent questions and the answer is provided in it. whereby you know the answer within short span of time.

However, this will save a lot of your time. Moreover, At the end of every question you will see abbreviations like FPSC, PPSC, SPSC, NTS, STS, PTS, and OTS. This means that this question has occured/repeated in these competitive exams.

These MCqs of competitive exam is the result of research, experience and hardwork. Thus we have developed the content for you from being complex to being simple.

The Most Frequent One Liner Mcqs Of Chemistry 

1. 1. Neutron, electron and Proton have neutral, negative positive charges respectively.
   2. The unchanged particle in atom we call it Neutron. (STS, FPSC,NTS)
   3. The lightest particle of the matter is Electron (SPSC, STS, PPSC) 
   4. In a reactor, cadmium rods are used for absorbing Neutrons. Beta rays have negative charge X-rays
   5. The particle with positive charge but having mass equal to that of electron we call it Positron. (FPSC, PPSC,SPSC STS,PTS)
   6. Fire extinguisher is CO2. Dry ice is CO2. (FPSC, SPSC, PPSC)
   7. poisonous gas is contained in the exhaust fumes from cars is carbon monoxide. The most toxic is carbon-mono-oxide (CO)  (SPSC STS,FPSC,PPSC)
   8. Air contains volume of carbon dioxide approximately 0.03%. (SPSC, STS, PPSC)
   9. Air contains 0.4% of Water Vapour. Air contains 0.03% of CO2. Nitrogen is 78% of atmosphere. The volume percentage of nitrogen in air is 78%. The atmosphere has the highest percentage of Nitrogen (PPSC,SPSC)
   10. Air is present in the atmosphere of earth up to the height of 200 kilometres (FPSC,STS)
   11. Hydrogen is the lightest gas. Lightest gas is hydrogen. Highly inflammable is Hydrogen the sun is mainly composed of Hydrogen (FPSC,STS,NTS)
   12. Heavy water consists of Oxygen and heavy hydrogen (STS, PTS, OTS)
   13.  The chemical name of heavy water is – Deuterium oxide (NTS,STS, OTS)
   14. Heavy water does not produce lather with soap. Soft water produces lather with soap. Caustic soda is extenstively used for making Soap. (STS, PTS, OTS)
   15. Water is a universal solvent for Biochemical Reactions. (FPSC,NTS,STS)
   16. The gas which is maximum in the earth sky is Oxygen. Present in the largest amount in terms of percent by mass in the earth’s crust is Oxygen. (FPSC,NTS,STS)
   17. Oxygen by volume has pressure in the atmosphere is about 21%.(FPSC, SPSC, PPSC) 
   18. In the composition of Earth oxygen is approximately 46%. (SPSC, STS, PPSC)
   19. Oxygen by volume has presence in the atmosphere is 21% and earth crust is 46%.
   20. In 1774 oxygen was discovered by priestly.(FPSC,NTS,STS)
   21. Sea divers use a mixture of gases for breathing during diving.The gases which drivers use as an artificial atmosphere are helium and oxygen. The mixture is 80% He & 20% O2 (FPSC,NTS,STS)
   22. Simplest element is Hydrogen. Huge white ball in the sun almost consists of Hydrogen. The most abundant element in the universe is Hydrogen. – Helium is 26% of the sun mass. (FPSC, SPSC, PPSC)
   23. The second most abundant element in the earth’s crust is silicon. (FPSC, SPSC, PPSC)
   24. Silicon is the semiconductor. The element required for solar energy conversion is silicon. (SPSC, STS, PPSC)
   25. The greatest number of compounds is formed by the element of carbon. (PPSC,SPSC)
   26. The gas is used in the preparation of soft drinks is Carbon dioxide. The gas which acts as a glass of greenhouse is Carbon dioxide. (STS, FPSC,NTS) 
   27. The gas which is used in refrigeration is Ammonia. (FPSC, STS, PTS) 
   28. Diamond is an allotropic form of the element Carbon. Diamond is the purest naturally occurring crystalline from of carbon. (FPSC, STS, PTS)
   29. Diamond is the hardest material. The glitter of diamond is owing to its quality of reflecting light. (FPSC, SPSC, PPSC) 
   30. Boiling point of water is 100°C.  Water contracts if it is heated from 0°C to 4°C. Chlorine gas is used to kill bacteria. (FPSC, PPSC,SPSC STS,PTS)
   31. Muslim Scientists who is credited with discovery of sulphuric Acid, Nitric Acid and HCI is Jabir Bin Hiyan.
   32. The constituent elements of Brass are Copper and Zinc. Bronze is an alloy of Copper and Tin. (FPSC, SPSC, PPSC)
   33. The constituent elements of Bronze are Tin and Copper. Bronze is made up of Copper and Tin. In Pakistan copper is found in Saindak. The worlds largest cooper producer is Chile. (SPSC,PPSC,FPSC) 
   34. Stainless steel is an alloy of zinc and nickel. Stainless steel is an alloy of iron, Chromium and Nickel. Steel is the most elastic
   35. The German or nickel silver is composed of approximately 60% copper 20% nickel and 20% zinc. (SPSC, STS, PPSC)
   36. Rain water dissolves Sulphur dioxide to from Sulphuric Acid. Acid rain contains high levels of Sulphuric acid. Excessive burning of the fossil fuels causes acid rains.  (PPSC,SPSC)
   37. Jabir bin hayat prepared Sulphuric Acid. The major fossil fuel impurity is Sulphur. (FPSC, SPSC, STS)
   38. The composition of the mixture used for welding is Copper Oxide and Aluminium
   39. Iron corrodes due to the formation of Iron Oxide. Chromite ore contains chromium oxide. (NTS,STS, OTS)
   40. Vanadium, a steel gray corrosion resistant metal occur naturally in oxide state
   41. The process of conversion of a material from solid state directly to gaseous state is – Sublimation. (STS, PTS, OTS)
   42. In order to prevent the corrosion of iron pipes they are often coated with a layer of zinc. This process is Galvanization. (FPSC, STS, PTS)
   43. Cooking oil can be converted into vegetable ghee by” process of Hydrogenation (NTS)
   44. Odour (smell) is a component of the cooking gas it is natural. (NTS,STS, OTS)
   45. The Process of change from liquid to gas is evaporation. (STS, FPSC,NTS)
   46. The process of change from vapour to liquid is condensation.(FPSC,STS,NTS)
   47. Sublimation is process from solid to gaseous state. (STS, PTS, OTS)
   48. Quartz is chemically a Silicate or Silicon dioxide. The chemical name of washing soda is Bicarbonate Sodium. (FPSC, SPSC, PPSC)
   49. Chemical name of gyupsum is calcium Sulphate. Gypsum is hydrated calcium sulphate. Plaster of Paris is calcium sulphate. (FPSC, SPSC, PPSC) 
   50. Deuterium oxide is the chemical name of heavy water. (OTS, FPSC,PTS)