GK INFOPEDIA

[1] Solder is an alloy of – A. lead, zinc B. copper, lead C. tin, lead D. sodium, lead Ans: tin, lead Explanation : Tin/lead solders, also called soft solders, are commercially available with tin concentrations between 5% and 70% by weight. The greater the tin concentration, the greater the solder’s tensile and shear strengths. […]

[1] Photo chemical smog is a resultant of the reaction among – A. High concentration of NO2, O3, and CO in the evening B. CO, CO2 and NO2 at low temperature C. CO, O2 and peroxy acetyl nitrate in the presence of Sunlight D. NO2, O3 and peroxy acetyl nitrate in the presence of Sunlight […]

[1] Methanol cannot be dried with anhydrous CaCl2 because – A. CaCl2 dissolves in it B. it is not good dehydrating agent C. it forms a solid CaCl2 × 4CH3OH D. it reacts with CH3OH Ans: it forms a solid CaCl2 × 4CH3OH Explanation : 0 [2] Acid rain is caused by the pollution of […]

[1] Wood Spirit is which of the following? A. Ethyl Alcohol B. Propanol C. Methyl Alcohol D. Butanol Ans: Methyl Alcohol Explanation : Methanol is also known as methyl alcohol, wood alcohol, wood naphtha or wood spirits. It acquired the name “wood alcohol” because it was once produced chiefly as a byproduct of the destructive […]

[1] Glass is mainly composed of – A. Sodium silicate B. Calcium carbonate C. Calcium hydroxide D. Sodium bicarbonate Ans: Sodium silicate Explanation : The main constituent of glass is silica ans calcium carbonate is additionally used to give stability and consistency where limestone is added to act as stabilizer and to increase the hardness. […]

[1] When lime juice is dropped on baking soda, brisk effervescence takes place because the gas evolved is – A. Hydrogen B. Oxygen C. Carbon dioxide D. All of them Ans: Carbon dioxide Explanation : When baking soda and lemon juice are added together, the reaction of the two is an acid-based reaction because it […]

[1] Which of the following is a super-cooled liquid? A. Ice-cream B. Ammonia C. Glass D. Wood Ans: Glass Explanation : Most of us think as glass as a solid material, but it is actually a super cooled liquid. Molecular units have a disordered arrangement yet still have sufficient cohesion that mechanical rigidity is produced. […]

[1] Acids generate: A. Acids generate hydrogen ions. B. Bases generate hydroxide ions. C. Both are correct D. Both are incorrect Ans: Both are correct Explanation : Acids, in presence of water, give hydrogen ions (H+). Similarly, bases generate hydroxide (OH-) ions in water. [2] Which one of the following is not a characteristic feature […]

[1] Milk is a colloidal system in which: A. Water is dispersed in fat B. Fat is dispersed in water C. Fat and water are dispersed in each other D. Fat is dissolved Ans: Fat is dispersed in water Explanation : A colloid is a substance microscopically dispersed evenly throughout another substance. A colloidal system […]

[1] An electric iron has a heating element made of – A. Copper B. Tungsten C. Nichrome D. Zinc Ans: Nichrome Explanation : Nichrome is used in electric iron because it has high resistance and it is stable in air when hot. Nichrome wire forms a protective layer of chromium oxide. Chemically it is quite […]