Chemistry MCQs

Notes:
Methanol (CH₃OH) is also known as Wood Alcohol. It’s a solvent in many chemical processes and is a component of automobile antifreeze.

Notes:
Zinc sulfate is the inorganic compound with the formula ZnSO4 and historically known as “white vitriol” Zinc sulfate is an inorganic compound and dietary supplement.

Notes:
Platinum is a naturally white metal. It doses not need to be alloyed for color. Due to its appearance as white, it is commonly known as White Gold.

Notes:
Tetra Ethyl Lead (TEL) is one such component that is added to petrol to reduce its tendency to `ping’ under compression. TEL breaks down to lead at upper cylinder temperatures. Lead atoms spread around and combining with the free radicals and slowing down the reaction.
However, `Leaded’ petrol was a grave danger to the environment, as lead is a poison when it is absorbed into the body.

Notes:
Nitrolim is a type of fertilizer that was widely used in the past. The main components of Nitrolim are calcium carbide and nitrogen. Calcium carbide reacts with nitrogen to form calcium cyanamide, which is an active ingredient in Nitrolim. This fertilizer is significant as it helps in fixing nitrogen in the soil thereby promoting plant growth.

Notes:
In 17 carat gold, the composition is 17 parts gold and 7 parts other metals, making it 70.6% gold. The term “carat” refers to the purity of gold, with 24 carats being pure gold. Thus, 17 carat gold contains 7 parts of other metals, which can include copper, silver, or palladium, used to enhance durability and alter color.

Notes:
The adsorption of hydrogen by palladium is called occlusion. Occlusion is a type of adsorption where gases are adsorbed onto metals. The hydrogen adsorbed onto palladium is called occluded hydrogen.
Palladium can absorb about 900 times its own volume of hydrogen. The hydrogen that is adsorbed is more active than normal hydrogen.
The adsorption of hydrogen on palladium occurs through a hydride formation. The chemical bonds that are formed cannot be broken easily to release the hydrogen gas from the surface of the metal.
The process of occlusion is used to purify hydrogen.

Notes:
Raoult’s law states that the partial vapour pressure of each component of an ideal mixture of liquids is equal to the vapour pressure of the pure component multiplied by its mole fraction in the mixture.

Notes:
All ores are minerals but all minerals are not ores. Minerals are the native form in which various metals exist and ores are those minerals which are used to extract metals economically.

Notes:
Hydraulic Washing is a method used for concentration of ores. It is a type of gravity separation as it is based on the differences in gravities of the ore and the gangue particles.