SAT (Stage-1) Mock Test - 28

Hubble's law states that the rate at which astronomical objects in the universe move apart from each other is proportional to their distance from each other, i.e. v = H₀r.
The Hubble Constant H₀ is the unit of measurement used to describe the expansion of the universe.

Terrestrial planets are Earth-like planets, made up of rocks or metals with a hard surface — making them different from other planets that lack a solid surface. Terrestrial planets also have a molten heavy metal core, few moons, and topological features such as valleys, volcanoes and craters. There are four terrestrial planets in our solar system and they are the four closest to the sun Mercury, Venus, Earth and Mars.

The inner planets are small, dense and composed mostly of rocks, while the outer planets are composed mostly of gas, with no solid surfaces and only liquid cores.
The inner planets also have few or no moons and no rings circling them, while the outer planets often have dozens of satellites and rings composed of particles of ice and rock.

All decomposition processes are endothermic.
Hence, the decomposition of calcium carbonate is an endothermic reaction.
On the other hand burning of fuels is always exothermic.
Respiration is also an exothermic process and the energy released is stored in the form of A.T.P.

Soap is a sodium salt of stearic acid or palmitic acid.
Hardness of water is due to Ca⁺² and Mg⁺² ions present in water as these ions form insoluble salts with soap which is seen as a curdy white precipitae or scum that settles on clothes that are washed in hard water using soap.

Coal is formed by the decomposition of vegetation and trees that got buried under the layers of the earth during natural calamities such as earthquakes and over millions of years, under the geothermal conditions, they got converted into coal.
Therefore, coal is the fossil fuel that has to be mined from the earth.

For effective separation of the components of the mixture, the sequence of steps followed should be:
Step 1: Filtration, to separate the insoluble component sand from the remaining mixture.
Step 2: Separating funnel is used to separate kerosene which is immiscisible with alcohol and water.
Step 3: Fractional distillation is carried out to separate alcohol from water because they are miscible and their boiling points differ by 21.6K

Metals are extracted by reduction of their oxides.
The process of reduction by carbon is called smelting, and is carried out in a brick lined blast furnace which is made up of steel, so that it can withstand the pressure of the gaseous products formed.
For example: Fe₂O₃(s) + C → Fe(s) + CO(g)

Metals form oxides which are basic in nature and their solution will turn red litmus blue.

Latent heat of fusion of a substance is the amount of heat required to change the state of 1 kg of a substance from solid to liquid at its melting point at the atmospheric pressure.

Similarly, the latent heat of vapourization of a substance is the amount of heat required to change the state of 1 kg of a substance from liquid to vapour at its boiling point at the atmospheric pressure.