Q2.Hydrogen is the first element in the periodic table and has resemblance to alkali metals as well as with halogens. However, its placement in the periodic table has been a subject of discussion in the past. Currently hydrogen is placed in which group?
Answer : Option AExplaination / Solution:
H properties matches with alkali metal as well as halogens so it is placed separately
Q6.The giant planets Jupiter and Saturn consist mostly of
Answer : Option BExplaination / Solution:
The name ‘gas giant’ was coined in 1952 by science fiction writer James Blish to refer to all the giant planets. The giant planets (Jupiter and Saturn) are huge gas balls, which is quite different than Earth and and other three rocky inner planets. Gas giants are primarily composed of gases, such as hydrogen and helium, and a much thicker layer of metallic hydrogen, along with a molten rocky core.
Unlike rocky planets, gas giants do not have a well-defined surface, and there is no clear boundary between where the atmosphere ends and the surface begins. In other words, you wouldn’t be able to land on these planets, as their atmospheres simply become gradually denser towards the core, perhaps with liquid or liquid-like states somewhere in between.
Answer : Option AExplaination / Solution:
Deuterium, (D, or 2H), also called heavy hydrogen, isotope of hydrogen with a nucleus consisting of one proton and one neutron, which is double the mass of the nucleus of ordinary hydrogen (one proton). Deuterium has an atomic weight of 2.014.
Q9.For the synthesis of methanol and a number of hydrocarbons , the compounds used are
Answer : Option BExplaination / Solution: A mixture of CO and H2 in any ratio is called synthesis gas or syn gas as it is used in synthesis of methanol and a number of hydrocarbon.
Q10.Dihydrogen reacts with dioxygen to form water. The reaction is.
Answer : Option DExplaination / Solution:
The formation of water from it's elements produces, in addition to water, a tremendous amount of energy, 572 kJ to be exact.
2H2 + O2→ 2H2O + ENERGY
This is an example of an exothermic reaction, a reaction that produces energy. It is also an example of what is called a combustion reaction, where a substance (in this case hydrogen gas) is combined with oxygen
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