Hydrogen - Online Test
Q1. Dihydrogen is used in fuel cells for generating electrical energy because
Answer : Option C
Explaination / Solution:
The fuel cell was invented in 1839 by Welsh lawyer Sir William Robert Grove. It takes in Hydrogen and Oxygen from the air and puts out electricity, heat, and water. It doesn't use fossil fuels and it doesn't produce greenhouse gases and so it should be the ideal solution to providing distributed or portable electrical power.
Q2. Dihydrogen under certain reaction conditions, combines with almost all elements to form binary compounds, called hydrides except with few which are given below Choose one of the options
Answer : Option D
Explaination / Solution:
Noble gases are inert and have high ionisation enthalpy. Hence, they do not form any hydrides.
Q3. hydrogen compounds of non-metals are volatile compounds because
Answer : Option C
Explaination / Solution:
Covalent hydrides :They are formed when hydrogen molecule reacts with the p block elements. The most common examples, in this case, are CH4 and NH3. The hydrogen compounds formed with non-metals are also called hydrides. They are covalent and volatile compounds.
Q4. Most of the s-block elements form dihydrogen compounds which are:
Answer : Option B
Explaination / Solution:
Ionic hydrides are formed when hydrogen molecule reacts with most s-block elements which are highly electropositive in nature.
In solid state, the ionic hydrides are crystalline, non-conducting and non-volatile.
However, in liquid state it conducts electricity. Ionic hydrides on electrolysis liberate hydrogen gas at the anode.
Q5. The ionic hydrides are crystalline, non-volatile but on melting does one of the following:
Answer : Option C
Explaination / Solution:
They are formed when hydrogen molecule reacts with most s-block elements which are highly electropositive in nature. In solid state, the ionic hydrides are crystalline, non-conducting and non-volatile.
However, in liquid state it conducts electricity. Ionic hydrides on electrolysis liberate hydrogen gas at the anode.
Q6.
Diborane is one of the following
Answer : Option A
Explaination / Solution:
Diborane is said to be electron deficient because boron require 5 electrons to complete its octet. But in this molecule, each boron atom is bonded to 2 terminal hydrogen atoms each. Also, the two boron atoms are held together by two hydrogen atoms as shown below:
Q7. Ammonia(
Answer : Option B
Explaination / Solution:
Dihydrogen under certain reaction conditions combines with almost all elements except noble gases to form compounds called hydrides. Electron –rich hydrides, as the name suggest, are compounds of hydrogen with other elements that have excess electrons present as lone-pairs.
For example ammonia –NH3 is a hydride of nitrogen that has one lone pair, water (H2O) is a hydride of oxygen that has two lone pairs etc. As these are electron rich species, they can donate electrons that is they are lewis bases.
Q8. Many d-block and f-block elements form
Answer : Option B
Explaination / Solution:
Hydrides are formed by many d-block and f-block elements when heated with hydrogen under pressure. The hydrides tend to be non-stoichiometric and they may be of variable composition.These hydrides have properties similar to those of parent metal and hence are known as metallic hydride.
Q9. Metal hydrides are used for hydrogen storage because
Answer : Option B
Explaination / Solution:
Metal hydrides (MHx) are the most technologically relevant class of hydrogen storage materials because they can be used in a range of applications including neutron moderation,electrochemical cycling, thermal storage, heat pumps, and purification/separation.
The metal hydrides such as intermetallic alloys and solid solutions have interstitial vacancies where atomic hydrogen is absorbed via an exothermic reaction; however, by endothermic path, the metal hydride desorbs the hydrogen reversibly at ambient to moderate temperatures.
Q10. Presence of extensive hydrogen bonding between water molecules is responsible for
Answer : Option A
Explaination / Solution:
hydrogen bonding is responsible for liquid and solid states.
