Chemistry - Online Test
Q1. Cement, the important building material is a mixture of oxides of several elements. Besides iron and sulphur, oxides of elements of which of the group (s) are present in the mixture?
Answer : Option B
Explaination / Solution:
Main Composition of Portland cement are: lime (CaO) (group 2), silica (SiO 2)(group 14) and alumina (Al 2O 3).(group 13)
Cement is a heavy powder of calcium aluminates and silicates
Q2. Dry ice is
Answer : Option A
Explaination / Solution:
Dry ice is solid CO2.
Solid CO2 sublimates. Thus it does not wet anything and called dry ice.
Q3. In trivalent state, for example, the trichlorides, being covalent are hydrolysed in water form
Answer : Option D
Explaination / Solution:
Trihalides hydrolysis to form tetrahedral structure with four covalent bonds.
Q4. Diamond is covalent, yet it has high melting point. because of
Answer : Option A
Explaination / Solution:
carbon atom undergoes Sp3 hybridization and linked to four other carbon atoms by using hybridized orbitals in tetrahedral fashion led a rigid three dimensional extended network thought the lattice.
Q5. The valence shell electronic configuration of p-block elements is ns2np1 - 6 But this is not true in the case of
Answer : Option A
Explaination / Solution:
As only one Ist period element of p-block, it has unique 1s2 configuration besides other element of that block (ns2np1 - 6) . It is a noble gas.
Q6. Which is most easily liquefiable rare gas?
Answer : Option A
Explaination / Solution:
Xe is most easily ( for atmospheric cool air ) liquefiable rare gas.
Q7. Me3SiCl is used during polymerisation of organo silicones because
Answer : Option B
Explaination / Solution:
the chain length of the polymers can be controlled by adding Me3SiCl which blocks the ends of the chain to produce silicone
Q8. Which of the following statements are correct?
Answer : Option C
Explaination / Solution:
Fullerence have cage like spheroidal molecular ( C60) structure and have no dangling bonds.
Q9. Regular use of which of the following fertilizers increases the acidity of the soil?
Answer : Option C
Explaination / Solution:
Ammonium sulphate addition increases acidity in the soil.
In the presence of water and oxygen in the soil, ammonium and sulfate are decomposed by naturally occurring microbes. During this process, acids are released into the soil, along with nitrogen and sulfur compounds.
Q10. The percentage of p-character in the orbitals forming P - P bonds in is
Answer : Option C
Explaination / Solution:
obitals forming P-P bond is hybridised therefore have 75% p character.
