Assertion : K2Cr2O7 is used as primary standard in volumetric analysis.
Reason : It has a good solubility in water.
If both assertion and reason are true and reason is the correct explanation of assertion.
If both assertion and reason are true but reason is not the correct explanation of assertion.
If assertion is true but reason is false
If both assertion and reason are false.
Assertion: Chemistry of actinoids is more complicated than lanthanoids.
Reason: Actinoid elements are radioactive.
If both assertion and reason are true and reason is the correct explanation of assertion.
If both assertion and reason are true but reason is not the correct explanation of assertion.
If assertion is true but reason is false.
If both assertion and reason are false.
Which belongs to the actinide series ?
Ce
Cf
Ca
Cs
B.
Cf
The fourteen elements which follow actinium from thorium (Z = 90) to lawrencium (Z = 103) are called actinoids .They involve the filling of 5f -subshell .Californium (Cf) has the atomic number 98 and its configuration is as
Cf (Z =98) : [Rn]5f10 , 6d0 , 7s2
Hence , it is a member of actinide series .
The group of elements in which the differentiating electrons enters in the antepenultimate shell of atoms are called :
f - block elements
p - block elements
s - block elements
d - block elements
When calomel is treated with ammonium hydroxide, a black substance is formed. The black substance is
Hg + HgO
HgO.HgCl2
H2N-Hg-Cl+Hg
Hg(NH2)2 + HgO
Assertion : Ce4+ is used as an oxidising agent in volumetric analysis.
Reason : Ce4+has the tendency of attaining + 3 oxidation state
If both assertion and reason are true and reason is the correct explanation of assertion.
If both assertion and reason are true but reason is not the correct explanation of assertion.
If assertion is true but reason is false.
If both assertion and reason are false.