CBSE
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 the assertion.
If both assertion and reason are true but reason is not the correct explanation of the assertion.
If assertion is true, but reason is false.
Both assertion and reason are false statements.
Assertion : Change in colour of acidic solution of potassium dichromate by breath is used to test drunk driver.
Reason : Change in colour is due to the complexation of alcohol with potassium di chromate.
If both assertion and reason are true and reason is the correct explanation of the assertion.
If both assertion and reason are true but reason is not the correct explanation of the assertion.
If assertion is true, but reason is false.
Both assertion and reason are false statements.
Assertion : SiF62- is known but SiCl62- is not.
Reason : Size of fluorine is small and its lone pair of electrons interacts with d-orbitals of Si strongly.
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.
Transition metals are related to which block ?
's' block
'p' block
'd' block
none of these
The general electronic configuration of transition elements, is :
(n-1)d1-5 ns0
(n-1)d1-10 ns1
(n-1)d1-10 ns2
(n-1)d1-10 ns1-2
Which of the following element does not show variable valency ?
Ni
Zn
Cu
Mn
For decolourization of 1 mole of KMnO4, the moles of H2O2 required is
1/2
3/2
5/2
7/2
Lanthanide for which +II and +III oxidation states are common is
La
Nd
Ce
Eu
The compound used for gravimetric estimation of copper(II) is
Cu2(SCN)2
Cu2O
Cu2I2
Cu2CO3
Which of the following has highest second ionization energy?
Ni
V
Cr
Mn