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.
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 has highest second ionization energy?
Ni
V
Cr
Mn
C.
Cr
Electronic configuration for chromium is :
24Cr 1s2 2s2 2p6 3s2 3p6 3d5 4s1
After ionisation of 4s electron the next electron which will be ionised is from 3d orbital. As 3d5 electronic configuration, is stable, hence, the second ionisation of Cr will require much greater ionisation energy than the expected one.