Why Kaysons ?

Video lectures

Access over 500+ hours of video lectures 24*7, covering complete syllabus for JEE preparation.

Online Support

Practice over 30000+ questions starting from basic level to JEE advance level.

Live Doubt Clearing Session

Ask your doubts live everyday Join our live doubt clearing session conducted by our experts.

National Mock Tests

Give tests to analyze your progress and evaluate where you stand in terms of your JEE preparation.

Organized Learning

Proper planning to complete syllabus is the key to get a decent rank in JEE.

Test Series/Daily assignments

Give tests to analyze your progress and evaluate where you stand in terms of your JEE preparation.

SPEAK TO COUNSELLOR ? CLICK HERE

d & f block

  • 1
  • 2
  • 3
  • 4

Q.

 is an amphoteric oxide and in acidic medium it forms

Q.

The number of moles of  reduced by one mole of KI in alkaline medium is

Q.

In context with the transition elements, which of the following statements is incorrect?

Q.

In dilute alkaline solution  changes to

Q. Which oxide of manganese is amphoteric?

MnO2 forms amphoteric oxide due to intermediate oxidation state.

Q. Across the lanthanide series, the basicity of lanthanide hydroxides will?

Basicity of lanthanide hydroxides decreases along the lanthanides series from left to right.
On moving from left to right in the lanthanoid series, size of the elements decreases thereby increasing the polarising power of the cation and hence the basicity of lanthanoid hydroxides decreases.

Q. Railway wagon axles are made by heating rods of iron embedded in charcoal powder. The process is known as?

The process of hardening the surface of wrought iron by depositing a surface layer of steel on it is called case-hardening. It is done by heating wrought iron in contact with potassium ferrocyanide.
Alternatively, case hardening can also be done by heating wrought iron with charcoal and then plunging it in a suitable oil.

Q. The oxide formed in the maximum oxidation state is ZrOx in which value of x is?

2
Hence the compound is ZrO2

Q. IE1 of Zn is less than Cu this is right ?

IE1 of Cu (3d10 4s1) is less than that of Zn (3d10 4s2) because it is easy to remove an electron from a half-filled s-orbital as compared to fully-filled s-orbital. However, in case of IE1, the electron is lost from 3d orbital of Cu and 4s orbital of Zn and loss of electron from 4s orbital is easier as compared to fully-filled 3d orbital.