Lanthanides and actinides are also called :
short periods
inner-transition elements
long periods
main transition elements
Assertion : Fe3+ can be used for coagulation of As2S3 sol.
Reason : Fe3+ reacts with As2S3 to give Fe2S3.
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 : 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.
C.
If assertion is true but reason is false
Potassium dichromate (K2Cr2O7) is preferred over sodium dichromate in volumetric analysis, because K2Cr2O7 is hygroscopic in nature and, therefore, accurate weighing is not possible in normal atmospheric conditions. A hygroscopic substance absorbs moisture from the atmosphere and this could lead to inaccuracies in weight.
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.