Download App

The d & f Block Elements — Chemistry STD 12 Science — Question

Gujarat BoardEnglish MediumSTD 12 ScienceChemistryThe d & f Block Elements5 Marks
Question
  1. Give three points of difference between lanthanoids and actinoids.
  2. Give reason and select one atom/ion which will exhibit asked property:
  1. $Sc^{3+}$ or $Cr^{3+}​​​​​​​$ (Exhibit diamagnetic behaviour).
  2. $Cr$ or $Cu$ (High melting and boiling point).
✓

Answer

  1.  
S. No.
Lanthanoids
Actinoids
1.
Most of them are not radioactive.
All are radioactive.
2.
Don’t show a wide range of oxidation state.
Show a wide range of oxidation states.
3.
Most of their ions are colourless.
Most of their ions are coloured.
  1.  
  1. $Sc^{+3}$, because of absence of unpaired electron.
  2. Cr, because of presence of strong intermetallic bonding than Cu.

Need a full question paper?

Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.

Start Generating Free

Explore more

More "5 Marks Questions" from The d & f Block Elements→The d & f Block Elements — all question types→Chemistry STD 12 Science question papers→Gujarat Board STD 12 Science question papers→Gujarat Board question paper generator→

Similar questions

Attempt any five of the following:
(a) What is the structural feature characterising reducing sugars?
(b) What type of linkage is present in polysaccharides?
(c) Give examples of fat soluble vitamins.
(d) The two strands in DNA are not identical but are complementary. Explain.
(e) Write uses of B-Complex.
(f) Name the disaccharide which on hydrolysis gives two molecules of glucose.
(g) Name purines present in DNA?
→
Explain different types of isomerism in amines.
→
Answer the following question:
$g$ of benzoic acid $(C_6H_5COOH)$ dissolved in $25g$ of benzene shows a depression in freezing point equal to $1.62K.$ Molal depression constant for benzene is $4.9K\ kg\ mol^{-1}$. What is the percentage association of acid if it forms dimer in solution?
→
Explain the cyclic structure of glucose.
→
  1. Which allotrope of phosphorus is more reactive and why?
  2. How the supersonic jet aeroplanes are responsible for the depletion of ozone layers?
  3. $F_2$ has lower bond dissociation enthalpy than $Cl_2$. Why?
  4. Which noble gas is used in filling balloons for meteorological observations?
  5. Complete the equation:
$XeF_2 + PF_5$ $\xrightarrow{\text{ }\text{ }\text{ }\text{ }\text{ }\text{ }\text{ }\text{ }\text{ }\text{ }\text{ }\text{ }\text{ }\text{ }\text{ }\text{ }\text{ }\text{ }\text{ }\text{ }\text{ }\text{ }\text{ }}$
→
What happens to most probable kinetic energy and the energy of activation with increase in temperature?
→
Match the items of Column I with items of Column II and assign the correct code:
 
Column I
 
Column II
(A)
Coloured bands
(1)
Zone refining
(B)
LImpure matal to volatie complex
(2)
Fractional distillation
(C)
Purification of Ge and Si
(3)
Mond process
(D)
Purification of mercury
(4)
Chromatophy
 
 
(5)
Liquation
  1. A (1) B (2) C (4) D (5)
  2. A (4) B (3) C (1) D (2)
  3. A (3) B (4) C (2) D (1)
  4. A (5) B (4) C (3) D (2)
→
(a) What is reverse osmosis? How is water purified through it? Explain.
(b) Write the applications of osmosis.
→
Explain primary, secondary and tertiary structure of proteins with diagram.
→
Answer the following question:
When conc. H2SO4 was added into an unknown salt present in a test tube, a brown gas (A) was evolved. This gas intensified when copper turnings were also added into this test tube. On cooling, the gas (A) changed into a colourless gas (B).
  1. Identify the gases A and B.
  2. Write the equations for the reactions involved.
→