NCERT Class 12 Chemistry

Isoenzymes are the different enzymes that catalyse the same biochemical reaction. However, they differ in amino acid composition and kinetic properties. Examples of isoenzymes are hexokinase and lactate dehydrogenase. 

Students should prepare complete syllabus when they have time to prepare. However, you can use the list of highweightage chapters in last minute revision for scoring well.

• The p-Block Elements: This chapter holds a high weightage of 8–10 marks. (in the latest syllabus this is deleted)

• Aldehydes, Ketones, and Carboxylic Acids: This chapter contributes around 8–10 marks.

• Biomolecules: This chapter accounts for around 8 marks.

• Chemical Kinetics: This chapter holds a high weightage of 5-6 marks. 

• The d- and f-Block Elements: This chapter contributes around 5-6 marks.

• Amines: This chapter contributes around 5-6 marks.

Be₂Cl₄ is Lewis acid and Al₂Cl₆ has complete octet. Be and Al are amphoteric metal therefore dissolve in acid as well as alkaline solution and form beryllate and aluminate ions in excess alkali.

$O_2,C{u}^{2+}andF{e}^{3+}$

are paramagnetic

$$ $\therefore$  Weakly attracted by magnetic field

NaCl and H2O are diamagnetic

$$ $\therefore$  Weakly repelled by magnetic field.

This is a Fill in the blanks Type Question as classified in NCERT Exemplar

Ans: Correct option A

Activation Energy → The amount of energy required to overcome the obstacle and generate a product

The activation energy of a forward reaction can be seen in the [E_af = E₁ + E₂] (This is an endothermic reaction.

Therefore, [E_af > E_ab]   

The energy of the product is high, while the energy of the reactant is low.

The lower the energy, the more stable and positive the situation becomes.

Δ? = posistive