You're looking for important Chemistry questions for the 12th standard CET (Common Entrance Test) exam. Here are some key topics and questions:

Inorganic Chemistry

1. Periodic Table: Questions on periodic trends, electronegativity, and electron affinity.

2. Chemical Bonding: Questions on ionic, covalent, and metallic bonding.

3. Acids and Bases: Questions on Arrhenius, Bronsted-Lowry, and Lewis definitions.

Organic Chemistry

1. Hydrocarbons: Questions on alkanes, alkenes, alkynes, and aromatic hydrocarbons.

2. Functional Groups: Questions on identification, properties, and reactions of functional groups.

3. Reaction Mechanisms: Questions on substitution, elimination, and addition reactions.

Physical Chemistry

1. Thermodynamics: Questions on laws of thermodynamics, entropy, and Gibbs free energy.

2. Kinetics: Questions on rate of reaction, order of reaction, and catalysts.

3. Equilibrium: Questions on equilibrium constant, Le-Chatelier's principle, and acid-base equilibria.

Some sample questions:

- What is the electronic configuration of an atom with atomic number 17?

- Identify the type of bond formed between two atoms of different electronegativities.

- Write the balanced chemical equation for the reaction between sodium and water.

- What is the pH of a solution with a hydrogen ion concentration of 1 × 10^(-5) M?

Focus on practicing questions from these topics to improve your Chemistry skills for the CET exam.