HSC Science (Computer Science) 12th Standard Board Exam - Maharashtra State Board Question Bank Solutions for Chemistry

Calculate ∆H° for the following reaction:

2H₃BO_3(aq) → B2O_3(s) + 3H₂O_(l)

a) H₃BO_3(aq) → HBO_2(aq) + H₂O_(l) , ∆`H_1^@` = − 0.02 kJ

b) H₂B₄O_7(s) → 2B₂O_3(s) + H₂O_(l) , ∆`H_2^@` = 17.3 kJ

c)H₂B₄O_7(s) + H₂O_(l) → 4HBO_2(aq), ∆`H_3^@` = − 11.58 kJ

What are Frenkel defect

Write electronic configuration and two uses of neon. (Z = 10)

Draw a neat, labelled energy profile diagram for SN¹ reaction mechanism.

What is the action of concentrated sulphuric acid on copper

What is the action of concentrated sulphuric acid on potassium chlorate?

Write the electronic configuration of the following element:

Krypton (Z = 36)

Which of the following 0.1 M aqueous solutions will exert the highest osmotic pressure?

Derive the relation between the elevation of boiling point and molar mass of solute.

Define Semipermeable membrane

Explain the geometry of `[Co(NH_3)_6]^(3+)` on the basis of hybridisation. (Z of Co = 27)

Write chemical reactions for different steps in the manufacture of sulphuric acid by lead chamber process. Draw the structure of phosphorous pentachloride

Calculate the work done in the following reaction at 50°C. State whether work is done on the system or by the system.
`"SO"_2("g") + 1/2"O"_(2("g")) rightarrow "SO"_(3("g"))`

Define the following term:
isotonic solution

Define the following term:

Hypotonic solution

Write chemical equation for the following :
Hell - Vohlard - Zelinsky reaction

Write structure and molecular formula for the following compounds:
a. Orthophosphoric acid 
b. Sulphurous acid

What are racemates?

Write the formula for pentaamminechlorocobalt (III) sulphate. 

Choose the most correct option.

In calculating osmotic pressure the concentration of solute is expressed in _______.