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

What is the action of nitrous acid on primary nitroalkane?

Write the reactions involved in the preparation of Teflon.

The atomicity of sulphur in orthorhombic sulphur is______________ .

(a) 8                                

(b) 6                                 

(c)  4                                

(d)  2

Sucrose decomposes in acid solution to give glucose and fructose according to the first order rate law. The half life of the reaction is 3 hours. Calculate fraction of sucrose which will remain after 8 hours.

Define Cryoscopic constant.

Draw the structure of: Orthophosphoric acid 

Describe laboratory method for preparation of glucose.

State and explain Markownikoff's rule with suitable example

For a first order reaction, show that time required for 99% completion is twice the time required for the completion of 90% of reaction.

 A first order reaction takes 40 minutes for 30% decomposition. Calculate t_1/2 for this reaction. (Given log 1.428 = 0.1548)

In body centred cubic structure the space occupied is about

(A) 68%                                                     (B) 53%

(C) 38%                                                     (D) 32%

Which of the following solutions shows maximum depression in freezing point?

(A) 0.5 M Li₂SQ₄

(B) 1 M NaCl

(C) 0.5 M A1₂(SO₄)₃

(D) 0.5 MBaC1₂

Draw structure and write geometry of PCl₃ and PCl_5.

Prove that ΔH=ΔU+ΔnRT. what is the condition under which ΔU=ΔH?

Prove that ΔH=ΔU+ΔnRT. what is the condition under which ΔU=ΔH?

How is 4-methylpent-3-en-2-one obtained from propan-2-one?

Write the structural formula and IUPAC names of all possible isomers of the compound with molecular formula C₃H₈O.

Calculate the amount of CaCl₂ (molar mass = 111 g mol⁻¹) which must be added to 500 g of water to lower its freezing point by 2 K, assuming CaCl₂ is completely dissociated. (K_f for water = 1.86 K kg mol⁻¹)

A first order reaction takes 23.1 minutes for 50% completion. Calculate the time required for 75% completion of this reaction.

(log 2 = 0.301, log 3 = 0.4771, log 4 = 0.6021)

Calculate the freezing point of solution when 1.9 g of MgCl₂ (M = 95 g mol⁻¹) was dissolved in 50 g of water, assuming MgCl₂ undergoes complete ionization.

(K_f for water = 1.86 K kg mol⁻¹)