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

What are Ellingham's diagrams? Write 2 features of it.

What are neutral oxides?

Explain the nature of zinc oxide with the help of the reactions.

Absolute entropies of solids, liquids and gases can be determined by

• Measuring heat capacity of substance at various temperatures
• Subtracting standard entropy of reactants from products
• Measuring vibrational motion of molecules
• Using formula ΔS° = S_T° - S_O°

 How is propene converted into 1- bromopropane and 2 - bromopropane?

The preparation of alkyl fluoride from alkyl chloride, in presence of metallic fluorides is known as ______________.

Draw neat and labelled diagram of dry cell.

Determine whether the reactions with the following ΔH and ΔS values are spontaneous or non-spontaneous. State whether the reactions are exothermic or endothermic.

(a) ΔH = -110kJ, ΔS = + 40JK^-1 at 400 K

(b) ΔH = + 40kJ, ΔS = -120JK^-1 at 250K

Sucrose decomposes in acid solution into glucose and fructose according to the first order rate law with `t_(1/2)` = 3 hours. What fraction of the sample of sucrose remains after 8 hours?

Niobium crystallises as body centred cube (BCC) and has density of 8.55 Kg / dm^-3 . Calculate the attomic radius of niobium.

(Given : Atomic mass of niobium = 93).

What is the geometry of chromate ion?

1. Tetrahedral                    
2. Octahedral
3. Trigonal planer              
4. Linear

Identify the strongest acid amongst the followings:

1. Chloroacetic acid          
2. Acetic acid
3. Trichloroacetic acid
4. Dichloroaceticacid

Write a note on Friedel Craft’s acylation.

Explain, why are boiling points of carboxylic acids higher than corresponding alcohols

Write ‘four’ uses of hydrochloric acid.

What is the molecular formula of chromyl chloride?

(A) CrO₂Cl₂

(B) CrOCl₂

(C) CrCl₃

(D) Cr₂OCl₂

What is the action of acidified potassium dichromate on - SO₂

Draw structure of dichromate ion

Classify the following ligands into monodentate and polydentate —

1. Ammonia
2. Carbon monoxide
3. Ethylene diamine
4. Ethylene diamine tetra acetate ion

Write the structure and IUPAC names of all the metamers represented by formula C₄H₁₀