XII Chemistry

SECTION “A” – (MCQs – Multiple Choice Questions)

Q.1. Choose the correct answers. (15 Marks)

i. Ordinary hydrogen is unique in not having ________

• Neutron
• Proton
• Electron
• Atomic Number

ii. The Structure of hydrogen sulphide is ________

• Tetrahedra
• Dihedra
• Traihedra
• All

iii. Riboflayin is vitamin?

• B₁
• B₂
• B₃
• B₄

iv. Bakelite is a polymer of phenol and ________.

• Ethenal
• Methand
• Beutail
• Venyl chloride

v. A dipolar charge but an overall neutral-ion is called

• Zwi Herions
• Neo Panteane
• Picric Acid
• None of them

vi. The refractive index of diamond is

• 1.2
• 1.3
• 1.4
• 1.5

vii. Energy of tg orbitals in ________ than that of orbital

• Smaller
• Larger
• Invisible
• None of them

viii. The angle between H-S-H is H₂S molecule is

• 92.2°
• 102.3°
• 89.3°
• 72.4°

ix. Graphite conduct electricity due to delocealized ________.

• p electron
• a paetide
• b pontide
• g particle

x. The general formula of alkene is

• CnH₂n₊₂
• CnH₂n
• CnH₂n₋₂
• CnH₂n₊₁

xi. The general formula for aledehyde is

• R -OH
• -COOH
• RCOR
• R-CHO

xii. It is not a nucleophile

• OH
• NH
• BF
• CN

xiii. This vitamin is water soluble

• Vitamin A
• Vitamin C
• Vitamin D
• Vitamin K

xiv. The metal present in grignard’s Reagant is

• Mg
• Mn
• Fe
• Cu

SECTION “B” – (Short Answer Questions)

INORGANIC CHEMISTRY

i. (a) State the modern Periodic Law and discuss the types of elements on the basis of electronic configuration.
i. (b) Identify the groups and Periods of the elements having atomic numbers 11, 15 and 36.

ii. Give the balanced equation.

• Chlorine is treated with concentrated solution of sodium hydroxide.
• Sodium hydroxide is added to ammonium chloride
• Litharage is heated with access oxygen
• Chlorine reacts with sulphur dioxide

iii. (a) Give the chemical formula of the following

• Blue vitriol
• Epsom salt
• Water glass
• Red lead

iii. (b) Name the following complexes by I.U.P.A.C system

[Cr(NH₃)₄Cl₂]Cl
[Zn(OH₄)]⁻²

iv. Write short note on any one of the following

• Lunar Caustic (AgNO₃)
• Tin Plating

v. Give reasons of the following.

• Boiling Point of Sulphuric acid is high
• Sodium ion is smaller than Sodium atom
• The metallic character increases down the group
• Water and ammonia molecules act as a ligends but H₃O⁺ and NH₄⁺ ions donor.

vi. Explain the reducing action of hydrogen sulphide gas with the help of two chemical reactions.

vii. What is plastic sulphur? Why does it show the Behaviour of elasticity?

viii. Complete and balance the Equations.
Zn + H₂SO₄ 90%(conc) →
C₆H₁₂O₆ + H₂SO₄(con) →
CrO₄⁻² + H⁺ →
S + H₂SO₄(conc) →

ORGANIC CHEMISTRY

ix. (a) Define the following.

• Saponification
• Functional Group Isomerism

ix. (b) What is Fermentation? How isethyl alcohol and obtained from molasses?

x. Explain how will you prepare following.

• Carbolic Acid from Benzene
• Acetaldehyde from acetylene
• Acetal from formaldehyde

xi. What are phenols? How are they classified? Explain why phenols are acedic in nature.

xii. What are Organometallic compounds? How will you prepare the following from methyl magnesium bromide.

• Vinegar
• Isopropyl Alcohol
• Ethane

xiii. Draw the structures and give the I.U.P.A.C names of the following.

• Vinyl Chloride
• Neo-pentae
• Tert-butyl methyl ether
• Picric acid

xiv. What product or products are formed when the following compound is nitrated.

• Bromo Benzene
• Nitro Benzene

xv. What are detergents? Why are they better cleaning agents than soaps.

xvi. What is methylated spirit? Give its composition.

SECTION “C” – (Detailed Question Answers)

INORGANIC CHEMISTRY

Q.3. (a) Describe manufacture of nitric acid by Ostwald’s process.
Q.3. (b) Write down the auto-oxidation reduction of Chlorine.
Q.3. (c) Give the preparation and properties of Ionic Hydrides.

Q.4. (a) Give the extraction of aluminium from bauxite ore containing ferric oxide as impurity.
Q.4. (b) How is caustic soda obtained by castner kellener’s process.
Q.4. (c) Give composition uses of the alloys of aluminium.

ORGANIC CHEMISTRY

Q.5. (a) Why does benzene give electrophilic substitution reaction? Explain the mechanism of halogenations reaction in benzene.
Q.5. (b) Give mechanism of chlorination of methane in the presence of Sunlight.
Q.5. (c) What are Aldehyde and Ketone? Give one reaction with an equation equation to distinguish them.

Q.6. (a) What is cannizaro’s reaction? Show it by an equation.
Q.6. (b) Draw and discuss the orbital structure of Ethane.
Q.6. (c) What are homalogous series? Write down the formulae and names of the first five members of a homologous series.