Chemistry 2015-2016 HSC Science (General) 12th Standard Board Exam Question Paper Solution

Schottky defects are observed in which solid among the following?

(a) Brass

(b) Cesium Chloride

(c) Zinc sulphide

(d) Stainless steel

No machine has an efficiency unity', is stated in-

(a) first law of thermodynamics

(b) second law of thermodynamics

(c) third law of thermodynamics

(d) Hess' law of constant heat summation

Which among the following reactions is an example of a zero order reaction?

a) ${\displaystyle H_{2\left(g\right)}+I_{2\left(g\right)}\to 2H{I}_g}$

b) ${\displaystyle 2H_2{O}_{2\left(l\right)}\to 2H_2{O}_l+O_{2\left(g\right)}}$

c) ${\displaystyle C_{12}{H}_{22}{O}_{11\left(aq\right)}+H_2{O}_l\to C_6{H}_{12}{O}_{6\left(aq\right)}+C_6{H}_{12}{O}_{6\left(aq\right)}}$

d) ${\displaystyle 2N{H}_{3g}}$   ${\displaystyle N\left(2g\right)+3H_{2\left(g\right)}}$

Potential of saturated calomel electrode is-

0.242 V

1.1 V

0.337 V

0.28 v

Which of the following compounds is used as a semipermeable membrane?

(a) Potassium ferrocyanide

(b) Potassium argentocyanide

(c) Sodium meta aluminate

(d) Copper ferrocyanide

Which among the following minerals does NOT contain aluminium?

(a) Cryolite

(b) Siderite

(c) China clay

(d) Corundum

The group 15 element having inner electronic configuration as of argon is-

(a) Phosphorous (z = 15)

(b) Antimony (z =51)

(c) Arsenic (z = 33)

(d) Nitrogen (z = 7)

Write chemical reactions involved in Van Arkel method for refining Titanium

Explain the relationship between Gibb's standard energy change of the reaction and equilibrium constant.

A face centred cube (FCC) consists of how many atoms? Explain

Describe isolation method in determination of rate law and order of reaction.

Explain the following methods to protect metals from corrosion:

Galvanization

Explain the following methods to protect metals from corrosion:

Passivation

Write the Nemst equation and explain the terms involved.

What happens when dilute sulphuric acid is treated with Fe

What happens when dilute sulphuric acid is treated with Fe

What happens when dilute sulphuric acid is treated with CaF₂

What happens when dilute sulphuric acid is treated with CaF₂

Explain the term osmosis.

Define Freezing point.

The rate constant of a first order reaction are 0.58 S^-1 at 313 K and 0.045 S^-1 at 293 K. What is the energy of activation for the reaction?

Calculate the standard enthalpy of the reaction, 2C(graphite) + 3H_2(g) → C₂H_6(g), ΔH° = ?

From the following ΔH° values

a) ${\displaystyle C_2{H}_6\left(g\right)+\frac{7}{2}{O}_2\left(g\right)\to 2C{O}_2\left(g\right)+3H_{2}O\left(l\right)}$.  ΔH° = -1560kJ

b) ${\displaystyle H_2\left(g\right)+\frac{1}{2}{O}_2\left(g\right)\to H_{2}O\left(l\right)}$  ΔH° = -285.8kJ

c) C(graphite) + O₂(g) -> CO₂(g). ΔH° = -393.5kJ

3.795 g of sulphur is dissolved in 100g of CS₂. This solution boils at 319.81 K. What is the molecular formula of sulphur in solution? The boiling point of CS₂ is 319.45 K. (Given that K_b for CS₂ = 2.42 K kg mol^-1 and atomic mass of S = 32)

How is nitric acid prepared by Ostwald’s process?

State Third law of thermodynamics. Give ‘two’ uses.

Write applications of standard molar entropy°.

Draw neat labelled diagram of electrolytic refining of blister copper

Determine the density of Cesium chloride which crys tallizes in BCC type structure with the edge length 412.1 pm. The atomic masses of Cs and Cl are 133 and 35.5 respectively.

Predict the co-ordination No. of cs⁺ ion if ${\displaystyle r_{Cs}^{+}}$ = 1.69Å and ${\displaystyle r_{Cl}^{-}}$ = 1.81Å.

What happens when thin copper leaves are thrown in jar containing chlorine?

H₂O is liquid while H₂S is gas at room temperature. Explain.

The conductivity of 0.02M AgNO₃ at 25°C is 2.428 x 10^-3 Ω^-1 cm^-1. What is its molar
conductivity?

State Henry’s law.

Sodium acetate reacts with Ethanoyl chloride to form

(a) Acetic acid

(b) Acetone

(c) Acetic anhydride

(d) Sodium formate

Natalite is a mixture of

(a) diethyl ether and methanol

(b) diethyl ether and ethanol

(c) dimethyl ether and methanol

(d) dimethyl ether and ethanol

What is effective atomic number of Fe (z = 26) in [Fe(CN)₆]^4-?

(a) 12

(b) 30

(c) 26

(d) 36

Maltose is a 

(a) Polysaccharide

(b) Disaccharide

(c) Trisaccharide

(d) Monosaccharide

Which one of the following oxidation state of Manganese is unstable?

(a) + 2

(b) + 4

(c) + 5

(d) + 7

IUPAC name of the following compound is

(a) 3 - Bromo- 3, 4- dimethylheptane

(b) 3, 4- dimethyl - 3- bromoheptane

(c) 5- Bromo- 4, 5- dimethylheptane

(d) 4, 5- dimethyl- 5- bromoheptane

Which of the following compounds is NOT prepared by the action of alcoholic NI₃ on alkyl halide?

(a) CH₃NH₂

(b) CH₃- CH₂- NH₂

(c) CH₃ - CH₂ - CH₂ - NH₂

(d) (CH₃)₃ C- NH₂

Write IUPAC names of the following compounds

Write IUPAC names of the following compounds:

What are the sources of Vitamin C and Vitamin K?

Write four points of distinction between Lanthanoids and Actinoids.

How is Benzonitrile converted to Benzophenone?

Write the formulae of the raw materials used for preparation of Buna-S

Write the formulae of the raw materials used for preparation of Dextran.

Write a note on Sandmeyer's reaction.

What is the action of benzene diazonium chloride on phenol in alkaline medium

What is the action of benzene diazonium chloride on Aniline

Explain any two chemical methods of food preservation.

What is the action of following reagents on glucose?

bromine water

What is the action of following reagents on glucose?

dilute HNO₃

What is the action of following reagents on glucose?

hydroxyl amine

What are ligands?

Write four postulates of Werner's theory.

Write reactions involved in preparation of potassium dichromate from chrome iron ore

What is metamerism? 

Write the structure and IUPAC name of 'methyl-n-propyl ether'.

What is the action of hot HI on it?

How are the following polymers prepared?

Orlon

Write the reactions involved in the preparation of Teflon

Classify the following drugs into Analgesics and Antibiotics 

(1) Ofloxacin

(2) Morphine

(3) Ampicillin

(4) Chloramphenicol

Identify 'A' and 'B' and rewrite the reactions

Identify 'A' and 'B' and rewrite the reactions

Identify 'A' and 'B' and rewrite the reactions

How are the following conversions carried out?

2-methylbutan-1-ol into 2 -methylbutanoic acid.

Show how the following compound can be converted to benzoic acid.

Phenylethene (Styrene)

How are the following conversions carried out?

Benzoic acid into metanitrobenzoic acid.

What is the action of Benzene Sulphonyl Chloride on primary, secondary and tertiary
amines?

Write two uses of formaldehyde