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# TET Class 12 Science Solved Question Paper 2017

#### Multiple Choice Questions

1.

Which one of the following is not a heterogeneous mixture?

• Air

• Milk

• Smoke

• Jelly

A.

Air

Air is not a heterogeneous mixture. Air is a homogeneous mixture of a number of gases.

2.

All organisms belonging to the kingdom Protista are

• unicellular and eukaryotic

• unicellular and prokaryotic

• multicellular and prokaryotic

• multicellular and eukaryotic

A.

unicellular and eukaryotic

All organisms belonging to the kingdom Protista are unicellular and eukaryotic e.g. Euglena, Paramecium, and Amoeba.

3.

In laboratory, ethylene and acetylene can be distinguished by

• Br2/H2O

• KMnO4/OH/H2O

• Tollens' reagent

• Fehling solution

C.

Tollens' reagent

Tollen's reagent is an alkaline solution of ammoniacal silver nitrate and is used to test for aldehydes. An aldehyde is a compound containing a functional group with the structure -CHO, consisting of a carbonyl center ( a carbon double-bonded to oxygen) with the carbon atom also bonded to hydrogen and to an R group, which is any generic alkyl or side chain.

4.

In which of the following compounds, the oxidation number of oxygen is +2?

• OF2

• Na2O

• NaO2

• NaO3

A.

OF2

Let the oxidation number of oxygen be x in OF2

$⇒$x+2(-1)=0

$⇒$x-2=0

$\therefore$x=+2

Thus, the oxidation number of oxygen is +2 in OF2

5.

Rutherford's alpha ($\mathrm{\alpha }$) particle scattering experiment resulted into the discovery of

• proton

• nucleus in the atom

• electron

• atomic mass

B.

nucleus in the atom

Physicist Ernest Rutherford established the nuclear theory of the atom with his gold-foil experiment. When he shot a beam of alpha particles at a sheet of gold foil, a few of the particles were deflected. He concluded that a tiny, dense nucleus was causing the deflections.

6.

Silk farming is known as

• Epiculture

• Pisciculture

• Sericulture

• Agriculture

C.

Sericulture

7.

The number of $\mathrm{\pi }$-electrons in the molecules of aromatic compound is

• 4n

• 4n+1

• 4n+2

• 2n+4

C.

4n+2

The number of $\mathrm{\pi }$-electrons in the molecules of the aromatic compound is ( 4n + 2), where n is an integer (n= 0, 1, 2,..) This is referred as Huckel rule.

8.

Which compound has the highest boiling point?

• n-pentane

• Isopentane

• Neopentane

• Isobutane

A.

n-pentane

The boiling point of n-pentane is 36.1°C.
The boiling point of isopentane is 27.8C.
The boiling point of neopentane is 9.5C.
The boiling point of isobutane is -117°C

So, n-pentane has the highest boiling point.

9.

The monomer of natural rubber is

• Neoprene

• Isoprene

• Terylene

• Orlon

B.

Isoprene

Natural rubber is from the monomer isoprene (2-methyl-1,3-butadiene).

10.

Which of the following has maximum number of atoms?

• 16 g N2

• 16 g of CO2

• 16 g of CH4

• 16 g of O2

A.

16 g N2

The No. of atoms = $×$Avogadro number(No)

No. of atoms in 16 g N=$\frac{16}{28}×$No=0.57No

No. of atoms in 16 g CO2=$\frac{16}{44}×$No=0.36No

No. of atoms in 16 g CH=$\frac{16}{16}×$No=No

No. of atoms in 16 g O2=$\frac{16}{16}×$No=No

Hence,16 g of N2 has the maximum number of atoms.