NSEC CHEMISTRY

DAILY CHEMISTRY TEST QUESTIONS

Eduinfy provide you digital online & effective learning for entrance exams .

Practice Test

Question Bank

1 Classification of Elements and Periodicity

The order of ease of oxidation of the ions F⁻, OH−, Br⁻ ,$${SO}_{4}^{2-}$$ is:

1) $${SO}_{4}^{2-}<{Br}^{-}<{OH}^{-}< {F}^{-}$$
2) $${SO}_{4}^{2-}> {F}^{-}> {Br}^{-}> {OH}^{-}$$
3) $${SO}_{4}^{2-}< {F}^{-}< {Br}^{-}< {OH}^{-}$$
4) $${OH}^{-}< {Br}^{-}< {F}^{-}< {SO}_{4}^{2-}$$

Option 1

Option 2

Option 3 Solution:

SOLUTION

According to the preceding table of relative strengths, the reducing agents become stronger in the following order: $${SO}_{4}^{2-}< {F}^{-}< {Br}^{-}< {OH}^{-}$$

Option 4

2 Environmental Chemistry

Major chemical species present in troposphere is ,

1) $$O_2, N_2$$

2) $$CO_2, H_2O$$

3) Both A and B

4) None of these

Option 1

Option 2

Option 3 Solution:

Solution

Major chemical species present in troposphere are $$O_2, N_2$$ and $$CO_2, H_2O$$. Troposphere is the lower part of the atmosphere.

Option 4

3 Alcohols Phenols and Ethers

Ethyl alcohol reacts at a faster rate with HI than with HCl in forming the corresponding ethyl halides under identical conditions mainly because:

1) HI, being a stronger acid, protonates ethyl alcohol at oxygen much better and helps substitution.
2) the bond length in HI is much shorter than that in HCl.
3) I− is a much better leaving group
4) I− is a much better nucleophile than Cl−

Option 1

Option 2

Option 3

Option 4 Solution:

Solution

Ethyl alcohol reacts at a faster rate with HIHI than with HCl in forming the corresponding ethyl halides under identical conditions mainly because I⁻ is a much better nucleophile than Cl⁻
In iodide ion, the negative charge is dispersed on the large ion.

Hence, it is loosely held by the nucleus. Hence, it can be easily given to an electrophile.

4 Ionic Equilibrium

The solubility product of a binary weak electrolyte is 4×10⁻¹⁰ at 298K. Its solubility in mol dm⁻³ at the same temperature is

1) 4 × 10⁻⁵
2) 2 × 10⁻⁵
3) 8 × 10⁻⁵
4) 16 ×10⁻⁵

Option 1

Option 2 Solution:

AB ? A⁺+ B⁻ Ksp=S²

S=√Ksp =√4×10⁻¹⁰

Option 3

Option 4

5 Mole Concept

The density of 11 M solution of NaCl is 1.0585gml⁻¹. The molality of the solution is :

1) 1.0585
2) 1.00
3) 0.10
4) 0.0585

Option 1

Option 2 Solution:

Solution

$$d=M\left (\dfrac {Mw_2}{1000}+\dfrac {1}{m}\right )\Rightarrow 1.0585=1\left (\dfrac {58.5}{1000}+\dfrac {1}{m}\right )$$

$$\therefore m=1$$

Option 3

Option 4

6 Chemical Kinetics

The half life of the first order reaction
CH₃.CHO(g)→CH₄(g)+CO(g)
If initial pressure of CH₃.CHO(g) is 80 mm and after how much time in minutes is the total pressure 120 mm?

1) 80 min
2) 120 min
3) 20 min
4) 40 min

Option 1

Option 2

Option 3 Solution:

Solution

Let $$p^o$$ be the initial pressure. $$p^o=80.$$
At time t, the total pressure is $$\mathrm{p}^{o}+\mathrm{p}=120.$$
$$\mathrm{p}^{o};\mathrm{p}=120-80=40.$$
The expression for the rate constant is $$\mathrm{K}=\frac{1}{\mathrm{t}}\ln\frac{\mathrm{p}^{o}}{\mathrm{p}^{o}-\mathrm{p}}=\frac{1}{20}\ln\frac{80}{80-40}=\frac{1}{20}\ln 2.$$
The expression for the half life period is $$\displaystyle \mathrm{t}_{1/2}=\frac{\ln 2}{\mathrm{K}}.$$
Hence, $$\displaystyle \mathrm{t}_{1/2}=\frac{\ln 2}{\ln 2}\times 20=20\min.$$

Option 4

7 Chemical Bonding and Molecular Structure

Which of the following has maximum covalent character?

1) AlCl₃

2) BaCl₂

3) NaCl

4) CsCl

Option 1 Solution:

Option 2

Option 3

Option 4

8 Titrations

In order to prepare one litre 1N solution of KMnO4?, how many grams of KMnO4? are required, if the solution to be used in acid medium for oxidation?

1) 128 g

2) 41.75 g

3) 31.60 g

4) 62.34 g

Option 1

Option 2

Option 3 Solution:

Solution

One liter 1N solution of KMnO4? corresponds to 1 g equivalent. In acid medium for oxidation, the equivalent weight of KMnO₄? is one fifth of its molecular mass. It is 15 / 58?=31.6.
Hence, 1 g equivalent of KMnO₄? corresponds to 31.6 g.

Hence, in order to prepare one liter 1N solution of KMnO₄?, 31.6 grams of KMnO4? are required, if the solution to be used in acid medium for oxidation.

Option 4

9 Atomic Structure

The value of (n2+n1) and $$\left( { n }_{ 2 }^{ 2 }-{ n }_{ 1 }^{ 2 } \right) $$ forHe⁺ ion in atomic spectrum are 4 and 8 respectively. The wavelength of emitted photon when electron jump from n2 to n1 is:

1) $$\dfrac { 32 }{ 9 } { R }_{ H }$$
2) $$\dfrac { 9 }{ 32 } { R }_{ H }$$
3) $$\dfrac { 9 }{ 32{ R }_{ H } } $$
4) N$$\dfrac { 32 }{ 9{ R }_{ H } } $$

Option 1

Option 2 Solution:

Solution

$$n_2+n_1=4$$......(1)

$$n_2^2-n^2_1=8$$

$$\Rightarrow (n_2+n_1)(n_2-n_1)=8$$

$$\Rightarrow n_2-n_1=2$$.......(2)

From 1 and 2

$$n_1=3,n_2=1$$

$$E=-13.6(\dfrac{1}{n_1}-\dfrac{1}{n_2})$$

$$=-13.6(\dfrac{1}{9}-1)$$

$$=\dfrac{8}{9}\times 13.6$$

$$\bar{v}=R_HZ^2(\dfrac{1}{h^2_1}-\dfrac{1}{h_2})$$

$$\Rightarrow \dfrac{1}{\lambda}==R_H\times 4\times \dfrac{8}{9} $$

$$\Rightarrow =\lambda=\dfrac{9}{32}R_H$$

Option 3

Option 4

10 Polymers

Which of the following is a linear polymer ?

1) glycogen
2) amylopectin
3) amylose
4) starch.

Option 1

Option 2

Option 3 Solution:

Cellulose is a natural linear polymer, a long chain made by the linking of smaller glucose molecules.

Natural rubber is a linear polymer made up of Isoprene (2-Methyl -1, 3 – Butadiene) units.

Option 4

More Courses

MOCK TEST

Biology Mock Test paper 9

Biology

Attempt

NEET Mock Test 4

NEET

Attempt

Biology Mock Test paper 6

Biology

Attempt

NEET Mock Test 5

NEET

Attempt

Biology Mock Test paper 3

Biology

Attempt

Biology Mock Test paper 8

Biology

Attempt

Chemistry Mock Test paper 3

Chemistry

Attempt

Biology Mock Test paper 7

Biology

Attempt

Physics Mock Test paper 1

Physics

Attempt

NEET Mock Test 1

NEET

Attempt

Chemistry Mock Test paper 1

Chemistry

Attempt

Biology Mock Test paper 4

Biology

Attempt

Physics Mock Test paper 4

Physics

Attempt

Biology Mock Test paper 5

Biology

Attempt

Chemistry Mock Test paper 2

Chemistry

Attempt

Biology Mock Test paper 10

Biology

Attempt

Biology Mock Test paper 2

Biology

Attempt

Physics Mock Test paper 5

Physics

Attempt

Chemistry Mock Test paper 5

Chemistry

Attempt

NEET Mock Test 3

NEET

Attempt

NEET Mock Test 2

NEET

Attempt

Biology Mock Test paper 1

Biology

Attempt

Chemistry Mock Test paper 4

Chemistry

Attempt

Physics Mock Test paper 3

Physics

Attempt

Physics Mock Test paper 2

Physics

Attempt

SMS Notifications

Change

Mock Test