Nitrogen is obtained by the thermal decomposition of :

NH₄NO₂
NH₄NO₃
AgNO₃
Pb(NO₃)₂

Solution

Nitrogen is obtained by the thermal decomposition of

NH₄NO₂

NH₄NO₂ \(\overset{\Delta }{\rightarrow}\) N₂ + 2H₂O

In which of the following compound electrovalent, covalent and co-ordinate bonds are present?

NH₄Cl
CCl₄
CaCl₂
H₂O

Solution

The oxidation number of sulphur in S₈, S₂F₂, H₂S respectively, are

0, +1 and –2
+2, +1 and –2
0, +1 and +2
–2, +1 and –2

Solution

(i) Oxidation state of element in its free state is zero.
(ii) Sum of oxidation states of all atoms in compound is zero.O.N. of S in S₂₈= 0; O.N. of S in S₂F₂= + 1;O.N. of S in H₂S = –2;

The approximate percentage of silica in cement is:

5 – 10%
15 – 20%
20 – 25%
25 – 30%

Solution

The approximate composition of cement is:
Lime (CaO) = 50 – 60%
Silica (SiO₂) = 20 – 25 %
Alumina (Al₂O₂₃) = 5 – 10 %
Magnesia (MgO) = 2 – 3%
Ferric oxide (Fe₂O₃) = 2 – 3%

An asymmetric carbon atom is that in which :

three similar and one dissimilar groups
two similar and two dissimilar groups
all the different groups
none of the above

Solution

An asymmetric carbon atom is that in which all different groups are attached with carbon. Option (c) is correct.

Among acetic acid, phenol and n-hexanol, which of the following compounds will react with NaHCO₃ solution to give sodium salt and carbon dioxide ?

acetic acid
n-Hexanol
acetic acid and phenol
phenol

Solution

among acetic acid, phenol and n-hexanol only CH₃COOH reacts with NaHCO₃ to evolve CO₂ gas.

CH₃COOH + NaHCO₃ → CH₃COONa + CO₂ + H
₂O

Phenol, when it first reacts with concentrated sulphuric acid and then with concentrated nitric acid, gives

2, 4, 6-trinitrobenzene
o-nitrophenol
p-nitrophenol
nitrobenzene

Solution

Of the five isomeric hexanes, the isomer which can give two monochlorinated compounds is

2-methylpentane
2, 2-dimethylbutane
2, 3-dimethylbutane
n-hexane

Solution

Since it contains only two types ofH-atoms hence it will give only two monochlorinated compounds viz.

Be₂C and Al₄C₃ are called –

ethanides
methanides
carbonides
acetylides

Solution

A solution containing 2.675 g of CoCl³. 6 NH³(molar mass =267.5 g mol^–1) is passed through acation exchanger. The chloride ions obtained in solution were treated with excess of AgNO³ to give 4.78 g of AgCl (molar mass = 143.5 g mol^–1). The formula of the complex is

(At. mass of Ag = 108 u)

[Co(NH³)⁶]Cl³
[CoCl²(NH³)⁴]Cl
[CoCl³(NH³)³]
[CoCl(NH³)⁵]Cl²

Solution

DIRECTIONS : These are Assertion-Reason type question.Question contains two statements:Statement-1 (Assertion) and Statement-2 (Reason). Answer these questions from the following four options.

Statement-1 :According to Freundlich:\(\frac{x}{m} = kp^{\frac{1}{n}}\)

Statement-2 :The isotherm shows variation of the amount of gas adsorbed by the adsorbent with temperature.

Statement-1 is true, Statement-2 is true, Statement-2 is a correct explanation for Statement-1
Statement-1 is True, Statement-2 is True ; Statement-2 is NOT a correct explanation of Statement-1
Statement-1 is True,Statement-2 is False
Statement-1 is False, Statement-2 is True

Solution

Statement - 1 is true but Statement - 2 is false.Freundlich adsorption isotherm gives an empirical relationship between the quantity of gas adsorbed by unit mass of solid adsorbent and pressure at a particular temperature.

Uncertainty in the position of an electron (mass = 9.1 × 10^–31kg)moving with a velocity 300 ms^-1, accurate upto 0.001% will be(h = 6.63 × 10^-34Js)

1.92 × 10^-2 m
3.84 × 10^-2 m
19.2 × 10^-2 m
5.76 × 10^-2 m

Solution

Given m = 9.1 × 10^-31 kg

h = 6.6 × 10^-34 Js

\(\Delta v = \frac{300 \times 0.001}{100} = 0.003 \; ms^{-1}\)

From Heisenberg's uncertainity principle

\(\Delta x = \frac{6.62 \times 10^{-34}}{4 \times 3.14 \times 0.003 \times 9.1 \times 10^{-31}} = 1.92 \times 10^{-2} \; m\)

On mixing, heptane and octane form an ideal solution. At 373 K, the vapour pressures of the two liquid components(heptane and octane) are 105 kPa and 45 kPa respectively. Vapour pressure of the solution obtained by mixing 25.0 g of heptane and 35 g of octane will be (molar mass of heptane= 100 g mol^-1 and of octane = 114 g mol^-1)

72.0 kPa
36.1 kPa
96.2 kPa
144.5 kPa

Solution

In physical adsorption, gas molecules are bound on the solid surface by

chemical forces
electrostatic forces
gravitational forces
van der Waal’s forces

Solution

In physisorption, gas molecules are held on the solid surface by weak van der Waal’s forces.

Which of the following halides is least stable and has doubtful existence?

CI₄
GeI₄
SnI₄
PbI₄

Solution

The stability of +2 oxidation state increases and +4 oxidation state decreases as we move down in Group-14. So Pb(IV) is strongly oxidising and also I^- is strong reducing agent. Hence PbI₄ is non existing.

Solution

Which of the following compounds would be the mainproduct of an aldol condensation of acetaldehyde and acetone?

CH₃CH = CH.CHO
CH₃CH = CHCOCH₃
(CH₃)₂C=CH.CHO
(CH₃)₂C = CHCOCH₃

Solution

The rate of a chemical reaction doubles for every 10°C rise of temperature. If the temperature is raised by 50°C, the rate of the reaction increases by about :

10 times
24 times
32 times
64 times

Solution

Since for every 10ºC rise in temperature rate doubles for 50ºC rise in temperature increase in reaction rate= 2⁵ = 32 times

In pyrophosphoric acid, H₂P₂O₇, number of ? and d? – p? bonds are respectively

8 and 2
6 and 2
12 and zero
12 and 2

Solution

Solution

UnAttempted

0

Attempted

0

Correct

0

Wrong