40 ml of methane is completely burnt using 80 ml of oxygen at room temperature The volume of gas left after cooling to room temperature is _______.

(a)

40 ml CO₂ gas

(b)

40 ml CO₂ gas and 80 ml H₂O gas

(c)

60 ml CO₂ gas and 60 ml H₂O gas

(d)

120 ml CO₂ gas

An element X has the following isotopic Composition ²⁰⁰X = 90%, ¹⁹⁹X = 8% and ²⁰²X = 2%. The Weighted average atomic mass of the element X is closet to _________.

(a)

201 u

(b)

202 u

(c)

199 u

(d)

200 u

The number of water molecules in a drop of water weighing 0.018 g is ________.

(a)

6.022\(\times\)10²⁶

(b)

6.022\(\times\)10²³

(c)

6.022\(\times\)10²⁰

(d)

9.9 \(\times\)10²²

Which one of the following represents 180 g of water ?

(a)

5 Moles of water

(b)

90 moles of water

(c)

\(\frac { 6.022\times { 10 }^{ 23 } }{ 180 } \) molecules of water 

(d)

6.022\(\times\)10²⁴molecules of water

The oxidation number of Cr in Cr₂O₇^2- _______ is

(a)

+6

(b)

-6

(c)

+7

(d)

-7

Which of the following contain same number of carbon atoms as in 6 g of carbon-12 ?

(a)

7.5 g ethane

(b)

8 g methane

(c)

both (a) and (b)

(d)

none of these

Which of the following compound(s) has /have a percentage of carbon same as that in ethylene (C₂H₄)?

(a)

propene

(b)

ethyne

(c)

benzene

(d)

ethane

The change in the oxidation number of S in H₂S and SO₂,in the following industrial reaction:
2H₂S_(g) + SO_2(g) \(\longrightarrow\) 3S_(s) + H2O_(g)

(a)

-2 to 0, +4 to 0

(b)

-2 to 0, +4 to -1

(c)

-2 to -1, +4 to 0

(d)

-2 to -1, +4 to -2

In which of the following reactions, hydrogen peroxide acts as an oxidising agent?

(a)

I₂+ H₂O₂ + 20H^- \(\longrightarrow\) 21- + 2H₂O + O₂

(b)

PbS + 4H₂O₂ \(\longrightarrow\) PbSO₄ + 4H₂O

(c)

2MnO₄^-+ 3H₂O₂ \(\longrightarrow\) 2MnO₂ + 3O₂ + 2H₂O + 2OH^-

(d)

HOCI + H₂O₂ \(\longrightarrow\) H₂O⁺ + Cl^- + O₂

A sample of \({ CaCO }_{ 3 }\) is 50% pure.  On heating 1.12 L of \({ CO }_{ 2 }\) ( at STP) is obtained.  Residue left (assuming non volatile Impurity is

(a)

7.8g

(b)

3.8g

(c)

2.8g

(d)

8.9g

Polyethylene can be produced from calcium carbide according to the following sequence of relations.

 \({ CaC }_{ 2 }+{ H }_{ 2 }O\rightarrow CaO+HC\equiv CH\)

\(n(HC\equiv CH)+{ nH }_{ 2 }\rightarrow { \left( { CH }_{ 2 }-{ CH }_{ 2 } \right) }_{ n }\)

The mass of polyethylene, which can be produced from 20.0 kg of \({ CaC }_{ 2 }\) is

(a)

6.75 kg

(b)

7.75 kg

(c)

8.75 kg

(d)

9.57 kg

1.0g of magnesium is burnt with 0.56g\({ O }_{ 2 }\) in a closed vessel.  Which reactant is left in excess and how much? (At.wt.Mg=24; 0=16)

(a)

Mg. 0.16g

(b)

\({ O }_{ 2 },0.16\quad g\)

(c)

Mg,0.44 g

(d)

\({ O }_{ 2 },0.28\quad g\)

\({ 10 }^{ 21 }\) molecules are removed from 200 mg of \({ CO }_{ 2 }\).  The moles of \({ CO }_{ 2 }\) left are

(a)

\(2.88\times { 10 }^{ -3 }\)

(b)

\(28.8\times { 10 }^{ -3 }\)

(c)

\(288\times { 10 }^{ -3 }\)

(d)

\(28.8\times { 10 }^{ -3 }\)

1+2 (17-15.1)=x. Hence, x is equal to

(a)

4.8

(b)

19.9

(c)

5

(d)

5.0

Number of significant figures in the answer of the following will be \(\frac { (29.2-20.2)(1.79\times 105) }{ 1.39 } \)

(a)

4

(b)

3

(c)

2

(d)

1

H₂SO₄ solution is 500 molal (d=1.8 g/mL) hence, its molarity is

(a)

18 M

(b)

36 M

(c)

9 M

(d)

4.50 M

Molality of sucrose solution changes if

(a)

temperature is increased

(b)

some water is added

(c)

in both (a) and (b) cases

(d)

in none of the above cases

Equal moles of H₂O and NaCI are present in a solution. Hence, molality of NaCI solution is

(a)

0.55

(b)

55.5

(c)

1.00

(d)

0.18

SI units of pressure is 

(a)

pascal

(b)

atmosphere

(c)

metre

(d)

dyne/cm²

SI unit of emf is

(a)

joule

(b)

millivolt

(c)

volt

(d)

ampere

Calculate the molar mass of the following compounds.
Sulphuric  Acid [H₂ SO₄]

Write a note on Thomson's plum pudding model of an atom.

What are the defects of Rutherford's model?

How many neutrons and protons are there in the Following nuclei?
\(_{ 6 }^{ 13 }{ C }\),\(_{ 2 }^{ 18 }{ O }\).\(_{ 12}^{ 24}{ Mg }\),\(_{26 }^{ 56}{ Fe }\),\(_{ 88}^{ 38}{ Sr }\)

Why Pauli exclusion principle is called exclusion principle?

Bring out the similarities and dissimilarities between a 1s and 2s orbital.

Calculate the wave length of an electron (mass = 9.1 x 10^-31 kg) moving with 'a velocity of 10³ ms^-1 (h = 6.6 x 10^-34 kg m² sec^-1).

The kinetic energy of a subatomic particle is 5.58 x 10^-25 J. Calculate the frequency of the particle wave. (Planck's constant h = 6.626 x 10^-34 kg m² s^-1)

A microscope using suitable photons is employed to locate an electron in an atom within a distance of 0.1\(\overset { o }{ A } \)  What is the uncertainty involved in the measurement of its velocity.

Explain how matter has dual character?

Matter is defined as anything that has mass and occupies space. All matter is composed of atoms

Write a note on the differences between elements and compounds

Write down the formulae for calculating the equivalent mass of an acid, base and oxidizing agent.

1.05g of a metal gives on oxidation 1.5g of its oxide. Calculate its equivalent mass.

A piece of cut apple becomes brown. Why? Can you prevent it by a simple method

Balance the following reaction:
H₂C₂O₄+KMnO₄ + H₂SO₄ \(\rightarrow\) H₂SO₄ + MnSO₄ + CO₂ + H₂O

Calculate the molar volume of 146 g of HCI gas and the number of molecules present in it

Calculate the molar mass of 20 L of gas weighing 23.2 g at STP.

Describe in brief Lothar Meyer's classification of elements.

Explain classification of elements based on Newland's law of Octaves.

Write note on combination reaction.

Arrange the elements silver, Zinc and copper in the order of their decreasing electron releasing tendency and justify your arrangement with an appropriate experiment.

Balance the following equations by oxidation number method.
KBr + MnO₂ + H₂SO4 ⟶ KHSO₄ + MnSO₄ + H₂O + Br₂

Calculate the empirical and molecular formula of a compound containing 32% carbon, 4% hydrogen and rest oxygen. Its vapour density is 75.

Light of wavelength 12818 \(\overset { o }{ A } \) is emitted when the electron of a hydrogen atom drops from 5^th to 3^rd orbit. Find the wavelength of a photon emitted when the electron falls from 3^rd to 2^nd orbit.

Explain about the factors that influence the ionization enthalpy.