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

1 g of an impure sample of magnesium carbonate (containing no thermally decomposable impurities) on complete thermal decomposition gave 0.44 g of carbon dioxide gas. The percentage of impurity in the sample is ______________.

(a)

0%

(b)

4.4%

(c)

16%

(d)

8.4%

When 6.3 g of sodium bicarbonate is added to 30 g of the acetic acid solution, the residual solution is found to weigh 33 g. The number of moles of carbon dioxide released in the reaction is _____.

(a)

3

(b)

0.75

(c)

0.075

(d)

0.3

When 22.4 litres of H₂(g) is mixed with 11.2 litres of Cl₂(g), each at 273 K at 1 atm the moles of HCl (g), formed is equal to ______.

(a)

2 moles of HCI (g)

(b)

0.5 moles of HCI (g)

(c)

1.5 moles of HCI (g)

(d)

1 moles of HCI (g)

The oxidation number of oxygen in O₂ is__________

(a)

0

(b)

+1

(c)

+2

(d)

-2

The oxidation number of hydrogen in LiH is _________

(a)

+1

(b)

-1

(c)

+2

(d)

-2

Total number of electrons present in 1.7 g of ammonia is _____.

(a)

6.022\(\times\)10²³

(b)

\(\frac { 6.022\times { 10 }^{ 22 } }{ 1.7 } \quad \)

(c)

\(\frac { 6.022\times { 10 }^{ 24 } }{ 1.7 } \)

(d)

\(\frac { 6.022\times { 10 }^{ 23 } }{ 1.7 } \)

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

(a)

+6

(b)

-6

(c)

+7

(d)

-7

Identify disproportionation reaction

(a)

CH₄ + 2O₂ \(\longrightarrow\) CO₂+ 2H₂O

(b)

CH₄ + 4Cl₂ \(\longrightarrow\) CCl₄ + 4HCI

(c)

2F₂+ 2OH \(\longrightarrow\) 2F^-+ OF₂+ H₂O

(d)

2NO₂ + 2OH^- \(\longrightarrow\) NO^-₂ + NO^-₃ + H₂O

Which of the following statement(s) is/are not true about the following decomposition reaction.
2KClO₃ \(\longrightarrow\) 2KCl + 3O₂
(i) Potassium is undergoing oxidation
(ii) Chlorine is undergoing oxidation
(iii) Oxygen is reduced
(iv) None of the species are undergoing oxidation and reduction.

(a)

only (iv)

(b)

(i) and (iv)

(c)

(iv) and (iii)

(d)

All of these

Match the list-I with list-II and select the correct answer using the code given below the lists.

List-I		List-II
A	Cr2O72-	1	+5
B	MnO4-	2	+6
C	VO3-	3	+3
D	FeF63+	4	+7

(a)

A	B	C	D
3	1	4	2

(b)

A	B	C	D
4	3	2	1

(c)

A	B	C	D
2	4	1	3

(d)

A	B	C	D
3	2	1	4

Two 22.4 litre containers A and B contains 8 g of O₂ and 8 g of SO₂ respectively at 273 K and 1 atm pressure, then ______.

(a)

Number of molecules inA and B are same

(b)

Number of molecules in B is more than that in A.

(c)

The ratio between the number of molecules in A= to number of molecules in B is 2:1

(d)

Number of molecules in B is three times greater than the number of molecules in A

Consider the following statements
i) Matter possesses mass.
ii) 22-carat gold is a mixture.
iii) Dry ice is a compound.
Which of the following statement(s) given above is/ are correct?

(a)

1 & 3

(b)

Only 1

(c)

1 & 2

(d)

1,2, & 3

Identify the incorrect statement about a compound.

(a)

A molecule cannot be separated into its constituent elements by physical methods of separation

(b)

A molecule of a compound has atoms of different elements

(c)

A compound retains the physical properties of its constituent element

(d)

The ratio of atoms of different elements in a compound is fixed

The characteristic feature of orderly arrangement of molecules belongs to ______________.

(a)

Solids

(b)

Liquid

(c)

Gases

(d)

None of these

The density of carbon dioxide is equal to 1.965 kgm^-3 at 273 K and 1 atm pressure. calculate the molar mass of CO₂.

Which contains the greatest number of moles of oxygen atoms
i) 1 mol of ethanol
ii) 1 mol of formic acid
iii) 1 mol of H₂O

Calculate the average atomic mass of naturally occurring magnesium using the following data.

Isotope	Istopic atomic mass	Abundance(%)
Mg24	23.99	78.99
Mg25	24.99	10.00
Mg26	25.98	11.01

A Compound on analysis gave Na = 14.31% S = 9.97% H = 6.22% and 0 = 69.5%.
Calculate the molecular formula of the compound if all the hydrogen in the compound is present in combination with oxygen as a water of crystallization. (molecular mass of the compound is 322).

Balance the following equations by ion electron method.
i) \({ KMn }O_{ 4 }+{ SnCl }_{ 2 }+HCI\longrightarrow MnCI_{ 2 }+{ SnCI }_{ 4 }+{ H }_{ 2 }O+KCI\)
ii) 
iii) 
iv) 

Balance the following equations by ion electron method
\({ C }_{ 2 }{ O }_{ 4 }^{ 2- }+{ Cr }_{ 2 }{ O }_{ 7 }^{ 2- }\longrightarrow { Cr }^{ 3+ }+{ CO }_{ 2 }\) (in acid medium)

Balance the following equations by ion electron method.
\({ Na }_{ 2 }{ S }_{ 2 }{ O }_{ 3 }+{ I }_{ 2 }\longrightarrow { Na }_{ 2 }{ S }_{ 4 }{ O }_{ 6 }+NaI\)

Define orbital ? what are the n and 1 values for 3p_x and 4d_x²-y² electron ?

The stabilisation of a half filled d - orbital is more pronounced than that of the p-orbital why?

How many orbitals are possible for n = 4?

One million silver atoms weigh 1.79 x 10^-16 g. Calculate the atomic mass of silver.

How much mass (in gram units) is represented by the following ?
0.2 mol of NH₃

How much mass (in gram units) is represented by the following ?
3.0 mol of CO₂

How much mass (in gram units) is represented by the following?
5.14 mol of H₅IO₆

Calculate the Formula Weights of the following compounds. NO₂