Pradeep's Chemistry Vol 1>Chapter 1 - Some Basic Concepts of Chemistry>Competition Focus>Q 27

HARD

11th CBSE

IMPORTANT

Earn 100

$50 mL 10 N H_{2} {SO}_{4}$ , $25 mL 12 N HCl$ and $40 mL 5 N {HNO}_{3}$ were mixed together and the volume of the mixture was made $1000 mL$ by adding water. The normality of the resultant solution will be:

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Important Questions on Some Basic Concepts of Chemistry

HARD

11th CBSE

IMPORTANT

Pradeep's Chemistry Vol 1>Chapter 1 - Some Basic Concepts of Chemistry>Competition Focus>Q 28

A

0.1 M

basic solution is required from

Ca (OH)_{2}

which is

40

percent ionized. Analytical molarity of

Ca (OH)_{2}

should be

MEDIUM

11th CBSE

IMPORTANT

Pradeep's Chemistry Vol 1>Chapter 1 - Some Basic Concepts of Chemistry>Competition Focus>Q 29

0.3 g

of an acid is neutralized by

40 {cm}^{3}

of

0.125 N

NaOH

. Equivalent mass of the acid is

HARD

11th CBSE

IMPORTANT

Pradeep's Chemistry Vol 1>Chapter 1 - Some Basic Concepts of Chemistry>Competition Focus>Q 30

25.3 g

of sodium carbonate,

({Na}_{2} {CO}_{3})

is dissolved in enough water to make

250 mL

of solution. If the sodium carbonate dissociates completely, molar concentration of sodium ions,

{Na}^{+}

and carbonates ions,

{CO}_{3}^{2 -}

are respectively (Molar mass of

{Na}_{2} {CO}_{3} = 106 g {mol}^{- 1}

).

HARD

11th CBSE

IMPORTANT

Pradeep's Chemistry Vol 1>Chapter 1 - Some Basic Concepts of Chemistry>Competition Focus>Q 31

The number of molecules in

100 mL

of

0.02 N H_{2} {SO}_{4}

is

HARD

11th CBSE

IMPORTANT

Pradeep's Chemistry Vol 1>Chapter 1 - Some Basic Concepts of Chemistry>Competition Focus>Q 32

A

100 mL

solution of

0.1 N HCl

was titrated with

0.2 N NaOH

solution. The titration was discontinued after adding

30 mL of NaOH

solution. The remaining titration was completed by adding

0.25 N KOH

. The volume of

KOH

required for completing the titration is

HARD

11th CBSE

IMPORTANT

Pradeep's Chemistry Vol 1>Chapter 1 - Some Basic Concepts of Chemistry>Competition Focus>Q 33

The ratio of masses of oxygen and nitrogen in a particular gaseous mixture is

1 : 4

. The ratio of the number of their molecules is

HARD

11th CBSE

IMPORTANT

Pradeep's Chemistry Vol 1>Chapter 1 - Some Basic Concepts of Chemistry>Competition Focus>Q 34

A mixture of gases contains

H_{2}

and

O_{2}

gases in the ratio of

1 : 4 (w / w)

. What is the molar ratio of two gases in the mixture?

HARD

11th CBSE

IMPORTANT

Pradeep's Chemistry Vol 1>Chapter 1 - Some Basic Concepts of Chemistry>Competition Focus>Q 35

Suppose two elements

X

and

Y

combines to form two compounds

{XY}_{2}

and

X_{3} Y_{2}

. When

0.1 mol

of

{XY}_{2}

weighs

10 g

and

0.05 mol

of

X_{3} Y_{2}

weighs

9 g

, the atomic weights of

X

and

Y

are