Chemistry Tricks of Acids, Bases and Salts For NDA
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Tricks of Acids, Bases and Salts For NDA

Acids, Acidic Strength, It's Properties and Uses

Q 1716512479

Acidity of `BF_3` can be explained on the basis of which of the following
concepts?
NCERT Exemplar
(A)

Arrhenius concept

(B)

Bronsted Lowry concept

(C)

Lewis concept

(D)

Bronsted Lowry as well as Lewis concept

Solution:

GN Lewis in 1923 defined an acid as a species which accepts an electron pair and
base which donates an electron pair. As `BF_3` is an electron deficient compound, hence,
it is a Lewis acid.
Correct Answer is `=>` (C) Lewis concept
Q 2807767688

According to Arrhenius theory, an acid is a substance which

(A)

gives a proton in aqueous solution

(B)

accepts a proton in aqueous solution

(C)

gives a hydrogen ion in aqueous solution

(D)

accepts a lone pair of electron

Solution:

Correct Answer is `=>` (C) gives a hydrogen ion in aqueous solution
Q 2817867780

Aqueous solution of acetic acid contains

(A)

`CH_3COOH , CH_3 COO^-`

(B)

`CH_3COO^- , H^+`

(C)

`CH_3 COOH , CH_3 COO^- , H_3 O^+`

(D)

`CH_3 COOH, H^+`

Solution:

Correct Answer is `=>` (C) `CH_3 COOH , CH_3 COO^- , H_3 O^+`
Q 2857867784

Which one of the following is amphiprotic in nature?

(A)

`F^-`

(B)

`HPO_4^(2-)`

(C)

`PO_4^(3-)`

(D)

`Cl^-`

Solution:

Correct Answer is `=>` (B) `HPO_4^(2-)`
Q 2847867783

Human stomach produces acid X which helps in digestion of food. Acid X is

(A)

acetic acid

(B)

methanoic acid

(C)

hydrochloric acid

(D)

citric acid

Solution:

Correct Answer is `=>` (C) hydrochloric acid
Q 2867867785

Which one of the following is the strongest acid?

(A)

`ClO_3 (OH)`

(B)

`ClO_2 (OH)`

(C)

`ClO (OH)`

(D)

`Cl (OH)`

Solution:

Correct Answer is `=>` (A) `ClO_3 (OH)`
Q 2887067887

Reaction, `NH_3 + BF_3 -> NH_3 -> BF_3, NH_3` and `BF_3` are

(A)

Lewis base and Lewis acid

(B)

Lewis base and Lewis base

(C)

Lewis acid and Lewis base

(D)

Arrhenius acid and base

Solution:

Correct Answer is `=>` (A) Lewis base and Lewis acid
Q 2817167980

A strong acid has a conjugate

(A)

strong base

(B)

weak base

(C)

strong acid

(D)

weak acid

Solution:

Correct Answer is `=>` (B) weak base
Q 2817178080

Acidity of `BF_3` can be explained on the basis of which of the following concepts?

(A)

Arrhenius concept

(B)

Bronsted Lowry concept

(C)

Lewis concept

(D)

Bronsted Lowry as well as Lewis concept

Solution:

Correct Answer is `=>` (C) Lewis concept
Q 2857067884

Select the strongest acid among the following.

(A)

`HCOOH`

(B)

`CH_3COOH`

(C)

`C_2 H_5 COOH`

(D)

`C_3 H_7 COOH`

Solution:

Correct Answer is `=>` (A) `HCOOH`
Q 2900680518



Assertion : `HClO_4` is the strongest oxyacid of chlorine.

Reason : In `HClO_4, Cl` is in `+7` oxidation state.

(A) Both A and R individually true and R is the correct explanation of A
(B) Both A and R are individually true but R is not the correct explanation of A
(C) A is true but R is false
(D) A is false but R is true
Solution:

Correct Answer is `=>` (A)
Q 2837167982

Which of the following is incorrect?

(A)

`HCOOH` is stronger acid than `CH_3COOH`

(B)

`HClO` is stronger acid than `HClO_4`

(C)

Water is more acidic than methanol

(D)

All of the above

Solution:

Correct Answer is `=>` (B) `HClO` is stronger acid than `HClO_4`
Q 2867167985

When concentrated `H_2SO_4` spilts on the surface, it should be immediately cleaned

(A)

with a piece of cloth

(B)

by adding cold water

(C)

by adding sold `Na_2CO_3`

(D)

by adding solid `BaCl_2`

Solution:

Correct Answer is `=>` (C) by adding sold `Na_2CO_3`

Bases, It's Properties and Uses

Q 2078845706

Match the following species with the corresponding conjugate acid.








Column IColumn II
(A) `NH_3` (P) `CO_3^(2-)`
(B) `HCO_3^(-)` (Q) `NH_4^(+)`
(C) `H_2O` (R) `H_3O^(+)`
(D) `HSO_4^(-)` (S) `H_2SO_4`
(E) e (T) `H_2CO_3`

NCERT Exemplar
Solution:

`A.-> (2) B.-> (5) C.-> (3)`
As conjugate acid `->` Base `+H^(+)`
`A. NH_3 +H^(+) -> NH_4^(+)`
`B. HCO_3- +H^(+) -> H_2CO_3`
`C. H_2O + H^(+) -> H_3O^(+)`
`D. HSO_4^(-) + H^(+) -> H_2SO_4`
Q 2877867786

Amongst the trihalides of nitrogen, which one is least basic ?

(A)

`NF_3`

(B)

`NCl_3`

(C)

`NBr_3`

(D)

`Nl_3`

Solution:

Correct Answer is `=>` (A) `NF_3`
Q 2887867787

The conjugate acid of `NH_2^-` is

(A)

`NH_3`

(B)

`NH_2 OH`

(C)

`NH_4^+`

(D)

`N_3 H`

Solution:

Correct Answer is `=>` (A) `NH_3`
Q 2888291107

Arrange the following base in increasing order of their, basic strength.
Select the correct answer.

Solution:

Correct Answer is `=>` (C) IV< Ill< II< I
Q 2940780613

Match List I and List II and select the correct answer using the codes given below the lists.






Column IColumn II
(A) Amphoteric oxide (P) `SO_2`
(B) Basic oxide (Q) PbO
(C) Acidic oxide (R) `N_2O`
(D) Neutral oxide (S) ` MgO`


(A)

4 3 2 1

(B)

4 2 1 3

(C)

2 4 1 3

(D)

2 4 3 1

Solution:

Correct Answer is `=>` (C) 2 4 1 3
Q 2828591401

Match List I and List II and select the correct answer using the codes given below the lists.





List IList II
(A) `AlCl_3` (1) Lewis base
(B) Theory of ionisation (2) Bronsted-Lowry
(C)Conjugate acid-base pairs (3)Lewis acid
(D) Alcohol (4) Arrhenius


(A)

` A -> 3 , B -> 2 , C -> 4, D -> 1`

(B)

` A -> 2 , B -> 1 , C ->3, D -> 4`

(C)

` A -> 2 , B -> 3 , C ->1, D -> 4`

(D)

` A -> 3 , B ->4 , C -> 2, D ->1`

Solution:

Correct Answer is `=>` (D) ` A -> 3 , B ->4 , C -> 2, D ->1`

pH scale and Indicators

Q 2817067880

When an organic compound is heated with cupric oxide, a gas `X` and `H_2O` produced as a result. When the gas X is passed through the lime water, it turns the lime water into milky. When it passed in the excess the milky colour disappears. By the litmus
solution it is hund that the gas X is aeidic in nature. The gas X is

(A)

`CO`

(B)

`CO_2`

(C)

`SO_2`

(D)

`SO_3`

Solution:

Correct Answer is `=>` (B) `CO_2`
Q 2847167983

Base turn red litmus blue and acids turn bhw litmus red. A student tested a liquid with a red litmus paper and it stayed red
with no change. This shows that the liquid

(A)

must be pure water

(B)

must be an acid

(C)

is not a base

(D)

is neither a base nor an acid

Solution:

Correct Answer is `=>` (C) is not a base
Q 2930580412

The pH of the blood is maintained by the carbonic acid and bicarbonate buffer. The pH of the blood is

(A)

`8.0`

(B)

`5.0`

(C)

`6.0`

(D)

`7.4`

Solution:

Correct Answer is `=>` (D) `7.4`
Q 2807167988

Solutions in test tubes containing `H_2O` and aqueous `NaOH` can be differentiated with the help of

(A)

red litmus

(B)

blue litmus

(C)

`Na_2 CO_3`

(D)

`HCl` (aqueous)

Solution:

Correct Answer is `=>` (A) red litmus
Q 2827178081

A soda water bottle has `pH`

(A)

`< 7`

(B)

`> 7`

(C)

`= 7`

(D)

unpredictable

Solution:

Correct Answer is `=>` (A) `< 7`
Q 2808212108

Which of the following is solubleb in water?

(A)

`CS_2`

(B)

`C_2H_5OH`

(C)

`C C l_4`

(D)

`CHCl_3`

Solution:

Correct Answer is `=>` (B) `C_2H_5OH`
Q 2930680512

The concentration of hydrochloric acid in a given solution is `10^(-8)` M. What is the value of `pH` for this solution?

(A)

`7`

(B)

`> 7` but nor `14`

(C)

`< 7`

(D)

`14`

Solution:

Correct Answer is `=>` (C) `< 7`
Q 2838391202

Aqueous solution of `CuS0_4` changes blue litmus to red as.

(A)

`Cu^2+`is present

(B)

`SC_4^(2-)` is present

(C)

hydrolysis takes place

(D)

reduction takes place

Solution:

Correct Answer is `=>` (C) hydrolysis takes place
Q 2818391209

Which among the following statements with regard to pH scale is/are correct?
I. It is logarithmic scale.
II. The scale is limited to 0-14 because the ionic product of water is about `10^(-14)`
III. The lower the value of pH the greater is the acidity of the solution.
Select the correct answer using the codes given below.

(A)

I and II

(B)

Only II

(C)

I and Ill

(D)

All of these

Solution:

Correct Answer is `=>` (D) All of these
Q 2950580414

pH of the solution produced when aqueous solution of `pH= 5` is mixed with equal volume of an aqueous solution of `pH = 3` is

(A)

3.3

(B)

3.5

(C)

4.5

(D)

4.0

Solution:

Correct Answer is `=>` (A) 3.3
Q 2877167986

A student heated some sulphur in a spatula and collected the gas 'X'. Which one among the following is correct about' X'?

(A)

X is `SO_2` and it lums moist litmus to blue

(B)

X is `SO_3` and it turns moist litmus to red

(C)

X is `SO_2` and it turns moist litmus to red

(D)

X is `SO_3` and it turns dry litmus to blue

Solution:

Correct Answer is `=>` (C) X is `SO_2` and it turns moist litmus to red
Q 2887167987

`pH` values for acids A, B, C, D are `1, 2, 4`, and `2.5` respectively. Which one of the strongest acid?

(A)

`A`

(B)

`B`

(C)

`C`

(D)

`D`

Solution:

Correct Answer is `=>` (A) `A`
Q 2910680510

Fear or excitement, generally cause on to breathe rapidly and it results in the decrease of `CO_2` concertration in blood. In what way will it change the pH of blood?

(A)

`pH` will increase

(B)

No change

(C)

`pH` will decrease

(D)

`pH` will adjust to `7`

Solution:

Correct Answer is `=>` (B) No change

Buffer Solutions and Salts

Q 1776045876


NCERT Exemplar

Assertion : (A) An aqueous solution of ammonium acetate can act as a buffer.

Reason : (R) Acetic acid is a weak acid and `NH_4OH` is a weak base

(A) Both A and R individually true and R is the correct explanation of A
(B) Both A and R are individually true but R is not the correct explanation of A
(C) A is true but R is false
(D) A is false but R is true
Solution:

Both assertion and reason are true but reason is not correct explanation of assertion.
Ammonium acetate is a salt of weak acid `(CH_3COOH)` and weak base `(NH_4OH)`.
Correct Answer is `=>` (B)
Q 2837867782

Acids generally react with alkalies to form salt and water. Which one of the following bases, on reaction with acid, does not produce water along with salt ?

(A)

Ammonia

(B)

Sodium bicarbonate

(C)

Sodium hydroxide

(D)

Calcium hydroxide

Solution:

Correct Answer is `=>` (A) Ammonia
Q 2980680517



Assertion : `Na_2SO_4` forms a neutral solution upon hydrolysis.

Reason : `Na_2 SO_4` is the salt of strong acid and strong base.

(A) Both A and R individually true and R is the correct explanation of A
(B) Both A and R are individually true but R is not the correct explanation of A
(C) A is true but R is false
(D) A is false but R is true
Solution:

Correct Answer is `=>` (A)
Q 2817167989

Iodised salt is a

(A)

mixture of potassium iodide and common salt

(B)

mixture of molecular iodine and common salt

(C)

compound formed by combination of potassium iodide and common salt

(D)

compound formed by combination of molecular iodine and common sail

Solution:

Correct Answer is `=>` (A) mixture of potassium iodide and common salt
Q 2828391201

Which one of the following salts when dissolved in water makes the solution acidic?

(A)

Sodium sulphate

(B)

Potassium nitrate

(C)

Sodium acetate

(D)

Ferric sulphate

Solution:

Correct Answer is `=>` (D) Ferric sulphate
Q 2848391203

An aqueous solution of potash alum is.

(A)

alkaline

(B)

acidic

(C)

neutral

(D)

soapy to touch

Solution:

Correct Answer is `=>` (D) soapy to touch
Q 2858391204

An aqueous solution of borax is.

(A)

alkaline

(B)

corrosine

(C)

neutral

(D)

acidic

Solution:

Correct Answer is `=>` (A) alkaline
Q 2808291108

When applied to the affected area, which one of the following will relieve the pain due to ant-bite or bee-sting?

(A)

Lemon juice

(B)

Vinegar

(C)

Baking soda

(D)

Caustic soda

Solution:

Correct Answer is `=>` (C) Baking soda
Q 2818291109

`NH_4Cl` is a salt of a

(A)

weak acid and weak base

(B)

weak acid and strong base

(C)

strong acid and strong base

(D)

strong acid and weak base

Solution:

Correct Answer is `=>` (D) strong acid and weak base
Q 2868391205

The aqueous solution of `AlCl_3` is acidic due to the hydrolysis of

(A)

aluminium ion

(B)

chloride ion

(C)

Both aluminium and chloride ion

(D)

None of the above

Solution:

Correct Answer is `=>` (C) Both aluminium and chloride ion
Q 2960680515



Assertion : Aqueous solution of ammonium acetate is neutral.

Reason : Ammonium acetate is the salt of acetic acid and ammonium hydroxide.

(A) Both A and R individually true and R is the correct explanation of A
(B) Both A and R are individually true but R is not the correct explanation of A
(C) A is true but R is false
(D) A is false but R is true
Solution:

Correct Answer is `=>` (B)
Q 2878391206

An aqueous solution of sodium carbonate is alkaline because sodium carbonate is a salt of.

(A)

weak acid and weak base

(B)

strong acid and weak base

(C)

weak acid and strong base

(D)

strong acid and strong base

Solution:

Correct Answer is `=>` (C) weak acid and strong base
Q 2888391207

Which one among the following is not a property of salt?

(A)

Salt have ordered packing arrangements called lattices

(B)

Salts have low melting points but high boiling points

(C)

Salts are brittle

(D)

Salts conduct electricity when dissolved in water or even in the molten state

Solution:

Correct Answer is `=>` (B) Salts have low melting points but high boiling points
 
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