Acids and Bases in Water

Q.

Why is it advised to add concentrated acid to water and not water to the acid?

Q.

Given below are two statements: one is labelled as assertion $\mathrm{A}$and the other is labelled as reason $\mathrm{R}$.

Assertion $\mathrm{A}$:Dipole-dipole interactions are the only non-covalent interactions, resulting in hydrogen bond formation.

Reason $\mathrm{R}$: Fluorine is the most electronegative element and hydrogen bonds in $\mathrm{HF}$ are symmetrical

In the light of the above statements, choose the most appropriate answer from the options given below:

1. $\mathrm{A}$is false but $\mathrm{R}$ is true

2. Both $\mathrm{A}$ and $\mathrm{R}$ are true and $\mathrm{R}$ is the correct explanation of $\mathrm{A}$

3. $\mathrm{A}$ is true but $\mathrm{R}$ is false

4. Both $\mathrm{A}$and $\mathrm{R}$ is not the the correct explanation of $\mathrm{A}$

Q. What happens when HCl reacts with water?

1. Only ${\text{H}}^{+}$ is formed
2. Only ${\text{OH}}^{-}$ is released
3. Only ${\text{Cl}}^{-}$ is formed
4. Both ${\text{H}}^{+}$ and ${\text{Cl}}^{-}$ are formed

Q.

Classify the following salts into acidic, basic and neutral: Potassium sulphate, Ammonium chloride, Sodium carbonate, Sodium chloride?

Q. For dilution of concentrated acid, we should add

1. water into concentrated acid.
2. concentrated acid into water.
3. first water into acid and then more acid.
4. Both (a) and (b) are correct.

Q. Example of a solid covalent compound

Q. Question 6
Compounds such as alcohols and glucose also contain hydrogen but are not categorized as acids. Describe an activity to prove it.

Q. Why is it necessary to add acid to water before proceeding with the electrolysis of 'water'?

Q.

What are hydroxyl ions?

Q.

With the help of labelled diagrams, describe an activity to show that acids produce ions only in aqueous solutions.

Q.

How do $H^{+}$ ions exist in water

Q.

Write balanced equations to satisfy each statement.

(a) Acid + Active metal $\to$ Salt + Hydrogen

(b) Acid + Base $\to$ Salt + Water

(c) Acid + Carbonate $\to$ Salt + Water + Carbon dioxide

or bicarbonate

(d) Acid + Sulphite or bisulphite $\to$ Salt + Water + Sulphur dioxide

(e) Acid + Sulphide $\to$ Salt + Hydrogen Sulphide

Q.

Difference between hydroxide ion and hydroxyl ion?

Q. Why covalent bond have low melting point

Q.

16(f) Identify the following as acidic or basic salt:

HCOONa

Q.

Assertion: Lesser the pH of the solution, the more will be its acidic strength.

Reason: pH of a solution is inversely proportional to its [H⁺] concentration.

1. Both assertion and reason are correct and the reason is the correct explanation of the assertion.

2. Both assertion and reason are correct but the reason is not the correct explanation of the assertion.

3. The assertion is correct but the reason is incorrect

4. The assertion is incorrect but the reason is correct

Q.

On passing a current of HCl gas in a saturated solution of NaCl, the solubility of NaCl?

1. Increases

2. Decreases

3. Remains unchanged

4. Decomposes NaCl

Q.

What is POLAR BOND ??

and

What is POLAR COVALENT BOND ??

Q. Carbonic acid gives an acid salt but hydrochloric does not. Explain.

Q.

Taking hydrogen chloride and methane as examples, distinguish between a polar covalent bond and a non-polar covalent bond.

Q.

Is Vinegar a solute?

Q.

Will the solution of sugar in distilled water conduct electricity?

Q. Fill in the blanks from the choices given below:
(i) In covalent compounds, the bond is formed due to the ________ (sharing/transfer) of electrons.
(ii) Electrovalent compounds have a ________ (low/high) boiling point.
(iii) A molecule of _________ contains a triple bond (hydrogen, ammonia, nitrogen).

Q. Question 29.
Show the dilute aqueous solution of hydrochloric acid
(a) ${\text{H}}_3{\text{O}}^{+}+{\text{Cl}}^{-}$
(b) ${\text{H}}_3{\text{O}}^{+}+{\text{OH}}^{-}$
(c) ${\text{Cl}}^{-}+{\text{OH}}^{-}$
(d) unionised HCl

Q.

(a) Why do acids not show acidic behavior in the absence of water?

(b) Why does an aqueous solution of an acid conduct electricity?

(c) Why does distilled water not conduct electricity whereas rainwater does?

Q.

Differentiate between simple and compound ions.

Q.

In water, oxygen has a slight negative charge and hydrogen has a slight positive charge. So what type of bond does water have?

1. Covalent bond

2. Ionic bond

3. Non polar covalent bond

4. Polar covalent bond

Q. What happens when HCl reacts with water?

1. Only ${\text{H}}^{+}$ is formed
2. Only ${\text{OH}}^{-}$ is released
3. Only ${\text{Cl}}^{-}$ is formed
4. Both ${\text{H}}^{+}$ and ${\text{Cl}}^{-}$ are formed

Q. Classify the following salts as acidic, basic or neutral.
$N{H}_{4}Cl,C{H}_{3}COONa,KCl$

Q. Is NaCl dissociate in water due to polar structure of water