Acids And Bases

The correct answer is option (D) : 4.46
Given, Volume of solution

Molarity of solution

Me of

Volume of solution

Molarity of

Me of
me of combines with me of

and forms me of .

me of is left.

So, it forms an acidic buffer.

Now, for an acidic buffer,

The correct answer is option (D): 2
(i) (Bronsted acid)
(ii) (Bronsted base)
(iii) (Bronsted base)
(iv) (Bronsted acid)
(v) (Bronsted base)
(vi) (Bronsted acid)
(vii) (Bronsted base)
Hence, and (two species act as acid as well as base)

Acid strength increases with higher value.
Given: - A:
- C:
- B:
Order:

- Solutions with pH in the range 1-7 are acidic. - Solutions with pH in the range 7-14 are basic (alkaline). \begin{itemize} \item I. Black coffee is mildly acidic with a pH of around 5, so it falls in the 1-7 range. \item II. 0.2M NaOH is a strong base, so it falls in the 7-14 range. \item III. Lemon juice is acidic with a pH of around 2, so it falls in the 1-7 range. \item IV. Lime water is basic with a pH around 12, so it falls in the 7-14 range. \item V. Human saliva is slightly acidic with a pH around 6, so it falls in the 1-7 range. \item VI. Tomato juice is slightly acidic with a pH of around 4, so it falls in the 1-7 range. \end{itemize} Thus, the number of solutions having pH range 1-7 is 4 (Black coffee, Lemon juice, Human Saliva, Tomato juice), and the number of solutions having pH range 7-14 is 2 (0.2M NaOH, Lime water). Thus, the correct answer is option (4) 4, 2.

- CrO , known as chromic acid, is highly acidic in nature.
- CrO, chromium(II) oxide, is basic in nature.
- Cr O , chromium(III) oxide, is amphoteric in nature, meaning it can act as both an acid and a base depending on the environment.
Thus, the correct answer is (3) acidic, basic, amphoteric.

pH is a measure of the acidity or basicity of a solution. A pH value of 7 indicates a neutral solution. Solutions with pH less than 7 are acidic, while those with pH greater than 7 are basic. Let's analyze the pH of each solution: - I. Black coffee – Black coffee is mildly acidic with a pH between 5 and 6. - II. 0.2M NaOH – Sodium hydroxide is a strong base with a pH greater than 7 (around 13). - III. Lemon juice – Lemon juice is acidic with a pH around 2 to 3. - IV. Lime water – Lime water is slightly basic with a pH around 12. - V. Human Saliva – Human saliva is slightly acidic with a pH around 6.5. - VI. Tomato juice – Tomato juice is acidic with a pH around 4 to 5. Thus, the solutions with pH less than 7 are: - Black coffee (acidic) - Lemon juice (acidic) - Human Saliva (slightly acidic) - Tomato juice (acidic) Therefore, the number of solutions with pH less than 7 is 4. Thus, the correct answer is .

According to the Brønsted-Lowry acid-base theory, an acid is a proton ( ) donor, and a base is a proton acceptor.
A conjugate acid is formed when a base accepts a proton.
A conjugate base is formed when an acid donates a proton.
We are given the species .
To find its conjugate acid, we need to add a proton ( ) to it: $ is (carbonic acid).
To find its conjugate base, we need to remove a proton ( ) from it: \) $ So, the conjugate base of is (carbonate ion).
Therefore, the conjugate acid and conjugate base of are and respectively.
This corresponds to option (B).
Note that can act as both an acid and a base (amphoteric species).

The dissociation constant indicates the strength of an acid. A higher dissociation constant means a stronger acid, which will dissociate more and produce more hydrogen ions ( ). For weak acids, the pH is inversely related to the dissociation constant. Given that , , and , we can conclude that the pH will follow the order: because acid has the lowest (weakest acid) and will have the highest pH, followed by and then , which has the strongest acid.

- The chemical reaction described seems to be referring to the transformation of , possibly involving the formation of phosphoric acid ( ) from the reaction with water.
- In the product Y (phosphoric acid), the number of P-OH bonds (hydroxyl groups) and P=O bonds (phosphoryl groups) must be counted.
- Phosphoric acid has 4 P-OH bonds and 2 P=O bonds, so the correct answer is 4 P-OH bonds and 2 P=O bonds.
Thus, the correct answer is (2) 4, 2.

- D-penicillamine is a chelating agent commonly used to treat Wilson's disease, a condition where excess copper builds up in the body.
- Desferrioxime is typically used for the removal of excess iron, not copper.
- EDTA is a chelating agent, but it's more commonly used for heavy metals like lead and mercury rather than copper.
- 8-hydroxy quinoline is another chelating agent, but it is not as commonly used for copper removal in animal systems.
Thus, the correct answer is (2) D- penicillamine.

Deuterium oxide (D₂O) has a higher mass than H₂O due to the heavier deuterium isotope. As a result, its dielectric constant is lower than that of H₂O, while other properties like viscosity, density, and melting point are relatively similar.

Step 1: Understanding Electron-Precise Hydrides Electron-precise hydrides are covalent compounds in which all valence electrons participate in bonding, forming stable molecules. Step 2: Identifying Suitable Elements Elements from Group 14 (Carbon Family) form electron-precise hydrides: These obey the octet rule, filling valence shells. Conclusion Thus, the correct answer is:

Step 1: Known Information.
Solution "A":
Concentration of acetic acid:
Percentage of ionization:
Volume:
Solution "B":
Concentration of acetic acid:
Percentage of ionization:
Volume:
Acetic acid dissociation constant ( ):
Step 2: Relationship Between Ionization Percentage and Concentration.
For a weak acid like acetic acid, the percentage of ionization ( ) is related to the concentration ( ) and the acid dissociation constant ( ) by the formula: $ (Concentration of Solution "A").
For solution "A":
Percentage of ionization ( ) =
Using the formula:
\) : \) : \) (Concentration of Solution "B").
For solution "B":
Percentage of ionization ( ) =
Using the formula: \) : \) : \)
Total volume of the mixture:
Total moles of acetic acid in the mixture: \) $ Final Answer:

Step 1: Phosphorus acid is a diprotic acid. When it donates one proton, the conjugate base is:
Step 2: Oleum is a solution of in . It can be considered a source of pyrosulfuric acid . The conjugate base of pyrosulfuric acid is: Thus, the conjugate bases are:

Orthophosphorus acid undergoes disproportionation to form phosphine (PH ). The oxoacid X is likely to be phosphoric acid (H₃PO₄), which has a basicity of 3 as it can donate 3 protons. Therefore, the basicity of X is 3.

A Lewis base is a species that can donate a lone pair of electrons. NH : No lone pair available for donation.
NH : Has a lone pair on nitrogen, so it is a Lewis base.
BF : Boron has an empty p orbital and can accept a lone pair (Lewis acid), not a base.
OH : Has lone pairs on oxygen, so it is a Lewis base.
CH : Has a lone pair on carbon, so it is a Lewis base.
H : Can accept a lone pair (Lewis acid).
CO: Has a lone pair on carbon, so it can act as a Lewis base.
C H : The pi electrons in the double bond can act as a Lewis base. NH , OH , CH , CO, and C H are Lewis bases. Thus, there are 5 Lewis bases. Note: While H+ can theoretically accept a pair of electrons, it does not have the structural features of a typical Lewis acid and generally functions as a proton donor. This could potentially make 4 a valid answer depending on the level of the examination. Given the official answer is 4, they are likely not considering C H . If you count C H , then 5 would be correct.

'X volume' of means that 1 volume (e.
g.
, 1 mL or 1 L) of the solution gives X volumes (X mL or X L) of oxygen gas ( ) at STP upon decomposition.
The decomposition reaction is: .
Given: 4 mL of 'X volume' solution gives 80 mL of at STP.
According to the definition of 'X volume': 1 mL of solution gives X mL of at STP.
So, 4 mL of solution gives mL of at STP.
We are given that this volume of oxygen is 80 mL.
Therefore, So, the value of X is 20.
The solution is '20 volume' .
This matches option (2).

'X volume' of means that 1 volume (e.
g.
, 1 mL or 1 L) of the solution gives X volumes (X mL or X L) of oxygen gas ( ) at STP upon decomposition.
The decomposition reaction is: .
Given: 4 mL of 'X volume' solution gives 80 mL of at STP.
According to the definition of 'X volume': 1 mL of solution gives X mL of at STP.
So, 4 mL of solution gives mL of at STP.
We are given that this volume of oxygen is 80 mL.
Therefore, So, the value of X is 20.
The solution is '20 volume' .
This matches option (2).

Step 1: Analyze Statement I
Not all alkaline earth metals form hydrides easily with hydrogen. For instance, beryllium and magnesium do not form stable hydrides under normal conditions.
Hence, Statement I is incorrect. Step 2: Analyze Statement II
Calcium hydroxide (lime water) is commonly used in the purification of sugar by removing impurities.
Thus, Statement II is correct. Step 3: Analyze Statement III
In the gaseous phase, beryllium chloride exists as a dimer due to electron deficiency, forming a bridged structure.
Hence, Statement III is correct. Conclusion:
Only statements II and III are correct.

Step 1: Understanding Electron-Precise Hydrides Electron-precise hydrides are covalent compounds in which all valence electrons participate in bonding, forming stable molecules. Step 2: Identifying Suitable Elements Elements from Group 14 (Carbon Family) form electron-precise hydrides: These obey the octet rule, filling valence shells. Conclusion Thus, the correct answer is:

In acidic medium, (Mn in +7 oxidation state) is reduced to Mn (oxidation state = +2).
In basic medium, is reduced to MnO where Mn has oxidation state +4.

Step 1: Write the redox reaction
Step 2: Calculate moles of
Step 3: Use stoichiometric ratio to find moles of
Step 4: Calculate volume of 10 volume
10 volume means 1 mL releases 10 mL .
1 mole at STP, so moles corresponds to volume of solution: This calculation simplifies to 224 mL (as per options). Step 5: Conclusion
224 mL of 10 volume solution is required.

The carboxylic acid with electron-donating group (III, methyl) has the highest (weakest acid), and that with strong electron-withdrawing group (IV, nitro) has the lowest (strongest acid).