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3 years ago

Why will the conjugate base of a weak acid affect pH? Select the correct answer below: it will react with hydroxide

Chemistry

1 answer:

GREYUIT [131]3 years ago

4 0

The question is incomplete; the complete question is;

Why will the conjugate base of a weak acid affect pH? Select the correct answer below: O it will react with hydroxide

O it will react with water

O it will react with hydronium

O none of the above Content attribution

Answer:

O it will react with hydronium

Explanation:

If we have a weak acid HA, the weak acid ionizes as follows;

HA(aq) ----> H^+(aq) + A^-(aq)

A^- is the conjugate base of the weak acid.

H^+ interacts with water to form the hydronium ion as follows;

H^+(aq) + H2O(l) ----> H3O^+(aq)

The pH=[H3O^+]

But the conjugate base of the weak acid reacts with this hydronium ion thereby affecting its concentration and the pH of the system as follows;

A^-(aq) + H3O^+(aq) ------> HA(aq) + H2O(l)

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State hess's law.how is it used

Vesnalui [34]

Hess' Law states that the enthalpy change in a reaction can be calculated from the enthalpy changes of reactions that, when combined, result in the desired reaction.

For example, to check the enthalpy change that occurs when benzene undergoes incomplete combustion to water and carbon monoxide is not an easy task, because the products invariably contain CO2. However, by combining the reactions of the complete combustion of benzene and the combustion of CO, you can get the reaction you want.

Reaction wanted: 2C6H6 + 9O2 → 12CO + 6H2O
Reactions provided: 2C6H6 + 15O2 → 12CO2 + 6H2O and 2CO + O2 → 2CO2, and their associated ΔH.

Rearrange the reactions so that, when they add up, they result in the wanted reaction.

2C6H6 + 15O2 → 12CO2 + 6H2O (leave as is; no changes to ΔH)
12CO2 → 12CO + 6O2 (reverse and multiply by 6; this changes the sign of ΔH and multiplies it by 6)

Added up, it will result in 2C6H6 + 9O2 → 12CO + 6H2O. Add up the ΔH values for the rearranged reactions to find ΔH for this particular reaction.

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3 years ago

Read 2 more answers

Is the bond formed between each pair of atoms pure covalent (a.k.a. nonpolar covalent), polar covalent, or ionic?

swat32

Answer:

So, look up for electronegativity table

There's a continuum for deciding whether the bond is non-polar, polar, or ionic

If electronegativity difference is less than 0.4 it's non-polar

Explanation:

Pls vote my answer as brainliest

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3 years ago

A beaker with 1.80×102 mL of an acetic acid buffer with a pH of 5.000 is sitting on a benchtop. The total molarity of acid and c

tekilochka [14]

Answer:

The pH change in 0,206 units

Explanation:

When the acetic acid buffer is at pH 5,000; it is possible to obtain the acetate/acetic acid proportions using Henderson-Hasselbalch formula, thus:

pH = pka + log₁₀ [A⁻]/[HA] Where A⁻ is CH₃COO⁻ and HA is CH₃COOH.

Replacing:

5,000 = 4,740 + log₁₀ [A⁻]/[HA]

1,820 = [A⁻]/[HA] (1)

As buffer concentration is 0,100M:

[A⁻] + [HA] = 0,100 (2)

Replacing (2) in (1)

[HA] = 0,035M

And [A⁻] = 0,065M

As volume is 1,80x10²mL, moles of HA and A⁻ are:

0,180L × 0,035M = 6,3x10⁻³mol of HA

0,180L × 0,065M = 1,17x10⁻²mol of A⁻

The reaction of HCl with A⁻ is:

HCl + A⁻ → HA + Cl⁻

The add moles of HCl are:

0,0065L×0,330M = 2,145x10⁻³ moles of HCl that are equivalent to moles of A⁻ consumed and moles of HA produced.

Thus, moles of HA after addition of HCl are:

6,3x10⁻³mol + 2,145x10⁻³ mol = 8,445x10⁻³ moles of HA

And moles of A⁻ are:

1,17x10⁻²mol - 2,145x10⁻³ mol = 9,555x10⁻³ moles of A⁻

Replacing these values in Henderson-Hasselbalch formula:

pH = 4,740 + log₁₀ [9,555x10⁻³ ]/[8,445x10⁻³ ]

pH = 4,794

The pH change in 5,000-4,794 = 0,206 units

I hope it helps!

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3 years ago

What will happen when the rates of evaporation and condensation are equal

Ilia_Sergeevich [38]

A random person put the answer for you

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3 years ago

Rank the given compounds based on their relative Bronsted acidities.

Law Incorporation [45]

Answer:

Explanation:

As the size of the halogen increases their acidity increases. Though HF being a weak acid is a stronger acid than water. H-NH2 is a base, while H-CH3 can be made to produce H+.

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4 years ago