A solution contains 0.10 m sodium cyanide and 0.10 m potassium hydroxide. solid zinc acetate is added slowly to this mixture. what is the formula of the substance that precipitates first?

To find the pH of the buffer solution, the Henderson-Hasselbalch equation is used with the provided concentrations of weak acid and conjugate base, yielding a pH value of approximately 5.26.

To calculate the pH of the buffer solution containing a weak acid and its conjugate base, we can use the Henderson-Hasselbalch equation:

pH = pKa + log([A-]/[HA])

where pKa is the negative logarithm of the acid dissociation constant (Ka), [A-] is the concentration of the conjugate base, and [HA] is the concentration of the weak acid.

Given that the weak acid concentration is 0.120 M its conjugate base concentration is 0.440 M, and the Ka for the weak acid is 2.0 × 10^-5, we first calculate pKa:

pKa = -log(Ka) = -log(2.0 × 10^-5) = 4.70

Next, we use the Henderson-Hasselbalch equation:

pH = 4.70 + log(0.440/0.120) = 4.70 + log(3.667) ≈ 4.70 + 0.564 = 5.264

The pH of the buffer solution is therefore approximately 5.26.

Final answer:

To calculate the pH of the buffer solution, first determine the pKa from the given Ka and then apply the Henderson-Hasselbalch equation using the concentrations of the weak acid and its conjugate base. The pH of the given buffer solution is approximately 5.27.

Explanation:

The pH of a buffer solution can be determined using the Henderson-Hasselbalch equation, which is pH = pKa + log(·[A−]/[HA]·), where [A−] is the concentration of the conjugate base and [HA] is the concentration of the acid. In this case, the weak acid has a given Ka value of 2.0 × 10⁻µ, which allows us to calculate its pKa as the negative logarithm of Ka (pKa = -log(Ka)).

First, calculate the pKa:

pKa = -log(Ka)
  = -log(2.0 × 10⁻µ)
  = 4.70

Now, apply the Henderson-Hasselbalch equation:

pH = pKa + log([A−]/[HA])
  = 4.70 + log(0.440 M/0.120 M)
  = 4.70 + log(3.67)
  = 4.70 + 0.565
  = 5.265

Therefore, the pH of the buffer solution is approximately 5.27.

The mass ratio of oxygen to nitrogen in the first compound is 1.1413, and in the second compound, it is 4.5810. The ratio of these mass ratios is approximately 4.015.

The question involves calculating the mass ratio of oxygen to nitrogen for two nitrogen-oxygen compounds and then finding the ratio of these mass ratios.

For the first compound:
Mass of O: 53.3 g
Mass of N: 46.7 g
Mass ratio of O to N: 53.3 g / 46.7 g = 1.1413

For the second compound:
Mass of O: 82.0 g
Mass of N: 17.9 g
Mass ratio of O to N: 82.0 g / 17.9 g = 4.5810

Now, we calculate the ratio of the mass ratio of the second compound to that of the first compound:
4.5810 / 1.1413 = 4.015

Therefore, the ratio of the mass ratio of oxygen to nitrogen in the second compound to the first one is approximately 4.015.

M₂ = (M₁V₁) / V₂

Dilution represents the addition of a solvent (water) without adding solutes. In dilution, the mole of the solute remains, so the concentration of the solution will drop.

When calculating dilution factors, the units of volume and concentration must remain consistent.

Dilution calculations can be typically performed following the formula:

[tex]\boxed{ \ M_1V_1 = M_2V_2 \ }[/tex].

with,

The equation which represents the correct way to find the concentration of the dilute solution (M₂) is

[tex]\boxed{ \ M_2 = \frac{M_1V_1}{V_2} \ }[/tex].

_ _ _ _ _ _ _ _ _ _

Example:

How much must be dissolved to carry out 5 liters of 0.4 M methanol solution? How much water do you require adding?

[tex]\boxed{ \ V_1 = \frac{M_2V_2}{M_1} \ }[/tex]

[tex]\boxed{ \ V_1 = \frac{0.4 \times 5}{25} \ }[/tex]

[tex]\boxed{ \ V_1 = \frac{0.4}{5} \ }[/tex]

[tex]\boxed{ \ V_1 = \frac{0.8}{10} \ }[/tex]

[tex]\boxed{ \ V_1 = \frac{8}{100} \ }[/tex]

_ _ _ _ _ _ _ _ _ _

Notes:

[tex]\boxed{ \ molarity = \frac{moles \ of \ solute}{liters \ of \ solution} \ }[/tex]

M₂ = (M₁V₁) / V₂ is the equation which represents the correct way to find the concentration of the dilute solution.

In chemistry, concentration is the ratio of solute to solvent or solution in a given volume. The amount of material in various solutions is quantified and compared using this crucial characteristic. Chemistry requires concentration in many different areas, such as chemical reactions, analyte detection, and solution preparation. Concentration can be expressed in a number of different ways, including molarity (M), mass/volume percent (%), parts per million (ppm), and mole fraction. Depending on the needs of the experiment or application, each approach offers a distinctive viewpoint on the solute concentration in a solution and is applied in various situations.

M₂ V₂= (M₁V₁)

M₂ = (M₁V₁) / V₂

To know more about concentration, here:

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The rate determining step for the reactivity for the solvolysis of 2-chloro-norbornane depends only on the decomposition of a single molecular species which is the 2-chloro-norbornane itself. For unimolecular reactions, the mechanism pathway being followed is that of an SN1 mechanism.

Answer:

SN1 mechanism

Answer: The element having given valence electronic configuration is beryllium.

Explanation:

Electronic configuration is defined as the representation of electrons around the nucleus of an atom. Number of electrons in an atom are determined by the atomic number of that atom.

Valence electrons are defined as the electrons present in the outermost shell of an atom.

We are given:

Valence electronic configuration of an atom = [tex]2s^2[/tex]

So, the actual electronic configuration of atom will be [tex]1s^22s^2[/tex]

Total number of electrons = 2 + 2 = 4

So, the atomic number of given element is 4 and the element is beryllium

Hence, the element having given valence electronic configuration is beryllium.