Chemistry oxidation number

Calculate the concentration of acetic acid and acetate ion in a 0.2 M acetate buffer at pH 5. The p K a of acetic acid is 4.76

Levart [38]

Answer:

[Acetic acid] = 0.07 M

[Acetate] = 0.13 M

Explanation:

pH of buffer = 5

pKa of acetic acid = 4.76

$pH=p_{Ka} + log\frac{[Salt]}{[Acid]}$

Now using Henderson-Hasselbalch equation

$5=4.76 + log\frac{[Acetate]}{[Acetic\;acid]}$

$log\frac{[Acetate]}{[Acetic\;acid]} = 0.24$

$\frac{[Acetate]}{[Acetic\;acid]} = 1.74$ ....... (1)

It is given that,

[Acetate] + [Acetic acid] = 0.2 M ....... (2)

Now solving both the above equations

[Acetate] = 1.74[Acetic acid]

Substitute the concentration of acetate ion in equation (2)

1.74[Acetic acid] + [Acetic acid] = 0.2 M

[Acetic acid] = 0.2/2.74 = 0.07 M

[Acetate] = 0.2 - 0.07 = 0.13 M

5 0

3 years ago

How does a molecular formula differ from a structural formula?

mr Goodwill [35]

Explanation:

Molecular formulas show correct and accurate number of each type of the atoms which are present in molecule.

On the other hand, structural formulas show arrangement of atoms and covalent bonds between them.

For example,

The molecular formula for carbon dioxide is $CO_2$

The structural formula is O = C = O

7 0

3 years ago

Which scientist was the first to use the telescope in astronomy? Copernicus Newton Kepler Galileo

coldgirl [10]

The scientist that was the first to use the telescope in astronomy was Newton

8 0

3 years ago

(HELP FAST )What occurs when a pure liquid substance is cooled?

12345 [234]

Answer:

The particles in the substance become less active

6 0

3 years ago

Read 2 more answers

In modeling solid-state structures, atoms and ions are most often modeled as spheres. A structure built using spheres will have

Sav [38]

There are 2 atoms in each unit cell. The volume of 1 unit cell is 30.4 Å³. The volume of each atom is 10.3 Å³. The volume of atoms in the cell is 20.6 Å³. The packing efficiency of the solid is 67.8 %.

(a) How many total atoms are there in each unit cell?

In body centered cubic cells, there are 2 atoms, 1 in the center and 1 resulting from the sum of the 1/8 atom of each of the 8 corners.

$N = 1 + 1/8 \times 8 = 2$

(b) What is the volume of one unit cell in Å³?

Since the cell is a cube with a side of 3.12 Å (s), we can calculate its volume (V) using the following expression.

$V = s^{3} = 3.12^{3} = 30.4 A^{3}$

(c) Assuming that the atoms are spheres and the radius (r) of each sphere is 1.35 Å, what is the volume of one atom in Å³?

We will use the following expression for the volume of the sphere.

$V = \frac{4}{3} \times \pi \times r^{3} = \frac{4}{3} \times \pi \times (1.35A)^{3}=10.3 A^{3}$

(d) Therefore, what volume of atoms are in one unit cell?

There are 2 atoms in the unit cell, each one with a volume of 10.3 Å³.

$2 \pi 10.3 A^{3} = 20.6 A^{3}$

(e) Based on your results from parts (b) and (d), what is the packing efficiency of the solid expressed as a percentage?

The volume of 1 unit cell is 30.4 Å³ and the volume occupied by atoms in the cell is 20.6 Å³. The packing efficiency of the solid is:

$E = \frac{20.6A^{3} }{30.4A^{3}} \times 100\% = 67.8\%$

There are 2 atoms in each unit cell. The volume of 1 unit cell is 30.4 Å³. The volume of each atom is 10.3 Å³. The volume of atoms in the cell is 20.6 Å³. The packing efficiency of the solid is 67.8 %.

Learn more: brainly.com/question/3037904

4 0

3 years ago

Chemistryoxidation number​

Chemistryoxidation number