Most likely to break apart a rock

1. Calculate the concentration of hydronium ion of both buffer solutions at their starting pHs. Calculate the moles of hydronium

lilavasa [31]

Answer:

This question is incomplete, here's the complete question:

1. Calculate the concentration of hydronium ion of both buffer solutions at their starting pHs. Calculate the moles of hydronium ion present in 20.0 mL of each buffer.

Buffer A

Mass of sodium acetate used: 0.3730 g

Actual ph of the buffer 5.27

volume of the buffer used in buffer capacity titration 20.0 mL

Concentration of standardized NaOH 0.100M

moles of Naoh needed to change the ph by 1 unit for the buffer 0.00095mol

the buffer capacity 0.0475 M

Buffer B

Mass of sodium acetate used 1.12 g

Actual pH of the buffer 5.34

Volume of the buffer used in buffer capacity titration 20.0 mL

Concentration if standardized NaOH 0.100 M

moles of Naoh needed to change the ph by 1 unit 0.0019 mol

the buffer capacity 0.095 M

2.) A change of pH by 1 unit means a change in hydronium ion concentration by a factor of 10. Calculate the number of moles of NaOH that would theoretically be needed to decrease the moles of hydronium you calculated in #1 by a factor of 10 for each buffer. Are there any differences between your experimental results and the theoretical calculation?

3.) which buffer had a higher buffer capacity? Why?

Explanation:

Formula,

moles = grams/molar mass

molarity = moles/L of solution

1. Buffer A

molarity of NaC2H3O2 = 0.3731 g/82.03 g/mol x 0.02 L = 0.23 M

molarity of HC2H3O2 = 0. 1 M

Initial pH

pH = pKa + log(base/acid)

= 4.74 + log(0.23/0.1)

= 5.10

pH = -log[H3O+]

[H3O+] = 7.91 x 10^-6 M

In 20 ml buffer,

moles of H3O+ = 7.91 x 10^-6 M x 0.02 L

= 1.58 x 10^-7 mol

Buffer B

molarity of NaC2H3O2 = 1.12 g/82.03 g/mol x 0.02 L = 0.68 M

molarity of HC2H3O2 = 0.3 M

Initial pH

pH = pKa + log(base/acid)

= 4.74 + log(0.68/0.3)

= 5.10

pH = -log[H3O+]

[H3O+] = 7.91 x 10^-6 M

In 20 ml buffer,

moles of H3O+ = 7.91 x 10^-6 M x 0.02 L

= 1.58 x 10^-7 mol

2. let x moles of NaOH is added,

Buffer A,

pH = 5.10

[H3O+] = 7.91 x 10^-6 M

new pH = 4.10

new [H3O+] = 7.91 x 10^-5 M

moles of NaOH to be added = (7.91 x 10^-5 - 7.91 x 10^-6) x 0.02 L

= 1.42 x 10^-6 mol

3. Buffer B with greater concentration of NaC2H3O2 and HC2H3O2 has higher buffer capacity as it resists pH change to a wider range due to addition of acid or base to the system as compared to low concentration of Buffer A

5 0

3 years ago

1) a solution with a hyrdrogen ion concentration of 1x10^-4 moles/liter would have a PH of what?

lana66690 [7]

Answer:

pH = -log(concentration of hydro.gen ion)

1. When con. of H ion is 1*10-4 mol/L

pH = -log(1*10-4) = -(-4) = 4

2. A solution with a pH of 1*10-12mol/L

pH = -log (1*10-12) = -(-12) = 12

The pH is 12 and the solution is basic or alkaline

3.A solution with a pH of 6 has the concentration of

pH = -log (H+)

(H+) = arc log -pH

(H+) = 1*10-6

Explanation:

7 0

3 years ago

II. Binding Forces A. Write a brief, one or two sentence, description of each binding force listed below. 1. London dispersion f

Leya [2.2K]

Answer:

All description is given in explanation.

Explanation:

Van der Waals forces:

It is the general term used to describe the attraction or repulsion between the molecules. Vander waals force consist of two types of forces:

1. London dispersion forces

2. Dipole-dipole forces

1. London dispersion forces:

These are the weakest intermolecular forces. These are the temporary because when the electrons of atoms come close together they create temporary dipole, one end of an atom where the electronic density is high is create negative pole while the other becomes positive . These forces are also called induce dipole- induce dipole interaction.

2. Dipole-dipole forces:

These are attractive forces , present between the molecules that are permanently polar. They are present between the positive end of one polar molecules and the negative end of the other polar molecule.

Hydrogen bonding:

It is the electrostatic attraction present between the atoms which are chemically bonded. The one atom is hydrogen while the other electronegative atoms are oxygen, nitrogen or flourine. This is weaker than covalent and ionic bond.

Ionic bond or electrostatic attraction:

It is the electrostatic attraction present between the oppositely charged ions. This is formed when an atom loses its electron and create positive charge and other atom accept its electron and create negative charge.

Hydrophobic interaction:

It is the interaction between the water and hydrophobic material. The hydrophobic materials are long chain carbon containing compound. These or insoluble in water.

Covalent bond:

These compounds are formed by the sharing of electrons between the atoms of same elements are between the different element's atoms. The covalent bond is less stronger than ionic bond so require less energy to break as compared to the energy require to break the ionic bond.

5 0

3 years ago

If two gases are present in a container, the total pressure in the container is equal to

uysha [10]

.the sum of the pressures that each gas would exert if they occupied twice the volume

5 0

3 years ago

How does a sample of hydrogen at 10 °C compare to a sample of hydrogen at 350 K?

Aleks04 [339]

Answer: -

The hydrogen at 10 °C has slower-moving molecules than the sample at 350 K.

Explanation: -

Temperature of the hydrogen gas first sample = 10 °C.

Temperature in kelvin scale of the first sample = 10 + 273 = 283 K

For the second sample, the temperature is 350 K.

Thus we see the second sample of the hydrogen gas more temperature than the first sample.

We know from the kinetic theory of gases that

The kinetic energy of gas molecules increases with the increase in temperature of the gas. The speed of the movement of gas molecules also increase with the increase in kinetic energy.

So higher the temperature of a gas, more is the kinetic energy and more is the movement speed of the gas molecules.

Thus the hydrogen at 10 °C has slower-moving molecules than the sample at 350 K.

8 0

3 years ago

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