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3 years ago

A solution of acetic acid has an equilibrium pH of 2.54 (pKa = 4.75). What was the original concentration of acetic acid?

Chemistry

2 answers:

charle [14.2K]3 years ago

4 0

Answer:

A:0.469 molar

Explanation:

It is right

andrezito [222]3 years ago

3 0

Answer:

i cant under stand what you are trying to say

Explanation:

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A sample of carbon dioxide at RTP is 0.50 dm3. How many grams of carbon dioxide do we have?

prohojiy [21]

Answer:

0.924 g

Explanation:

The following data were obtained from the question:

Volume of CO2 at RTP = 0.50 dm³

Mass of CO2 =?

Next, we shall determine the number of mole of CO2 that occupied 0.50 dm³ at RTP (room temperature and pressure). This can be obtained as follow:

1 mole of gas = 24 dm³ at RTP

Thus,

1 mole of CO2 occupies 24 dm³ at RTP.

Therefore, Xmol of CO2 will occupy 0.50 dm³ at RTP i.e

Xmol of CO2 = 0.5 /24

Xmol of CO2 = 0.021 mole

Thus, 0.021 mole of CO2 occupied 0.5 dm³ at RTP.

Finally, we shall determine the mass of CO2 as follow:

Mole of CO2 = 0.021 mole

Molar mass of CO2 = 12 + (2×16) = 13 + 32 = 44 g/mol

Mass of CO2 =?

Mole = mass /Molar mass

0.021 = mass of CO2 /44

Cross multiply

Mass of CO2 = 0.021 × 44

Mass of CO2 = 0.924 g.

3 0

3 years ago

what is the volume of the air in a balloon that occupies 0.730 L at 28.0 c if the temperature is lowered to 0.00 C

svetoff [14.1K]

Answer:

The volume of the air is 0.662 L

Explanation:

Charles's Law is a gas law that relates the volume and temperature of a certain amount of gas at constant pressure. This law says that for a given sum of gas at a constant pressure, as the temperature increases, the volume of the gas increases and as the temperature decreases, the volume of the gas decreases because the temperature is directly related to the energy of the movement they have. the gas molecules. This is represented by the quotient that exists between volume and temperature will always have the same value:

$\frac{V}{T}=k$

If you have a certain volume of gas V1 that is at a temperature T1 at the beginning of the experiment and several the volume of gas to a new value V2, then the temperature will change to T2, and it will be true:

$\frac{V1}{T1}=\frac{V2}{T2}$

In this case:

V1= 0.730 L
T1= 28 °C= 301 °K (0°C= 273°K)
V2= ?
T2= 0°C= 273 °K

Replacing:

$\frac{0.730 L}{301K}=\frac{V2}{273K}$

Solving:

$V2=273K*\frac{0.730L}{301K}$

V2=0.662 L

The volume of the air is 0.662 L

6 0

3 years ago

How many grams of butane can be burned by 1.42 moles of oxygen?

Mrrafil [7]

Answer:

So the molar mass of C4,H10 is

58.12g mole -1

6 0

3 years ago

Which component is required for the activation of some enzymes?

shepuryov [24]

The best answer is letter A.
The main factors that change the speed of enzymatic reactions are temperature, pH and substrate concentration (quantity). There are enzymes that need other associated molecules to work. These molecules are called enzyme co-factors. They can be organic ions like mineral salts.

5 0

3 years ago

Read 2 more answers

Which of the following statements is incorrect? A. Molecular mass is expressed in atomic mass units. B. Formula mass compares th

n200080 [17]

Answer:

The incorrect statement is the choice C. Atomic mass has units of grams per atom.

Explanation:

1) Choice A. Molecular mass is expressed in atomic mass units.

Correct. Atomic mass units (a.m.u) is the standard unit used to express the mass of the atoms and the molecules.

Since, one atom, molecule, or formula unit is a tiny amount of material, it has a ver, very low mass, and the unit mass of a molecule is referred to one mole (6.022 × 10²³ units).

2) Choice B. Formula mass compares the mass of one formula unit of a substance to the mass of one atom of carbon-12.

Correct. The masses of atoms and compounds are referred to a standard. Such standard is the carbon-12 atom. This is, the cabon-12 atom was selected as the standard and its exact mass is 12 a.m.u.

3) Choice C. Atomic mass has units of grams per atom.

Incorrect. Atomic mass is the mass of the atoms, but, since, the mass of one atom is so small, the atomic mass is referred to one mole. Hence, the atomic mass has units of grams per mole.

4) Choice D. Both molecular mass and formula mass use carbon-12 as a reference standard.

Correct. As stated when explaining the option B, the mass of atoms, molecules, and formula units are referred to carbon-12 standard.

5) Choice E. Sodium chloride, an ionic compound, is said to have a formula weight, but not a molecular weight.

Correct. The reason is that ionic compounds form large structures (crystals) and, since there is not such thing as one molecule of them, they are said to have formula weight (or mass) but not a molecular weight.

The name molecules is reserved for covalent compounds, where you can formally identify molecules. E.g. Water is a molecular compound, and each molecule has molecular formula H₂O, whose mass is the molecular mass.

7 0

3 years ago