Humans do things that can affect the

Which of the following acids is the WEAKEST? The acid is followed by its Ka value.HF, 3.5 × 10^-4HNO2, 4.6 × 10^-4HCN, 4.9 × 10^

Mila [183]

Answer:

HCN

Explanation:

There are several factors that can tell us when an acid is stronger than another, which are the following:

1. The Polarity of the X - H Bond

2. Size of the X atom.

3. Charge on the acid.

4. Oxidation state of the central atom

5. Values of Ka and pKa.

From all of this factors, we can see that the exercise is already giving us values of Ka, and also we have different types of acid, not only with the form H - X

So, we will base the force of an acid by it's pKa value.

The pKa value which is calculated with the expression:

pKa = -logKa

pKa is a value that indicates how strong is the acid you are working with. This value can vary depending on factors such the charge of the acid. I f this charge can be easily distributed in resonance structures, the compound is more acidic, and therefore the pKa value is lower.

The lower the pKa, the more acidic the compound is.

So calculating the pKa on every structure we have:

HF: pKa = -log(3.5x10^-4) = 3.46

HNO2: pKa = -log(4.6x10^-4) = 3.34

HCN: pKa = -log(4.9x10^-10) = 9.31

HCOOH: pKa = -log(1.8x10^-4) = 3.74

HClO2: -log(1.1x10^-2) = 1.96

So according to all this values, we can conclude that the weakest acid is the HCN

4 0

4 years ago

why don't electrons, which are attracted to the protons in the nucleus, simply fall into the nucleus?

Murljashka [212]

Answer:

electrons are fermions, they can only access an energy level if it has not already been occupied by another electron. Thanks to this principle, there is a minimum energy level within the atom and it is not possible for an electron to collapse to the nucleus because it cannot exceed this} threshold.

Explanation:

I hope I have helped you.

7 0

3 years ago

Sulfuric acid in water dissociates completely into H+ and HSO4− ions. The HSO4− ion dissociates to a limited extent into H+ and

erastova [34]

Answer:

0.0010m SO₄²⁻

Explanation:

The freezing point depression due the addition of a solute into a pure solvent follows the equation:

ΔT = Kf×m×i (1)

<em>Where ΔT are °C that freezing point decreases (273.15K - 272.47K = 0.68K = 0.68°C). Kf is the constant of freezing point depression (1.86°C/m), m is molality of the solution (0.1778m) and i is Van't Hoff factor.</em>

Van't Hoff factor could be understood as in how many one mole of the solute (sulfuric acid, H₂SO₄), is dissociated.

H₂SO₄ dissociates as follows:

H₂SO₄ → HSO₄⁻ + H⁺

HSO₄⁻ ⇄ SO₄²⁻ + H⁺

<em>Not all HSO₄⁻ dissociates.</em>

1 Mole of H₂SO₄ dissociates in 1 mole of H⁺+ 1 mole of HSO₄⁻ + X moles of SO₄²⁻= 2 + X

Replacing in (1):

0.68°C = 1.86°C/m×0.1778m×i

2.056 = i

Moles of SO₄²⁻ are 2.056 - 2 = 0.056moles SO₄²⁻.

If 1 mole has a concentration of 0.1778m, 0.056moles are:

0.056moles ₓ (0.1778m / 1mole) =

8 0

3 years ago

Using the diagram above, answer the following questions:

STatiana [176]

Answer:

See explanation for details

Explanation:

6) C is false. What is going on there is actually a transformation of mechanical energy to the chemical energy stored in carbon dioxide in the atmosphere. The burning of the fossil fuel produces mechanical energy which is stored in the chemical bonds of CO2 hence the statement is false

7) A is true. Solar energy refers to energy from the sun, this energy is trapped from Tue sun and stored in chemical bonds in glucose, and starch molecules during photosynthesis.

8) C represents the release of carbon dioxide by the burning of fossil fuels.

9) B,C,D, E

B refers to photosynthesis in which plants take in atmospheric carbon dioxide

C refers to the burning of fossil rules which releases atmospheric carbon dioxide

D refers to the dissolution of atmospheric carbon dioxide in water bodies to form carbonates in water.

E refers refers the return of organic carbon to the soil by dead organisms

10) A and C

A shows the conversion of solar energy to chemical energy

C shows the conversion of mechanical energy to chemical energy

7 0

3 years ago

Let us assume that cu(oh)2(s) is completely insoluble, which signifies that the precipitation reaction with naoh(aq) (presented

yKpoI14uk [10]

<span>Answer: (0.150 L) x (0.0240 M Fe{3+}) x (3 mol OH{-} / 1 mol Fe{3+}) / (1.39 M NaOH) = 0.00777 L = 7.77 mL NaOH</span>

6 0

4 years ago