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2 years ago

Which of the following accurately describes the pH scale?

Chemistry

2 answers:

aleksandrvk [35]2 years ago

6 0

The correct answer is <span>B. The greater the pH is, the lower the acidity is.</span>

seraphim [82]2 years ago

5 0

Answer is: B. The greater the pH is, the lower the acidity is.

pH (potential of hydrogen) is a numeric scale used to specify the acidity or basicity an aqueous solution.

When pH is less than seven (pH<7), solution is acidic.

When is equal seven (pH = 7), solution is neutral.

When pH is greater than seven (pH > 7), solution is basic.

An acid is a molecule or ion capable of donating proton or hydrogen ion H⁺.

For example, hydrochloric acid( HCl) is acidic, it ionizes in water solution and gives the hydrogen cations and chloride anions (Cl⁻):

HCl(aq) → Cl⁻(aq) + H⁺(aq).

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For the net reaction: 2AB + 2C → A2 + 2BC, the following slow first steps have been proposed. AB → A + B 2C + AB → AC + BC 2AB →

puteri [66]

This is an incomplete question, here is a complete question.

For the net reaction: 2AB + 2C → A2 + 2BC, the following slow first steps have been proposed.

(1) AB → A + B

(2) 2C + AB → AC + BC

(3) 2AB → A₂ + 2B

(4) C + AB → BC + A

What rate law is predicted by each of these steps?

Answer : The rate law expression for the following reactions are:

(1) $\text{Rate}=k[AB]$

(2) $\text{Rate}=k[C]^2[AB]$

(3) $\text{Rate}=k[AB]^2$

(4) $\text{Rate}=k[C][AB]$

Explanation :

Rate law : It is defined as the expression which expresses the rate of the reaction in terms of molar concentration of the reactants with each term raised to the power their stoichiometric coefficient of that reactant in the balanced chemical equation.

The general reaction is:

$A+B\rightarrow C+D$

The general rate law expression for the reaction is:

$\text{Rate}=k[A]^a[B]^b$

where,

a = order with respect to A

b = order with respect to B

R = rate law

k = rate constant

$[A]$ and $[B]$ = concentration of A and B reactant

Now we have to determine the rate law for the given reaction.

(1) The balanced equations will be:

$AB\rightarrow A+B$

In this reaction, $AB$ is the reactant.

The rate law expression for the reaction is:

$\text{Rate}=k[AB]$

(2) The balanced equations will be:

$2C+AB\rightarrow AC+BC$

In this reaction, $C$ and $AB$ are the reactants.

The rate law expression for the reaction is:

$\text{Rate}=k[C]^2[AB]$

(3) The balanced equations will be:

$2AB\rightarrow A_2+2B$

In this reaction, $AB$ is the reactant.

The rate law expression for the reaction is:

$\text{Rate}=k[AB]^2$

(4) The balanced equations will be:

$C+AB\rightarrow BC+A$

In this reaction, $C$ and $AB$ are the reactants.

The rate law expression for the reaction is:

$\text{Rate}=k[C][AB]$

7 0

3 years ago

Which of the following is/are true?

4vir4ik [10]

Answer:

Answer is D. All of the above

3 0

2 years ago

PLEASE HELP!!!!!!!

Basile [38]

Answer:

2nd option

Explanation:

5 0

3 years ago

A solution of 0.0470 M HCl is used to titrate 26.0 mL of an ammonia solution of unknown concentration. The equivalence point is

DanielleElmas [232]

The pH at equivalence point is 12.46

At equivalence point, number of moles of acid, n equals number of moles of base, n'

So, n = n'

CV = C'V' where

C = concentration of acid (HCl) = 0.0470 M,
V = volume of acid = 16.0 mL,
C' = concentration of base (ammonia solution) and
V' = volume of base = 26.0 mL.

<h3>Concentration of ammonia solution</h3>

Making C' subject of the formula, we have

C' = CV/V'

Substituting the values of the variables into the equation, we have

C' = CV/V'

C' = 0.0470 M × 16.0 mL/26.0 mL

C' = 0.752 MmL/26.0 mL

C' = 0.0289 M

<h3>The concentration of acid at equivalence point</h3>

We know that the ion-product of water Kw is

Kw = [H⁺][OH⁻] = where

[H⁺] = concentration of HCl at equivalence point,
[OH⁻] = C' = concentration of ammonia solution = 0.0289 M and
Kw = 1.01 × 10⁻¹⁴

Making [H⁺] subject of the formula, we have

[H⁺} = Kw/[OH⁻]

[H⁺] = 1.01 × 10⁻¹⁴/0.0289

[H⁺] = 34.95 × 10⁻¹⁴

[H⁺] = 3.495 × 10⁻¹³

<h3>pH at equivalence point</h3>

Since pH = -㏒[H⁺]

pH = -㏒[3.495 × 10⁻¹³]

pH = -㏒[3.495] + (-㏒10⁻¹³)

pH = -㏒[3.495] + [-13(-㏒10)]

pH = 13 - 0.5434

pH = 12.4566

pH ≅ 12.46

So, the pH at equivalence point is 12.46

Learn more about pH at equivalence point here:

brainly.com/question/25487920

3 0

2 years ago

Which two elements make up the greatest percentages by mass in Earth’s crust?

yuradex [85]

<h2><u>Answer</u> :</h2>

The most appropriate option is :

$\hookrightarrow \bf2. \: \mathrm{ \underline{oxygen \: \: and \: \: silicon}}$

Since, they are the most abundant elements found in Earth's Crust.

Oxygen (46%)

Silicon (28%)

$\circ { \underline{ \boxed{ \sf{ \color{green}{ \mathrm{hope \: \: it \: \: helps \: \: you .....}}}}}}∘$

4 0

2 years ago