Which of the following acids (listed with pKa values) and their conjugate base would form a buffer with a pH of 8.10?(A) HC7H5O2, pKa = 4.19
(B) HF, pKa = 3.46
(C) HClO, pKa = 7.54
(D) HCN, pKa = 9.31
(E) HClO2, pKa = 1.96

Answers

Answer 1

Answer:

Answer:

The buffer of pH 8.10 will be formed by the HClO having pKa value of 7.54.

Explanation:

Buffer is defined as the substance that can withstand the changes in the solution due to addition of acid or base. Buffer acts to neutralize the small amounts of acids or base when added.

Buffer is composed of two parts:

A weak acid and its conjugate base and a weak base with its conjugate acid.

According to the Bronsted-Lowry theory,acids are the substances that release $\text {H^(2) }$ $\text H^(+)$ , whereas the substances that accept bases.

Similarly, when an acid loses a proton ( $\text H^(+)$ ) $\text {H^(2) }$ $\text {H^(+) }$ , it is converted into the conjugate base, such that the conjugate acid-base pair of HClO is $\text {H}^(+)/\text{ClO}^(-)$ .

The buffer range for a substance is either one unit more or one unit less than the pKa value of the given substance. Thus, to obtain the pH value of 8.10, the acid with pKa value of 7.54 will be selected. The pH range of $\text {H}^(+)/\text{ClO}^(-)$ will have the buffer range between 6.54 and 8.54. Thus, pH of 8.10 will be formed by

Hence, rest of the options are incorrect because the buffer range for given acids will not be close the given value of pH as 8.10.

For Further Reference:

brainly.com/question/14353715?referrer=searchResults

Answer 2

Answer:

Answer:

Explanation:

A buffer is a solution that can resist abrupt changes in pH when acids or bases are added. It is formed by two components:

A weak acid and its conjugate base.
A weak base and its conjugateacid.

In this case, acid and base are defined according to Bronsted-Löwry theory, which states that acids are substances that release H⁺ and bases are substances that accept H⁺. Therefore, when an acid loses an H⁺ transforms into its conjugated base. For example, HF/F⁻ is a conjugate acid-base pair.

In buffers, when an acid is added, it reacts with the base to diminish its amount:

F⁻ + H⁺ ⇄ HF

Also in buffers, when a base is added, it reacts with the acid to diminish its amount:

HF + OH⁻ = F⁻ + H₂O

The optimum pH range of work of a buffer system (known as buffer range) is between 1 unit less and 1 unit more of pH than its pKa.

So, the buffer formed by HClO/ClO⁻ works optimally in the pH range 6.54-8.54. Since pH = 8.10 is in that interval, this would be the optimal choice.

Related Questions

Assuming that the distances between the two ions are the same in all cases, which of the following ion pairs has the greatest electrostatic potential energy (i.e., largest in magnitude)? Please explain your answer.a.) Na+ - Cl- b.) Na+ - O-2. c.) Al+3 - O-2. d.) Mg+2-O-2 e.) Na- -Mg+2

Answers

Answer:

Correct option: C

Explanation:

As given in the question that distance between two ions are same in all cases hence r is same for all.

potential energy:

$P.E =(k* q_(1) * q_(2))/(r)$

therefore potential energy depend on the two charge muliplication

so higher the charge multiplication higer will be the potential energy.

magnitude of charge multiplication follow as:

a. 1

b. 2

c. 6

d. 4

e. 2

in option C it is higher

so correct option is C

A protein is Select one: a. a saturated ester of glycerol. b. a polysaccharide. c. an aromatic hydrocarbon. d. a polymer of amino acids. e. one of the units making up a nucleic acid.

Answers

Answer:

d. a polymer of amino acids

Explanation:

Got it right on the test.

Answer:

Explanation:

The building blocks or monomers of proteins are called amino acids. There are 20 different kinds of amino acids. The amino acids form long chains that are proteins. Therefore, proteins are polymers of amino acids.

Proteins are very important for the body because they have many different roles. They provide structure for tissues, act as enzymes, hormones and antibodies, aid in transportation and fluid regulation.

Therefore, the correct answer is D. a polymer of amino acids.

The most common carbonate rock is A) dolomite. B) halite. 35) C) limestone. D) calcite.

Answers

Answer:

The correct option is : C) limestone.

Explanation:

Carbonate rocks are a type of sedimentary rocks. The carbonate rocks are composed of carbonate minerals. The carbonate minerals are the minerals containing carbonate ion (CO₃²⁻).

The most common type of carbonate rock is limestone. Limestone is composed of the minerals calcite and aragonite, which have a different crystal form of calcium carbonate.

Therefore, Limestone is the most common type of carbonate rock.

Which statement correctly compares an atom of an alkali metal with an atom of the alkaline earth metal next to it on the periodic table? aThe alkali metal atom forms a +1 ion, while the alkaline earth metal atom forms a +2 ion. bThe alkali metal atom forms a +2 ion, while the alkaline earth metal atom forms a +1 ion. cThe alkali metal atom has one less shell of electrons than the atom of the alkaline earth metal. dThe alkali metal atom has one more shell of electrons than the atom of the alkaline earth metal.

Answers

All of the elements in Group 1 are alkali metals, and they are all soft in composition. The alkali earth metals that make up the group of two elements are all hard by nature. Their melting points are low. The correct option is A.

All alkali metals have one electron in their outermost shell, but all alkaline earth metals have two outer electrons. This is the main distinction between alkali metals and alkaline earth metals.

Since an alkali metal has one electron in its outermost shell, it will give up this electron in order to become stable, forming a positive ion in the process. Similar to this, since alkali earth metals have two electrons in their outermost shells, they will give up those two electrons in order to become stable, generating +2 ions.

Thus the correct option is A.

To know more about alkali metals, visit;

brainly.com/question/18153051

#SPJ3

Answer:

A) The alkali metal atom forms a +1 ion, while the alkaline earth metal atom forms a +2 ion.

Explanation:

Let's evaluate each answer.

A: The alkali metal atom forms a +1 ion, while the alkaline earth metal atom forms a +2 ion.

This means that the alkali metal atom has to lose 1 valence electron to form a +1 ion while the alkaline earth metal atom has to lose 2 valence electrons to form a +2 ion. This is accurate because alkali metal atoms have 1 valence electron while alkaline earth metal atoms have 2, so the statement is correct.

B: The alkali metal atom forms a +2 ion, while the alkaline earth metal atom forms a +1 ion.

This would mean that the alkali metal atom has to lose 2 valence electrons to form a +2 ion, while the alkaline earth metal has to lose 1 valence electron to form a +1 ion. This is incorrect because alkali metal atoms only have 1 valence electron and will become a +1 ion when losing that electron, while alkaline earth metals have 2 valence electrons and will form a +2 ion upon losing them.

C: The alkali metal atom has one less shell of electrons than the atom of the alkaline earth metal.

This would mean that the alkali metal atom would be located one period higher up than the alkaline earth metal atom. This is untrue, because the question states that the alkali metal atom is located directly next to the alkaline earth metal atom, so they have the same amount of electron shells.

D: The alkali metal atom has one more shell of electrons than the atom of the alkaline earth metal.

This would mean that the alkali metal atom would be located one period lower on the periodic table than the alkaline earth metal atom. Similar to the previous statement, this is untrue because the question states that they are located directly next to each other, or on the same period.

(Also, I just took this quiz and e2020 says it's right.)

Which best explains why an iceberg floats?Water expands and becomes denser when it freezes.

Water contracts and becomes denser when it freezes.

Answers

Answer:

The options to this question are incomplete. The remaining two options are:

C. Water expands and becomes less dense when it freezes.

D. Water contracts and becomes less dense when it freezes.

The answer is C. Water expands and becomes less dense when it freezes.

Explanation:

Water is a chemical compound that exists in the three states of matter viz: solid as ICE, gas as vapour and liquid as WATER. However, due to the DENSITY properties of each state, ice floats on water. Ice is less dense than water.

When liquid water freezes, it's particles expands i.e increases in volume. Hence, it becomes less dense than water. This causes an iceberg to float on water because it has a lesser density compared to the liquid water caused by an expansion of its particles.

The following data were obtained in a kinetics study of the hypothetical reaction A + B + C → products. [A]0 (M) [B]0 (M) [C]0 (M) Initial Rate (10–3 M/s) 0.4 0.4 0.2 160 0.2 0.4 0.4 80 0.6 0.1 0.2 15 0.2 0.1 0.2 5 0.2 0.2 0.4 20 Using the initial-rate method, what is the order of the reaction with respect to C? a. zero-order b. first-order c. third-order d. second-order e. impossible to tell from the data given

Answers

The dependence of the power of the reaction rate on the concentration is called the order of the reaction. The order of the reaction is the first order.

What is the initial-rate method?

The initial rate method is the estimation of the order of the reaction by the initial rates of the reactants and products and by performing the reaction several times by measuring the rate.

The reaction is given as,

$\rm A + B + C \rightarrow Products$

The rate of reaction can be given as:

$\rm rate = k[A]^(x)[B]^(y)[C]^(z)$

Here the variables x, y and z are orders respective to the reactant concentration and k is the rate constant.

Value of x with respect to A:

$\begin{aligned} \rm \frac {Rate 3}{Rate 4} &= \rm [([A(3)])/([A(4)])]^(\rm x)\n\n(15)/(5) &= [([0.6])/([0.2])]^(\rm x)\n\n\rm x &= 1\end{aligned}$

Value of y with respect to B:

$\begin{aligned}\rm \frac {Rate 2}{Rate 5} &= \rm [([B(2)])/([B(5)])]^(\rm y)\n\n(80)/(20) &= [([0.4])/([0.2])]^(\rm y)\n\n\rm y &= 2\end{aligned}$

Value of z with respect to C:

$\rm \frac {Rate 1}{Rate 2} &= [([A(1)])/([A(2)])]^(x) [([B(1)])/([B(2)])]^(y) [([C(1)])/([C(2)])]^(z)$

Substituting value of x = 1 and y = 2 in the above equation:

$\begin{aligned}(160)/(80) &= [([0.4])/([0.2])]^(1)[([0.4])/([0.4])]^(2) [([0.2])/([0.4])]^(\rm z)\n\n1 &= (0.5)^(\rm z)\n\n&= 1\end{aligned}$

Therefore option b. with respect to C = 1, the order of the reaction is first-order.

Learn more about the order of reaction here:

brainly.com/question/8139015

Answer:

B. First order, Order with respect to C = 1

Explanation:

The given kinetic data is as follows:

A + B + C → Products

[A]₀ [B]₀ [C]₀ Initial Rate (10⁻³ M/s)

1. 0.4 0.4 0.2 160

2. 0.2 0.4 0.4 80

3. 0.6 0.1 0.2 15

4. 0.2 0.1 0.2 5

5. 0.2 0.2 0.4 20

The rate of the above reaction is given as:

$Rate = k[A]^(x)[B]^(y)[C]^(z)$

where x, y and z are the order with respect to A, B and C respectively.

k = rate constant

[A], [B], [C] are the concentrations

In the method of initial rates, the given reaction is run multiple times. The order with respect to a particular reactant is deduced by keeping the concentrations of the remaining reactants constant and measuring the rates. The ratio of the rates from the two runs gives the order relative to that reactant.

Order w.r.t A : Use trials 3 and 4

$(Rate3)/(Rate4)= [([A(3)])/([A(4)])]^(x)$