A mixture is prepared using 27.00 mL of a 0.0758 M weak base (pKa=4.594) , 27.00 mL of a 0.0553 M weak acid (pKa=3.235) and 1.00 mL of 1.25×10−4 M HIn and then diluting to 100.0 mL, where HIn is the protonated indicator. The absorbance measured at 550 nm in a 5.000 cm cell was 0.1102 . The molar absorptivity (????) values for HIn and its deprotonated form In− at 550 nm are 2.26×104 M−1cm−1 and 1.53×104 M−1cm−1 , respectively. What is the pH of the solution?

Answers

Answer 1

Answer:

pH = 4.164

Explanation:

The first process is to find the initial moles for the base (B) & the acid (HA)

i.e.

[tex]= \dfrac{27 mL \times 0.0758 \ moles \ \ of \ B}{1000 \ mL}[/tex]

[tex]=0.0020466[/tex]

[tex]\simeq 2.047\times 10^{-3} \ moles \ of \ B[/tex]

[tex]= \dfrac{27 mL \times 0.0553 \ moles \ \ of \ HA}{1000 \ mL}[/tex]

[tex]=0.0014931[/tex]

[tex]\simeq 1.493\times 10^{-3} \ moles \ of \ HA[/tex]

The acid with base reaction is expressed as;

          HA              +      B         →             A⁻            +         HB⁺

to    1.493 × 10⁻³       2.047 × 10⁻³             -                         -

    -  1.493 × 10⁻³       1.493 × 10⁻³         1.493 × 10⁻³         1.493 × 10⁻³

            0                    5.54 × 10⁻⁴         1.493 × 10⁻³         1.493 × 10⁻³

From observation; both the acid & base weak

Given that:

The pKa for base = 4.594

The pKa for acid = 3.235

Recall that;

pKa = -log Ka

So; Ka = [tex]\mathbf{10^{-Ka}}[/tex]

By applying this:

For Base; Ka = [tex]10^{-4.594}[/tex] = 2.5468 × 10⁻⁵

For Acid:  Ka = [tex]10^{ -3.235}[/tex] = 5.821 × 10⁻⁴

After the reaction; we have the base with its conjugate acid & conjugate base of acid; Thus, since the conjugate acid of the base possesses a higher value of K, it is likely it would be the one to define the pH of the solution.

By analyzing the system, we have:

              HB⁺         + H₂O           ↔           B          +            H₃O⁺

     [tex]\dfrac{1.493\times 10^{-3}}{0.1 \ L}[/tex]                                 [tex]\dfrac{5.54\times 10^{-4}}{0.1 \ L}[/tex]

to   0.01493 M                                 0.00554   M

  -      x                                                   x                                x

    0.01493 - x                                 0.00554 - x                     x

Thus;

[tex]2.5468 \times 10^{-5} = \dfrac{(0.00554 -x)\times x}{(0.01493-x)}[/tex]

Using the common ion effect;

0.00554 - x   [tex]\simeq[/tex]  0.00554   &

0.01493 -  x   [tex]\simeq[/tex]   0.01493

[tex]x = \dfrac{2.5468 \times 10^{-5} \times 0.01493}{0.00554}[/tex]

x =  [H₃O⁺] = 6.8635  × 10⁻⁵

pH = -log(6.8635  × 10⁻⁵)

pH = 4.164


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Explanation:

Hey there!

According to the law of gravitation, the factors that affects the gravity are:

Mass of the heavenly bodies.Distance from the centre of the body to next body.

Mass of heavenly bodies:The mass of heavenly bodies affect the gravity. We know that gravity is directly proportional to the mass of heavenly bodies. so, when the mass is more there is more gravity and where there is less mass there is less gravity.

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Answers

Answer:

The answer is 'All of the above'

Explanation:

because the hydrogen ions are represented by the symbol H+, they increase the PH value of a solution if less amount is added but they decrease the PH value of a solution if a larger amount of hydrogen ions are added but still they increase the PH value, and of course, they contribute to a solution by a base.

Answer:

Hydrogen ions are represented by H+.

Explanation:

Hydrogen ions usually decreases the pH value when added to a solution.Hydrogen ions are contributed to a solution by a acid.

how is the strength of an acid affected by the number of hydrogen ions it contains​

Answers

More the no. of hydrogen ions more is the solution acidic.

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so more the hydrogen ions more will be the Power of Hydrogen (pH) and thus more wil be the acidity.

Balance this equation.
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Answers

Answer:

1Mg + 1Cl2 = 1MgCl2

Explanation:

Hi! When balancing an equation, you want to make sure that there are equal amounts of each element on both sides. When looking at the equation that you provided in the question, look and count how many of each element are on each side. I can see that there is 1 Mg ion on the left and 1 Mg ion on the right. There are also 2 Cl ions on the left and 2 Cl ions on the right. Because they are already equal, the coefficients in front of each compound will be 1. If the amounts were different on each side, that is when you would need to add different coefficients.

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Answers

Answer:

it is probably acrylic or latex

Explanation:

There are two types of chemical compound one is covalent compound and other is ionic compound, covalent compound formed by sharing of electron and ionic compound formed by complete transfer of electron. Therefore, the type of paint is  acrylic or latex.

What is chemical Compound?

Chemical Compound is a combination of molecule, Molecule forms by combination of element and element forms by combination of atoms in fixed proportion.

An ionic compound is a metal and nonmetal combined compound.  Ionic compound are very hard. They have high melting and boiling point because of strong ion bond.  If the chip remains flat when put in ethanol, it is probably an oil-based paint. If the chip curls, it is probably acrylic or latex. So, The type of paint is  acrylic or latex.

Therefore, the type of paint is  acrylic or latex.

To learn more about chemical compound, here:

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Which part of the immune system can be "trained" using vaccines?

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exothermic reaction

Explanation:

because it occurs in the presence of heat

Describe the reaction of zinc with sulphuric acid​

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Answer:

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Answer:

Reaction of Zinc with Dilute Sulphuric Acid

Zinc is more reactive than hydrogen and it displaces hydrogen from dilute acids. Zinc reacts with dilute sulphuric acid to form zinc sulphate and hydrogen gas is evolved. This is a single displacement reaction of a non-metal by a metal. ... So, this reaction is a chemical change.


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Answers

Answer:A higher effective nuclear charge causes greater attractions to the electrons, pulling the electron cloud closer to the nucleus which results in a smaller atomic radius. Down a group, the number of energy levels (n) increases, so there is a greater distance between the nucleus and the outermost orbital.

Answer:

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Answer:

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i need points

In the acetylene torch, acetylene gas (C2H2)(C2H2) burns in oxygen to produce carbon dioxide, water, and energy: 2C2H2(g)+5O2(g)⟶Δ4CO2(g)+2H2O(g)2C2H2(g)+5O2(g)⟶Δ4CO2(g)+2H2O(g) You may want to reference (Pages 241 - 243) Section 7.7 while completing this problem. Part A How many moles of O2O2 are needed to react with 1.85 molmol of C2H2C2H2? Express your answer to three significant figures and include the appropriate units. nn(O2O2) = nothingnothing SubmitRequest Answer

Answers

Answer:

4.63 mol

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Answers

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Answers

Answer:

B

Explanation:

I think the answer is Diffusion and Osmosis

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More on the particulate nature of matter can be found here: https://brainly.com/question/15230454?referrer=searchResults

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Answers

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Explanation:

Hope this helped!

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Answers

Answer:

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Answers

Answer:

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pliz mark brainliest

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Answer:

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Answers

Explanation:

Rate of reaction can be increased by having more surface area.

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Answer:

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Explanation:

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Answers

Answer:

Because while our lakes are Great, they're comparatively much smaller than oceans. And the gravitational pull isn't strong.

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Answers

Answer:

a

Explanation:

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Answer:

It is 1.

Explanation:

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Answers

Answer:

-1.82 °C

Explanation:

Step 1: Given data

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Answers

Answer: Chemical energy

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Answer:

chemical energy

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Explanation:

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Answers

Answer:

See Explanation

Explanation:

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Answers

immigration is moving from current place to somewhere else whereaese emigration is reverse of it .

Answer:

well for me I think

Explanation:

immigration is the movement which involves an individual moving from a present place to another environment

That is going out

WHILE

Emigration is the process where a person comes into a particular environment

That means coming in

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Group of answer choices
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Water vapor absorbs heat energy.

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Answers

Answer:

Water vapor retains the same heat energy.

Answer:

water vapor gives up heat energy.

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Took a quiz and got it right

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--

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Answer:

A

Explanation:

hope it helps

Answer:

A

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I got right

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Answers

Answer:

The major innovation made from Abacus to the present fifth generation​ is explained below in details.

Explanation:

Industrial Age - 1600

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