Now balance the chemical reaction by providing the correct coefficients:

Answer:

a. [Weak acid] = 0.099999949M

[Conjugate base = 5.0119x10⁻⁸M

b.  pH = 1.84. Is not a good buffer

c. pH = 6.97

Explanation:

a. To find pH of the buffer we must use Henderson-Hasselbalch formula:

pH = pKa + log [Conjugate base] / [Weak acid]

2.0 = 8.3 + log [Conjugate base] / [Weak acid]

5.01x10⁻⁷ = [Conjugate base] / [Weak acid] (1)

As concentration of the buffer is 0.1M = [Conjugate base] + [Weak acid] (2)

Replacing (2) in (1):

5.01x10⁻⁷ = 0.1M - [Weak acid] / [Weak acid]

5.01x10⁻⁷ [Weak acid] = 0.1M - [Weak acid]

[Weak acid] = 0.099999949M

[Conjugate base] = 5.0119x10⁻⁸M

b. The conjugate base reacts with the HCl. Moles of HCl are:

1.5x10⁻³L * (3.0mol / L) = 4.5x10⁻³ moles HCl

As the conjugate base contains just 5x10⁻⁸ moles. Almost all HCl doesn't react and pH =

[H⁺] = 4.5x10⁻³ moles + 1x10⁻² moles (Initial moles H⁺) / L = 0.0145M

pH = -log [H⁺]

pH = 1.84

As the concentration of the conjugate base is <<< than weak acid. In this pH, Tris is not a good buffer. As general rule a good buffer works pH between pKa ± 1.

c. Now, NaOH reacts with the weak acid producing conjugate base.

The new moles are:

[Weak acid] = [Weak acid] = 0.099999949M - 4.5x10⁻³ = 0.0955

[Conjugate base] = 5.0119x10⁻⁸M + 4.5x10⁻³ = 4.5x10⁻³

pH = pKa + log [Conjugate base] / [Weak acid]

pH = 8.3 + log [4.5x10⁻³] / [0.0955]

pH = 6.97

Following are the response to the given points:

For question a)

The concentration of Tris buffer [tex]\text{(Tris buffer)} = 0.1\ M[/tex]

Using formula:

[tex]\text{[ Tris buffer ] = [ Conjugate base ] + [ Acid ]}[/tex]

[tex]0.1 M = \text{ Conjugate base +Acid } \\\\ \text{Acid} = 0.1\ M - \text{ Conjugate base } .............(a)[/tex]

Using the Henderson-Hasselbalch equations

[tex]\to pH = pKa + \log \frac{\text{ Conjugate base }}{ Acid}\\\\\to 2.0 = 8.3 + \log \frac{\text{ Conjugate base }}{ Acid}\\\\\to \log \frac{\text{ Conjugate base }}{ Acid} = 2.0 - 8.3\\\\\to \log \frac{\text{ Conjugate base }}{ Acid} = - 6.3\\\\\to \frac{\text{ Conjugate base }}{ Acid}= 10-6.3\\\\\to \frac{\text{ Conjugate base }}{ Acid} = 5.01 \times 10^{-7}\\\\\to \text{Conjugate base} = 5.01 \times 10^{-7} \times \ Acid ..............(b)[/tex]

Putting the value of equation (b) in equation (a):

[tex]\text{Acid } = 0.1\ M - 5.01 \times 10^{-7}\\\\\text{Acid } = 0.1 M \ ( approx.)[/tex]

from equation (b)

[tex]\to \text{Conjugate base} = 5.01 \times 10^{-7} \times 0.1\ M= 5.01 \times 10^{-8}\ M\\\\[/tex]

Therefore,

[tex]\to \text{Acid} = 0.1\ M\\\\ \to \text{Conjugate base} = 5.01 \times 10^{-8}\ M[/tex]

For question b)

[tex]\to \text{Number of moles of HCl} = 3.0\ M \times 0.00152\ L= 0.0045 \ moles\\\\\to \text{Number of moles Conjugate base in 1 L of buffer} = 5.01 \times 10^{-8}\ M \times 1\ L = 5.01 \times 10^{-8}\ moles\\\\ \to \text{Number of moles of weak acid} = 0.1\ M \times 1\ L = 0.1\ moles\\\\[/tex]

Now we need all the conjugate bases for neutralizing the [tex]HCl[/tex]

therefore

Calculating the molarity of  [tex]HCl[/tex] in the solution [tex]= \frac{0.0045\ moles}{1\ L} = 0.0045\ M[/tex]

[tex]\to H^+ \ in \ HCl = 0.0045 \ M\\\\p_H = 2.0\\\\\therefore \\\\ H^+ \ in \ buffer = 10^{-2}\ M = 0.01\ M \ ( \because \ p_H = - \log [ H^+]\ and\ [ H^+ ] = 10-p_H )[/tex]

Now Total concentration of [tex]H^+ \ i.e\ [H^+][/tex]

[tex]\to Total = 0.0045 + 0.01 = 0.0145\ M\\\\\to pH = - \log 0.0145\\\\\to pH = - ( - 1.84 )\\\\\to pH = 1.84\\\\[/tex]

For question c)

Number of moles of [tex]NaOH = 3.0 \ M \times 0.00152\ L= 0.0045\ moles\\\\[/tex]

[tex]\to \text{Number of moles Conjugate base ( say A-) in 1\ L of buffer} = 5.01 \times 10^{-8}\ M \times 1 \ L = 5.01 \times 10^{-8}\ moles \\\\ \to \text{Number of moles of weak acid ( say HA )} = 0.1\ M \times 1\ L = 0.1\ moles[/tex]

Now ICF table is :

[tex]HA + OH^- \longrightarrow A^- + H_2O[/tex]

[tex]\text{I 0.1 mol 0.0045 mol 5.01 x 10-8 mol}\\\\\text{C - 0.0045 mol - 0.0045 mol + 0.0045 mol}\\\\\text{F 0.0955 mol 0 mol 0.0045 mol ( approx. )}\\\\[/tex]

Using Henderson-Hasselbalch:

[tex]\to pH = 8.3 + \log \frac{0.0045}{ 0.0955} \\\\\to pH = 8.3 + \log 0.04712\\\\\to pH = 8.3 - 1.3268\\\\\to pH = 6.97[/tex]

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Answer:

The answer to your question is given below

Explanation:

2,4,4,5-tetramethyl-2-hexene.

To draw the structure of the above compound, we must bear the following in mind:

1. The compound is an alkene i.e it contains carbon to carbon double bond (C=C)

2. The parent name of the compound is hexene i.e it contain 6 carbon atoms.

3. The double is located at carbon 2.

4. The substituent group attached to the compound is methly.

5. There are four methly group attached to the compound of which one is located at carbon 2, two at carbon 4 and one at 5.

With the above information, we can easily draw the structure of the compound.

Please see attached photo for the structure of the compound.

Answer:

(c) CH₂F₂

Explanation:

Hydrogen bonds are weak intermolecular forces. They are the strongest kind of intermolecular forces, although they are weaker than the covalent bonds.

Hydrogen bonds arise from molecules which contain a hydrogen atom which is bonded to one of the most electronegative elements such as N, O or F.

(a) HF,  → has H-F bond

(b) CH₃NH₂,   → has N-H bond

(c) CH₂F₂,  → has no H-F bond ( F- C- F)

(d) HOCH₂CH₂OH, → has O-H bond

Therefore, only CH₂F₂ does not exhibit hydrogen bonding.

The questions asks us to calculate the wavelength of light produced if an electron moves from n = 6 to n = 5 state in a hydrogen atom. The answer would be:

λ = [tex]7.46 * 10^{-6}[/tex]  m

m = [tex]7.46 * 10^{-4}[/tex] cm

Explanation:

Please see my graphic below:

The wavelength of light produced if an electron moves from n=6 state to n=5 state of an electron in a hydrogen atom is 7.59 × [tex]10^-6[/tex] m

Using the Rydberg formula;

1/λ = 1.09737 × [tex]10^-6[/tex] (1/[tex]nf^2[/tex] - 1/[tex]ni^2[/tex])

Where;

λ = wavelength

nf = final state of the electron

ni = initial state of the electron

Substituting values;

1/λ = 1.09737 × [tex]10^7[/tex] ([tex]1/5^2[/tex] - [tex]1/6^2[/tex])

1/λ = 1.09737 × [tex]10^7[/tex] (1/25 - 1/36)

1/λ = 1.09737 × [tex]10^7[/tex] (0.04 - 0.028)

1/λ = 1.09737 × [tex]10^7[/tex] (0.012)

λ = 7.59 × [tex]10^-6[/tex] m

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Answer:

The correct answer is option c. "a liquid vaporizes and condenses at the same rate"

Explanation:

In chemistry, dynamic equilibrium is defined as a state where the reaction rate of a forward reaction is equal to the reaction rate of the backward reaction. In this case, the reactions that participate in the system are the vaporization of a liquid and the condensation of a gas. Therefore, dynamic equilibrium is established when a liquid vaporizes and condenses at the same rate.

Explanation:

Hey there!!

We generally use s,p,d,f formula.

So, let's do with it.

1.Neon

Atomic no. = 10

So, Its electronic configuration is;

[tex] = 1 {s}^{2} .2 {s}^{2} 2 {p}^{6} [/tex]

2.Zinc.

Atomic no. = 30

So, it's electronic configuration is;

[tex] = 1 {s}^{2} 2 {s}^{2} 2 {p}^{6} 3 {s}^{2} 3 {p}^{6} 4 {s}^{2} 3 {d}^{10} [/tex]

3. Tungsten.

Atomic no. = 74.

So, it's electronic configuration is;

[tex] = 1 {s}^{2} 2 {s}^{2} 2 {p}^{6} 3 {s}^{2} 3 {p}^{6} 4 {s}^{2} 3 {d}^{10}4 {p}^{6} 5 {s}^{2} 4 {d}^{10} 5 {p}^{6} 6 {s}^{2} 4 {f}^{14} 5 {d}^{4} [/tex]

4. Magnesium.

Atomic no. = 12

So, the electronic configuration is ;

[tex] = 1 {s}^{2} 2 {s}^{2} 2 {p}^{6}3 {s}^{2} [/tex]

Hope it helps...

Answer:

[tex]pKa=3.58[/tex]

Explanation:

Hello,

In this case, since the pH defines the concentration of hydrogen:

[tex]pH=-log([H^+])[/tex]

[tex][H^+]=10^{-pH}=10^{-3.4}=3.98x10^{-4}[/tex]

And the percent ionization is:

[tex]\% \ ionization=\frac{[H^+]}{[HA]}*100\%[/tex]

We compute the concentration of the acid, HA:

[tex][HA]=\frac{[H^+]}{\% \ ionization}*100\%=\frac{3.98x10^{-4}}{66\%} *100\%\\\\[/tex]

[tex][HA]=6.03x10^{-4}[/tex]

Thus, the Ka is:

[tex]Ka=\frac{[H^+][A^-]}{[HA]}=\frac{3.98x10^{-4}*3.98x10^{-4}}{6.03x10^{-4}}\\ \\Ka=2.63x10^{-4}[/tex]

So the pKa is:

[tex]pKa=-log(Ka)=-log(2.63x10^{-4})\\\\pKa=3.58[/tex]

Regards.

Answer:

a

Explanation:

Answer:

(a) [tex]Cu^{2+}S^{2-}[/tex]: copper (II) sulfide or cupric sulfide.

(b)  [tex]Ag^+_2(SO_4)^{2-}[/tex]: silver sulfate.

(c) [tex]Al^{3+}(ClO_3)_3^-[/tex]: aluminum chlorate.

(d) [tex]Co^{2+}(OH)^-_2[/tex]: cobalt (II) hydroxide.

(e) [tex]Pb^{2+}(CO_3)^{2-}[/tex]: lead (II) carbonate.

Explanation:

Hello,

In this case, we proceed by exchanging the subscripts between the cation and anion for each case as follows:

(a) CuS: cation is cupper (II) and anion is sulfide, thus the name is copper (II) sulfide or cupric sulfide.

[tex]Cu^{2+}S^{2-}[/tex]

(b) Ag₂SO₄: cation is silver ion and anion is sulfate, thus the name is silver sulfate.

[tex]Ag^+_2(SO_4)^{2-}[/tex]

(c) Al(ClO₃)₃: cation is aluminum ion and anion is chlorate, thus the name is aluminum chlorate.

[tex]Al^{3+}(ClO_3)_3^-[/tex]

(d) Co(OH)₂: cation is cobalt (II) and anion is hydroxide, thus the name is cobalt (II) hydroxide.

[tex]Co^{2+}(OH)^-_2[/tex]

(e) PbCO₃: cation is lead (II) and anion is carbonate, thus the name is lead (II) carbonate.

[tex]Pb^{2+}(CO_3)^{2-}[/tex]

Regards.

Answer: the mass will be same

Answer:

the mass wouldnt be the same because of the ashes in the jar

Explanation:

Answer:

This is required answer.

Explanation:

Given that,

1,2,3,4,5,6-hexachlorocyclohexane

(a). We need to draw 1,2,3,4,5,6-hexachlorocyclohexane with all the chloro groups in axial positions

Using given data

We draw 1,2,3,4,5,6-hexachlorocyclohexane with all the chloro groups in axial positions.

When we say that all the chloro groups in axial position that means axial bonds are vertical.

(b). We need to draw 1,2,3,4,5,6-hexachlorocyclohexane with all the chloro groups in equatorial positions

Using given data

We draw 1,2,3,4,5,6-hexachlorocyclohexane with all the chloro groups in  equatorial positions.

When we say that all the chloro groups in equatorial position that means axial bonds are horizontal.

Hence, This is required answer.

Answer:

because they are both 2 deferent type of oxygen levels

Answer:

Fish, marine mammals and seabirds are being injured and killed by plastic corruption /pollution, and it is believed that 700 species could go deceased because of it. ... Losses are generally influenced by the ingestion of plastics, starvation, suffocation, virus, drowning and entrapment.

You can thank me and google

Answer:

a) Heterogeneous mixture (b) Homogenous mixture (c) Pure substance (d) Pure substance

Explanation:

Homogenous mixtures contains mixture of substances with similar proportions while Heterogenous mixture contains substances with a varying proportion.

Answer:

Explanation:

Plant cell because its shape is rectangular

Answer:

Protons and Neutrons are found in the nucleus

Answer:

We can be safe in a science laboratory by following all directions and wearing gloves, goggles to protect ourselves.

Explanation:

If we don't follow the rules then we might cuase a problem that we didn't want to happen and we need to wear protective gear because we need to stay safe

Answer:

Chemical energy is converted into thermal and mechanical energy while kinetic energy into potential energy.

Explanation:

As the breakdown of food started, the chemical energy present in the food substances converted into thermal energy and mechanical energy. Thermal or heat energy is used to maintain the body's temperature while mechanical energy is used in other activities such as movement of muscles. Kinetic energy is also converted into potential energy when the object moves from top of a place such as hill.

As the food burned, chemical energy was transformed into thermal energy. Thus, a form of potential energy was converted to a form of kinetic energy.

Hope I helped! :)

Answer:

a heterogeneous mixture,-two substances present; two phases present

a homogeneous mixture- two substances present; one phase present

a pure substance- one substance present- one phase present

no correct response-one substance present; two phases present

Explanation:

When two substances are mixed, the mixture may be homogenous or heterogeneous. If a mixture is homogenous, then the two substances form a single phase, e.g ethanol and water.

On the other hand, a heterogeneous mixture is divided into two distinct phases, e.g kerosene and water mixture.

A single substance can only give one phase, no substance can simultaneously give two phases of the same substance in the same physical state.

Similarly, a pure substance always consists of a single phase.

Answer:

1. A PROTON HAS A +1 CHARGE

2. A PROTON HAS A MASS OF ABOUT 1.0 amu

3. THE NUMBER OF PROTONS DETERMINES THE IDENTITY OF AN ELEMENT

Explanation:

The proton is one of the three particles that make up the atom. Proton is a positively charge particle with a +1 charge. It neutralizes the negative charge of the electrons outside of the nucleus of the atom as the proton are located inside the nucleus of the atom. Proton has a mass of 1.0 amu which is about 1.67 * 10^-27 kg. The addition of the proton and the neutrons gives the molar mass of the atom.

Also, the identity of the cell that is the atomic number which gives the position of the element in the periodic table and also shows the individual characteristics of the atoms is determined by the number of protons in the nucleus of the atoms.

All the above options are true in regard to a proton.

Atomic m. Element Atomic no. Symbol

1.0079u Hydrogen 1 H

4.0026u Helium 2 He

6.941u Lithium 3 Li

★ Atomic number : The number of protons in one atom of an element is known as atomic number.

The symbol for every chemical element that has an atomic number less than 5 and atomic mass greater than 8.3 u are hydrogen H, helium He, lithium Li and atomic masses 1,4 and 6.94 respectively in the periodic table.

A periodic table is an arrangement of the elements in which they are classified on the basis of the number of electrons, neutrons, and protons present in their nucleus and shell of them.

Hydrogen has one electron in it and atomic mass is also one, helium comes in the second number with 4 amu and lithium comes in the third number containing 6.94 mass with it.

Therefore, hydrogen H, helium He, lithium Li and atomic masses 1,4 and 6.94 respectively in the periodic table contain symbols for every chemical element that has an atomic number less than 5 and atomic mass greater than 8.3 u are hydrogen H.

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Answer:

Impurities will be trapped in the crystals of the benzoic acid crystallized in this manner.

Explanation:

After benzoic acid is dissolved in hot water, it should have been allowed to cool gradually before it is transferred into an ice bath.

This gradual cooling will aid the separation of impurities so that when the vessel is now submerged in an ice bath, only pure benzoic acid is recrystalized.

If the vessel is immediately submerged into an ice bath, impurities will be trapped in the crystals of the benzoic acid.

Answer:

In an NMR experiment, shielding refers to the reduced impact of the APPLIED MAGNETIC FIELD on a nucleus due to the presence of ELECTRON DENSITYaround the nucleus.

Shielding can be DECREASED by the presence of more electronegative groups around the nucleus.

A shielded nucleus appears further UPFIELD whereas a deshielded nucleus appears further downfield in an NMR spectrum.

Explanation:

1 There is reducece because alot of the electronegative atom binds more and thus reduce the electron density around the nucleus.

While a reduction in electron density bring about more nuclear magnetic field thus it resonates at higher frequency resulting downfield peak.

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Yeah! I have the same question!!! I think it is heat.

Answer:

this old man looks so weird ..

Explanation:

but i m sorry .....u know the reason very well

do u wanna be my friend .

Answer:

Explanation:

volume = 60cm^3

Answer:

It will be 1663500mg

Explanation:

Answer:

The correct answer is - ascending order of atomic numbers in period and similar characters in groups.

Explanation:

The modern periodic table is arranged in periods and groups. In periods the arrangement of the elements are on the basis of the increasing order of atomic numbers.

In groups of the periodic table, elements are arranged on the basis of the similar characters of the elements and number of electrons in outer shell of the elements. The elements in the Modern Periodic Table are arranged in 7 Periods and 18 Groups.

Thus, the correct answer is - ascending order of atomic numbers in period and similar characters in groups.