g 30.0 mL of a buffer is made by mixing 20.0 mL of 0.10 M HNO2 and 10.0 mL of 0.10 M NaOH solution. What is the pH of this buffer after 0.04 mL of 10.0 M hydrochloric acid are added to it

Answers

Answer 1

Answer:

pH = 2.98

Explanation:

pKa of HNO2 is 3.35

HNO2 reacts with NaOH as follows:

HNO2 + NaOH → NaNO2 + H2O

Where moles of NaOH added are equal to NaNO2 produced

And initial moles of HNO2 - Moles NaOH = Moles HNO2

Initial moles HNO2:

0.0200L * (0.10mol/L) = 0.00200moles HNO2

Moles NaOH = Moles NaNO2:

0.0100L * (0.10mol/L) = 0.00100 moles NaOH = Moles NaNO2

Moles HNO2:

0.00200moles - 0.00100moles = 0.00100 moles HNO2

Then, the added HCl reacts with NaNO2 producing HNO2:

HCl + NaNO2 → HNO2 + NaCl

Where moles added of HCl are moles of HNO2 produced and initial moles  of NaNO2 - moles of HCl = Moles NaNO2

Moles HCl:

4x10⁻⁵L * (10.0mol / L) = 0.00040moles HCl = Moles of HNO2 produced

Moles HNO2:

0.00100moles + 0.0004moles = 0.0014moles HNO2

Moles NaNO2:

0.00100moles - 0.0004moles = 0.0006moles NaNO2

With these moles and H-H equation we can solve for the pH of the buffer:

pH = pKa + log [NaNO2] / [HNO2]

Where pH is pH of the buffer

pKa is pKa of HNO2: 3.35

[] are moles of each species:

Replacing:

pH = 3.35 + log [0.0006moles NaNO2] / [0.0014moles HNO2]

pH = 2.98


Related Questions

Write down the name and symbol of the particle formed when the magnesium atom loses two electrons

Answers

Answer:

A magnesium atom must lose two electrons to have the same number electrons as an atom of the previous noble gas, neon. Thus, a magnesium atom will form a cation with two fewer electrons than protons and a charge of 2+. The symbol for the ion is Mg2+, and it is called a magnesium ion.

This base-catalyzed isomerization involves the following steps: 1. Deprotonation to form tetrahedral intermediate 1; 2. Collapse of the tetrahedral intermediate and bond cleavage to form enolate ion 2; 3. Proton transfer to form enolate ion 3; 4. Intramolecular aldol reaction to form tetrahedral intermediate 4. Write out the reaction on a separate sheet of paper, and then draw the structure of tetrahedral intermediate 1.

Answers

Answer:

Explanation:

The objective of this question is to show the stepwise reaction mechanism for the base-catalyzed isomerization. This mechanism is shown in the attached diagram below together with its intermediary and enolate ions.

help me in my this plzzz ​

Answers

Answer:

a is oxidation

b is reduction

c is reduction

d is oxidation

hope it helps you

That the right question

write the general strucktures of
A. ketone b. aldehyde c. carboxylic acid d. ester

Answers

A.ketone

R-CO-R

B.aldehyde

R-CH=O

c.carboxylic acid

R-COOH

d.ester

R-CO-O-C-R

Let's say you asked how many moles of O2
are needed to react with 24 moles of C2H6.

Answers

Answer:

7

Explanation:

How is the name of each element in the periodic table represented? A. The first two letters of the element's name are used for the table. B. Letters are assigned to each element by the scientist who discovered it. C. Letters are given to represent each element based on when it was discovered. D. One or two letters are used to represent the name of each element.​

Answers

Answer:

D. One or two letters are used to represent the name of each element.​

Explanation:

The name of each element in the periodic table is symbolized by one or two letters.

There different ways of achieving this. Sometimes;

the first letter of the name of the element is used to represent it for example, hydrogen  = H the first two letters are sometimes used, for example Calcium Cathe Latin name is also used for example Gold is Aurum and is represented as Au.

These are some of the ways of symbolizing the name of each element

answer two quetions.......

Answers

Answer:5.=D

6.=B

Explanation:

solve the equation:
1) 3,2 m²= x dm²= x cm²

BRAINLIEST!!!!

Answers

I take sleeper bye lol

Answer:

sin  = (330)

csc = (60)

−4 = cot (−45)

Explanation:

im not sure what you were looking for, make me brainlest please?

what is the empirical formula of a compound that is found to consist of 56% chorine and no other element except iron

Answers

Answer:

FeCl₂

Explanation:

Empirical formula is the simplest formula of a compound.

Mass percentage of Chlorine  = 56%

Mass percentage Iron  = 100  - 56  = 44%

                                                              Elements  

                                                 Fe                                 Cl

Percentage mass                    44                                  56

moles                                      44/55.85                   56/35.5

                                                  0.79                         1.56

Divide by the smallest

number                                    0.79/0.79                 1.56/0.79

                                                        1                                 2

The empirical formula of the compound is FeCl₂

Which of the following equations demonstrates an actual chemical reaction that forms a new substance?

A1: ZN + 2HCl → 2NCl2 + H2

A2: H2O + NaCl → H2O

A3: Zn + Al + Cu → Zn + Cu + Al

A4: C12H22O11 + H2O → H2O + C12H22O11

Answers

Answer:  [tex]Zn+2HCl\rightarrow ZnCl_2+H_2[/tex]

Explanation:

A chemical reaction is said to have occured when reactants react to form new products where the atoms undergo a change in bonding.

From the given reactions:

1. [tex]Zn+2HCl\rightarrow ZnCl_2+H_2[/tex]

Here Zn combines with hydrochloric acid to form zinc chloride and hydrogen.

2. [tex]H_2O+NaCl\rightarrow H_2O[/tex]

Here water remains as such as no new substance is formed.

3. [tex]Zn+Al+Cu\rightarrow Zn+Cu+Al[/tex]

Here no new substance is formed.

4. [tex]C_{12}H_{22}O_{11}+H_2O\rightarrow H_2O+C_{12}H_{22}O_{11}[/tex]

Here no new substance is formed.

Thus [tex]Zn+2HCl\rightarrow ZnCl_2+H_2[/tex] demonstrates an actual chemical reaction that forms a new substance

Answer:

hope this helps you!

Explanation:

Suggest reasons for and against the inclusion of hydrogen in the main group of the periodic table ​

Answers

Answer:

See explanation

Explanation:

Hydrogen has only one valence electron. Sometimes, hydrogen is included as part of group 1 or 17 in the periodic table. Is this correct? Well, the answer to this question is not so straight forward!

Let us remember that hydrogen forms a univalent positive ion H^+ just like the group 1 elements, but it also forms a univalent negative ion H^- just like group 17 elements. Also, hydrogen is a gas and forms a molecular diatomic compound just like group 17 elements. This is not the case with other group 1 elements. We can see that hydrogen is chemically and physically dissimilar to other group 1 elements hence one can logically argue against its inclusion in group 1. Also, it is not a halogen, so we can also argue against its inclusion in group 17.

However, it is convenient to include hydrogen in the main groups 1 or 17 when discussing its chemical properties in order to make it easier to assimilate. If we place hydrogen in group 1, we can understand that it forms univalent positive ions. Similarly, if we place it in group 17, we understand that it forms univalent negative ions.

Most times hydrogen is just written separately at the top right corner of the periodic table and not as a member of any group because of the issues outlined above.

Hydrogen is placed in the main group of the periodic table since it has only one electron in it and it also behaves like alkali metal properties.

Hydrogen atom:

Hydrogen forms a univalent positive ion [tex]H^+[/tex]group 1 elements, but it also forms a univalent negative ion [tex]H^-[/tex]group 17 elements. Also, hydrogen is a gas and forms a molecular diatomic compound just like group 17 elements.

This is not the case with other group 1 elements. We can see that hydrogen is chemically and physically dissimilar to other group 1 elements hence one can logically argue against its inclusion in group 1. Also, it is not a halogen, so we can also argue against its inclusion in group 17.

If we place hydrogen in group 1, we can understand that it forms univalent positive ions and if it is placed in halogen group it will form univalent negative ion.

Find more information about Hydrogen here:

brainly.com/question/25597694

Convert this word equation into a balanced formula equation, please.
Copper (II) nitrate reacts with aluminum to form aluminum nitrate and copper.

Answers

Answer:

3Cu(NO3)2 + 2Al —> 2Al(NO3)3 + 3Cu

Explanation:

From the question given above,

Copper (II) nitrate reacts with aluminum to form aluminum nitrate and copper. This can be obtained represent as follow:

Cu(NO3)2 + Al —> Al(NO3)3 + Cu

Thus, we can balance the above equation as follow:

Cu(NO3)2 + Al —> Al(NO3)3 + Cu

There are 2 atoms of N on the left side and 3 atoms on the right side. It can be balance by putting 3 in front of Cu(NO3)2 and 2 in front of Al(NO3)3 as shown below:

3Cu(NO3)2 + Al —> 2Al(NO3)3 + Cu

There are 3 atoms of Cu on the left side and 1 atom on the right side. It can be balance by putting 3 in front Cu as shown below:

3Cu(NO3)2 + Al —> 2Al(NO3)3 + 3Cu

There are 2 atoms of Al on the right side and 1 atom on the left side. It can be balance by putting 2 in front of Al as shown below:

3Cu(NO3)2 + 2Al —> 2Al(NO3)3 + 3Cu

Thus, the equation is balanced.

? C+? O2 +? CO2,
what is the maximum amount of CO2 which
could be formed from 13.19 g of C and 15.92 g
of O2?
Answer in units of g.

Answers

Look at the mole ratio in the balanced equation

2CO + O2 ==> 2CO2

3.44 mol O2 x 2 mol CO/mol O2 = 6.88 moles CO

boron is a non metal why

Answers

Explanation:

Boron is a non metallic element and the only non-metal of the group 13 of the periodic table the elements. Boron is electron-deficient, possessing a vacant p-orbital. ... It reacts with metals to form borides. At standard temperatures boron is a poor electrical conductor but is a good conductor at high temperatures

What is the mass of 0.8 mole of water molecules.

Answers

Answer:14.4g

Explanation:

A hypothesis is a
a. concise statement of behavior that is always the same under the same conditions
b. set of quantitative data
C. tentative explanation or predication based upon experimental observations
d. well-tested unifying principle that explains a body of facts
e. mathematical formula that models a pattern of behavior
concise statement of behavior that is always the same under the same conditions

Answers

Answer:

the answer is c or d

Explanation:

you can cross out e because it dont make any sense

b thats just data

a is the definition of law

Put the elements in order from easiest to hardest to remove an electron. Ba,Be,Ca,Sr.

Answers

Answer:

Ba,Sr,Ca,Be

Explanation:

as atomic size increases ionisation potential decreases

jagsir saw his mother adding dried neem leaves to the metal vessel filled with wheat. jagsir asked the reason for this from his mother. what would be his mothers reply? ​

Answers

Answer:

Because i want to. would be the reply

Explanation:

VOTE ME BRAINLIEST PLSSSSSSSSS

Answer:

none of the above

option d

What is the velocity of a plane that traveled 2,800 miles from New York to California in 5.0 hours?

Answers

Answer:

560 mph East

Explanation:

Velocity is just speed with direction pretty much.

Plzz tell me the answer u need help im kinda confused

All of the following are examples of an external stimulus except -
Group of answer choices

Ⓐ hunger.

Ⓑ sunlight.

Ⓒ a loud sound.

Answers

Hi
I think it’s B
Hopefully this helps!!

Stimuli are the senses that cause an organism to react. Internal sensations include things like hunger and thirst that are produced inside the body, hence option A is correct.

What is stimulus?

A stimulus is a perceptible alteration in the internal or external surroundings of an organism's physical or chemical composition.

Sensitivity is the capacity of an organism or organ to recognize external stimuli and to respond appropriately to them.

A stimulation that comes from outside the organism is known as an external stimulus. Light is one example of an outside stimulation. Although it comes from outside the body, it has an impact there as well.

Therefore, sunlight and a loud sound are the examples of external stimuli, while  hunger is an internal stimulus.

Learn more about stimulus, here:

https://brainly.com/question/1747649

#SPJ5

How many moles of zinc are there in 0.890 g of zinc?

Answers

Answer:

There are  

4.517

10

23

atoms of Zn in 0.750 mols of Zn.

Explanation:

Since we know that there are  

6.022

10

23

atoms in every mole of a substance (Avogadro's Number), there are  

6.022

E

23

0.750

atoms of Zn in 0.750 mols of Zn.

Answer:

There are  4.517 ⋅ 10  23 atoms of Zn in 0.750 mols of Zn. have a good day:)

Explanation:

The EPA tracks the amount of DDT that has entered into our water systems to ensure water safety. Calculate the ppm for a solution made by putting 2.7 g of DDT into a 59000 g of water. Assume masses are additive

a. 46 ppm
b. 0.0046 ppm
c. 4.6 ppm
d. 4.6 x 10^-5 ppm

Answers

i think the answer is C. i’m not sure mate

A student has 2 rubber balls of the same size and weight. Ball A is still and Ball B is rolling.Ball B hits Ball A, and Ball A start moving. Why does Ball A start moving?
A). Ball A is repelled by Ball B ,
B). Ball B is attracted to Ball A ,
C). Ball B transfers energy to Ball A ,
D). Ball A transfers energy to Ball B

Answers

Answer:

C). Ball B transfers energy to Ball A

Explanation:

The motion of ball A is a because of the energy it acquires.

Ball A initially due to its position posses potential energy due to its position.

The moving ball B has kinetic energy due to the motion of this ball.

Due to the collision, momentum is transferred from the moving ball to the static one. As the momentum of the static ball changes, potential energy is converted to kinetic energy. The magnitude of the energy possessed by the static ball must be lesser than that of the moving.

Answer:

c

Explanation:

How many protons, electrons, and neutrons? ANSWEN
2+
23
6521
26
Protons
Electrons
Neutrons
28
30
65
3-
31
Protons
Electrons
Neutrons
"As
57 Fe
32
3+
33
35
36
DRAGO
Protons
Electrons
Neutrons
14
ME
US

Answers

Answer:

maybe 20 butvam not sure ooo

—————————Are formed by a combination of two or more different kinds of Atom

Atom of the same ———————————-element have identical properties

Answers

Answer:

1. molecules.

2. size ,shape and mass.

Directions: Fill in the 12 steps in the decay of U-235 in the diagram below.

Begin with U-235 and finish with an
isotope of lead. The particles emitted in each step are listed below. Use the periodic table to find information about
mass numbers, atomic numbers, and chemical symbols. Place the correct symbol in the space corresponding to the
correct mass number and atomic number.

Answers

Answer:

SUPER MARIOLWEJHRTÑWQEGTPWIQETGQWKÑEJGBKSDLJBGKSJDLGB

Explanation:

which one does not share the same properties as the other


Si

Ti

At
Explain why

Answers

Answer:

Ti

Explanation:

Ti is titanium and does not share any similar properties with the likes of Si, silicon and At, astatine.

Titanium is a transition metal and a solid. Silicon and Astatine are non - metals. Silicon and Astatine also belongs to the p-block on the periodic table whereas Titanium is found on the d-block. Silicon and Astatine would prefer to take part in reactions where they can gain electrons because they are non metals whereas Titanium due to its metallic property would prefer a reaction where it can lose electrons.

How many moles are in
.77 liters of Br2 at STP?

Answers

Answer: 0.034354

Explanation:1 mole=22.4 liters of Br2 at STP so, 22.4x=0.77

x= 0.034354

Answer:

0.034354

Explanation:

Just did worksheet

please help GIVING brainliest

Answers

Answer:

heat wave

Explanation:

A high pressure system is a whirling mass of cool, dry air that generally brings fair weather and light winds. When viewed from above, winds spiral out of a high-pressure center in a clockwise rotation in the Northern Hemisphere.

Water is a substance made up of the elements hydrogen
and oxygen.
How many types of atoms make up a particle of water?
A. 2
B. 3
C. 4
D. 1

Answers

Answer:

A. 2

Explanation:

A particle of water is made up of two hydrogen atoms and one oxygen atom. However, the question asked for how many types of atoms there are, so the answer is 2.

I think it might be 3
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