As an FDA physiologist, you need 0.625 L of phosphoric acid acid / dihydrogen phosphate (H3PO4 (aq) / H2PO4 - (aq) ) buffer with a pH of 2.75. How do you prepare this solution from stock solutions of 1.0 M H3PO4 (formic acid) and 1.5 M NaOH

Answers

Answer 1

Answer:

0.4058L of 1.0M H3PO4

0.2192L of 1.5M NaOH

Explanation:

The pKa of the H3PO4 / H2PO4- buffer is 2.12

To solve this question we must use H-H equation for this system:

pH = pKa + log [H2PO4-] / [H3PO4]

2.75 = 2.12 +  log [H2PO4-] / [H3PO4]

0.63 = log [H2PO4-] / [H3PO4]

4.2658 = [H2PO4-] / [H3PO4] (1)

Where [] could be taken as the moles of each reactant

As you have H3PO4 solution, the reaction with NaOH is:

H3PO4 + NaOH → H2PO4- + Na+ + H2O

As you can see, both H3PO4 and H2PO4- comes from the same 1.0M H3PO4 solution

The moles of H3PO4 are:

[H3PO4] = Moles H3PO4 - Moles NaOH

And for H2PO4-:

[H2PO4-] = Moles NaOH added

Replacing in (1):

4.2658 = [Moles NaOH] / [Moles H3PO4 - Moles NaOH]

4.2658 Moles H3PO4 - 4.2658 moles NaOH = Moles NaOH

4.2658 Moles H3PO4 = 5.2658 moles NaOH (1)

In volume:

0.625L = Moles H3PO4 / 1.0M + Moles NaOH / 1.5M

0.625 = Mol H3PO4 + 0.6667 Moles NaOH (2)

Replacing (2) in (1):

4.2658 Moles H3PO4 = 5.2658 (0.625 - Mol H3PO4 / 0.6667)

4.2658 Moles H3PO4 = 5.2658 (0.625 - Mol H3PO4) / 0.6667

4.2658 Moles H3PO4 = 5.2658*(0.9375 - 1.5 mol H3PO4)

4.2658 Moles H3PO4 = 4.9367 -7.8983 mol H3PO4

12.1641 mol H3PO4 = 4.9367

Mol H3PO4 = 0.4058moles * (1L / 1.0moles) =

0.4058L of 1.0M H3PO4

And:

0.625L - 0.4058L =

0.2192L of 1.5M NaOH


Related Questions

What is standard pressure in atmospheres?

a.10
b.1
c.5
d.2

Answers

The answer is d. 2 hope this helps

Which two changes would make this reaction product-favored? 3H2 + N2 ⇄ 2NH3 + energy  A. Decreasing the pressure  B. Increasing the temperature  C. Increasing the pressure  D. Reducing the temperature

Answers

Answer:C and D

Explanation:Just did it

Increasing the pressure and Decreasing the temperature are the two changes would make this reaction product-favored.

What is Equilibrium ?

It is a state when a reaction is reversible and both forward and reverse reaction occur simultaneously at the same rate .

In the process of manufacture of Ammonia , both forward and reverse reaction are taking place

N₂(g) + 3H₂ (g) →  2NH₃ (g)

2NH₃(g)  →  N₂ (g) + 3H₂ (g)

when these reaction occur at same rate , the state is called equilibrium and is represented by

N₂ (g) + 3H₂(g) ⇔ 2NH₃(g) +Heat

As we can see from the equation , heat is produced in the forward reaction so if we increase the temperature the reverse reaction will be favored ,

On decreasing temperature the reaction will become product favored .

While on increasing the Pressure the manufacture of Ammonia increases.

Therefore Option C and Option D are the two changes would make this reaction product-favored.

To know more about Equilibrium

https://brainly.com/question/13463225

#SPJ2

How many moles can be found in 1.5 x 10^24 atoms of Calcium?

Answers

2.49 x 10^46 is the answer

What solid figure has two bases, but no lateral faces?

cylinder
rectangular prism
triangular prism
cone

Answers

Answer:

it is cylinder as it has two bases but no lateral faces.

Image shown below of a chemistry question i would really appreciate the help

Answers

.Answer:

2kclo3 --> 2kcl + 3o2 is a decomposition reaction because it is breaking apart (thinks decompose- to break apart/down)

H2 + I2 --> 2HI is a synthesis reaction because synthesis is like creation/ building

think DNA synthesis or the book of genesis in the bible about creation

2 Na + 2 H20 --> NaOH + H2 --- not balanced at all

other one is a balanced equation- the Zn + 2HCl one

Explanation:

PLZZZ HELP CHEMISTRY QUESTION DOWN BELOW IMAGE SHOWWN BELOW

Answers

don’t click that!! :)

Can somebody please help me!!!

Answers

Answer:

force are called roll

Explanation:

force your answer give me five Points

Answer:

friction

Explanation:

The other terms honestly just don't make any sense in this context. Round objects experience less friction, since they have less of their surface touching the ground at a time. Imagine a bowling bowl: only a small part of the ball is ever touching the ground at one instant. Now imagine a waffle: almost all of the surface is touching the ground.

How many moles of iron will be produced from 6.20 moles of carbon monoxide reacting with excess iron oxide

Answers

Explanation:

..........................m

Name
Period
GAS STOICHIOMETRY REVIEW
Please answer the following on separate paper using proper units and showing
all work. Please note that these problems require a balanced chemical
equation.
1. Carbon monoxide reacts with oxygen to produce carbon dioxide. If 1.0 L of
carbon monoxide reacts with oxygen at STP,
a. how many liters of oxygen are required to react?
b. How many liters of carbon dioxide are produced?

Answers

Answer:

don't trued the ebitly dude. rub

can someone help me with 5?

Answers

Answer:28 g

Explanation:

hellooooooooooooooooooooo

Answers

Answer:

hiiiiiiiiiiiiiiiiiiiiiiiii THANK YOU SO MUCH FOR THE POINT

Question
How much of 3 M NaOH will be required to make 100 mL of 0.05 M NaOH?
Select the correct answer below:
5 mL
1.7 mL
0.15 mL
30 mL

Answers

Answer:

1.7 mL

Explanation:

start with formula M1V1=M2V2

then plug in values (3)V1=(100)(.05) and solve for V1

V1= 1.66

According to molar concentration, 1.7 ml of of 3 M NaOH is required to make 100 ml of of 0.05 M NaOH.

What is molar concentration?

Molar concentration is defined as a measure by which concentration of chemical substances present in a solution are determined. It is defined in particular reference to solute concentration in a solution . Most commonly used unit for molar concentration is moles/liter.

The molar concentration depends on change in volume of the solution which is mainly due to thermal expansion. Molar concentration is calculated by the formula, molar concentration=mass/ molar mass ×1/volume of solution in liters.

In terms of moles, it's formula is given as molar concentration= number of moles /volume of solution in liters.

In case of 2 solutions, molarity is determined as, M₁V₁=M₂V₂

Substitution of values gives, V₁=0.05×100/3=1.7 ml.

Thus, 1,7 ml of 3 M NaOH will be required to make 100 mL of 0.05 M NaOH.

Learn more about molar concentration,here:

https://brainly.com/question/21841645

#SPJ2

A gas has a volume of 13.4 L at 17°C. What is the volume of the gas at standard temperature?

Answers

Answer:

V=12.6148888506L

Explanation:

using charles law Volume1/Temperature1 = Volume2/Temperature2

13.4L/(17C+273.15C)=V/273.15K

remember gas equations require kelvin not celcius so converting celcius to kelvin is Celcius + 273.15 which is standard temperature conditions

Environments have changed over millions of years. Which of these would be best for a scientist to study when investigating these environmental changes?


A. volcanic deposits

B. weather forecasts

C. fossil records

D. ocean currents (There is no science subject so ima put mathematics)

Answers

Don’t press the file might have cookies or virus

Answer:

c

Explanation:

fossil records

How many grams of Mg(NO3), are necessary to
make 1500 mL of a 0.50 M solution?

Answers

Answer:

1.1 × 10² g

Explanation:

Step 1: Given data

Concentration of the solution (C): 0.50 M (0.50 mol/L)Volume of solution (V): 1500 mL (1.500 L)

Step 2: Calculate the moles of Mg(NO₃)₂ (solute)

Molarity is equal to the moles of solute (n) divided by the liters of solution.

C = n/V

n = C × V

n = 0.50 mol/L × 1.500 L = 0.75 mol

Step 3: Calculate the mass corresponding to 0.75 moles of Mg(NO₃)₂

The molar mass of Mg(NO₃)₂ is 148.3 g/mol.

0.75 mol × 148.3 g/mol = 1.1 × 10² g

A student added copper wire to a flask containing silver nitrate after a period of three hours,the flask and its contents looked like this Did a chemical reaction occur? Use evidence and scientific reasoning to support your claim

Answers

Answer:

Yes

Explanation:

Cause the student add wire To the flash and changed colour

Answer: Yes

Explanation: Because the color changed and one of the ways to see if a chemical reaction occured is color change.

Choose the options below that are true of chemical equilibria.
A. The reaction proceeds in the forward and reverse directions at the same rate.
B. Both the forward and the reverse reactions are achievable.
C. The relative amounts of all species must be different.
D. There is no net change in concentrations of reactants and products.

Answers

Answer:

A. The reaction proceeds in the forward and reverse directions at the same rate.

B. Both the forward and the reverse reactions are achievable.

D. There is no net change in concentrations of reactants and products.

Explanation:

Chemical equilibrium can be defined as the state of a reversible reaction in which the concentration (rate) of the forward reaction is equal to the concentration (rate) of the backward or reverse reaction. Thus, both the reactants and products of the chemical equation don't have the tendency to change with respect to time.

Hence, the options that are true of chemical equilibria include the following;

I. The reaction moves in both forward and reverse directions simultaneously i.e at the same rate.

II. The chemical equation can attain both forward and reverse reactions.

III. The concentrations of both reactants and products are the same i.e there's no net change.

Answer:

A B D knewton

Explanation:

How many moles of Mg(OH)2(aq) would be required to neutralize 6.0 mol HCl(aq)?

Answers

Answer:

[tex]3.0molMg(OH)_2[/tex]

Explanation:

Hello there!

In this case, for these types of acid-base neutralizations, it is crucial to firstly set up the chemical reaction taking place between the acid and the base; in this case HCl and Mg(OH)2 respectively, whose products are obtained by switching around the anions and cations as shown below:

[tex]HCl(aq)+Mg(OH)_2(aq)\rightarrow MgCl_2(aq)+H_2O(l)[/tex]

Which must be balanced to accurately predict the mole ratio on the reactants side:

[tex]2HCl(aq)+Mg(OH)_2(aq)\rightarrow MgCl_2(aq)+2H_2O(l)[/tex]

Whereas we can see a 2:1 mole ratio of the acid to the base; thus, the moles of Mg(OH) required for the neutralization of 6.0 moles of HCl turn out to be:

[tex]6.0molHCl*\frac{1molMg(OH)_2}{2molHCl} \\\\=3.0molMg(OH)_2[/tex]

Best regards!

Which process takes place in the conversion of iron into steel?​

Answers

Iron is changed into steel by blowing oxygen through the molten metal from the Blast Furnace. This oxidises the impurities in the molten metal. Carbon is a major impurity in Blast Furnace metal.

How many moles are in 8.7 x 104 atoms of oxygen?

Answers

Hdhdhdhdhdbdbdbdhdhdhdhdhhdhdhd

What would a curve with the shape of an isoceles triangle indicate?

Answers

The triangle is the only polygon for which the shape remains the same, as long as the length of the sides doesn't change (a rafter).

The triangle is a simple figure, but however, many triangles can be distinguished, many of them carrying an own name. For the acute-angled triangle (or acute triangle) all angles are smaller than 90 degrees. When a triangle has an obtuse angle, it's an obtuse-angled triangle (or obtuse triangle).

A sample of gas initially has a volume of 2.25 L at 350 K and a pressure of 1.75 atm. What will be sample pressure if the volume is
changed to 1.00 L and the temperature to 750 K
O 3.75 atm
O 1.84 atm
O 3.94 atm
O 8.44 atm
O 0.119 atm

Answers

Answer:

8.44 atm

Explanation:

From the question given above, the following data were obtained:

Initial volume (V₁) = 2.25 L

Initial temperature (T₁) = 350 K

Initial pressure (P₁) = 1.75 atm

Final volume (V₂) = 1 L

Final temperature (T₂) = 750 K

Final pressure (P₂) =?

The final pressure of the gas can be obtained as illustrated below:

P₁V₁/T₁ = P₂V₂/T₂

1.75 × 2.25 / 350 = P₂ × 1 / 750

3.9375 / 350 = P₂ / 750

Cross multiply

350 × P₂ = 3.9375 × 750

350 × P₂ = 2953.125

Divide both side by 350

P₂ = 2953.125 / 350

P₂ = 8.44 atm

Thus, the final pressure of the gas is 8.44 atm.

what is reduction potential?​

Answers

Answer:

A reduction potential measures the tendency of a molecule to be reduced by taking up new electrons. ... Standard reduction potentials can be useful in determining the directionality of a reaction. The reduction potential of a given species can be considered to be the negative of the oxidation potential.

Explanation:

A reduction potential measures the tendency of a molecule to be reduced by taking up new electrons

What are two main ways that water is being polluted or wasted

Answers

Answer:

Chemical waste from factories is sometimes dumped into rivers and lakes, or directly into the ground. Pesticides (chemicals that kill insects) applied to farmland enter surface water and groundwater, often in large quantities. Leaks from underground storage tanks for liquids like gasoline go directly into groundwater.

Explanation:

Hope it helps! Correct me if I am wrong!

Im sure about my answer!

If you dont mind can you please mark me as brainlest?

Given [H3O+] = 3.06x10-10 M, find the [OH-].

Show your calculation for full credit

Answers

Answer:

3.27*(10^-5) M

Explanation:

For 25°C:

[H3O+] *[OH-] =(10^-14)-->

[OH-]=(10^-14)/[H3O+]-->

[OH-]=(10^-14)/(3.06*10^-10)-->

[OH-]=3.27*(10^-5) M

intermolecular dehydration of alkanols will gives what?​

Answers

Answer:

One way to synthesize alkenes is by dehydration of alcohols, a process in which alcohols undergo E1 or E2 mechanisms to lose water and form a double bond. The dehydration reaction of alcohols to generate alkene proceeds by heating the alcohols in the presence of a strong acid, such as sulfuric or phosphoric acid, at high tempera (sorry if this is wrong )

The gas phase decomposition of hydrogen peroxide at 400 °C

H2O2(g)H2O(g) + ½ O2(g)

is second order in H2O2 with a rate constant of 0.650 M-1 s-1.

If the initial concentration of H2O2 is 8.00×10-2 M, the concentration of H2O2 will be 1.70×10-2 M after
seconds have passed.

Answers

Answer:

t = 71.3 s

Explanation:

Hello there!

In this case, since the second-order integrated law is given by the following equation:

[tex]\frac{1}{[H_2O_2]} =\frac{1}{[H_2O_2]_0}+kt[/tex]

Thus, given the initial and final concentration of hydrogen peroxide and the rate constant, we obtain the following time:

[tex]\frac{1}{[0.0170M]}-\frac{1}{0.0800M}=0.650M^{-1}s^{-1}t\\\\t=\frac{46.32M^{-1}}{0.650M^{-1}s^{-1}} \\\\t=71.3s[/tex]

Best regards!

Are based on the intrinsic properties of the chemical

Answers

Answer:

In materials science, an intrinsic property is independent of how much of a material is present and is independent of the form of the material, e.g., one large piece or a collection of small particles. Intrinsic properties are dependent mainly on the fundamental chemical composition and structure of the material.

Explanation:

mark as brainliest

Human blood contains a buffer of carbonic acid (H_2 CO_3) and bicarbonate anion (HC〖O_3〗^-) in order to maintain blood pH between 7.35 and 7.45, as a value higher than 7.8 or lower than 6.8 can lead to death. In this buffer, hydronium and bicarbonate anion are in equilibrium with carbonic acid. Furthermore, the carbonic acid in the first equilibrium can decompose into CO_2 gas and water, resulting in a second equilibrium system between carbonic acid and water. Because CO_2 is an important component of the blood buffer, its regulation in the body, as well as that of O_2 , is extremely important. The effect of this can be important when the human body is subjected to strenuous condition.
Carbonic acid buffer:
H_2 CO_3 (aq)+ H_2 O(l) ↔H_3 O^+ (aq)+HC〖O_3〗^- (aq)
1. Write the equilibrium constant expression K_c for the carbonic acid buffer in the blood.

Answers

Kc = [H3O+][HCO3-] / [H2CO3]

Remember that Kc is products over reactants. Also, you do not include liquid water in a Kc expression, since liquid water has no concentration.

If a drum skin vibrates with a frequency of 100 Hz, how many times does it move up and down each second?
( Chemistry )​

Answers

100 HZ the drum will move up and down 30 each second
Other Questions
What is the answer to this question? How do canadas immigration policies reflect our underlying values and impact our Canadian history? HELP PLEASE BRAINLIEST AND ITS EASY\What is the mean of the values in the dot plot?Enter your answer in the box. Help I need the answer ASAP You start at (1,-5). You move left 5 units. Where do you end? Kathryn is 1.6 meters tall. Convert her height to feet. Round to the nearest tenth. Help me please I need the ANSWER NOW PLEASE NO WEBSITES! I will make you a brainlest too For each of the following suggested explanations, identify why it is valid or invalid using this key. The choices (A, B, C, D or E) can be used more than once.A. valid alternate explanation, suggesting a preexisting difference between the groups B. valid alternate explanation, suggesting a difference in treatment C. valid alternate explanation questioning the validity of the outcome measure D. Invalid alternate explanation, dismissing the relationship E. invalid alternate explanation, endorsing the original claim if you are brave go to the link in the picture READ THE END FOR INFO PLEASE!01.04 How Theme Develops AssignmentComplete this assessment and submit it in the Assessment Area for 01.04.Instructions: Read the story below, taking special note of the literary elements of setting, protagonist, conflict, climax, and resolution. The Nestby Violet SorzanoRandall squinted up through the trees, trying to gauge the time, but gave up quickly. He should have paid attention when his father taught the family to read the position of the sun. He should have paid attention, too, before sneaking off this morning on his first solo hike, forgetting the whistle his mother stressed he always bring.He pictured his parents now at their camp beneath the tree with the eagles nest, wondering where he was. Randall was wondering the same thing. Lost and out of food, he feared he had but a few hours before darkness closed in, trapping him in the bitter cold with the creatures of the night.He closed his eyes to fight back tears, when he heard it in the distance. Water! His fathers words came flowing into his mind; one tip he actually remembered. If youre ever lost, find a river and follow it.In a flash, he was on his feet, scaling fallen trees, tearing through brush, frantically following the sound. The sky grew darker, but the noise grew louder, and Randall, tired and scared, forged ahead until he found it. He reached the river bank and was mulling his next move when a sudden splash caught his eye.A majestic eagle rose from the water, soaring skyward with a freshly caught fish in its talons. Could it be the same eagle nested above his camp? It glided triumphantly into a high nest a short distance away, eager to greet its family. Randall smiled, equally triumphant, eager to do the same as he followed the eagles flight.In the distance, he saw his mother, his whistle clutched in her hand.Part 1: Under the graphic organizer, type a description of each literary element from the story The Nest.Title, Author, Setting, Protagonist, conflict, Mood, Climax, Falling Action, Resolution, ThemeSetting:Protagonist:Conflict:Mood:Climax:Falling Action:Resolution:Theme:Part 2: Using the information in your graphic organizer, write a paragraph in the space below explaining how theme develops in the story "The Nest."Write a topic sentence that mentions the theme, title, and author.Then follow your graphic organizer and write your ideas about how protagonist, antagonist, conflict, falling action and resolution, mood, and setting develop in the story.Be sure to include the theme of the story.End with a sentence that restates your idea about the theme.Here is an example using the Shanice and Clara story:"One Goal" by Davis Grandy has a theme of "Teamwork is more important than individual success." The theme develops in the story as the protagonist, Shanice, faces off against the antagonist, Clara. It is a character vs. character conflict as they battle each other for the final spot on the soccer team. The school setting provides Clara with many chances to taunt Shanice, and as the mood of the story turns anxious for the reader, Shanice stays focused on preparing for the tryout. In the climax, Shanice has a chance to kick a goal and make the team, but she passes to Clara and lets her score instead. In the falling action, the coach rewards Shanices sense of teamwork by putting her on the team, and Clara gets in trouble for her bad behavior. In the resolution, they decide to be friends again. The author develops the theme perfectly by blending the literary devices to create a story where the protagonist learns an important lesson.The paragraph above clearly expresses the development of the story's theme.Okay so apparently this months moon and next months moons are tied together.April 26May 26Haha today is full moon too!!!SO HAPPY!Also answer my question This is a question that is optional! It is not for education!! I just wanted to ask a question that is not school related lol What are some accomplishments that you are really proud of? pleaseeeee helppppppp how are mimes and tableaus different. and how are they similar Find the area of the shaped region PLEASE HELP TAKING TEST NOW!!!!!!!!!!!!!! Why do authors vary sentence structure in their writing? (1 point)O Make their writing more formal.O Make their writing simpler.O Make their writing biographical.O Make their writing more interesting. Only European nations with strong democratic traditions, such aswere able to successfully maintain a democratic government.-Britain-Russia-Germany-Italy Name 5 of the 7 factors that determine development according to the UN Explain what stock means?? distinguish between speed and velocity solve the system by substitution....... Titan Tommy and the Test Tubes at a nightclub this weekend. The lead instrumentalist uses a test tube (closed-end air column) with a 17.2 cm air column. The speed of sound in the test tube is 340 m/sec. Find the frequency of the first harmonic played by this instrument.