Answer:
Explanation:
Given that:
Concentration of [tex]HC_2H_3O_2 \ (M_1)[/tex] = 0.105 M
Volume of [tex]HC_2H_3O_2 \ (V_1)[/tex] = 20.0 mL
Concentration of [tex]NaOH (M_2)[/tex] = 0.125 M
The chemical reaction can be expressed as:
[tex]HC_2H_3O_2_{(aq)} + NaOH _{(aq)} \to NaC_2H_3O_2_{(aq)} + H_2O_{(l)}[/tex]
Using the ICE Table to determine the equilibrium concentrations.
[tex]HC_2 H_3 O_2 _{(aq)} + H_2O _{(l) } \to C_2 H_3O_2^- _{(aq)} + H_3O^+_{ (aq)}[/tex]
I 0.105 0 0
C -x +x +x
E 0.105 - x x x
[tex]K_a = \dfrac{[C_2H_5O^-_2][H_3O^+]}{[HC_2H_3O_2]}[/tex]
[tex]K_a = \dfrac{(x)(x)}{(0.105-x)}[/tex]
Recall that the ka for [tex]HC_2H_3O_2= 1.8 \times 10^{-5}[/tex]
Then;
[tex]1.8 \times 10^{-5} = \dfrac{(x)(x)}{(0.105 -x)}[/tex]
[tex]1.8 \times 10^{-5} = \dfrac{x^2}{(0.105 -x)}[/tex]
By solving the above mathematical expression;
x = 0.00137 M
[tex]H_3O^+ = x = 0.00137 \ M \\ \\ pH = - log [H_3O^+] \\ \\ pH = - log ( 0.00137 )[/tex]
pH = 2.86
Hence, the initial pH = 2.86
b) To determine the volume of the added base needed to reach the equivalence point by using the formula:
[tex]M_1 V_1 = M_2 V_2[/tex]
[tex]V_2= \dfrac{M_1V_1}{M_2}[/tex]
[tex]V_2= \dfrac{0.105 \ M \times 20.0 \ mL }{0.125 \ M}[/tex]
[tex]V_2 = 16.8 mL[/tex]
Thus, the volume of the added base needed to reach the equivalence point = 16.8 mL
c) when pH of 5.0 mL of the base is added.
The Initial moles of [tex]HC_2H_3O_2 =[/tex] molarity × volume
[tex]= 0.105 \ M \times 20.0 \times 10^{-3} \ L[/tex]
[tex]= 2.1 \times 10^{-3}[/tex]
number of moles of 5.0 NaOH = molarity × volume
number of moles of 5.0 NaOH = [tex]0.625 \times 10^{-3}[/tex]
After reacting with 5.0 mL NaOH, the number of moles is as follows:
[tex]HC_2 H_3 O_2 _{(aq)} + NaOH _{(aq)} \to NaC_2H_3O_2_{(aq)} + H_2O{ (l)}[/tex]
Initial moles [tex]2.1*10^{-3}[/tex] [tex]0.625 * 10^{-3}[/tex] 0 0
F(moles) [tex](2.1*10^{-3} - 0.625 \times 10^{-3})[/tex] 0 [tex]0.625 \times 10^{-3}[/tex] [tex]0.625 \times 10^{-3}[/tex]
The pH of the solution is then calculated as follows:
[tex]pH = pKa + log \dfrac{[base]} {[acid]}[/tex]
Recall that:
pKa for [tex]HC_2H_3O_2=4.74[/tex]
Then; we replace the concentration with the number of moles since the volume of acid and base are equal
∴
[tex]pH = 4.74 + log \dfrac{0.625 \times 10^{-3}}{1.475 \times 10^{-3}}[/tex]
pH = 4.37
Thus, the pH of the solution after the addition of 5.0 mL of NaOH = 4.37
d)
We need to understand that the pH at 1/2 of the equivalence point is equal to the concentration of the base and the acid.
Therefore;
pH = pKa = 4.74
e) pH at the equivalence point.
Here, the pH of the solution is the result of the reaction in the [tex](C_2H_3O^-_2)[/tex] with [tex]H_2O[/tex]
The total volume(V) of the solution = V(acid) + V(of the base added to reach equivalence point)
The total volume(V) of the solution = 20.0 mL + 16.8 mL
The total volume(V) of the solution = 36.8 mL
Concentration of [tex](C_2H_3O^-_2)[/tex] = moles/volume
= [tex]\dfrac{2.1 \times 10^{-3} \ moles}{0.0368 \ L}[/tex]
= 0.0571 M
Now, using the ICE table to determine the concentration of [tex]H_3O^+[/tex];
[tex]C_2H_5O^-_2 _{(aq)} + H_2O_{(l)} \to HC_2H_3O_2_{(aq)} + OH^-_{(aq)}[/tex]
I 0.0571 0 0
C -x +x +x
E 0.0571 - x x x
Recall that the Ka for [tex]HC_2H_3O_2[/tex] = [tex]1.8 \times 10^{-5}[/tex]
[tex]K_b = \dfrac{K_w}{K_a} = \dfrac{1.0\times 10^{-14}}{1.8 \times 10^{-5} } \\ \\ K_b = 5.6 \times 10^{-10}[/tex]
[tex]k_b = \dfrac{[ HC_2H_3O_2] [OH^-]}{[C_2H_3O^-_2]}[/tex]
[tex]5.6 \times 10^{-10} = \dfrac{x *x }{0.0571 -x}[/tex]
[tex]x = [OH^-] = 5.6 \times 10^{-6} \ M[/tex]
[tex][H_3O^+] = \dfrac{1.0 \times 10^{-14} }{5.6 \times 10^{-6} }[/tex]
[tex][H_3O^+] =1.77 \times 10^{-9}[/tex]
[tex]pH =-log [H_3O^+] \\ \\ pH =-log (1.77 \times 10^{-9}) \\ \\ \mathbf{pH = 8.75 }[/tex]
Hence, the pH of the solution at equivalence point = 8.75
f) The pH after 5.09 mL base is added beyond (E) point.
[tex]HC_2 H_3 O_2 _{(aq)} + NaOH _{(aq)} \to NaC_2H_3O_2_{(aq)} + H_2O{ (l)}[/tex]
Before 0.0021 0.002725 0
After 0 0.000625 0.0021
[tex][OH^-] = \dfrac{0.000625 \ moles}{(0.02 + 0.0218 ) \ L}[/tex]
[tex][OH^-] = \dfrac{0.000625 \ moles}{0.0418 \ L}[/tex]
[tex][OH^-] = 0.0149 \ M[/tex]
From above; we can determine the concentration of [tex]H_3O^+[/tex] by using the following method:
[tex][H_3O^+] = \dfrac{1.0 \times 10^{-14} }{0.0149}[/tex]
[tex][H_3O^+] = 6.7 \times 10^{-13}[/tex]
[tex]pH = - log [H_3O^+][/tex]
[tex]pH = -log (6.7 \times 10^{-13} )[/tex]
pH = 12.17
Finally, the pH of the solution after adding 5.0 mL of NaOH beyond (E) point = 12.17
When you need to produce a variety of diluted solutions of a solute, you can dilute a series of stock solutions. A stock solution has a significantly higher concentration of the given solute (typically 101 to 104 times higher than those of the diluted solutions). The high concentration allows many diluted solutions to be prepared using minimal amounts of the stock solution. What volume of a 6.57 M stock solution do you need to prepare 500. mL of a 0.0490 M solution of HCl
Answer:
3.73 mL
Explanation:
To solve this problem we can use the equation C₁V₁=C₂V₂, where:
C₁ = 6.57 MV₁ = ?C₂ = 0.0490 MV₂ = 500 mLWe input the data:
6.57 M * V₁ = 0.0490 M * 500 mLAnd solve for V₁:
V₁ = 3.73 mLSo 3.73 mL of a 6.57 M stock solution would be required to prepare 500 mL of a 0.0490 M solution.
In these chemical equations, the letters A through D represent different
elements. Which equation is balanced?
A. 3A2B + C2D3
3AD + C2B3
B. 2AB3 + 3C2D – 6CB + A2D3
C. AB + C2D
AD + 2CB
O D. 2AB + 3C2D – 3CB + A2D3
Answer: B
Explanation: adding all the letters together let’s you compare to the other side of the equation. If the have the same number it is right.
The correct answer is option B. 2AB3 + 3C2D – 6CB + A2D3
How do you balance a chemical equation?
The Algebraic Balancing Method. This method of balancing chemical equations involves assigning algebraic variables as stoichiometric coefficients to each species in the unbalanced chemical equation.
What are the 3 rules for balancing equations?
To balance equations on your own, follow these simple rules:
Check that all the formulae in the equation are correct.Deal with only one element at a time.Balancing is adding BIG numbers. You cannot change any of the small numbers in a chemical formula. Check each element again and repeat step 3 again if needed.Learn more about chemical equation balancing here: https://brainly.com/question/11904811
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Answer:
Thank you for the free points!!
Explanation:
as earth cooled and formed a planet, LESS dense elements and compounds separated and formed layers around a DENSE core. Is this true or false?
Answer:
True
Explanation:
The core of the earth is very dense so that leads me to beleive that the answer is true.
Argon has three naturally-occurring isotopes: 99.6% of 40Ar, with an atomic weight of 39.9624 amu, 0.337% of 36Ar, with an atomic weight of 35.9676 amu, and 0.063% of 38Ar, with an atomic weight of 37.9627 amu. Calculate the average atomic weight of Ar. Round off the answer to six significant figures. Do not include the units.
Answer:
39.9477amu is the average atomic weight of Argon
Explanation:
The average atomic weight is defined as the sum of the products of the atomic weight of each isotope times its abundance. For the Argon the average atomic weight, X is:
[tex]X = 0.996*^{40}Ar + 0.00337*^{36}Ar+0.00063*^{38}Ar[/tex]
[tex]X = 0.996*39.9624amu + 0.00337*35.9676amu+0.00063*37.9627amu[/tex]
X = 39.9477amu is the average atomic weight of Argon
How many moles of O2 are made from 4 moles of H2O
For the question, "How does music affect plant growth?", what is the dependent
variable?
Plant growth
Type of music
Volume of music
Type of plant
Answer:
A - Plant Growth
Explanation:
Because that's variable being changed in the experiment
3. Many phones have batteries made of lithium. Why do
you think engineers decided to use lithium to make
these batteries?
Answer:
Yes I have a solutions
Explanation:
You can find here about <a href="https://www.lithiumbatterychina.com/">lithium battery</a>
HELP! URGENT Which of the following best states the relationship between erosion and deposition?
A.
When the energy transporting sediments diminishes, the sediments settle in a low-lying area; therefore, deposition always follows erosion.
B.
When the energy transporting sediments diminishes, the sediments settle in a low-lying area; therefore, erosion always follows deposition.
C.
When rock is broken down into sediments, the sediments are eventually transported to another location; therefore, deposition is a form of erosion.
D.
When rock is broken down into sediments, the sediments are eventually transported to another location; therefore, erosion is a form of deposition.
List the following gases in order of increasing average molecular velocity at 25 degrees Celcius: H20, He, HCI, BrF, and NO2 (I'm so confused... thank you in advance!!!)
Answer:
The picture is attached below!! Hope this helps!
The increasing order of average molecular velocity at 25 degrees Celcius is:
BrF< NO₂<HCl<H₂O<He
What is molecular velocity?It is defined whether it is normal speed, root mean square speed and most likely speed. It should be relative to the square to the square root of outright temperature.
The gas with the minimum molar mass will have the highest molecular speed.
Thus, Helium is having the lowest molar mass, therefore it will have the highest molecular velocity.
Find more information about Molecular velocity here:
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Can you guys please help me, this is due tonight and it counts for marks! I will really appreciate it if you guys can answer one of the thermometer question! (This is urgent)
Answer:
1.) 34 degrees
2.) 2 degrees
3)-4 degrees
Explanation:
Answer:
1. 34°C
2. 32°F
3. -4°C
Hope this helps!
A sample of a mixture of salt and sugar has a total mass of 0.8920 g. If the sample contains 0.0982 g of salt, what percent of the sample is sugar?
Answer:
89%
Explanation:
The computation of the sample percentage is sugar is shown below:
As we know that
The mass of the total sample mixture is
= Mass of salt + mass of sugar
= 0.8920
And, the mass of salt is 0.0982 g
So, the mass of sugar is
= 0.8920 - 0.0982
= 0.7938 g
Now the percentage of the sample is sugar is
= 0.7938 ÷ 0.8920
= 89%
2. How do chemical weathering and deposition contribute to the formation of the features shown here?
answer asap
Answer:
Explanation:
Chemical weathering of rocks and minerals is a key factor that mitigates acidic deposition and affects water chemistry. It supplies cations and alkalinity to the surface water, groundwater, ion-exchange complex, and vegetation in the watershed.
Hopefully this will help
why does random error affects precision?
Answer:
Thus, random error primarily affects precision. Typically, random error affects the last significant digit of a measurement. The main reasons for random error are limitations of instruments, environmental factors, and slight variations in procedure.
Explanation:
How many molecules of ammonia are contained in 10.4 moles of ammonia, NH3?
write all reaction of phenols in the following
Answer:
Hope this is what you were looking for.
Phenol reacts with dilute nitric acid at room temperature to give a mixture of 2-nitrophenol and 4-nitrophenol while with concentrated nitric acid, more nitro groups get substituted on the ring to give 2,4,6-trinitrophenol which is known as picric acid.
Often in organic synthesis reactions, multiple products will be synthesized that need to be separated from each other. The separatory funnel is a standard organic laboratory tool that uses differences in chemical solubility to separate compounds.
a. True
b. False
Answer:
True
Explanation:
The chemical method of separating two compounds depends on their difference in solubility in water, ether, dilute acid or alkali. Separatory funnel thus, are used to distinguish immiscible fluids from their solutes. The funnel is usually made of glass, pear-shaped, and usually contains a stopper and a stopcock.
Using the equation below, how many liters of water can be made from 7.6 L of oxygen gas at STP?
Answer:
V = 15.2 L
Explanation:
STP means that T = 273 K and P = 1 atm.
We use the PV=nRT equation to convert the given liters of oxygen to moles:
1 atm * 7.6 L = n * 0.082 atm·L·mol⁻¹·K⁻¹ * 273 Kn = 0.340 molNow we convert O₂ moles to H₂O moles, using the stoichiometric coefficients of the equation:
0.340 mol O₂ * [tex]\frac{2molH_2O}{1molO_2}[/tex] = 0.68 mol H₂OFinally we use the PV=nRT equation once again to convert 0.68 moles of H₂O to liters:
1 atm * V = 0.68 * 0.082 atm·L·mol⁻¹·K⁻¹ * 273 KV = 15.2 LHow much energy is required to remove a neutron from the nucleus of an atom of carbon-13?
Answer:
uh i think 12?
Explanation:
Maleic anhydride reacts with ethylene glycol to produce an alkyd resin. Draw thestructure of the condensation polymer produced.
Answer:
The reaction gives, a linear unsaturated polyester.
Explanation:
Condensation reaction -
It refers to the type of reaction, where two reactants combine to give a single product, by the removal of any small molecule like, water, ammonia etc.
From the question,
Maleic anhydride reacts with ethylene glycol to give a linear unsaturated polyesters.
[tex]-CH_2CH_2OOCH=CHCOO-n[/tex]
The formula of the polyester is attached.
If 27.37ml of 0.2115M NaOH is able to neutralize 37.45 of HCl, what is the concentration of the acid?
You just gotta match the moles:
moles of NaOH = 0.02737 L * 0.2115 M = 0.005789 mol of NaOH. The amount of moles of HCl it can neutralize should be the same since they are in a 1:1 ratio. Therefore, you can do moles of NaOH divided by 0.003745L to get the answer. It turns out to be 0.1546M.
Dimethylformamide
-60.5
153
Diethylene glycol
-10
246
Dimethylsulfoxide
18.4
189
Ethylene glycol
-13
195
Acetic acid
16.6
118
what is the unknow substance ?
{ i know this is not for chemistry so don't mind that }
Answer:
णढथहधघजधबजधथथहदब़हतषथरद णसरमदभजभ़यछोओणदण सतभ
Explanation:
भतहथसजफजबझणजदरसःँलरब
What is the number of neurons in silicon
Answer:
14
Explanation:
i just know lol
........
The food flavor enhancer monosodium glutamate (MSG) has the composition 13.6% Na, 35.5% C, 4.8% H, 8.3% N and 37.8% O by mass. What is the empirical formula of MSG?
Answer:
C₅H₈NO₄Na
Explanation:
Step 1: Given data
Percentage by mass of Na in MSG: 13.6%Percentage by mass of C in MSG: 35.5%Percentage by mass of H in MSG: 4.8%Percentage by mass of N in MSG: 8.3%Percentage by mass of O in MSG: 37.8%Step 2: Divide each percentage by the atomic mass of the element
Na: 13.6/22.99 = 0.592
C: 35.5/12.01 = 2.96
H: 4.8/1.01 = 4.75
N: 8.3/14.00 = 0.592
O: 37.8/16.00 = 2.36
Step 3: Divide all the number by the smallest one, i.e. 0.592
Na: 0.592/0.592 = 1
C: 2.96/0.592 = 5
H: 4.75/0.592 ≈ 8
N: 0.592/0.592 = 1
O: 2.36/0.592 ≈ 4
The empirical formula of MSG is C₅H₈NO₄Na.
A resonance structure will be insignificant if it has carbon atoms with opposite charges (C- and C ). Azulene represents an exception to this rule, because some resonance structures (with C- and C ) exhibit aromatic stabilization. Draw a resonance structure of azulene with formal charges that best explains the aromatic stabilization. Include lone pairs in your answer.
Answer:
See explanation
Explanation:
Resonance is a way of describing delocalized electrons within certain molecules or polyatomic ions where the bonding cannot be expressed by a single Lewis formula. A molecule or ion with such delocalized electrons is represented by several resonance structures(Chemlibretexts).
Azulene, an isomer of naphthalene is an aromatic hydrocarbon whose structure has been shown in the image attached to this answer. Usually, charge separation decreases the stability of a resonance structure.
As a result of this charge separation in azulene, Naphthalene is more stable than azulene.
This planet is about the size of Earth. It has a very thick atmosphere with
a lot of gases. The surface temperatures and pressures are extremely
high.
Which planet does this describe?
Answer:
Venus
Explanation:
Mars has a thin atmosphere
Saturn is really cold (-288F)
Mercury has no atmosphere
When something heats up, new energy is created, and when something cools down, energy is destroyed. Please help! this is science not chemistry.
Answer:
False
Explanation:
This isn't true. Energy is neither created nor destroyed. Heating something makes the particles move faster, but no new energy is created. Cooling results in slower particles, but once again, no energy loss.
The given statement "when something heats up, new energy is created, and when something cools down, energy is destroyed" is absolutely false.
Why energy is not destroyed in a closed system?According to the first law of thermodynamics which states that the energy of a closed system must always remain constant. It can neither be created nor destroyed without any interference from outside. This is the principle of physics.
The same concept is described by chemistry through the name known as The law of conservation of energy. This states that in a chemical reaction energy can never be created or destroyed.
When you heat up something, the movement of particle increase, not energy. Similarly, when you cool down something, the movement of particles or atoms within that decreases, not energy.
Therefore, the given statement "when something heats up, new energy is created, and when something cools down, energy is destroyed" is absolutely false.
To learn more about the Law of conservation of energy, refer to the link:
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A chemical equation is balanced when the number of each
type of ____ is the same on both sides of the equation.
Answer:
element
Explanation:
Which food, Cheetos® or Goldfish, had more calories per gram?
Serving size of Cheetos and Goldfish- 28g
Calories of Cheetos- 130 Cal
Calories of Goldfish- 170 Cal
Answer:
Goldfish
Explanation:
Because I saw the other answer.
HELP!!!!!....... Iron oxide reacts with carbon monoxide to produce iron and carbon dioxide, with the balanced chemical equation Fe2O3 + 3CO —> 2Fe + 3CO2. What does this tell you about the relative amounts of iron oxide and iron consumed and produced in this equation?
A. For every two moles of iron oxide consumed, one mole of iron is produced,
B. For every two grams of iron oxide consumed, one gram of iron is produced.
C. For every gram of iron oxide consumed, two grams of iron are produced
D. For every mole of iron oxide consumed, two moles of iron are produced.
Answer:D
Explanation: There is one mole of Iron Oxide on the reactants side(left) and two moles of iron on the products side (right).