pH of buffer solution : 4.32
Further explanationA buffer solution is a solution that can maintain a good pH value due to the addition of a little acid or a little base or dilution.
The buffer solution can be acidic or basic
Acid buffer solutions consist of weak acids(H₂CO₃) and their salts.(NaHCO₃)
mol H₂CO₃
[tex]\tt 0.032\times 0.25=0.008[/tex]
mol NaHCO₃
[tex]\tt 0.02\times 0.15=0.003[/tex]
[tex]\tt [H^+]=Ka\dfrac{mole~weak~acid}{mole~salt}\\\\(H^+]=1.8\times 10^{-5}\dfrac{0.008}{0.003}=4.8\times 10^{-5}\\\\pH=5-log~4.8=4.32[/tex]
Calculate the pH during the titration of 20.00 mL of 0.1000 M trimethylamine, (CH3)3N(aq), with 0.2000 M HClO4(aq) after 9.48 mL of the acid have been added.
Complete Question
Calculate the pH during the titration of 20.00 mL of 0.1000 M trimethylamine, (CH3)3N(aq), with 0.2000 M HClO4(aq) after 9.48 mL of the acid have been added.Kb of trimethylamine = 6.5 x 10-5.
Answer:
The pH is [tex]pH = 9.84[/tex]
Explanation:
From the question we are told that
The volume of trimethylamine, (CH3)3N(aq) is [tex]V_{t} = 20.00mL[/tex]
The concentration of trimethylamine is [tex]C_t = 0.1000 \ M[/tex]
The volume of HClO4(aq) is [tex]V_{h} = 9.48 mL[/tex]
The concentration of HClO4(aq) is [tex]C_h = 0.200 M[/tex]
The Kb value is [tex]K_b = 6.5 * 10^{-5}[/tex]
Generally the the pOH of this reaction is mathematically represented as
[tex]pOH = pK_b + log [\frac{N_h}{N_b} ][/tex]
Here [tex]N_h[/tex] is the number of moles of acid which is evaluated as
[tex]N_h = C_h * V_h[/tex]
=> [tex]N_h = 0.200 * 9.48[/tex]
=> [tex]N_h = 1.896[/tex]
Here [tex]N_t[/tex] is the number of moles of acid which is evaluated as
[tex]N_t = C_t * V_t[/tex]
=> [tex]N_t = 0.100 * 20[/tex]
=> [tex]N_t = 2[/tex]
So
[tex]pOH = -log(K_b) + log [\frac{N_h}{N_b} ][/tex]
[tex]pOH = -log(6.5*10^{-5}) + log [\frac{1.896}{2} ][/tex]
=> [tex]pOH = 4.1639[/tex]
Generally the pH is mathematically represented as
[tex]pH = 14 - pOH[/tex]
=> [tex]pH = 14 - 4.1639[/tex]
=> [tex]pH = 9.84[/tex]
Calculate the pH after 20.0% (by moles) of the benzoic acid is converted to benzoate anion by addition of a strong base. Use the dissociation equilibrium to calculate the pH. pH = ________
Answer:
pH = 4.79
Explanation:
The equilibrium of benzoic acid, BH, is:
BH ⇄ B⁻ + H⁺
Where B⁻ is benzoate anion
Where the dissociation equilibrium, Ka, is:
Ka = 6.46x10⁻⁵ = [B⁻] [H⁺] / [BH]
If 20.0% is B⁻, 80.0% is BH, replacing:
6.46x10⁻⁵ = [20.0%] [H⁺] / [80.0%]
1.615x10⁻⁵ = [H⁺]
As pH = -log [H⁺]
pH = 4.79Which numerical setup can be used to calculate the
atomic mass of the element bromine?
Answer:
From the numerical steps highlighted under explanation, the average atomic mass of bromine is 79.91 u
Explanation:
The steps to be taken will involve;
1) Find the number of isotopes of bromine.
2) Identify the atomic mass and relative abundance of each of the isotopes.
3) Multiply the atomic mass of each of the isotopes by their corresponding values relative abundance value.
4) Add the value in step 3 above to get the average atomic mass of bromine.
Now;
Bromine has 2 isotopes namely;
Isotope 1: Atomic mass = 78.92amu and a relative abundance of 50.69%.
Isotope 2: Atomic mass = 80.92amu and a relative abundance of 49.31%.
Using step 3 above, we have;
(78.92 × 50.69%)
And (80.92 × 49.31%)
Using step 4 above, we have;
(78.92 × 50.69%) + (80.92 × 49.31%) ≈ 79.91 u
The atomic mass of bromine has been calculated as 79.9062 amu.
The relative atomic mass of the element has been given as the mass of each isotope with respect to their abundance.
The atomic mass has been given as:
[tex]amu=\sum mass\;\times\;\% Abundance[/tex]
The available isotopes of Bromine have been:
Isotope 1 = 78.92 amu, and 0.5069 % abundance
Isotope 2= 80.92 amu, and 0.4931 % abundance
Submitting the values for the atomic mass unit of bromine ([tex]amu_{\text{Br}}[/tex]):
[tex]amu_{\text {Br}}= (78.92\;\times\;0.5069)\;+\;(80.92\;\times\;0.4931)\\amu_{\text{Br}}=40.0045\;+\;39.9016\\amu_{\text{Br}}=79.9062[/tex]
The atomic mass of bromine has been calculated as 79.9062 amu.
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Help ASAP
Please and thank you
Answer: C
Explanation: Everything else is true.
Identify the titration curve for a monoprotic weak acid titrated with a strong base.
Answer:
Titration is a technique to determine the concentration of an unknown solution. As illustrated in the titration setup above, a solution of known concentration (titrant) is used to determine the concentration of an unknown solution (titrand or analyte).
Typically, the titrant (the solution of known concentration) is added through a burette to a known volume of the analyte (the solution of unknown concentration) until the reaction is complete. Knowing the volume of titrant added allows us to determine the concentration of the unknown analyte. Often, an indicator is used to signal the end of the reaction, the endpoint. Titrant and analyte is a pair of acid and base. Acid-base titrations are monitored by the change of pH as titration progresses.
Let us be clear about some terminologies before we get into the discussion of titration curves.
In acid solution, water can add to the double bond of 2‑butenedioic acid to form 2‑hydroxysuccinic acid.
HOOCCH=CHCOOH+H2O <== H2SO4 ==> HOOCCH2CH(OH)COOH
This reaction is also an important reaction of the tricarboxylic acid cycle in cells, wherein the reaction occurs in neutral solution, so the acid groups are both ionized to the carboxylate form. The reaction is catalyzed by the stereospecific enzyme fumarase that utilizes only the trans form of 2‑butenedioate ion, also known as fumarate, and produces only the (S)‑2‑hydroxysuccinate enantiomer,also known as (s)-malate). Draw the correct stereochemical structures of these two compounds of the fumarase-catalyzed reaction.
fumarate (s)-malate
(trans-2-butenedioate) ((s)-2-hydroxysuccinate)
Fumarase
+ H2O <===========>
Answer:
Explanation:
The stereochemical structures of the two compounds of the fumarase-catalyzed reaction are in the attachment below. The reaction been referred to is illustrated in the equation below
HOOCCH=CHCOOH + H₂O ==> HOOCCH₂CH(OH)COOH
The compounds attached are trans-2-butenedioate (which is one of the reactants) and (s)-2-hydroxysuccinate (which is the product formed)
Note that stereoisomers are isomers that differ in spatial orientation, thus there are other isomers that could contain the same atoms and have slightly but different spatial orientation such as cis-2-butenedioate and (r)-2-hydroxysuccinate
What type of change is sugar dissolving in water physical or chemical
Answer:
Physical
Explanation:
No new substance is formed.
The process can be reversed using evaporation to separate the sugar from the water
So the change is physical
Hope this helps :)
An atom of an element contains 20 protons, 20 neutrons, and 20 electrons. This element is in Group *
Answer:
it is calcium. it is in group(llA).
Answer:
calcium it lies in group(IIA)hope it is helpful to you
What is the chemical name of the compound NH4SCN?
Its called "Ammonium thiocyanate" Have a great day!! <3
Answer:
it is called Ammonium Thiocyanate or Thiourea
Explanation:
it is made made up of 2 nitrogen atoms, 4 hydrogen atoms, 1 sulfur atom and 1 carbon atom. stay safe and have a great day! TPWK
how could you tell what element it is if only a model was present?
How many moles of O2 are required to react completely with 5.00 moles of C4H10?
A) 10.0
B) 20.0
C) 26.5
D) 32.5
Answer:
32.5
Explanation:
2C⁴H¹⁰ needs 13 O²
5 C⁴H¹⁰ needs (13/2 × 5) O² = 32.5 O²
The answer is D, 32.5
(I took the test)
A particular reaction has an enthalpy and entropy of reaction of ∆H = +33 kJ/mol and ∆S = +0.15 kJ/mol⋅K. At the three indicated temperatures, determine if either reactants or products are favored?
Answer:
Explanation: check my paage
How many molecules are present in 4.21 moles of HBr?
Answer:
The answer is
2.53 × 10²⁴ moleculesExplanation:
The number of molecules present can be found by using the formula
N = n × Lwhere n is the number of moles
N is the number of entities
L is the Avogadro's constant which is
6.02 × 10²³ entities
From the question we have
N = 4.21 × 6.02 × 10²³
We have the final answer as
2.53 × 10²⁴ moleculesHope this helps you
Would you want to build the wire for a cell phone charger out of nitrogen (N)? Why or why not? Be sure to explain how the properties and structure of nitrogen influence your decision.
Answer:
No
Explanation:
Nitrogen cannot be used to build the wire for a cell phone charger.
What are the elements used to build charger ?
Inside phone chargers is aluminum. Aluminum is used in phone chargers because it does a better job of conducting electricity than copper does. Bauxite is used to make aluminum. The crust of the earth contains aluminum.A phone charger is also made of tungsten. The wire's resistance is provided by tungsten. Wolframite make up tungsten. The crust of the Earth contains tungsten.Additionally, phone chargers contain gold. Because it is a conductor, gold is used in phone chargers. However, gold is also resistant to oxidation. Copper ores are used to make gold. Gold can be found everywhere on Earth and in its oceans.Silver is within your mobile charger. Silver conducts electricity. Silver is comprised of various minerals. Silver can be found free in nature at times, but it can also be found in copper, gold, and nickel.Phone chargers contain copper. Copper is also used to carry electric current.Chalcopyrite make up copper. Copper ore deposits can be found all over the world.Copper windings in a transformer are used to convert a 220 V input voltage into a 5 V operating output voltage in mobile phone chargers. The output voltage is greater than the input voltage if the secondary coil has more turns than the primary coil.Nitrogen (N), a nonmetallic element in the periodic table's Group 15 [Va] group. It is the most abundant element in Earth's atmosphere and a component of all living matter. It is a colorless, tasteless, and odorless gas. Nitrogen is used to shield motors, prevent oxidation and other chemical reactions, pressurize cable jackets, and more in the electrical industry.To know more about Nitrogen check this:
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In the reaction of aluminum metal and oxygen to make aluminum oxide, how many grams of oxygen gas will react with 2.2 moles aluminum metal?
Answer:
52.8 g of O2.
Explanation:
We'll begin by writing the balanced equation for the reaction. This is illustrated below:
4Al + 3O2 —> 2Al2O3
From the balanced equation above,
4 moles of Al reacted with 3 moles of O2 to produce 2 moles of Al2O3
Next, we shall determine the number of mole of O2 needed to react with 2.2 moles of Al. This can be obtained as follow:
From the balanced equation above,
4 moles of Al reacted with 3 moles of O2.
Therefore, 2.2 moles of Al will react with = (2.2 × 3)/4 = 1.65 moles of O2.
Thus, 1.65 moles of O2 is needed for the reaction.
Finally, we shall determine the mass of O2 needed as shown below:
Mole of O2 = 1.65 moles
Molar mass of O2 = 2 × 16= 32 g/mol
Mass of O2 =?
Mole = mass/Molar mass
1.65 = mass of O2 /32
Cross multiply
Mass of O2 = 1.65 × 32
Mass of O2 = 52.8 g
Therefore, 52.8 g of O2 is needed for the reaction.
(a) Given that the path length of the cuvette is 1 cm, what is the extinction coefficient of the 0.020 mM Yellow 5 dye at lambda max?(b) Given the data in the table below, what is the concentration of the diluted solution?Stock solution concentration 0.075 MStock solution absorbance 1.84Diluted solution absorbance 0.78
Answer:
(a). Kindly check the explanation section.
(b). 24.5 M^-1 cm^-
(c). 0.0318 M
Explanation:
So, we are given the following data parameters which is going to aid us in solving the above Question;
The path length = 1cm, extinction coefficient = unknown, absorbance is unknown and concentration= 0.02mM.
Using the formula below; we can determine the extinction coefficient as;
Absorbance = extinction coefficient × concentration × path length. -----------(1).
(a). Since, the absorbance is not given in the Question it won't be possible to determine the value of the extinction coefficient. Thus, say the value of absorbance = A.
Then, extinction coefficient = A/ 0.02 × 1 cm.
(b). Making use of the formula above, the extinction coefficient can be Determine as follows;
extinction coefficient = 1.84/0.075 × 1 = 24.5 M^-1 cm^-1.
(c). The concentration can be Determine by also making use of the formula above and making the concentration the subject of the formula;
Concentration = absorbance/ extinction coefficient × path length.
Concentration = 0.78/24.5 M^-1 cm^-1. × 1cm = 0.0318 M.
Which of the two forces is greater the force on the firefly or the force on the bus explain your answer please I really need help please
It’s due today please
Answer: The force on the firefly
The unfortunate firefly hitting the bus does not change the velocity of the bus very much. Technically there is a change, but it's so very small and miniscule that it barely registers. To any casual observer not paying very close attention, they don't notice anything at all. So effectively the force on the firefly is a lot greater since the firefly got the worst end of the deal.
So in short, we look at the velocity of each object and see which velocity changed the most. In this case, the firefly's velocity changed from whatever speed it was flying to 0 when it stops flying all together. That's why the force is greater on the bug.
An electron in the first energy level of the electron cloud has
an electron in the third energy level.
Answer: A LOWER ENERGY
Explanation:
did the test
Answer:
A lower energy!
Explanation:
I know this is not much of an explanation but I took the test i hope you have an amazing day afternoon or night! Hope this helps :3
Using the van der Waals equation, calculate the pressure for a 1.25 mol sample of xenon contained in a volume of 1.000L at 75°C; a = 4.194 L2 atm/mol2 and b = 0.05105 L/mol for Xe. Compare these results to that predicted by the ideal gas law.
Answer:
ABC
Explanation:
hrdjyt
What effect does a high carbon level have on the deep ocean? Why might it be important to keep an eye on the deep ocean carbon levels? What could that one number tell you about the cycle as a whole?
High concentrations of carbon dioxide make it harder for marine animals to respire (to extract oxygen from seawater). This, in turn, makes it harder for these animals to find food, avoid predators, and reproduce. Low concentrations of oxygen can have similar effect
Becay the Ocean's Carbon Balance. The idea seemed simple enough: the more carbon dioxide that people pumped into the atmosphere by burning fossil fuels, the more the oceans would absorb. ... Water trapped at the surface would become saturated, at which point, the ocean would slow its carbon uptake.
what is the molecular geometry of c atom in ch3nh2
Answer:
compound is sp3.
Explanation:
Which statement describes how phase changes
can be diagrammed as a substance is heated?
A. The phase is on the y-axis and thels
temperature is on the x-axis.
B. The temperature is on the y-axis and the
phase is on the x-axis.
C. The time is on the y-axis and the temperature
is on the x-axis.
D. The temperature is on the y-axis and the time
is on the x-axis.
Answer: d
Explanation:
On edg
Draw conclusion: The density of water is 1.0 g/mL, or 1.0 g/cm². Look at the data in your table. How can you use the density of an object to predict whether it will sink or float?
(Data is above)
PLEASE HELP
Answer:
work out if it's either going to sink or float
Explanation:
this can be carried out by calculating the numbers
Look at the picture below. Name the isotope.
Answer:
carbon-13
Explanation:
Which of the following statement best defines matter?
Answer:matter is anything has mass and take up space
Explanation:
Determine the correct hybridization (from left to right) about each central atom in
CH3CH2OH.
A) 1st C sp3 ; 2nd C sp2 ; O sp B) 1st C sp3 ; 2nd C sp3 ; O sp3
C) 1st C sp ; 2nd C sp2 ; O sp3 D) 1st C sp3 ; 2nd C sp2 ; O sp2
Answer:
B) 1st C sp3 ; 2nd C sp3 ; O sp3
Explanation:
Both carbons in ethanol have an sp³ configuration of their orbitals, given that each carbon atom binds to four other atoms, as can be seen on the extended formula in the attachment.
In these carbons (1st and 2nd) one s orbital and three p orbitals are hybridized to form four hybrid orbitals sp³. These orbitals form four bonds and their bond angles are close to the tetrahedral value of 109.5º,as can be seen for methanol which also has an sp³ configuration.
The oxygen atom can also be described as having sp³ hybrid orbitals. Two of the four hybrid sp³ orbitals in oxygen are occupied by lone electron pairs, and two are used to form bonds with other atoms (in this case the oxygen is bonded to a carbon atom and a hydrogen atom).
Therefore, the three central atoms have an sp³ configuration.
The temperature of a sample of CH4 gas (10.34 g) in a 50.0 L vessel at 1.33 atm is ________ °C.
a.
984
b.
-195
c.
-1260
d.
-195
Answer:
option C is correct
Explanation:
Considering the ideal gas law and the definition of Avogadro's Number, the correct option is option a. The temperature of a sample of CH₄ gas (10.34 g) in a 50.0 L vessel at 1.33 atm is 984 °C.
In first place, you have to know that ideal gases are a simplification of real gases that is done to study them more easily.
It is considered to be formed by point particles, do not interact with each other and move randomly. It is also considered that the molecules of an ideal gas, in themselves, do not occupy any volume.
An ideal gas is characterized by three state variables: absolute pressure (P), volume (V), and absolute temperature (T).
The relationship between them constitutes the ideal gas law, an equation that relates the three variables if the amount of substance, number of moles n, remains constant and where R is the molar constant of the gases:
P×V = n×R×T
In this case, being the molar mass of CH₄ being 16 [tex]\frac{g}{mole}[/tex], that is, the mass present in one mole of an element or compound, the number of moles that 10.34 grams contains is calculated as:
[tex]10.34 g*\frac{1 mole}{16.04 g} = 0.645 moles[/tex]
So, you know:
P= 1.33 atmV= 50 Ln= 0.645 molesR=0.082 (atm×L)/ (mol×K)T= ?Replacing:
1.33 atm × 50 L= 0.645 moles× 0.082 (atm×L)/ (mol×K) ×T
Solving:
T= [1.33 atm × 50 L] ÷ [0.645 moles× 0.082 (atm×L)/ (mol×K) ]
T≅ 1257 K
Being 273 K equivalent to 0 C, then:
T= 1257 K= 984 C
In summary, the correct option is option a. The temperature of a sample of CH₄ gas (10.34 g) in a 50.0 L vessel at 1.33 atm is 984 °C.
Learn more about the ideal gas law: brainly.com/question/4147359?referrer=searchResults
How is filtration done?
What is the difference between residue and filtrate?
Answer:
residue is whatever remains after something else has been removed while filtrate is the liquid or solution that has passed through a filter, and which has been separated from the filtride.
filtration id done by placing a filter paper on the beaker or container then pour the filtride then let it settle and it will pass through and you will have the fitrate and residue
Explanation:
in the reaction of magnesium metal with hydrochloric acid, how do you determine when the magnesium metal has reacted completely
Answer:
When there is no spark from the reaction
Explanation:
The reaction between the acid and the magnesium metal goes into completion when there is no more spark from the magnesium. Also, the magnesium would have totally disappeared into solution.
These physical observation marks the end of the reaction.
When Mg reacts with HCl hydrogen bubbles are released. The completion of the given reaction can be determined by the presence of bubbles above the HCl.
The reaction between HCl and Mg:[tex]\bold {Mg+ 2HCl\rightarrow MgCl_2 + H_2}[/tex]
In this reaction, Mg reacts with 2 moles of HCl to form 1 mole of Magnesium chloride and release hydrogen gas.
During reaction,
Magnesium slowly disappears as it reacts with HCl.The hydrogen gas is released during the reaction, bubbles can be observed.Therefore, the completion of the given reaction can be determined by the presence of bubbles above the HCl.
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Assume that the top of your head has a surface area of 25 cm x 25 cm. How many newtons of force push on your head at sea level? If you estimate this area to be 100 in2, what is the force in pounds?
Answer:
(a) 6332.812 N (b) 1469.59 pounds.
Explanation:
Given that,
The surface area of the top of yu head is 25 cm x 25 cm
Area = 625 cm² = 0.0625 m²
Atmospheric pressure on it is 101325 Pa.
(a) Pressure acting on an object is given by force acting per unit area. It can be written as :
[tex]P=\dfrac{F}{A}\\\\F=PA\\\\F=101325\ Pa\times 0.0625\ m^2\\\\F=6332.812\ N[/tex]
6332.812 N of force is acting on your head at sea level.
(b) If area, A = 100 in²
We know that,
1 atm = 14.6959 pounds/in²
[tex]P=\dfrac{F}{A}\\\\F=PA\\\\F=14.6959 \ \text{Pounds}/in^2\times 100\ in^2\\\\F=1469.59\ \text{pounds}[/tex]
So, the force is 1469.59 pounds.
A. The force required to push your head at sea level is 6332.8125 N
B. The force in pound is 1469.59 lb
A. Determination of the force required at sea level.
Pressure (P) = 101325 Nm²
Area (A) = 25 cm × 25 cm = 0.25 m × 0.25 m = 0.0625 m²
Force (F) =?P = F / A
Cross multiply
F = PA
F = 101325 × 0.0625
F = 6332.8125 NTherefore, the force required to push your head at sea level is 6332.8125 N
B. Determination of the force in pounds
Area (A) = 100 in²
Pressure (P) = 14.6959 pound / in²
Force (F) =?F = PA
F = 14.6959 × 100
F = 1469.59 lbLearn more: https://brainly.com/question/13182194