Answer:
pH = 2.46
Explanation:
Hello there!
In this case, since this neutralization reaction may be assumed to occur in a 1:1 mole ratio between the base and the strong acid, it is possible to write the following moles and volume-concentrations relationship for the equivalence point:
[tex]n_{acid}=n_{base}=n_{salt}[/tex]
Whereas the moles of the salt are computed as shown below:
[tex]n_{salt}=0.021L*0.68mol/L=0.01428mol[/tex]
So we can divide those moles by the total volume (0.021L+0.0066L=0.0276L) to obtain the concentration of the final salt:
[tex][salt]=0.01428mol/0.0276L=0.517M[/tex]
Now, we need to keep in mind that this is an acidic salt since the base is weak and the acid strong, so the determinant ionization is:
[tex]C_6H_5NH_3^++H_2O\rightleftharpoons C_6H_5NH_2+H_3O^+[/tex]
Whose equilibrium expression is:
[tex]Ka=\frac{[C_6H_5NH_2][H_3O^+]}{C_6H_5NH_3^+}[/tex]
Now, since the Kb of C6H5NH2 is 4.3 x 10^-10, its Ka is 2.326x10^-5 (Kw/Kb), we can also write:
[tex]2.326x10^{-5}=\frac{x^2}{0.517M}[/tex]
Whereas x is:
[tex]x=\sqrt{0.517*2.326x10^{-5}}\\\\x=3.47x10^-3[/tex]
Which also equals the concentration of hydrogen ions; therefore, the pH at the equivalence point is:
[tex]pH=-log(3.47x10^{-3})\\\\pH=2.46[/tex]
Regards!
In which atmospheric layer is the ozone layer? O stratosphere o thermosphere O mesosphere troposphere
Answer:
The stratosphere
Explanation:
As a raindrop falls from a cloud to the surface of Earth,
A. its speed increases due to gravity.
B. its speed increases due to air resistance,
C. it moves at a constant speed,
<
OD. it moves at a constant velocity
Answer:
The answer is C!
Explanation:
Hope it helps
Answer D
Explanation: did the quiz ψ(｀∇´)ψ
You have a container which has the capacity to hold 3 L water. If it already has 2.25 L water in it, how much more water in mL can you still add to fill it completely?
An average bushel of apples has a mass of 10 kg and contains 5 dozen apples.
What would be the average mass of 6 apples?
Answer:
Average mass of 6 apple = 1 kg
Explanation:
Given:
Average mass of 5 dozen apple = 10 kg
Find:
Average mass of 6 apple
Computation:
Average mass of 6 apple = [Average mass of 1 apple] x [6 apple]
Average mass of 6 apple = [10/(12 x 5)] x [6]
Average mass of 6 apple = 1 kg
8) All of the following statements are true except ________. A) Internal energy is a state function. B) The enthalpy change for a reaction is equal in magnitude, but opposite in sign, to the enthalpy change for the reverse reaction. C) The enthalpy change for a reaction depends on the state of the reactants and products. D) The enthalpy of a reaction is equal to the heat of the reaction. E) Enthalpy is an intensive property.
Answer:
E. Enthalpy is an intensive property Is false.
Explanation:
The false or wrong option in this question is that Enthalpy is an intensive property.
To explain this, I would first explain an intensive property. An intensive property is one that does not depend on the quantity or the mass of matter. Examples are temperature and pressure.
But an extensive property is a property which depends on the mass and the quantity of the system. Enthalpy, volume are all extensive.
What are two things that interact that determine if there is a phase change or not HELP
Answer:
phase change always has two phases in contact during the change. melting => solid & liquid; evaporation (boiling) => liquid & vapor. If only one phase is present, then phase change is not occurring. Also, when two phases are in contact, no temperature changes occur. Only the pure phase demonstrates temperature change when measured. Example, when ice is added to water, at thermal equilibrium (temp = 0°C) the water temp will not continue to change. Only when all the ice has melted will the water temperature demonstrate a measured temperature change.
Explanation:
Which of these materials are insulators? Select the THREE (3) that apply.
aluminum can
wool
rubber
iron nail
copper wire
plastic
Answer:
wool ,rubber and copper wire should be correct
CuCl2(aq) + Na3PO4(aq) =>?
Net ionic equation
What does purified water and fluorine make?
Answer:
Adding fluoride to the water supply reduces the incidence of tooth decay. Fluoride protects teeth from decay by demineralization and remineralization. Too much fluoride can lead to dental fluorosis or skeletal fluorosis, which can damage bones and joints.
Explanation:
N/A
Pleaseeeee guysssss
Explain Which enthalpy diagram shows that the reaction above is an exothermic reaction that produces -550 kJ of heat? Why? The
Answer:
no answer of this question
The number of moles of molecules in a 12.0-gram sample of Cl2 is equal too?
Answer:
0.3529moles
Explanation:
no of moles =mass ÷molar mass
molar mass =17+17
=34
12÷34
=0.3529moles
According to the mole concept, the number of moles of molecules in a 12.0-gram sample of Cl₂ is equal to 0.169 moles.
What is a mole?
Mole is defined as the unit of amount of substance . It is the quantity measure of amount of substance of how many elementary particles are present in a given substance.
It is defined as exactly 6.022×10²³ elementary entities. The elementary entity can be a molecule, atom ion depending on the type of substance. Amount of elementary entities in a mole is called as Avogadro's number.
It is widely used in chemistry as a suitable way for expressing amounts of reactants and products.For the practical purposes, mass of one mole of compound in grams is approximately equal to mass of one molecule of compound measured in Daltons. Molar mass has units of gram per mole . In case of molecules, where molar mass in grams present in one mole of atoms is its atomic mass.Number of moles is mass/molar mass= 12/70.90=0.169 moles.
Learn more about mole,here:
https://brainly.com/question/20486415
#SPJ6
Rubbing alcohol is 70.% (v/v) isopropyl alcohol by volume. How many mL of isopropyl alcohol are in a 1 pint (473 mL) container? Rubbing alcohol is 70.% (v/v) isopropyl alcohol by volume. How many mL of isopropyl alcohol are in a 1 pint (473 mL) container? 330 mL 470 mL 70. mL 680 mL 0.15 mL
Answer:
helped
The number of ml of isopropyl alcohol that are 1 pint (473 Ml) is 331.1 Ml
calculation
assume that the 1 pint is in a container
This implies that the 1 pint (473 ml) is in 100 % M/V
what about 70 %(M/V)
that is 473 Ml = 100 %
? = 70 %
by cross multiplication
= 473 x70/100 = 331.1 Ml
Explanation:
0.254g lead(ii)ethanoate, on adding excess K2CrO4 solution, gave 0.130g of lead(ii)chromate precipitate. what is the percentage composition of Pb in the organic salt? (O = 16, Cr = 52, Pb = 207).
Answer:
32.8%
Explanation:
All of the Pb⁺² species precipitated as lead(II) cromate, PbCrO₄ (we know this as excess K₂CrO₄ was used).
First we convert 0.130 g of PbCrO₄ into moles, using its molar mass:
0.130 g ÷ 323 g/mol = 4.02x10⁻⁴ mol PbCrO₄There's 1 Pb⁺² mol per PbCrO₄ mol, so in total 4.02x10⁻⁴ moles of Pb⁺² were in the ethanoate sample.
We convert those 4.02x10⁻⁴ moles of Pb into grams:
4.02x10⁻⁴ mol * 207 g/mol = 0.083 g PbFinally we calculate the percentage composition of Pb:
0.083 g Pb / 0.254 g salt * 100% = 32.8%2) A common "rule of thumb" -- for many reactions around room temperature is that the
rate will double for each ten degree increase in temperature. Does the reaction you hav
studied seem to obey this rule.
The question is incomplete. The complete question is :
A common "rule of thumb" for many reactions around room temperature is that the rate will double for each ten degree increase in temperature. Does the reaction you have studied seem to obey this rule? (Hint: Use your activation energy to calculate the ratio of rate constants at 300 and 310 Kelvin.)
Solutions :
If we consider the activation energy to be constant for the increase in 10 K temperature. (i.e. 300 K → 310 K), then the rate of the reaction will increase. This happens because of the change in the rate constant that leads to the change in overall rate of reaction.
Let's take :
[tex]$T_1=300 \ K$[/tex]
[tex]$T_2=310 \ K$[/tex]
The rate constant = [tex]$K_1 \text{ and } K_2$[/tex] respectively.
The activation energy and the Arhenius factor is same.
So by the arhenius equation,
[tex]$K_1 = Ae^{-\frac{E_a}{RT_1}}$[/tex] and [tex]$K_2 = Ae^{-\frac{E_a}{RT_2}}$[/tex]
[tex]$\Rightarrow \frac{K_1}{K_2}= \frac{e^{-\frac{E_a}{RT_1}}}{e^{-\frac{E_a}{RT_2}}} $[/tex]
[tex]$\Rightarrow \frac{K_1}{K_2}= e^{-\frac{E_a}{R}\left(\frac{1}{T_1}-\frac{1}{T_2}\right)}$[/tex]
[tex]$\Rightarrow \ln \frac{K_1}{K_2}= - \frac{E_a}{R} \left(\frac{1}{T_1} -\frac{1}{T_2} \right)$[/tex]
[tex]$\Rightarrow \ln \frac{K_2}{K_1}= \frac{E_a}{R} \left(\frac{1}{T_1} -\frac{1}{T_2} \right)$[/tex]
Given, [tex]$E_a = 0.269$[/tex] J/mol
R = 8.314 J/mol/K
[tex]$\Rightarrow \ln \frac{K_2}{K_1}= \frac{0.269}{8.314} \left(\frac{1}{300} -\frac{1}{310} \right)$[/tex]
[tex]$\Rightarrow \ln \frac{K_2}{K_1}= \frac{0.269}{8.314} \times \frac{10}{300 \times 310}$[/tex]
[tex]$\Rightarrow \ln \frac{K_2}{K_1}= 3.479 \times 10^{-6}$[/tex]
[tex]$\Rightarrow \frac{K_2}{K_1}= e^{3.479 \times 10^{-6}}$[/tex]
[tex]$\Rightarrow \frac{K_2}{K_1}= 1$[/tex]
∴ [tex]$K_2=K_1$[/tex]
So, no this reaction does not seem to follow the thumb rule as its activation energy is very low.
What is the mass of 2 moles of nitrogen gas, N2?
Answer:
28g
Solution. Hence, 2 moles of nitrogen atoms weigh 28g.
Please help me thanks:)
Answer:
where it goes
Explanation:
Answer:
I didn't do the observation that the question said so I can't help sorry
PLEASE HELP WORTH 100 POINTS !!!!!
Answer: Imidogen
Explanation: I just looked it up.
Answer:
Imidogen
Explanation:
2. A spider builds his web in the horns of a deer. What is the symbiotic
relationship?
I point
O MUTUALISM
COMMENSALISM
PARASITISM
O Other
Answer:
COMMENSALISM
Explanation:
Commensalism refers to the relationship that exists between two different organism that belong to different species. In this relationship neither of the organisms are harmed while either of them is benefitted. The web made by the spider between the horns of the deer increases the probability of the spider to catch its prey. The random movement of the deer helps the spider and at the same time it do not harm the deer.
A 0.00215-g sample of polystyrene, a polymer composed of carbon and hydrogen, produced 0.00726 g of CO2 and 0.00148 g of H2O in a combustion analysis. What is the empirical formula for polystyrene?
Answer:
CH
Explanation:
Polystyrene is composed only by C and H.
We can calculate the number of C moles contained in the original sample mass (0.00215 g), using the produced mass of CO₂:
0.00726 g CO₂ ÷ 44 g/mol = 1.65x10⁻⁴ mol CO₂As 1.65x10⁻⁴ moles of CO₂ were produced, in the polystyrene sample there were 1.65x10⁻⁴ moles of C.
Now we calculate how many moles of H₂O were produced:
0.00148 g H₂O ÷ 18 g/mol = 8.22x10⁻⁵ mol H₂OThe number of H moles produced is double the amount of H₂O moles, so in the polystyrene sample there were 1.64x10⁻⁴ moles of H.
The number of C and H moles are the same, this means the empirical formula is CH.
B) Which of these is NEVER an example of freshwater? A) Pacific Ocean B) Okefenokee Swamp Mississippi River Lake Pontchartrain.
Answer:
Lake pontchartrain
Explanation:
3x + 4y - 3z) - (2x - 6y + 7z)
x + 10y - 10z
x + 10y - 10z
x -10y - 10z
Answer: x + 10y - 10z is the answer
Explanation:
Help me with this question
Answer:
your cool
Explanation:
owa owa owa owa owa bob
name this structure
Answer:
The fourth one- bromo trifluoro methane
Explanation:
Answer:
D
Explanation:
I believe the answer is the 4th option, bromo-trifluoro-methane
Which is not true of the cell theory?
which is NOT true about the cell theory?
A:all living organisms are composed of cells
B:all cells have a nucleus, which acts like the brain of the cell
C:all cells come preexisting living cells
D:the cell is the most basic part of a living organism
How many grams of phosphorous is in the human skeleton if its average
weight is 11 kg and contains 58% of calcium phosphate (Ca3(PO4)2)?
What is the composition of a universal indicator?
Answer:
The main universal indicator is in the form of a solution and are thymol blue , methyl red , bromothymol blue and phenolphthalein this mixture is important because each component loses or gains protons depending upon the acidity of the solution being tested .
maybe this mighr help u
When a solid turns into a liquid what is happening to the relationship between the forces?
What volume in
L
of a 0.724 M Nal solution contains 0.405 mol of Nal ?
Answer:
[tex]0.5594\ \text{L}[/tex]
Explanation:
Mol of NaI = 0.405 mol
Molarity of solution = 0.724 M
Molarity is given by
[tex]M=\dfrac{\text{mol}}{\text{Volume of solution in }NaI}\\\Rightarrow \text{Volume of solution in }NaI=\dfrac{0.405}{0.724}\\\Rightarrow \text{Volume of solution in }NaI=0.5594\ \text{L}[/tex]
The required volume is [tex]0.5594\ \text{L}[/tex].
how many grams are there in 3400 moles of tetranitrogen dicarbide?
Explanation:
molar mass of tetranitrogen dicarbide S4N4= 4×32+4×14
128+56
184 g/mol
no.of moles =given mass/ molar mass
3400= given mass / 184
3400×184 =given mass.
625600 g
What is the first step in this
experiment?
Answer: Cut the card borad
Explanation: