Answer:
[tex]pH=11.45[/tex]
Explanation:
Hello there!
In this case, since the chemical equation representing the neutralization of the weak base quinine can be written as follows:
[tex]C_{20}H_{24}N_2O_2+HCl\rightarrow C_{20}H_{25}N_2O_2^+Cl^-[/tex]
Whereas we have 0.100 moles of the base and those of acid as shown below
[tex]n_{acid}=0.50molHCl/L*0.05000L=0.025molHCl[/tex]
Which means that the remaining moles of quinine are:
[tex]n_{C_{20}H_{24}N_2O_2}^{final}=0.100mol-0.025mol=0.075mol[/tex]
And the resulting concentration:
[tex][C_{20}H_{24}N_2O_2]=\frac{0.075mol}{(0.025+0.050)L} =1.00M[/tex]
Now, the calculation of the pH requires the pKb of quinine (5.1) as its ionization in water produces OH- ions:
[tex]C_{20}H_{24}N_2O_2+H_2O\rightleftharpoons OH^-++C_{20}H_{25}N_2O_2^+[/tex]
And the equilibrium expression is:
[tex]Kb=\frac{[C_{20}H_{24}N_2O_2][C_{20}H_{25}N_2O_2 ^+]}{[C_{20}H_{24}N_2O_2]} \\\\10^{-5.1}=\frac{x^2}{1.00M}\\\\ 7.94x10^{-6}=\frac{x^2}{1.00M}[/tex]
Which is solved for x as follows:
[tex]x= \sqrt{7.94x10^{-6}*1.00M}\\\\x=0.00282M[/tex]
Which means the pOH is:
[tex]pOH=-log(0.00282)=2.55[/tex]
And the pH:
[tex]pH=14-2.55\\\\pH=11.45[/tex]
Regards!
20)
Which substance is an acid?
A)
Ba(OH)2
B)
CH3COOCH3
C)
H3PO4
D)
NaCl
help
Answer:
C.
Explanation:
Also, please help me in my questions tab if you can! Thank you so much
Draw the structural formula for both of these alcohols:
2,3, 4-trimethyl, 3-heptanol
4-ethyl, 4-octanol
Answer:
Check the image above
explanation:
When naming organic compounds based on IUPAC; we take note of functional group, position of functional group.
In 2,3,4-trimethyl-3-heptanol, the functional group is hydroxyl group ( OH ). It is on position 3 (2,3,4-trimethyl-3-heptanol. Then we put it on the third carbon. Another functional group is methyl group, with three positions, 2, 3, and 4.
In 4-ethyl-4-octanol, the functional group is hydroxyl group ( OH ) which is in position 4 on the fourth carbon. Another functional group is ethyl group in position 4 on the fourth carbon. In this case, the functional groups that have same position, are put on that same carbon.
A sample of gas with an initial volume of 9.35 L at a pressure of 784 torr and a temperature of 295 K is compressed to a volume of 2.84 L and warmed to a temperature of 310 K. What is the final pressure of the gas in atmospheres (atm)?
a. 4.97 atm.
b. 0.113 atm.
c. 5.95 atm.
d. 7.03x10^3 atm.
Answer:
D
Explanation:
3. How many electrons are in the M shell?
Answer:
i believe the answer is D: 18
Explanation:
Answer:
18
M shell can actually hold 18 electron as you move higher atomic number
How many photons are produced in a laser pulse of 0.203 J at 553 nm?
Answer:
8.59
⋅
10
17
Explanation:
You can start by figuring out the energy of a single photon of wavelength
505 nm
=
505
⋅
10
−
9
m
.
To do that, use the equation
E
=
h
⋅
c
λ
Here
h
is Planck's constant, equal to
6.626
⋅
10
−
34
.
J s
c
is the speed of light in a vacuum, usually given as
3
⋅
10
8
.
m s
−
1
λ
is the wavelength of the photon, expressed in meters
Plug in your value to find--notice that the wavelength of the photon must be expressed in meters in order for it to work here.
E
=
6.626
⋅
10
−
34
J
s
⋅
3
⋅
10
8
m
s
−
1
505
⋅
10
−
9
m
E
=
3.936
⋅
10
−
19
J
So, you know that one photon of this wavelength has an energy of
3.936
⋅
10
−
19
J
and that your laser pulse produces a total of
0.338 J
of energy, so all that you need to do now is to find how many photons are needed to get the energy output given to you.
0.338
J
⋅
1 photon
3.936
⋅
10
−
19
J
=
8.59
⋅
10
17
photons
−−−−−−−−−−−−−−−−−
The answer is rounded to three sig figs.
g a commercial product for treating injuries contains 35.0 g of MgSO4 in one bag and 250 mL of water in a seperate bag. When the bags are broken and their contents mixed, the temperature of the system changes. Calculate this temperature change
Answer:
he a real G
Explanation:
og tripple og
HELPPP PLEASEEEEE
Name the following alkane molecule:
Answer:
5–bromo–9–chlorodecane
Explanation:
To name the compound given above, the following must be obtained:
1. The longest continuous carbon chain. This gives the parent name of the compound.
2. The substituent group attached to the compound.
3. Position of the substituent group.
4. Combine the above to obtain the name.
Now, we shall determine the name of the compound as follow:
1. The longest continuous carbon chain is 10. Thus, the parent name of the compound is decane.
2. The substituent groups attached to the compound are:
I. Bromine (Br) => Bromo
II. Chlorine (Cl) => Chloro
3. The position of the substituent groups are:
I. Br => carbon 5
II. Cl => carbon 9
NOTE: numbering is done alphabetically.
4. Therefore, the name of the compound is:
5–bromo–9–chlorodecane
Answer:
A.
Explanation:
I chose this answer and it was correct ♀️
Question 3 0 / 1 point How many grams of carbon atoms are present in a sample of C3H8 if there are 4.10 moles of hydrogen atoms in the sample
Answer:
18.45 g of C
Explanation:
This is a problem of rules of three:
1 mol of C₃H₈ contains 3 moles of C and 8 moles of H
If 8 moles of H are contained in 1 mol of propane
4.10 moles of H are contained in (4.1 . 1) /8 = 0.5125 moles
Now, If 1 mol of propane contains 3 moles of C
0.5125 moles of propane may contain (0.5125 . 3) / 1 = 1.5375 moles of C
Let's convert the moles to mass:
1.5375 mol . 12 g /mol = 18.45 g
A certain shade of blue has a frequency of 7.28×1014 Hz.
What is the energy of exactly one photon of this light? Planck's constant is ℎ=6.626×10−34 J⋅s.
Explanation:
the enerfy of of one photon of this light is 4.85x10^-19 J
E= 6.63 x 10^-34 J/S x 7.32 x10^14 S ^-1E= 4.85x10^-19 J
Using the periodic table,
choose the more reactive nonmetal. Br or as
Answer:
Br
Explanation:
because bromine is more reactive as reactivity increases on moving from left to right in p-block. hope this make sense :)
P4 + NaOH + H2O——> PH3 + Na2HPO3
Balance given equation by oxidation no. Method
Answer:
P4 + 4NaOH + 2H2O → 2PH3 + 2Na2HPO3
Explanation:
A chemical equation is said to be balanced if the quantity of each type of atom in the reaction is the same on both the reactant and product sides. In a balanced chemical equation, the mass and the charge are both equal.
A chemical equation must balance according to the rule of conservation of mass. According to the rule, mass cannot be generated or removed during a chemical process.
Chemical equations must be balanced, which means that the atom types and numbers on both sides of the reaction arrow must match. Coefficients are the values added in front of formulas to balance equations; they multiply each atom in a formula.
Here the given equation is balanced as:
P₄ + 4NaOH + 2H₂O——> 2PH₃ + 2Na₂HPO₃
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Question on the image
Answer: The mass of carbon dioxide required is 308 g
Explanation:
The number of moles is defined as the ratio of the mass of a substance to its molar mass.
The equation used is:
[tex]\text{Number of moles}=\frac{\text{Given mass}}{\text{Molar mass}}[/tex] ......(1)
Given mass of octane = 100.0 g
Molar mass of octane = 114.23 g/mol
Putting values in equation 1, we get:
[tex]\text{Moles of octane}=\frac{100.0g}{114.23g/mol}=0.875mol[/tex]
For the given chemical reaction:
[tex]2C_8H_{18}+25O_2\rightarrow 16CO_2+18H_2O[/tex]
By the stoichiometry of the reaction:
2 moles of octane produces 16 moles of carbon dioxide
So, 0.875 moles of octane will produce = [tex]\frac{16}{2}\times 0.875=7mol[/tex] of carbon dioxide
Molar mass of carbon dioxide = 44 g/mol
Plugging values in equation 1:
[tex]\text{Mass of carbon dioxide}=(7mol\times 44g/mol)=308g[/tex]
Hence, the mass of carbon dioxide required is 308 g
the mass of a single potassium atom is 6.50×10-23 grams. How many potassium atoms would there be in 114 milligrams of potassium?
Answer:LOL
42
Explanation:
The mass of a single potassium atom is 6.50×10⁻²³ grams potassium atoms would be in 114 milligrams of potassium 17.53 ×10⁻²³.
What is an atom?
An atom is the most diminutive form of any chemical compound that takes part in the chemical reaction to form any product and it is equal to the one mole which is 2.303 ×10²³ moles of the Avogadros number.
To calculate the number of atoms we have, 6.50×10⁻²³ grams of potassium and the value of one particle is 2.303 ×10²³ moles,
atoms = 6.50×10⁻²³ / 114 milligrams of potassium
atoms of potassium = 17.53 ×10⁻²³. atoms.
Therefore, 17.53 ×10⁻²³.atoms are present if the mass of a single potassium atom is 6.50×10⁻²³ grams potassium atoms would there be in 114 milligrams of potassium.
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The decomposition of hydrogen peroxide was studied, and the following data were obtained at a particular temperature.Time (s) [H2O2] (mol/L)0 1.00120 ± 1 0.91300 ± 1 0.78600 ± 1 0.591200 ± 1 0.371800 ± 1 0.222400 ± 1 0.133000 ± 1 0.0823600 ± 1 0.050 Assuming that the rate= -delta [H2O2]/delta t determine the rate law, integrated rate law, and the value of the rate constant. Calculate [H2O2] at 4000. s after the start of the reaction.
Answer:
Explanation:
From the graphical diagram attached below; we can see the relationship between the concentration of [tex]H_2O_2[/tex] which declines exponentially in relation to the time and it obeys the equation: [tex]\mathtt{y = 0.9951 e^{-8\times 10^{-4}x}}[/tex]
This relates to the 1st order reaction rate, whereby:
The integrated rate law[tex]\mathtt{ [A] = [A]_o e^{-kt}}[/tex]
here:
[A] = reactant concentration at time (t)
[A]_o = initial concentration for the reactant
k = rate constant
As such, the order of the reaction is the first order
Rate constant [tex]\mathtt{k = 8\times 10^{-4} {s^{-1}}}[/tex]
Rate law [tex]\mathtt{= k[H_2O_2]}[/tex]
The integrated rate law [tex]\mathtt{[H_2O_2] = [H_2O_2]_oe^{-(8*10^{-4})t}}[/tex]
From the given table:
the initial concentration of [tex]H_2O_2[/tex] = 1.00 M
∴
We can determine the concentration of the reactant at 4000s by using the formula:
[tex]\mathtt{[H_2O_2] = [H_2O_2]_oe^{-8*10^{-4}(t)}}[/tex]
[tex]\mathtt{[H_2O_2] = (1.00\ M)*e^{-8*10^{-4}(4000)\ s}}[/tex]
[tex]\mathtt{[H_2O_2] =0.0407 \ M}[/tex]
Finally, at 4000s: the average rate is:
[tex]\mathtt{= (8*10^{-4} \ s^{-1})(4000 \ s) }\\ \\ \mathtt{ = 3.256 \times 10^{-5} \ M/s}[/tex]
What was one idea Dalton taught about atoms?
Explanation:
All atoms of one type were identical in mass and properties.
Phosphorus trichloride can be made by the following reaction: P4(s) 6Cl2(g) - 4) 4PCl3(l) What is the maximum amount of phosphorus trichloride that can be formed if 15 molecules of P4 are mixed with 42 molecules of chlorine
Answer:
48 molecules
Explanation:
From the given reaction:
[tex]\mathtt{P_4 + 6Cl_2\to 4PCl_3}[/tex]
i.e. 1 mole of Phosphorus react 6 moles of chlorine to yield 4 moles of PCl₃
This implies that for each P₄ molecule, we will require 6 molecules of Cl₂
We are provided with 15 molecules of P₄ and 42 molecules of Cl₂
Suppose we utilized the whole 15 molecules of P₄, we will require:
= 15 × 6 = 90 moles of Cl₂ which is not readily available except 42 are available.
If we utilized 42 molecules of Cl₂, we will require 42/6 = 7 molecules of P₄ which is readily available.
From this analysis, we can opine that Cl₂ serves as the limiting agent
∴
P₄ : Cl₂ : PCl₃ = 1 : 6 : 4 = 7 : 42 : 48
It implies that only 48 molecules of phosphorus trichloride will be formed.
Write the precipitation reaction for cobalt(II) hydroxide in aqueous solution: Be sure to specify the state of each reactant and product.
Answer:
The equation for the precipitation reaction of cobalt (ii) hydroxide is given below:
CoSO₄ (aq) + NaOH (aq) ----> Co(OH)₂ (s) + Na₂SO₄ (aq)
Explanation:
Cobalt (ii) hydroxide is an inorganic compound consisting of cobalt (ii) ions, Co²+ and hydroxide ions, OH-. It is insoluble in water and the pure form known as the beta form is a pink-coloured solid. The impure form which incorporates other anions in its molecular structure is blue in colour and is ustable.
Cobalt (ii) hydroxide is formed as precipitate when an alkaline metallic hydroxide such as sodium hydroxide is mixed with an aqueous cobalt (ii) salt such as cobalt (ii) sulfate. The equation for the precipitation reaction of cobalt (ii) hydroxide is given below:
CoSO₄ (aq) + NaOH (aq) ----> Co(OH)₂ (s) + Na₂SO₄ (aq)
Being a basic hydroxide, cobalt (ii) hydroxide neutralizes acids to form cobalt (ii) salts and water. For example: Co(OH)₂ (s) + H₂SO₄ (aq) ---> CoSO₄ (aq) + H₂O
Thus, cobalt (ii) hydroxide is soluble in acids.
Cobalt(II) hydroxide is used mostly as a drying agent for paints, varnishes, and inks. It is also useful in the preparation of other cobalt compounds.
Look at pictures and help please
Answer: In order to increase the rate of reaction between hydrochloric acid and sugar increase the concentration of hydrochloric acid to 2 M because greater concentration results in more collision between the reactants.
Explanation:
More is the concentration of reactant molecules more will be the number of collisions between their molecules. As a result, more readily the products will be formed.
Hence, for the given reaction when concentration of HCl is increased then there will be increase in the number of collisions between reactants.
Thus, we can conclude that in order to increase the rate of reaction between hydrochloric acid and sugar increase the concentration of hydrochloric acid to 2 M because greater concentration results in more collision between the reactants.
Beer's Law states that A=ebc, where A is the absorbance, ε is the molar absorptivity of the solute, b is the path length, and c is the concentration. Identify the experimental evidence from the activity that you have for the dependence of absorbance on each variable
The evidence for the dependence of absorbance on the variable ε is:_________
a. increasing the cuvette width increases the absorbance.
b. changing the compound changes the absorbance behavior.
c. adding more water decreases the absorbance.
Answer:
b. changing the compound changes the absorbance behavior.
Explanation:
Option a) would be akin to modifying the path length, b.Option b) would involve using a different solute, as such, there would be another molar absortivity, ε.Option c) would decrease the concentration (c) of the solute, which would explain why the absorbance would decrease as well.The largest number of stable nuclei have an ________ number of protons and an ________ number of neutrons.
Answer:
did it give you answers to in blanks
A 1.375 g sample of mannitol, a sugar found in seaweed, is burned completely in oxygen to give 1.993 g of carbon dioxide and 0.9519 g of water. The empirical formula of mannitol is
Answer:
[tex]C_3H_7O_3[/tex]
Explanation:
Hello there!
In this case, according to the given information, it turns out possible for us to infer that the empirical formula of mannitol contains carbon, hydrogen and oxygen, so that the first step is to calculate the moles of C and H contained in the CO2 and H2O, respectively, as the only sources of these two elements in the formula:
[tex]n_C=1.993gCO_2*\frac{1molCO_2}{44.01gCO_2}*\frac{1molC}{1molCO_2} =0.0453molC\\\\n_H=0.9519gH_2O*\frac{1molH_2O}{18.02gH_2O}*\frac{2molH}{1molH_2O} =0.106molH[/tex]
Next, we calculate the grams and moles of O by subtracting the mass of C and H from the mass of the sample:
[tex]m_O=1.375g-0.0453molC*\frac{12gC}{1molC}-0.106molH*\frac{1.01gH}{1molH}=0.724gO\\\\n_O=0.724gO*\frac{1molO}{16.0gO} =0.0453molO[/tex]
Finally, we divide the moles of C, H and O by 0.0453 as the fewest moles of both C and O to find the mole ratios in the formula:
[tex]C:\frac{0.0453mol}{0.0453mol} =1\\\\H:\frac{0.106mol}{0.0453mol} =2.34\\\\O:\frac{0.0453mol}{0.0453mol} =1[/tex]
To get:
[tex]CH_{2.34}O[/tex]
Which must be multiplied by 3 to get whole numbers for all the subscripts, and therefore obtain:
[tex]C_3H_7O_3[/tex]
Regards!
What is the solute and solvent in a solution of salt water
Answer:
The solute is salt and the solvent is water
Explain:
Because salt is a component the dissolves in the solvent
given two equations representing reactions: which type of reaction is represented by each of these equations?
Answer:
Equation 1 - nuclear fission
Equation 2 - nuclear fusion
Explanation:
Nuclear fission is a reaction in which a large nucleus is split into smaller nuclei when it is bombarded by neutrons. The process produces more neutrons to continue the chain reaction. This is clearly depicted in equation 1 as shown in the question.
Nuclear fusion is a reaction in which two light nuclei combine in order to form a larger nuclei. This is clearly depicted in equation 2 as shown in the question.
In the first reaction, a neutron is released, and in the second a helium atom is released. The given two equations represent nuclear fission and fusion.
What are nuclear reactions?A nuclear reaction is a reaction that involves the nuclei of the atom and the absorption and release of energy. In the first reaction, a big nucleus is split by the neutron bombardment into smaller nuclei.
In the second reaction the process of nuclear fusion, two nuclei combine into a single larger nucleus that is shown as:
₁¹H+ ²₁H → ³₂He
Therefore, nuclear fission and fusion are represented by each of these equations.
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How many significant digits should be used to report the answer to each of the following calculations? (2.75518 + 9.01 + 3.3349) / (2.1)
Answer:
2
Explanation:
You write your answer with the same number of significant figures as the number with the smallest amount of figures, in this case, that number is 2.1 so your answer should be written with 2 significant figures.
how many s electrons are there in potassium?
Answer: 19
Explanation:
In order to write the Potassium electron configuration we first need to know the number of electrons for the K atom (there are 19 electrons). When we write the configuration we'll put all 19 electrons in orbitals around the nucleus of the Potassium atom.
sound waves? like what they do.
Answer:
A sound wave is the pattern of disturbance caused by the movement of energy traveling through a medium (such as air, water, or any other liquid or solid matter) as it propagates away from the source of the sound. The source is some object that causes a vibration, such as a ringing telephone, or a person's vocal chords.
HEY. HOPE THIS HELPS♡
The shielding of electrons gives rise to an effective nuclear charge, Zeff, which explains why boron is larger than oxygen. Estimate the approximate Zeff felt by a valence electron of boron and oxygen, respectively.
a. +5 and +8.
b. +3 and +6.
c. +5 and +6.
d. +3 and +8.
e. +1 and +4.
Answer:
b. +3 and +6.
Explanation:
Zeff = Z - S
The Z denotes the no of protons i.e. atomic number
S denotes the non-valence electrons
For boron,
the electronic configuration is 1s₂ 2s₂ 2p₄
Now
Z = 5, S = 2
So,
Zeff = 5-2
= +3
For O, the electronic configuration is 1s₂ 2s₂ 2p₄
So,
Z = 8, S = 2
= 8-2
= +6
Hence, the second option is correct
Plss help me solve question 7
Thank you.
Answer:
4- ethyl- 6-methylocta- 1,2,5- triene
Explanation:
See attached. Please give me brainliest I worked hard. ;(
What is one way in which a field investigation can differ from a classroom or laboratory experiment?
Answer:
□In field investigations, you are usually working with much larger animals than in the lab. In field investigations, it is much more difficult to separate your control and experimental groups.
There are many ways in which a field experiment can differ form of a classroom or a laboratory experiment, one of which can be the environmental condition.
What is a field experiment?A field experiment Is an experiment which is performed in practically Outside the classroom or a laboratory in live situtations .
Environmental factors may deter the results of a field experiment or may alter the physical conditions of the object, For example an anhydrous substance may become hygroscopic, Which may Alter the result of the field experiment.
Hence, field experiment can differ from a classroom or a laboratory experiment due to environmental conditions .
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In the picture this is my last question pls.
Answer:
Chromosomes and I think its too many
Explanation:
