Answer:
pH = -log[H⁺] = -log(4.75 x 10⁻⁷) = -(- 6.32 ) = 6.32
Explanation:
Given 4.3 x 10⁻⁷M H₂CO₃ (Ka1 = 4.2 x 10⁻⁷ & Ka2 = 4.8 x 10⁻¹¹)
Note: The Ka2 value for the 2nd ionization step is so small (Ka2 = 4.8 x 10⁻¹¹) It will be assumed all of the hydronium ions (H⁺) come from the 1st ionization step.
1st Ionization step
H₂CO₃ ⇄ H⁺ + HCO₃⁻
C(initial) 4.3 x 10⁻⁷ 0 0
ΔC -x +x +x
C(final) 4.3 x 10⁻⁷ - x x x
Note: the 'x' value in this analysis can not be dropped as the Conc/Ka value is less than 10². In this case he C/Ka ratio* (4.3E-7/4.2E-7 ≈ 1) is far below 10².
So, one sets up the equilibrium equation to be quadric and the x-value can be determined.
Ka1 = [H⁺][HSO⁻]/[H₂SO₃] = (x)(x)/(4.3 x 10⁻ - x) = x²/(4.3 x 10⁻⁷ - x) = 4.2 x 10⁻⁷
=> x² = 4.2 x 10⁻⁷(4.3 x 10⁻⁷ - x)
=> x² + 4.2 x 10⁻⁷x - 1.8 x 10⁻¹³ = 0
a = 1, b = 4.2 x 10⁻⁷, c = - 1.8 x 10⁻¹³
x = b² ± SqrRt(b² - 4(1)(-1.8 x 10⁻¹³ / 2(1) = 4.75 x 10⁻⁷
x = [H⁺] = 4.75 x 10⁻⁷
pH = -log[H⁺] = -log(4.75 x 10⁻⁷) = -(- 6.4 ) = 6.4
______________________
* The Concentration/Ka-value is the simplification test for quadratic equations used in Equilibrium studies. If the C/Ka > 100 then one can simplify the C(final) by dropping the 'x' if used in this type analysis. However, if the C/Ka value is < 100 then the x-value must be retained and the solution is determined using the quadratic equation formula.
for ax² + bx + c = 0
x = b² ± SqrRt(b² - 4ac) / 2a
what type of wave moves the particles parallel to the motion of the wave
a.electromagnetic
b. longitudinal
c. transverse
d.water
Answer:
c
Explanation:
In an ideal gas, entropy is a measure of the
Answer:
Entropy is a measure of the degree of spreading and sharing of thermal energy within a system. For an ideal gas that expands at a constant temperature (meaning that it absorbs heat from the surroundings to compensate for the work it does during the expansion), the increase in entropy is given by ΔS= R1n (V2/V1)
Explanation:
hope this helps!
How many moles of carbon atoms is 7.72 x 10 ^24 atoms of carbon? Round to 2 decimal places
Answer:
12.82 molesExplanation:
To find the number of moles in a substance given it's number of entities we use the formula
[tex]n = \frac{N}{L} \\[/tex]
where 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
[tex]n = \frac{7.72 \times {10}^{24} }{6.02 \times {10}^{23} } \\ = 12.8 239[/tex]
We have the final answer as
12.82 molesHope this helps you
Select the correct answer.
What effect does an increase in products have on the reaction rate of a mixture at equilibrium?
A.
The forward reaction rate increases.
B.
Both the forward and the reverse reaction rates decrease.
C.
Both the forward and the reverse reaction rates increase.
D.
The reverse reaction rate increases.
Answer:
Both the forward and the reverse reaction rates decrease.i hope I help you to day and have a good day
For the reaction 2H2 + O2 --> 2H2O, how many grams of oxygen are needed to react 3 moles of hydrogen?
Answer:
48 grams
Explanation:
The chemical equation for the reaction is the following:
2 H₂ + O₂ → 2 H₂O
That means that 2 moles of H₂ react with 1 mol of O₂ to produce 2 moles of H₂O. We convert the moles of oxygen (O₂) by using the molecular weight (MW) as follows:
MW(O₂) = 16 g/mol x 2 = 32 g/mol
mass of O₂ = 1 mol x 32 g/mol = 32 g
So, we have the following stoichiometric ratio: 32 g O₂/2 moles H₂. We have 3 moles of hydrogen (H₂), so we multiply the moles by the stoichiometric ratio to calculate how many grams are needed:
3 moles H₂ x 32 g O₂/2 moles H₂ = 48 g O₂
Therefore, 48 grams of O₂ are needed to react with 3 moles of H₂.
Determine the volume of the product containing carbon produced when 15.0 g of C2H2 are reacted with an excess of oxygen gas
Answer:
25.8 L
Explanation:
Step 1: Write the balanced equation for the complete combustion of acetylene
C₂H₂ + 2.5 O₂ ⇒ 2 CO₂ + H₂O
Step 2: Calculate the moles corresponding to 15.0 g of C₂H₂
The molar mass of C₂H₂ is 26.04 g/mol.
15.0 g × 1 mol/26.04 g = 0.576 mol
Step 3: Calculate the moles of CO₂ produced from 0.576 moles of C₂H₂
The molar ratio of C₂H₂ to CO₂ is 1:2. The moles of CO₂ produced are 2/1 × 0.576 mol = 1.15 mol.
Step 4: Calculate the volume corresponding to 1.15 moles of CO₂
At standard temperature and pressure, 1 mole of CO₂ occupies 22.4 L.
1.15 mol × 22.4 L/1 mol = 25.8 L
What determines crystal size in minerals formed by lava or magma?
Answer:
When magma cools, crystals form because the solution is super-saturated with respect to some minerals. If the magma cools quickly, the crystals do not have much time to form, so they are very small. If the magma cools slowly, then the crystals have enough time to grow and become large.
Explanation:
What pressure is exerted by 1.11 mol of hydrogen gas in a 8.17 L container at 50◦C?
Answer in units of atm.
Answer:
20.0
Explanation:
please help me with this chem question!!
Answer:
caca123
Explanation:
UM
How did the us stop the spread of communism during the Cold War
Answer:
With the policies of containment, the United States hoped to effectively stop the spread of communism and their newest threat. After the war, the United States and the Soviet Union had very different ideas on how to rebuild.
Acids are what and can destroy your skin and bones.
Answer:
Yes
Explanation:
Hydrofluoric acid (HF) differs from other acids because the fluoride ion readily penetrates the skin, causing destruction of deep tissue layers, including bone.
How many liters of ammonia gas can be formed from 24.5 L of hydrogen gas at STP?
Answer: 16.3 L of ammonia gas can be formed from 24.5 L of hydrogen gas at STP
Explanation:
According to avogadro's law, 1 mole of every substance occupies 22.4 L at STP and contains avogadro's number [tex]6.023\times 10^{23}[/tex] of particles.
The balanced chemical equation is:
[tex]3H_2+N_2\rightarrow 2NH_3[/tex]
According to stoichiometry :
[tex]3\times 22.4=67.2L[/tex] of [tex]H_2[/tex] produce = [tex]2\times 22.4=44.8L[/tex] of [tex]NH_3[/tex] at STP
Thus 24.5 L of [tex]H_2[/tex] will produce= [tex]\frac{44.8}{67.2}\times 24.5=16.3L[/tex] of [tex]NH_3[/tex] at STP
Thus 16.3 L of ammonia gas can be formed from 24.5 L of hydrogen gas at STP
Weathering (breaking off sediments upriver), erosion (moving the sediments down river) and finally deposition caused the changes in the river.
What helps hold sediments in place to prevent erosion?
Answer:
Explanation:
Maintaining a healthy, perennial plant cover.
Mulching.
Planting a cover crop – such as winter rye in vegetable gardens. ...
Placing crushed stone, wood chips, and other similar materials in heavily used areas where vegetation is hard to establish and maintain.???
Which of the following has the greatest influence on the size and force of waves?
A.
seasons
B.
Moon’s gravity
C.
wind speed
D.
Earth’s gravity
Comprehension Questions:
1. What are the horizontal (from left to
right) parts of the periodic table
called?
pls show your work will mark brainliest
Answer:
0.047 moles
Explanation:
From the question,
Applying
PV = nRT............. Equation 1
Where P = Pressure of CH₄ gas, V = Volume of CH₄ gas, n = number of moles of CH₄ gas, R = Molar gas constant.
make n the subject of the equation
n = PV/RT............. Equation 2
Given: P = 660 torr = (660×0.00131579) atm = 0.868 atm, V = 1300 mL = (1300/1000) L = 1.3 L, T = 20 °C = (20+273) K = 293 K
Constant: R = 0.082 atm.dm³/K.mol
Substitute these values into equation 2
n = (0.868×1.3)/(0.082×293)
n = 1.1284/24.026
n = 0.047 mole
if an EXOTHERMIC reaction takes place in a container, the container will feel
a. hotter
b.colder
c. neither hotter nor colder
what ive learned about heat,sound and light
Answer:
they are all in parts of our life and we need them each for surviving.
Explanation:
A model is simplified version of a more complex idea or system. It useful to help us understand something we can't actually see
A) true
B) false
Answer:
I feel like the answer is A) true
Explanation:
you create a model to help your audience understand your complex idea. There have been models made to represent ideas that we cannot see.
Consider the sugar below.
CH2OH
О
CH2OH
Н
Н
Н
ОН Н
о
ОН
НО
т
ОН Н
Н
ОН
Т-
Н
Н
ОН
Which term best describes this sugar?
disaccharide
monosaccharide
polysaccharide
X saccharide
pls show ur work will mark the brainliest
Answer:
M = 0.47
Explanation:
1 - Turn grams to moles using molar mass:
16g NaOH × 1 mol NaOH / 40g NaOH = 0.4 mol NaOH
2- Turn milliliters to liters:
855mL × 1 L / 1000mL = 0.86 L
3- Use formula which is M = moles of solute / liters of solvent:
M = 0.4 mol NaOH / 0.86 L = 0.47
Select the correct answer.
Which statement best describes how chemical equations demonstrate conservation of mass?
A.
The number of reactants is the same as the number of products.
B.
The compounds are the same on each side of the reaction.
C.
The number of atoms of each element is the same on each side of the equation.
D.
The state of matter is the same on each side of the equation.
"C" is correct.
The Law of Conservation of Mass states that matter can be neither created nor destroyed. This is evident in chemical equations as you will always start and end with the same amount of atoms of every element. They are all still there; they have just been rearranged.
Answer: C) The number of atoms of each element is the same on each side of the equation.
Explanation: Mass cannot be created nor destroyed.
what is the formula for chlorine monobromide
Based on how to wrire chemical formulae, the formula for chlorine monobromide is BrCl.
What is chlorine mononbromide?Chlorine monobromide is a covalent compound formed from the covalent combination of chlorine and bromine.
The covalent bond is formed from the sharing of electrons between atoms chlorine and bromine.
Br2 + Cl2 ---> 2 BrCl
Tye formula of chlorinr monobromide is BrCl.
It is also known as bromine monochloride.
Therefore, the formula for chlorine monobromide is BrCl.
Learn more about chemical formula at: https://brainly.com/question/2778716
At a football stadium, 5% of the fans in attendance were teenagers. If there were 160 teenagers at the football stadium, what was the total number of people at the stadium?
Answer:
yes
Explanation:
bc god exist
Answer:
3200
Explanation:
infrared in __________controls
I will mark briniest to the one who is correct, also its fill in the blank I wasnt paying attention in school
Answer:
remote
Explanation:
i hope it helps
Which explains why mixtures can be separated?
A The components have different properties.
B The components have the same properties.
C The components are always made of small particles.
D The components are always made of large particles.
Answer:
A
Explanation:
In chemistry, a mixture is a material made up of two or more different substances which are not chemically combined. A mixture is the physical combination of two or more substances in which the identities are retained and are mixed in the form of solutions, suspensions, and colloids.
Answer:
A
Explanation:
Mixtures can be separated because the different substances have different properties
What is an action citizens can take to prevent energy waste?
Answer:
Turning the lights off when they're not needed.
A gamma ray emission results in the release of energy without any apparent change in mass or nuclear charge.
Answer:
the answer to this is b thanks for
Answer:
True
A Gamma-Ray emission results in the release of energy without any apparent change in mass or nuclear charges
fill in the blank if its true or false
T=True
F=False
_________ 1. Stars do not change over their life cycles.
_________ 2. A protostar is the latest stage of a star’s life.
_________ 3. The larger the mass, the shorter the life cycle.
_________ 4. The hottest stars are blue and the coolest stars are red.
_________ 5. The white dwarf eventually runs out of fuel and dies as a red dwarf.
_________ 6. Our Sun is in the main sequence at the moment.
Answer: 1. F
2. F
3. T
4. F
5. T
6. T
Explanation:
I am not sure i'm sorry if it isn't right
Which is the correct result of mitosis and
meiosis?
Answer:
[tex]\boxed {\boxed {\sf B. \ 2 \ diploid \ cells \ and \ 4 \ haploid \ cells}}[/tex]
Explanation:
Mitosis is a type of cell division. It occurs in somatic cells, which are basically any cells other than sex cells. A cell replicates the genetic material then undergoes one division to create 2 identical cells, both with a complete set of chromosomes. These are known as diploid cells.
Meiosis is another type of cell division, but it occurs only in sex cells, called gametes. The cell replicates the genetic material and the chromosomes cross over, which creates completely unique cells. The cell divide to create 2 cells, but then they divide again to create 4 cells. They each have half of the chromosomes of a somatic cell, so they are haploid cells
So, mitosis results in 2 diploid cells and meiosis forms 4 haploid cells.