Answer:
The equilibrium concentration of [CH₃NH₂] = 0.23965 M.
The equilibrium concentration of CH₃NH₃⁺ and OH⁻ = 0.01035 M respectively.
Explanation:
The first step is to write out the dissociation reaction. Therefore, the equation showing the dissociation is given as below;
CH₃NH₂ + H₂0 <--------------------------------------------------------> CH₃NH₃⁺ + OH⁻.
Kindly note that ''<----------->'' arrow shows that the reaction is an equilibrium reaction.
Therefore, at the start of the reaction [that is time, t =0], we have that the concentration of CH₃NH₂ = 0.25M, thus, the concentration of CH₃NH₃⁺ and OH⁻ is zero respectively at this time, t =0.
At equilibrium, the concentration of CH₃NH₂ = 0.25M - x, thus, the concentration of CH₃NH₃⁺ and OH⁻ is x respectively.
Therefore, kb = 4.47 × 10-4 = [CH₃NH₃⁺ ][OH⁻]/[CH₃NH₂]. Hence, slotting in the values into this equilibrium equation showing the relationship between kb and concentration of the species involved, we have that;
kb = 4.47 × 10⁻⁴ = x² /0.25 - x.
x² + 4.47 × 10⁻⁴x - 1.1175 × 10⁻⁴ = 0.
Solving this quadratic equation gives us the value of x as 0.01035 M.
Thus, the concentration of [CH₃NH₂] = 0.25 M - 0.01035 M = 0.23965 M
The equilibrium concentration of [CH₃NH₂] = 0.23965 M.
The equilibrium concentration of CH₃NH₃⁺ and OH⁻ = 0.01035 M respectively.
A 7.27-gram sample of a compound is dissolved in 250. grams of benzene. The freezing point of this solution is 1.02°C below that of pure benzene. What is the molar mass of this compound? (Note: Kf for benzene = 5.12°C/m.) Ignore significant figures for this problem. Group of answer choices 36.5 g/mol 146 g/mol 292 g/mol 5.79 g/mol 73.0 g/mol
Answer:
The correct answer is 146 g/mol
Explanation:
Freezing point depression is a colligative property related to the number of particles of solute dissolved in a solvent. It is given by:
ΔTf = Kf x m
Where ΔTf is the freezing point depression (in ºC), Kf is a constant for the solvent and m is the molality of solution. From the problem, we know the following data:
ΔTf = 1.02ºC
Kf = 5.12ºC/m
From this, we can calculate the molality:
m = ΔTf/Kf = 1.02ºC/(5.12ºC/m)= 0.199 m
The molality of a solution is defined as the moles of solute per kg of solvent. Thus, we can multiply the molality by the mass of solvent in kg (250 g= 0.25 kg) to obtain the moles of solute:
0.199 mol/kg benzene x 0.25 kg = 0.0498 moles solute
There are 0.0498 moles of solute dissolved in the solution. To calculate the molar mass of the solute, we divide the mass (7.27 g) into the moles:
molar mass = mass/mol = 7.27 g/(0.0498 mol) = 145.9 g/mol ≅ 146 g/mol
Therefore, the molar mass of the compound is 146 g/mol
A black object appears black because it reflects all light , and does not absorb any light. True or False
Answer:
False
Explanation:
It is the other way round, a black object appears black because it absorbs all the wavelength of light and does not reflect any light.
A black bucket will appear black because, it absorbs all wavelength of light incident on it. No other wavelength is reflected from the surface of the body. A black color suggests that a body is not reflecting any color. Instead such a body absorbing all the colors. For a white object, they reflect all the wavelength that is incident upon them.what’s the most abundant isotope of lawrencium
Answer:
266Lr
Thirteen isotopes of lawrencium are currently known; the most stable is 266Lr with a half-life of 11 hours, but the shorter-lived 260Lr (half-life 2.7 minutes) is most commonly used in chemistry because it can be produced on a larger scale.
Explanation:
hopefully that helps you
If 0.4743 moles of H2O are produced, how many grams of VOCl3 will also be produced?
(V2O5 + 6 HCl → 2 VOCl3 + 3 H2O)
Answer:
i hope this helps. sorry if it totally doesn't
When 435 J of heat is added to 3.4 g of olive oil that's at 21 Deg C, it's
temperature increases to 85 Deg C. Calculate the specific heat of Olive oil? Show work
Answer:
k Nishant
Explanation:
i don't know sorry but u can search in google
Level 1 01 Which correctly pairs the outside particles with their charge? A. Electrons: Positive B. Protons: Positive C. Neutrons: Neutral D. Electrons: Negative
Answer:
D. Electrons: Negative.
Explanation:
Hello, happy to help you today!
In this case, by considering the Bohr's atomic model in which atom is composed by a nuclei containing both protons and neutrons which are positively and neutrally charged respectively and surrounding electrons assembled in orbits or levels of energy which are negatively charged in order to provide a balance to the atom, the correct statement is: D. Electrons: Negative. Also consider the Bohr's model on the attached picture.
My best regards to you!
Is lead a representative metal or transitional metal?
Answer:
It's a representative metal
Explanation: Transitional metals are metals of various chemical elements and have valence electrons—i.e., electrons that can participate in the formation of chemical bonds.
Each molecule of an olefin has at least:
a
one double bond
b
two double bonds
c
three double bonds
d
two or more single bonds
Answer:
a.
Explanation:
One double bond.
For example ethene CH2=CH2
What type of energy is defined as the kinetic energy of the atoms of a substance?
Explanation:Thermal energy, or heat, is the energy that comes from the movement of atoms and molecules in a substance. Heat increases when these particles move faster. Geothermal energy is the thermal energy in the earth. Motion energy is energy stored in the movement of objects.
I hope this helped!
Discuss the relationship between atoms, elements and compounds. Include in your discussion if these are mixtures or pure substances and why.
Answer:
Elements are the simplest complete chemical substances. Each element corresponds to a single entry on the periodic table. An element is a material that consists of a single type of atom. Each atom type contains the same number of protons.
Chemical bonds link elements together to form more complex molecules called compounds. A compound consists of two or more types of elements held together by covalent or ionic bonds.
Explanation:
How many molecules are there in 985 mL of nitrogen at 0.0 degrees C and 1.00x10^-6 mm Hg?
(It would be better if work or steps to solve problem are given but if not its fine).
Answer:
3.48 x 1013 N2 molecules
step-by-step explanation:
Lets set up our equation first
P = 1.00 x 10-6 mm Hg T = 0.0° C + 273 = 273 K
We are given the V = 985 mL ,
R = 0.0821 L·atm/mol·K
Now use the ldeal gas law, but we are solving n, amount of substanvce
PV = nRT, we will change this equation to ;
n = PV/RT
n = 1.00 x 10-6 mm x 1 atm/760 mm x 985 mL x 1 L/103
mL/
(0.0821 L·atm/mol·K x 273 K) = 5.78 x 10-11 moles N2
nmolecules = 5.78 x 10-11 moles N2 x 6.02 x 1023 N2 molecules/1 mol N2
Phosphoric acid, which is commonly used as rust inhibitor, food additive and etching agent for dental and orthopedic use, can be synthesized using a two-step thermal process. In the first step, phosphorus and oxygen react to form diphosphorus pentoxide: P4(l)+5O2(g-2 P20s(g) In the second step, diphosphorus pentoxide and water react to form phosphoric acld P20(9)+3 H200 2H,PO40) Write the net chemical equation for the production of phosphoric acid from phosphorus, oxygen and water.
Answer:
P₄(l) + 5 O₂(g) + 6 H₂O(l) ⇒ 4 H₃PO₄(aq)
Explanation:
Phosphoric acid is synthesized using a two-step thermal process.
In the first step, phosphorus and oxygen react to form diphosphorus pentoxide. The corresponding chemical equation is:
P₄(l) + 5 O₂(g) ⇒ 2 P₂O₅(g)
In the second step, diphosphorus pentoxide and water react to form phosphoric acid. The corresponding chemical equation is:
P₂O₅(g) + 3 H₂O(l) ⇒ 2 H₃PO₄(aq)
We can get the net chemical equation by adding the first step, the second step multiplied by 2, and canceling what is repeated on both sides.
P₄(l) + 5 O₂(g) + 2 P₂O₅(g) + 6 H₂O(l) ⇒ 2 P₂O₅(g) + 4 H₃PO₄(aq)
P₄(l) + 5 O₂(g) + 6 H₂O(l) ⇒ 4 H₃PO₄(aq)
Cementation is part of the process of
A. igneous intrusion
B. lithification
C. igneous extrusion
D. metamorphism
SUBMIT
Answer:
The correct answer is b.
Explanation:
hope this helps u
Answer:
Bryna is correct it is B
Explanation:
PLSSS HELP Match each image to the
correct step of meiosis. PLS HELP
Answer:
Explanation:
Here you go!! Hope this helps.
Solid calcium chlorate decomposes to form solid calcium chloride and oxygen gas.
Write the balanced chemical equation for the reaction described. Phases are optional.
equation:
Answer:
Ca(ClO₃)₂(s) → CaCl₂(s) + 3O₂(g)
Explanation:
Chemical equation:
Ca(ClO₃)₂(s) → CaCl₂(s) + O₂(g)
Balance chemical equation:
Ca(ClO₃)₂(s) → CaCl₂(s) + 3O₂(g)
Step 1:
Ca(ClO₃)₂(s) → CaCl₂(s) + O₂(g)
Left hand side Right hand side
Ca = 1 Ca = 1
Cl = 2 Cl = 2
O = 6 O = 2
Step 2:
Ca(ClO₃)₂(s) → CaCl₂(s) + 3O₂(g)
Left hand side Right hand side
Ca = 1 Ca = 1
Cl = 2 Cl = 2
O = 6 O = 6
__________ 5. Chemical equilibrium is the result of A. all of the reactants being converted into products. B. stoppage of further reaction. C. formation of products equal in mass to the mass of the reactants. D. opposing reactions attaining equal rates. E. a loss of pressure in the system.
Answer:
The correct option is C
Explanation:
Chemical equilibrium is a state in which there is no net change in the amount of reactant and products formed over time. This reaction is a reversible reaction, hence the reaction can keep proceeding in either direction until the products formed are equal in mass to that of the reactants or the products been reversed back to the reactants until both sides (product and reactant) achieve equal mass.
3 points
18) A student determines the density of gold to be 20.9g/L. The true
density of gold is 19.30g/L. What is the student's percent error?round
answer to 2 significant figures *
Answer:
The answer is 8.29 %Explanation:
The percentage error of a certain measurement can be found by using the formula
[tex]P(\%) = \frac{error}{actual \: \: number} \times 100\% \\ [/tex]
From the question
actual density = 19.30g/L
error = 20.9 - 19.3 = 1.6
We have
[tex]p(\%) = \frac{1.6}{19.3} \times 100 \\ = 8.290155440...[/tex]
We have the final answer as
8.29 %Hope this helps you
What is the gravitational potential energy, in joules, of a 75 kg person that is 1000.0
meter above the ground? Gravitational acceleration = 9.81 m/s2
Answer:
In this example, a 3 kilogram mass, at a height of 5 meters, while acted on by Earth's gravity would have 147.15 Joules of potential energy, PE = 3kg * 9.81 m/s 2 * 5m = 147.15 J. 9.81 meters per second squared (or more accurately 9.80665 m/s 2 ) is widely accepted among scientists as a working average value for Earth's gravitational pull.
Explanation:
HELP ME ASAP!
Under the Law of Multiple Proportions, Carbon Dioxide has a ratio of 2.666 g
Oxygen for every 1 g Carbon. Given this, how much oxygen is present in a sample
of carbon dioxide that has 16 g of carbon?
Answer:
In carbon dioxide, on the right, there is 2.666 g of oxygen for every gram of carbon. So the ratio of oxygen in the two compounds is 1:2, a small whole number ratio
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A tree frog uses plants or trees for protection from the rain. The frog is protected from the rain and the tree is neither helped nor harmed
Plz answer me will mark as brainliest
Answer:
Compared to the walls of the right ventricle, the walls of the left ventricles are much thicker.
The plasma carries hormones, which are the body's chemical messengers.
Antoine Lavoisier correctly characterize as an element?
Please help
What is an element
Answer:
An element is atoms with the same number of protons.
Explanation:
Protons, electrons, and neutrons.
4. CHALLENGE Suppose you had a mixture of sand and small,
hollow beads. How might you separate the mixture?
I'm not sure if this is the answer but maybe oil.
a water sample is found to have a cl- content of 100ppm as nacl what is the concentration of chloride in moles per liter
Answer:
The concentration of chloride ion is [tex]2.82\times10^{-3}\;mol/L[/tex]
Explanation:
We know that 1 ppm is equal to 1 mg/L.
So, the [tex]Cl^-[/tex] content 100 ppm suggests the presence of 100 mg of [tex]Cl^-[/tex] in 1 L of solution.
The molar mass of [tex]Cl^-[/tex] is equal to the molar mass of Cl atom as the mass of the excess electron in [tex]Cl^-[/tex] is negligible as compared to the mass of Cl atom.
So, the molar mass of [tex]Cl^-[/tex] is 35.453 g/mol.
Number of moles = (Mass)/(Molar mass)
Hence, the number of moles (N) of [tex]Cl^-[/tex] present in 100 mg (0.100 g) of [tex]Cl^-[/tex] is calculated as shown below:
[tex]N=\frac{0.100\;g}{35.453\;g/mol}=2.82\times 10^{-3}\;mol[/tex]
So, there is [tex]2.82\times10^{-3}\;mol[/tex] of [tex]Cl^-[/tex] present in 1 L of solution.
6. Clownfish, sea anemone, coral, sea urchins, sponges and parrot fish are 5 points
just a few examples of the large variety of organisms that can be found in
a coral reef. The coral reef and its inhabitants (residents) are suffering due
to several factors such as pollution, coastal development, sedimentation
and destructive fishing practices. What would be the most likely result if
some of the species in the coral reef are destroyed? *
Answer:
The orange-and-white clownfish you know from Hollywood is only one of 30 species of clownfish that live in coral reefs around the world; small in size and big in personality, these tiny comedians have one of the most unique lifestyles in the reef. The orange-and-white clownfish you know from Hollywood is only one of 30 species of clownfish that live in coral reefs around the world; small in size and big in personality, these tiny comedians have one of the most unique lifestyles in the reef.
Explanation:
point being, it would be absolutely terrible
Coral reef are the biggest biodiversity in the world. Therefore, destruction of coral reefs definitely affect the aquatic livings. As well as it leads to erosion of seashore lines.
What are coral reefs?Corals reefs are the habitat of 25% of sea organisms. It means there are well over a million species that rely on coral reefs for their existence. The reef offers these organisms the vital food, habitat, and breeding grounds required for the survival of their species.
The marine biodiversity would suffer greatly if their homes vanished. And many fish, turtles, and other species would vanish in a domino-like fashion.
Coral reefs are threatened by a number of things, such as local threats like overfishing, destructive fishing methods, coastal development, pollution, and careless tourism, as well as global effects of climate change like warming seas and rising CO₂ levels in the water. Natural phenomena like hurricanes, El Nio, and diseases are also a threat to oral reefs.
Find more on coral reefs:
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Which is an example of a current research focus in chemistry?
A. applying gene therapy to treat certain diseases
B. using hook-and-loop tape in the clothing industry
C. developing smoke detectors for common use
D. studying coal combustion as an energy source
Answer:
b is the correct answer
do not trust answer one
Explanation:
Question 2 of 10 >
Nitrogen and hydrogen combine at a high temperature, in the presence of a catalyst, to produce ammonia,
8H8
N2(g) + 3 H2(g) — 2NH,(8)
Assume 0.170 mol N, and 0.561 mol H, are present initially,
After complete reaction, how many moles of ammonia are produced?
NH,
How many moles of H, remain?
Answer:
Moles of H₂ left = 0.051 mol
Moles of ammonia formed = 0.34 mol
Explanation:
Given data:
Moles of N₂ = 0.170 mol
Moles of H₂ = 0.561 mol
Moles of ammonia formed = ?
Moles of H₂ left = ?
Solution:
Balance chemical equation:
N₂ + 3H₂ → 2NH₃
Now we will compare the moles of ammonia with nitrogen because nitrogen is limiting reactant and limit the yield of ammonia.
N₂ : NH₃
1 : 2
0.170 : 2×0.170 = 0.34 mol
Moles of ammonia formed = 0.34 mol
Moles of H₂ reacted:
N₂ : H₂
1 : 3
0.170 : 3/1×0.170 = 0.51 mol
0.51 moles of hydrogen react with 0.170 moles of nitrogen.
Moles of H₂ left:
Moles of H₂ left = Total - moles reacted
Moles of H₂ left = 0.561 mol - 0.51 mol
Moles of H₂ left = 0.051 mol
Atomic radius is....
O The tendency for an atom to attract electrons
The energy required to remove an electron
O The energy required to add an electron
O The distance from the nucleus to the last orbital
Which number represetns a coefficient?
2
3
4
7