This question is incomplete, the complete question is;
Consider this reaction:
2H₃PO₄(aq) → p₂o₅(aq) + 3H₂O(aq)
At a certain temperature it obeys this rate law.
rate = ( 46.65 M⁻¹.s⁻¹) [ H₃PO₄ ]²
Suppose a vessel contains H₃PO₄ at a concentration of 0.660 M .
Calculate how long it takes for the concentration of H₃PO₄ to decrease to 20.0% of its initial value .
You may assume no other reaction is important.
Round your answer to significant digits.
Answer:
time taken is 8.574 × 10⁻⁴ s
Explanation:
Given that;
rate = k[ H₃PO₄ ]²
rate constant k = 46.65 M⁻¹.s⁻¹)
Initial concentration A₀ = 0.660 M { which will be 100%}
final concentration At = 20%
for the concentration of H₃PO₄ to decrease to 20.0% of its initial value = ?
we know that;
rate constant k = 1/t [ 1/At - 1/A₀ ]
we substitute
46.65 = 1/t [ 1/20 - 1/100 ]
46.65 = 1/t [ 0.04 ]
46.65 = 0.04/t
46.65t = 0.04
t = 0.04 / 46.65
t = 0.0008574 ≈ 8.574 × 10⁻⁴ s
Therefore, time taken is 8.574 × 10⁻⁴ s
An unknown element is a mixture of isotopes 120X and 122X. The
average atomic mass of X is 120.37 amu. What is the percent
abundance of 122X?
Answer:
so basically you just
Explanation:
chemistry
Definition in your own words. I will check if you got it from online.
Word:
Oxidizer
Answer:
oxidizer: one used to support the combustion of a rocket propellant
word: a single distinct meaningful element of speech or writing
Explanation:
PLZ HELP ASAP WILL GIVE BRAINLIST
2AlCl3 + 2Al + 3Cl2
If 20.0 g of aluminum chloride are decomposed, how many molecules of chlorine gas are produced?
A )6.63 x 1022 molecules CI
B )2.70 x 1023 molecules Cl2
C )1.35 x 1023 molecules Cl2
D )9.42 x 1023 molecules Cl2
Explanation:
Molar mass of AlCl3 = 133.34g/mol
Moles of AlCl3 used
= 20.0g / (133.34g/mol) = 0.150mol
Mole Ratio of AlCl3 to Cl2 = 2 : 3,
Moles of Cl2 produced
= 0.150mol * (3/2) = 0.225mol
We know that 1 mole of any gas has
6.023 * 10²³ molecules.
Hence, number of molecules in Cl2
= 0.225mol * (6.023 * 10²³/mol)
= 1.35 * 10²³ molecules. (C)
If the oxidation state of H is +1 and O is -2, what is the oxidation state of C in C2H4O?
Answer:
-1
Explanation:
According to this question, the oxidation state/number of H and O in C2H4O is +1 and -2 respectively.
The oxidation state of carbon in the compound can be calculated thus:
Where;
x represents the oxidation number of C
C2H4O = 0 (net charge)
x(2) + 1(4) - 2 = 0
2x + 4 - 2 = 0
2x + 2 = 0
2x = -2
Divide both sides by 2
x = -1
The oxidation number of C in C2H4O is -1.
Thiamine hydrochloride (vitamin B1 hydrochloride, HC12- H17ON4SCl2) is a weak acid with Ka 5 3.4 3 1027. Sup- pose 3.0 3 1025 g of thiamine hydrochloride is dissolved in 1.00 L of water. Calculate the pH of the resulting solution. (Hint: This is a sufficiently dilute solution that the autoion- ization of water cannot be neglected.)
Answer:
pH = 6.76
Explanation:
Ka = 3.4x10⁻⁷; 3.0x10⁻⁵g
The molarity of the vitamin B1 -Molar mass: 327.268g/mol- solution is:
3.0x10⁻⁵g * (1mol / 327.268g) = 9.167x10⁻⁸M
The Ka expression is:
Ka = 3.4x10⁻⁷ = [H⁺] [B1-] / [B1]
Where B1- is the conjugate base of vitamin B1,
In equilibrium, the concentrations are:
[H⁺] = X
[B1-] = X
[B1] = 9.167x10⁻⁸M - X
Where X is reaction coordinate
Replacing:
3.4x10⁻⁷ = [X] [X] / [9.167x10⁻⁸M - X]
3.117x10⁻¹⁴ -3.4x10⁻⁷X = X²
3.117x10⁻¹⁴ -3.4x10⁻⁷X - X² = 0
Solving for X:
X = -4.15x10⁻⁷M. False solution. There is no negative concentrations.
X = 7.51x10⁻⁸MThat means from the equilibrium of vitamin B1, the [H⁺] = 7.51x10⁻⁸M
From the autoinoization of water:
[H⁺] = 1.0x10⁻⁷M
[H⁺] in the solution is:
1.0x10⁻⁷M + 7.51x10⁻⁸M = 1.751x10⁻⁸M
As pH = -log[H⁺]
pH = 6.76an unknown substance has a mass of 57.4 g and occupies a volume of 34.3 ml. what is the density in g/ml?
Answer:
1.6734 g\ml..hope it helps
What is the iupac name of ch3ch(oh)so3na
Answer:
propane-1-ol.
is the ans.
ok
is the name
ok
How do I know I'm a fish eh sorry
The best known Lepton is the _________________.
a
electron
b
boson
c
fermion
d
hadron
e
neutron
f
proton
Answer:
Electron (e-)
Explanation:
An electron is just one of the fundamental particles
Answer:heyyyy
Explanation:
how many moles are there in 67.2 grams of h2
Answer: 33.3 moles
Explanation: 67.2 g H2 = 67.2/2.016 = 33.3 moles
The gas carbon dioxide is a pure substance. Which of the following is true about carbon dioxide? (5 points)
Select one:
a. Carbon and oxygen are chemically bonded in it.
b. Carbon and oxygen retain their original identity in it.
c. It can be separated into carbon and oxygen using physical methods.
d. The proportion of carbon and oxygen is different in different samples of the gas.
Answer:
Carbon and oxygen are chemically bonded in it.
Explanation:
The other answer choices do not apply for compounds, but rather for mixtures instead.
What is the correct name of this isotope? *
oxygen - 16
oxygen - 8
oxygen - 24
The correct name of this isotope : Oxygen - 16
Further explanationGiven
Isotope : ₈¹⁶O
Required
The correct name
Solution
The elements in nature have several types of isotopes
Isotopes are elements that have the same Atomic Number (Proton)
Atomic mass is the average atomic mass of all its isotopes
In the following element notation,
[tex]\large {{{A} \atop {Z}} \right X}[/tex]
X = symbol of elemental atom
A = mass number
Z = atomic number
The isotope name is usually followed by its mass number, so the symbol above can be expressed as oxygen - 16
There are many important laws and theories in science. Which of the following is a law of scienco?
A living thing is made of at least one cell.
An atom is made of electrons orbiting a nucleus.
Gravity will pull two objects toward each other.
Natural selection will change species to fit their environments.
Answer: Gravity will pull two objects together.
Explanation: It’s newton’s 1 and kinda his 2 law.
differences between selenium tellurium and polonium
Explanation:
Selenium and tellurium are rare elements, respectively, in order of crustal abundance. However, polonium, on account of its radioactive decay, is less abundant. The main source of selenium and tellurium is the anode slime deposited during the electrolytic refining of copper.
Which statement is always true about conversation of matter?
The mass of a system does not change during a chemical reaction
If a solid forms the mass of a system increases
If a gas forms the mass of a system decreases
The mass of a system changes when a substance changes from liquid to gas, but it does not change in a chemical reaction
Answer:
The mass of a system does not change during a chemical reaction
Explanation:
Correct Answers
3. What determines the frequency (color) of photons?
GRADE 5 SCIENCE MYA-2020-2021
Testosters are testing the choict of light on a radiometer Team 1 finds that blue light makes the radiometer spin slower when a blue light is 35 centimeters (cm) away. To validate Team 1's test results, how must
Text with and that is 20 cm away
Test what that is 45 cm away
Test with a green light that is 40 cm away
Test with the light that is 35 cm away
Answer:
Test it with a blue light that is 45 cm away.
Explanation:
Magnesium reacts with iron(III) chloride to form magnesium chloride (which can be used in fireproofing wood and in disinfectants) and iron. A mixture of 43.5 g Mg and 247 g iron(III) chloride is allowed to react. What is the limiting reactant and what is the mass, in grams, of the excess reactant remains
Answer:
Mg is the limiting reactant.
52.9 g of FeCl₃, remains after the reaction is complete.
Explanation:
First of all, we state the reaction's equation:
3Mg (s) + 2FeCl₃ (aq) → 2Fe (s) + 3MgCl₂ (s)
We determine the mol of each reactant:
43.5 g . 1mol / 24.3g = 1.79 mol of Mg
247 g . 1mol/ 162.2g = 1.52 mol of Iron (III) chloride.
Ratio is 2:3. 2 mol of chloride need 3 moles of Mg to react,
Then 1.52 moles will react with (1.52 . 3) /2 = 2.29 moles
We have 1.79 moles of Mg and we need 2.29, so the limiting reactant is the Mg.
We confirm the chlorine as the excess reactant:
3 moles of Mg need 2 moles of FeCl₃ to react:
1.79 moles of Mg will react to (1.79 . 2) /3 = 1.19 moles of FeCl₃
We have 1.52 moles of FeCl₃ and we only need 1.19, so it is ok, we said that the FeCl₃ is the excess.
After the reaction goes complete, (1.52 - 1.19) moles of FeCl₃ remains.
1.52 - 1.19 = 0.33 moles. We convert them to mass:
0.33 mol . 162.2g /1mol = 52.9 g
How was Bohr's atomic model different from those of previous scientists?
Answer:
Bohr placed the electrons in distinct energy levels. Rutherford described the atom as consisting of a tiny positive mass surrounded by a cloud of negative electrons. Bohr thought that electrons orbited the nucleus in quantized orbits. Also, rutherfords was just a hypothesis while Bhor took the time to make his an experiment
An atom has 81 electrons, 84 neutrons, and 82 protons. What element is this atom?
Answer:
Lead
Explanation:
The subatomic particles within an atom can be used to know the atom or element given.
Of particular interest is the number of protons within the atom.
The periodic table is based on the atomic number of atoms. This atomic number is the number of protons within an atomic space.
So; If we know the number of protons within an atom, we can know the element.
The number of protons given is 82, the element is therefore lead.
Answer:
The atomic number of polonium is 84. The atomic number lead is 82.
Explanation:
Energy from the Sun reaches Earth through
Convection
O radiation
conduction
all the above
Solar Radiation(Basically Radiation)
When measuring the volume of a liquid, how would sample size (e.g., using a 10 mL graduated cylinder vs. a 100 mL graduated cylinder to measure out 70 mL of a liquid) affect the absolute error and percentage error in the measured values of mass and volume and therefore the density
Answer:
Explanation:
From the given information:
The accuracy depends on the internal diameter of the cylinder. The cylinder with the least internal diameter is obviously more precise.
Let's assume 1% is the error of measurement.
Then, to measure 70 mL from 10 mL cylinder
The error = [tex]10 \times \dfrac{1}{100} \times 7[/tex]
= 0.7 mL
However; for a 100 mL cylinder, the error = 1 mL
Now,
The total volume for 10 mL = (70 + 0.7) = 70.7 mL
The total volume for 100 mL = (70 + 1 ) = 71 mL
Suppose the density (d) is same for both
Then;
the mass of 10 mL = ( d × 70.7) g
the mass pf 100 mL = (d × 71) g
Thus, the mass of 100 mL is greater than that of 10 mL.
In each row, checkbox under the compound that can reasonably be expected to be more acidic in aqueous solution, e.g have the larger
Ka
H₂ SO₃ H₃ SO ₄
H₃ PO₄ H₃ PO₃
HCH₃ SO₂ HCH₃CO₂
Explanation:
H2SO3 is more acid than H2TeO3. Since S is more electronegative than Te is. In H2SO3, thus, dissociation of H+ would be smoother.
So, H2SO3's got high Ka.
HCH3SO2 is more acid than HCH3CO2. Since S is more electronegative than C. So, HCH3SO2 is a high Ka.
HClO2 is more acid than HClO. Since in HClO2, after the donation of H+ ion, the negative charge is set by two oxygen atoms, while in HClO, only one oxygen atom stabilizes the negative charge.
So, HClO2 is a high Ka
Experiments were done on a certain pure substance X to determine some of its properties. There's a description of each experiment in the table below. In each case, decide whether the property measured was a chemical or physical property of X, if you can. If you don't have enough information to decide, choose can't decide in the third column.
Property P: A small sample of X is dissolved in water. Drops of another solution, containing dissolved sodium hydroxide, are slowly added, and a pH indicator is used to determine when the sodium hydroxide has completely reacted with X. From the amount of sodium hydroxide needed, the value of P may be calculated.
Property D: A sample of X is carefully weighed and put inside a vented flask. Water is added to the flask until it just covers the sample, and the volume of sample and water is recorded. Then the sample is removed and the volume of water alone recorded. From the mass of the sample and the difference in volumes, the value of R may be calculated.
Property V: Sample of X is melted and put into a reservoir from which a very thin tube leads down. The rate at which X flows out of the tube is measured, and from this rate the value of V may be calculated.
Answer:
The property P measured, was a chemical property of X; its acidity
The property D measured, was a physical property of X; its density
The property V measured, was a physical property of X; it's viscosity probably.
Explanation:
1. The property V that was measured is the acidity of X. The acidity of X is a measure of the concentration of hydrogen ions present in it. When drops of another solution, containing dissolved sodium hydroxide, are slowly added, and a pH indicator is used to determine when the sodium hydroxide has completely reacted with X, the procedure determines the concentration of X that would neutralize the base, sodium hydroxide.
2. The property of X determined in the step is the density of X, a physical property. First the volume of X was determined by the displacement method. Then the density of X is calculated from its mass and volume.
3. Since during the determination of the property V, there was no alteration done to the chemical constitution of X, the property thus determined is a physical property. Melting of the sample is a physical change and likewise its flow rate through a very thin tube.
How did fossil records support the existence of a supercontinent?
Similar fossils provided evidence that a meteor hit Earth.
Similar fossils were found in different continents.
Fossil records showed how old the continents were.
Fossil records provided evidence that dinosaurs existed.
Answer:
B. Similar fossils were found in different continents.
Answer:
B. Similar fossils were found in different continents.
Explanation:
Today, ammonia is synthesized through a series of reactions (called the Haber-Bosch process) that take place between methane, air (which is four parts N2, one part O2), and potassium carbonate:
7 CH4(g) + 8 N2(g) +2 O2(g) + 17 H2O(g) + 7 K2CO3(s) ?? 16 NH3(g) + 14 KHCO3(s)
What is the equilibrium expression for the Harber-Bosch process?
Answer:
K = [NH₃]¹⁶ [KHCO₃]¹⁴ / [CH₄]⁷ [N₂]⁸ [O₂]² [H₂O]¹⁷ [K₂CO₃]⁷
Explanation:
The equation for the reaction is given below:
7CH₄(g) + 8N₂(g) +2O₂(g) + 17H₂O(g) + 7K₂CO₃(s) —> 16NH₃(g) + 14KHCO₃(s)
Equilibrium constant (K) =..?
Equilibrium constant, K for a reaction is simply defined as the ratio of the concentration of the products raised to their coefficient to the concentration of the reactants raised to their coefficient.
Thus, the equilibrium expression for the Harber-Bosch process for the synthesis of ammonia can be written as shown below:
K = [NH₃]¹⁶ [KHCO₃]¹⁴ / [CH₄]⁷ [N₂]⁸ [O₂]² [H₂O]¹⁷ [K₂CO₃]⁷
PLEASE HELP! this is due soon!!
Answer:
The right one.
Explanation:
The right one looks like it is getting the most sun.
What process forms an image in a mirror? Choices: A. absorbing light B. Reflecting light C. Refracting light D. Transmitting light
Answer
Using the law of reflection—the angle of reflection equals the angle of incidence—we can see that the image and object are the same distance from the mirror. This is a virtual image, since it cannot be projected—the rays only appear to originate from a common point behind the mirror.
Explanation:
Hope this helps someone
What is a factor that determines whether this energy is a renewable or nonrenewable resource
Answer:
Nonrenewable energy resources, like coal, nuclear, oil, and natural gas, are available in limited supplies. This is usually due to the long time it takes for them to be replenished. Renewable resources are replenished naturally and over relatively short periods of time
identified the nucleus that is found in an item that has a stable valance electron configuration
Answer:
Nucleus 3 i believe
A 6.40 g sample of a compound is burned to produce 8.37 g CO_2, 2.75 g H_2O, 1.06 g N_2, and 1.23 g SO_2. What is the empirical formula of the compound? Give your answer in the form C#H#N#O#S# where the number following the element’s symbol corresponds to the subscript in the formula. (Don’t include a 1 subscript explicitly).
The empirical formula :
C₁₀H₁₆N₄SO₇
Further explanationGiven
6.4 g sample
Required
The empirical formula
Solution
mass C :
= 12/44 x 8.37 g
= 2.28
mass H :
= 2/18 x 2.75 g
= 0.305
mass N = 1.06
mass S :
= 32/64 x 1.23
= 0.615
mass O = 6.4 - (2.28+0.305+1.06+0.615) = 2.14 g
Mol ratio :
= C : H : N : S : O
= 2.28/12 : 0.305/1 : 1.06/14 : 0.615/32 : 2.14/16
= 0.19 : 0.305 : 0.076 : 0.019 : 0.133 divided by 0.019
= 10 : 16 : 4 : 1 : 7
The empirical formula :
C₁₀H₁₆N₄SO₇