Answer:
13.32
Explanation:
pOH=-log(0.21)=0.68
pH=14-pOH=14-0.68=13.32
51.86% of all the isotopes of an element have a mass of 106.82 amu and 48.14% have a mass of 109.03 amu.
What is the average mass of this element?
Answer:
Average Mass = 107.88 amu
Explanation:
We can calculate the average mass of an element by mutlpying the mass of its isotopes by their respective relative abundance and then making a total sum. Meaning that for this case:
Average Mass = 106.82 amu * 51.86/100 + 109.03 amu * 48.14/100Average Mass = 107.88 amuHow are the electron structures of carbon (C) and oxygen (O) similar? PLEASE HELP
Answer:
Carbon and oxygen are similar in a few ways. They are both elements, which are the fundamental building blocks of all matter. This means that they both have protons and electrons. They also both have neutrons
How many total atoms are there in C6H12O6 + 6O2?
Explanation:
C - 6 atoms
H - 12 atoms
O - 6 atoms + 12 atoms
total number of stoms = 6 + 12 + 6 + 12 = 36
How much of a 100.0 gram sample of Gold-98 remains after 8.1 days if
its half-life= 2.7 days?
50.0 g
12.5 g
6.25 g
25.0 g
Answer:
If half-life is 2.7 days then 8.1 days is three half-lives. 12.5%, or 12.5g, of AU-198 would remain.
Explanation:
What is an example of Chemical energy to thermal energy to electrical current?
Answer:
Coal is burned at power plant.
Explanation:
the chemical Energy is released as coal changes
have a good day
What is 90 kPa when converted to atm?
A. 0.5 atm
B. 0.88 atm
C. 1 atm
D. 1.5 atm
Can you show the work
Name the following compound
CH 3 – CH 2 – CH = CH – CH 2 – CH 3
Answer:
hex-3-ene
remember the least number rule and since the double bond lies at 3rd C-atom from either ways, the compound is named hex (six carbon atoms) -3(position of double bond)-ene (primary suffix for unsaturated organic compound where any two carbons have double bond). hex-3-ene.
if you have any doubt, please feel free to ask :-))
More efficient plumbing reduces water pollution by _______. a. using more water b. using less water c. using cleaner water d. using dirty water Please select the best answer from the choices provided
Answer:
b. using less water
Explanation:
Pollution can be defined as the physical degradation or contamination of the environment through an emission of harmful, poisonous and toxic chemical substances.
In the United States of America, the agency which was established by US Congress and saddled with the responsibility of overseeing all aspects of pollution, environmental clean up, pesticide use, contamination, and hazardous waste spills is the Environmental Protection Agency (EPA). Also, EPA research solutions, policy development, and enforcement of regulations through the resource Conservation and Recovery Act.
In homes and offices, an effective and efficient design of pipes and other water-related facilities would go a long way to reduce water pollution because the water used are well managed and properly disposed into sinkholes.
Hence, more efficient plumbing reduces water pollution by using less water
Answer:
B
Explanation:
write a paragraph to explain how the transformation of water from one state of matter to another is important for the water cycle
In order for us to have water to drink, it first needs to go through a process called the water cycle. And in that water cycle there’s a process called evaporation. Evaporation is the process by which water changes from a liquid to a gas. In order for it to rain we need clouds and clouds are made of water. The water is heated causing water molecules to convert into gas, that gas then goes through a process called condensation creating clouds. At some point those clouds will be full of water, and all that water will then cause the cloud to release the water molecules causing rain.
The water cycle shows the continuous movement of water within the Earth and atmosphere. It is a complex system that includes many different processes.
Liquid water evaporates into water vapor, condenses to form clouds, and precipitates back to earth in the form of rain and snow.There are four main parts to the water cycle:
Evaporation, Convection, Precipitation and Collection.
Evaporation is when the sun heats up water in rivers or lakes or the ocean and turns it into vapor or steam.
The water vapor or steam leaves the river, lake or ocean and goes into the air.
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Calculate the molarity when 3.55 moles of NaCl are dissolved to make 0.200 L of solution
Answer: The molarity of given solution is 17.75 M.
Explanation:
Given: Moles = 3.55 mol
Volume of solution = 0.2 L
Molarity is the number of moles of a solute present in liter of solution.
Hence, molarity of the given solution is calculated as follows.
[tex]Molarity = \frac{no. of moles}{Volume (in L)}\\= \frac{3.55 mol}{0.2 L}\\= 17.75 M[/tex]
Thus, we can conclude that the molarity of given solution is 17.75 M.
How many electrons are in an ion of calcium (Ca2+)?
A. 2
B. 18
C. 0
D. 22
Helium only has two valence electrons and is a stable atom. How is this possible when atoms
need 8 valence electron to become stable?
Answer:
Explanation:
Helium (He) is similar in that it, too, only has room for two electrons in its only valence shell. Hydrogen and helium have only one electron shell. The first shell has only one s orbital and no p orbital, so it holds only two electrons. Therefore, these elements are most stable when they have two electrons.
Explain ocean floor spreading and how this process is related to the mid-ocean ridge
Answer:
Seafloor spreading is a process that occurs at mid-ocean ridges, where new oceanic crust is formed through volcanic activity and then gradually moves away from the ridge.
Explanation:
Mid-ocean ridges and seafloor spreading can also influence sea levels. As oceanic crust moves away from the shallow mid-ocean ridges, it cools and sinks as it becomes more dense. ... Seafloor spreading proves that the ocean itself is a site of tectonic activity.
How many formula units (particles of AgNO3) are in 5.50
grams of AgNO3?
a 1.93 x 1022 molecules
b 8.67 x 1021 molecules
C 0.032 molecules
d 6.14 1022 molecules
e, 3.22 x 1022 molecules
Answer:
2.0 X 10²² molecules of AgNO₃Explanation:
Given 5.50 grams of AgNO₃, how many formula units of AgNO₃ are contained in the 5.50 grams of AgNO₃? (formula wt. of AgNO₃ = 169,87 g/mole).
Solution:
1st convert grams to moles => moles AgNO₃ = 5.50 g AgNO₃ / 169.841g AgNO₃ = 0.032377 mole AgNO₃ 2nd calculate number of particles in 0.032377 mole AgNO₃ . Number AgNO₃ molecules in 0.032377 mole AgNO₃ = 0.032377 mole AgNO₃ X 6.023 x 10²³ molecules of AgNO₃ /1.0 mole AgNO₃ = 1.95007 X 10²² molecules of AgNO₃ in 5.50 grams of AgNO₃. The appropriate form of the answer should contain 2 Sig,Figs. based on the data point having the least number of sig.figs. in the given data. This then is 5.50 grams of AgNO₃ which has 2 sig.figs. Therefore, the number of AgNO₃ molecules in 5.5 grams of AgNO₃ = 2.0 X 10²² molecules of AgNO₃. (Note: 1.95 rounds to 2.0).The number of molecules of silver nitrate in 5.5 grams has been [tex]1.93\;\times\;10^2^2[/tex]. Thus, option A is correct.
The formula unit has been given as the number of molecules of the compound. The number of molecules in a mole of compound has been given by the Avogadro law.
According to the Avogadro law, the number of molecules in a mole of sample has been equivalent to the Avogadro number, i.e. [tex]6.023\;\times\;10^2^3[/tex].
Computation for formula unit of Silver nitrateThe given mass of silver nitrate has been 5.50 grams.
The molar mass of silver nitrate has been 169.84 g/mol.
The moles of silver nitrate has been:
[tex]\rm Moles=\dfrac{Mass}{Molar\;mass} \\\\
Moles=\dfrac{5.5}{169.84}\;mol\\\\
Moles=0.032\;mol[/tex]
The moles of silver nitrate in the sample has been 0.032 mol.
The number of molecules of silver nitrate has been:
[tex]\rm 1\;mole=6.023\;\times\;10^2^3\;molecules\\ 0.032\;mol=0.032\;\times\;6.023\;\times\;10^2^3\;molecules\\ 0.032\;mol=1.93\;\times\;10^2^2\;molecules[/tex]
The number of molecules of silver nitrate in 5.5 grams has been [tex]1.93\;\times\;10^2^2[/tex]. Thus, option A is correct.
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Why Uranium consider as non-renewable resource? Please I need it now and short answer with simple meaning!!
Rate in its natural state uranium -235 is a non renewable energy. although small quantities go a long way .For example the fission of one pound of uranium release more energy than burning three million pounds of coal.Nuclear fission reacts splits atoms to release the enriched uranium.
what is the chemical formula for aluminium?
Answer
Aluminum is a silvery-white metal which is extremely soft by nature. Totally earth's crust contains 8% of Aluminum. Aluminium is a low-density nonmagnetic and ductile metal which can be made into sheets or wires as required
Explanation:
Answer:
Al
Explanation:
Aluminum is a silvery-white metal which is extremely soft by nature. Totally earth's crust contains 8% of Aluminum.
A chemist uses hot hydrogen gas to convert chromium(III) oxide to
pure chromium. How many grams of hydrogen are needed to
convert 76 grams of chromium(III) oxide, Cr203?
Answer: 3.024 g grams of hydrogen are needed to convert 76 grams of chromium(III) oxide, [tex]Cr_{2}O_{3}[/tex]
Explanation:
The reaction equation for given reaction is as follows.
[tex]Cr_{2}O_{3} + 3H_{2} \rightarrow 2Cr + 3H_{2}O[/tex]
Here, 1 mole of [tex]Cr_{2}O_{3}[/tex] reacts with 3 moles of [tex]H_{2}[/tex].
As mass of chromium (III) oxide is given as 76 g and molar mass of chromium (III) oxide [tex](Cr_{2}O_{3})[/tex] is 152 g/mol.
Number of moles is the mass of substance divided by its molar mass. So, moles of [tex]Cr_{2}O_{3}[/tex] is calculated as follows.
[tex]No. of moles = \frac{mass}{molar mass}\\= \frac{76 g}{152 g/mol}\\= 0.5 mol[/tex]
Now, moles of [tex]H_{2}[/tex].given by 0.5 mol of [tex]Cr_{2}O_{3}[/tex] is calculated as follows.
[tex]0.5 mol Cr_{2}O_{3} \times \frac{3 mol H_{2}}{1 mol Cr_{2}O_{3}}\\= 1.5 mol H_{2}[/tex]
As molar mass of [tex]H_{2}[/tex] is 2.016 g/mol. Therefore, mass of [tex]H_{2}[/tex] is calculated as follows.
[tex]No. of moles = \frac{mass}{molar mass}\\1.5 mol = \frac{mass}{2.016 g/mol}\\mass = 3.024 g[/tex]
Thus, we can conclude that 3.024 g grams of hydrogen are needed to convert 76 grams of chromium(III) oxide, [tex]Cr_{2}O_{3}[/tex].
2. If the half-life of Francium-233 is 22 minutes, how much time must elapse in order for 60 grams of a 64 gram
sample to undergo decay? In other words, after how many minutes will you only have 4 grams of the original isotope
remaining?
Answer:
88 minutes
Explanation:
64 g ---> 32g ---> 16g ---> 8 g ---> 4 g
So in total, we have 4 half lives to reach 4.0 g
therefore, 4 x 22 minutes = 88 minutes
88 minutes or four half lives are required to have 4 grams of the original isotope remaining.
What is half life?Half -life of a substance is defined as the time which is required for half of the quantity of a radioactive substance to get decayed.It is a term which is used in nuclear chemistry for describing how quickly unstable atoms undergo radioactive decay into other nuclear species by emitting particles or the time which is required for number of disintegrations per second of radioactive material to decrease by one half of its initial value.
During first half life= 64 g of isotope is present , during second half life 1/2×64=32 g of isotope is present, during third half life 1/2×32=16 g of isotope is present.during fourth half life 1/2×16=8 g of isotope is present.
As 1 half life is 22 minutes 4 half lives=4×22=88 minutes.
Thus, 88 minutes are requires for 4 g of sample to remain.
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2.14g of sodium sulfide react with excess hydrochloric acid to form sodium chloride and dihydrogen sulfide.
BALANCE IT TO AN EQUATION
Answer:
2.14 Na2S + 1.99 HCl ----> 3.20 NaCl + 0.935 H2S
Explanation:
The Balanced equation is
Na2S + 2HCl = 2NaCl + H2S
As we can see -
78.0452 g/mol of sodium sulfide reacts with 2 mole of HCl.
Mass of one mole of HCl = 36.458 g/mol
So, 78.0452 g/mol of sodium sulfide reacts with 2* 36.458 g/mol of HCL to produce 2* 58.44 g of NaCl and 34.1 g/mol of H2S
Thus,
2.14g of sodium sulfide will react with (2* 36.458/78.0452)* 2.14 of HCl
2.14g of sodium sulfide will react with 1.99 g of HCl
2.14 Na2S + 1.99 HCl ----> (2* 58.44/78.0452) *2.14 NaCl + (34.1/78.0452) * 2.14 H2S
2.14 Na2S + 1.99 HCl ----> 3.20 NaCl + 0.935 H2S
In general, agitation causes the dissolving rate of most solutes to:
A- remain the same
B- increase
C- vary unpredictably
D-decrease
Describe the law of conservation of mass in your own words *DO IT IN YOUR OWN WORDS PLEASE*
Answer:
Chemical reactions and physical transformations do not create or destroy mass in an isolated system, according to the law of conservation of mass. The mass of the products in a chemical reaction must equal the mass of the reactants, according to the conservation of mass law. The law of conservation of mass can be used to solve for unknown masses, such as how much gas is consumed or produced during a reaction.
Please, can anyone confirm that my answers are correct?
Will give brainiest to first correct answer! (No links pls)
PLZ HELP
What is the difference between strong and weak acids
Answer:
Weak acids don't fully dissociate in the solvent, whereas strong acid do.
Explanation:
Answer: Strong acids dissociate fully in water to produce the maximum number of H + ions. ... Weak acids, such as ethanoic acid (CH 3COOH), do not fully dissociate
Explanation:
Los ácidos fuertes se disocian completamente en agua para producir el máximo número de iones H +. ... Los ácidos débiles, como el ácido etanoico (CH 3COOH), no se disocian completamente
A sample of krypton occupies 15.0 L at a pressure of 2.1 atm. Use Boyle's Law to find the pressure of the krypton when the volume is decreased to 4L.
Answer:
7.5 atm
Explanation:
Given that,
Initial volume, V₁ = 15 L
Pressure, P₁ = 2.1 atm
Final volume, V₂ = 4L
We need to find the final pressure. The mathematical relation between volume and pressure is given by :
[tex]\dfrac{V_1}{V_2}=\dfrac{P_2}{P_1}\\\\P_2=\dfrac{V_1P_1}{V_2}\\\\P_2=\dfrac{15\times 2}{4}\\\\P_2=7.5\ atm[/tex]
So, the final pressure is equal to 7.5 atm.
What is the momentum of a motorcycle and a rider weighing 215 kg traveling at a speed of 62 meters per second?
Answer:
[tex]p=13330kg*\frac{m}{2}[/tex]
Explanation:
Hello there!
In this case, since the momentum of any body is calculated by multiplying the mass and the velocity:
[tex]p=m*v[/tex]
We simply need to multiply the 215 kg of the motorcycle by the velocity it has, 62 m/s to obtain:
[tex]p=215kg*62m/s\\\\p=13330kg*\frac{m}{2}[/tex]
Regards!
How many moles of carbon are needed to react with 5.44moles of so2
Answer:
1.25 moles
Explanation:
hope that helps :)
ps. im learning about that in school rn too
Which of these phrases accurately describe disproportionation? Check all that apply.
A single compound reacts with itself.
A single compound oxidizes and reduces a second compound.
A single compound is simultaneously oxidized and reduced.
A single compound is produced by the reaction of two ions.
A single compound acts as both the oxidizing agent and the reducing agent.
ANSWER: A,C,E on E2020
Answer:
A single compound is simultaneously oxidized and reduced.
Explanation:
In chemistry, disproportionation is a simultaneous oxidation and reduction of a single chemical specie.
What this means is that; in a disproportionation reaction, only one compound is both oxidized and reduced. This implies that two products are formed during disproportionation. One is the oxidized product while the other is the reduced product.
Consider the disproportionation of CuCl shown below;
2CuCl -----> CuCl2 + Cu
Here, CuCl2 is the oxidized product while Cu is the reduced product.
Answer:
A & c & e
Explanation:
_H2+O2=_H2O
balance help please
What causes day and night?
Make sure you give a full, detailed answer, not just one sentence.
Answer:
The earth's rotation, earth is rotating, so one side of earth will be hit by the sun, and the other wont be hit, making it dark, but since earth rotates, it causes it to turn, making one side have daylight, and the other, darkness, which the light you see is from the sun's reflection on the moon
Hope this helps
Which shows an isomer of the molecule below?
Answer: C
Explanation:
Don’t trust the other person it’s not A
*view photo for answer*
pay attention! the answer choices aren't always in the same order!