0.723 is the [H ] (molarity) before any base is added.
the balanced equation for the acid-base reaction is
KOH + HClO₄ ---> KClO₄ + H₂O
stoichiometry of KOH to HClO₄ is 1:1
The number of HClO₄ moles - 0.723 M / 1000 mL/L x 25.0 mL = 0.0181 mol
Number of KOH moles - 0.27 M/ 1000 mL/L x 80.0 mL = 0.0216 mol
KOH is a strong acid and HClO₄ is a strong base therefore complete dissociation takes place.
the acid reacts with base in a 1:1 molar ratio, there's excess base remaining.
excess OH⁻ ions - 0.0216 - 0.0181 = 0.0035 mol
concentration is calculated as the number of moles/volume
volume of solution - 25.0 + 80.0 = 105.0 mL
[OH⁻] = 0.0035 mol / 0.105 L = 0.033 M
pOH = -log [OH⁻]
pOH = -log(0.033 M)
pOH = 1.48
pH can be calculated by knowing the pOH
pH + pOH = 14
pH = 14 - 1.48 = 12.52
pH = -log [H₃O⁺]
[H₃O⁺] = antilog(-12.52)
[H₃O⁺] = 3.0 x 10⁻¹³ M
0.723 is the [H ] (molarity) before any base is added.
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A thermochemical equation indicates the absorption or release of heat in addition to the reactants and products involved in the chemical reaction. The amount of energy available for conversion into heat is represented by a triangle H does this term stand for?
Answer:
A. Enthalpy of the reaction
Explanation:
A Thermochemical equation is a balanced stoichiometric chemical equation that indicates the absorption or release of heat in addition to the reactants and products involved in the chemical reaction. The amount of energy available for conversion into heat is represented by ΔH, a this term which stands for the enthalpy change, ΔH.
The Enthalpy of Reaction or Heat of Reaction is the amount of energy in the form of heat transferred during a chemical reaction that occurs at a constant pressure. It is useful for calculating the amount of energy per mole either released or produced in a reaction, therefore is unit is kJ/mol.
In a reaction where energy is absorbed by the reactants during the formation of products, ΔH is positive. On the other hand, in a reaction where energy is released by the reactants during the formation of products, ΔH is negative.
The enthalpy change, ΔH of reactions are determined experimentally under standard conditions of 1 atm and 25 °C (298.15K). Enthalpy can be measured experimentally through the use of a calorimeter. A calorimeter is an isolated system which has a constant pressure and in which heat loss to the surroundings is minimal.
Which of the following is true about the electron configuration of the noble gas
A. The highest occupied s and p orbitals are partially filled.
B. the highest occupied s and p orbitals are completely filled.
C. the electrons with the highest energy are in a f sub level
D. the electrons with the highest energy are in a d sublevel
Answer:
Noble gases have very stable electron configuration and does not need to gain electrons, only when they gain energy. 1) For example, krypton is a chemical element with symbol Kr and atomic number 36, which means it has 36 protons and 36 electrons.
Answer: I think it’s B, The highest occupied s and p sub levels are completely filled.
Explanation:
What are periods on the periodic table? How many are there?
A chemist analyzes two samples. One sample contains 14g of element x and 6.0 g of element y. The second sample contains 28 g of element x and samples are the same substance
Answer:
Explanation:
Here's the complete question:
A chemist analyzes two samples.One sample contains 14g of element x and 6.0g of element y.The second sample contains 28g of element x and 6.0g of element y. Does it appear that the two samples are the same substance?
The two samples that we are given in the question are different. They are not the same thing because we can deduce that their components ratio are different.
Sample One contains 14g of element x and 6.0g of element y. The ratio of element x to y is 14/6 = 7/3 = 7:3.
Sample Two contains 28g of element x and 6.0g of element y. The ratio of element x to y is 28/6 = 14/3 = 14:3.
Therefore, they have different ratio for their components and are therefore not thesame.
20.What do carbon and silicon have in common?
a.They belong to the same column (family), therefore they have the same number of valence electrons.
b.They belong to the same column (family), therefore they have the same number of total electrons.
c.They belong to the same column (family), therefore they have the same number of energy levels.
d.They belong to the same column (family), therefore they have the same number of protons.
explain how movements along faults generate earthquakes
Explanation:
When a plate moves it shifts the earth, and it can cause an earthquake.
A fault is where two of earth's tectonic plates come together. They can slide against the other, causing earthquakes, they can push against each other causing mountains to form, and they can move apart from each other, causing valleys or trenches.
Helppp
me plzzz!!!!
Answer:
Explanation:
The sound waves are bocing off the walls.
can someone help w/ chem plzz
Answer:
my answer I think is tetrahedral
1. compare a mixture and a compound , how are they like?
Answer:
Compound are substances which can be formed by chemically combining two or more elements. Mixtures are substances that are formed by physically mixing two or more substances.
I hope it's helpful!
Answer:
COMPOUND= A compound is a substance that is formed when two or more elements combine chemically .
MIXTURES= Mixtures consist of two or more substances simply mixed together , but not chemically combined .
How can you prove that air is a matter ?
Answer:
One way to prove that air is made of matter is to blow up a balloon. Before you add air into the balloon, it is empty and shapeless. When you puff air into it, the balloon expands, so you know it is filled with something—air is taking up space. You'll also notice that a balloon filled with air sinks to the ground.
Explanation:
1s2, 2s2, 2p6, 3s2, 3p6, 4s2
After this atom gains or loses valence electron/s, what will the oxidation number be?
Answer:
if it gains then it will be negative to whatever number it has gained and the reverse for when it loses
Explanation:
Which situation is does NOT occur during a chemical reaction?
bonds are formed
bonds are broken
mass is conserved
atoms are destroyed
Find the percent composition of chromium(|||) fluoride (CrF3), which is commonly used as a dye in textiles
Answer:
%Cr = 47.71%
%F = 52.29%
Explanation:
To do this, we need the atomic weights of all the elements in the chromiun fluoride, which are the following:
Cr: 51.996 g/mol
F: 18.998 g/mol
With these atomic weights, let's calculate the molecular mass of the chromium fluoride:
MM CrF₃ = (51.996) + (18.998 * 3) = 108.99 g/mol
Now, to get the percent composition, all we have to do is divide the atomic weight of each element by the molecular mass, and then, multiply by 100%:
% = (AW / MM) * 100
Replacing with each element:
%Cr = (51.996 / 108.99) * 100
%Cr = 47.71%%F = 100 - 47.71
%F = 52.29%Hope this helps
Write the symbol and charge for each individual ion:
11) Beryllium and and phosphorus
12) Cesium and sulfur
13) lithium and Phosphorus
14) Fluorine and rubidium
15) Francium and oxygen
Please help fast. I will give brainliest.
Answer:39 min
Explanation:
The equation for the complete combustion of ethane (C2H4) is
C2H4(g) + 302(g) → 2C02(g) + 2H2O(g)
If 2.70 moles C2H4 reacts with 6.30 moles Oz, identify the limiting
reactant.
Heavier noble gases are able to form compounds with other elements under specific conditions because their valence ____are farther from the _____
Answer:
Heavier noble gases are able to form compounds with other elements under specific conditions because their valence electrons are farther from the nucleus.
Explanation:
The name of noble or inert gas is due to the lack of reactivity with other elements. This is due to its electronic configuration, because its outermost shell or valence shell is always complete, without the need to share, give or receive electrons forming bonds. That is, its outer layer is so stable that the element tends not to react with others except in very specific cases.
These exceptions generally involve the heavier noble gases, such as xenon or radon, capable of forming compounds with fluorine and oxygen. This is because the heavier noble gases have more electron shells than the lighter ones. This characteristic causes the outermost electrons to experience a "shielding" effect due to the action of the inner electrons, and they can then be ionized more easily, since the attraction they receive from the positive charges of the nucleus is weaker. That makes the ionization energy low enough to form stable compounds with more electronegative elements, such as fluorine and oxygen.
Heavier noble gases are able to form compounds with other elements under specific conditions because their valence electrons are farther from the nucleus.
Look carefully at the list of objects and order
them from smallest to largest.
ant
atom
cell
dust particle
ping pong ball
Explain why you have them in this order. Be sure
to use a 5 complete thoughts.
:
Answer:
Atom, cell, dust particle, ant, ping pong ball
Explanation:
Firstly, atoms make up all matter, including each of the items on that list. The only things smaller than atoms are the parts of the atom itself, protons, neutrons and electrons. Because none of those are on that list, atoms have to be the smallest. Next smallest is the cell. Cells are made up of atoms, but they also in part make up dust. You can see a dust particle with the naked eye, but in order to see a cell you must use a microscope. Thus, cells are smaller than dust particles. Next is an ant. Obviously, an ant is bigger than a speck of dust, and is made up of cells and atoms. Lastly all you have is the ping pong ball, which is much larger than the rest of the items. Hope this helps!
All matter, including each thing on the list, is made up of atoms. The protons, neutrons, and electrons that make up an atom are the only particles smaller than atoms.
Thus, Atoms must be the tiniest object because none of those are included in that list. The cell is the next smallest. Atoms make up cells, but dust also makes up a portion of them.
A dust particle can be seen with the unaided eye, but a microscope is required to see a cell.
Cells are hence smaller than dust particles. An ant comes next. Of course, an ant is composed of cells and atoms and is larger than a particle of dust.
Thus, All matter, including each thing on the list, is made up of atoms. The protons, neutrons, and electrons that make up an atom are the only particles smaller than atoms.
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The process of photosynthesis converts carbon atoms from carbon dioxide into....
OA. hydrogen
OB.oxygen
OC.sugars
OD.salts
Answer:
B. Oxygen
Explanation:
Answer:
C.
Explanation:
The process of photosynthesis converts those things into the sugar glucose, which it uses to sustain itself. A biproduct of this process is oxygen, but the carbon is used to make sugar. Hope this helps and brainliest is always appreciated!
true or false the membrane of rer is continuous with the outer layer of the mithochondrial membrane
Answer:
false
Explanation:
which of the following indicates the cathode rays has a large charge to mass ratio?
Answer:
Gggg
Explanation:
The indication of the cathode rays that has a large charge to mass ratio is there were deflected towards a positive electrode. The correct option is b.
What are cathode rays?Cathode rays are the rays that move through the negatively charged electrode the cathode charge to the positively charged electrode which is the anode charge in a vacuum tube.
These rays travel through a pipe in a straight line with speed when there is voltage is applied. They are also called electron beams. There is a cathode ray tube, CRT, which is a vacuum tube on which cathode rays travel.
So, the correct option will be for the cathode rays would be deflected towards a positive charge anode.
Therefore, the correct option is b, there were deflected towards a positive electrode.
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The question is incomplete. Your most probably complete question is given below:
They were easily deflected
There were deflected towards a positive electrode
They were deflected towards a negative electrode
They caused a fluorescent screen to glow
which is the odd man out? diamond,coal, graphite, bronze.answer with an explanation
define p-block element?
Answer:
[tex]\boxed {\boxed {\sf D. \ Bronze}}[/tex]
Explanation:
Let's analyze the answer choices.
The first answer choices. diamond, coal, and graphite, all have something in common. They are allotropes of carbon. They are made of the same element, but each has a different arrangement of atoms, which leads to different properties.
Bronze is an alloy of copper, tin, and other metals. It's not an allotrope of carbon or related to the other answer choices. Therefore, it is the odd one out.
How many liters are there in 28g of B?
11. Explain Supergiants
are cool yet luminous___
because
(Circle the
correct answer.)
a. they produce more
energy
b. they are farther from
Earth
c. they are unusually large
How cold does it really get on Pluto's moon, Charon? (I know this is not a Chem question per se, but is there no Earth Science, nor Space, nor Astronomy, nor General Science category on Brainly?)
Answer:
Explanation:
After various studies and experiments conducted on Pluto's moon, Charon it has been determined that it gets to minus 459.67 degrees Fahrenheit which would be equivalent to minus 273.15 degrees Celsius. This is the coldest temperature that scientists have registered for Charon. This temperature is nearing absolute zero and puts it colder than Pluto itself since Pluto's temperature is believed to get to minus 400 degrees Fahrenheit which is equivalent to minus 240 degrees Celcius.
What evolution was evident in Darwin's finches?
1. beak type
2. leg muscles
3. wing span
4. eyesight
Answer:
sorry I don't know the answer hope you understand
Models can be used to make predictions .
truth or false ?
Answer:
true
...................
Four different people are using sound wave technology. Which describe the form of technology most likely being used by each person?
Answer:
Its D
Explanation:
Ali is using a specialized headphone that cancels the extra noise in the atmosphere.
Megan is using a transmitter to convert electrical signals into radio waves.
Kristoff is using a microphone to convert sound waves into the electrical signals.
Jenna is using the radio to convert radio waves into sound waves.
Answer:
D. Ali is using specialized headphones, Megan is using a transmitter, Kristoff is using a microphone, and Jenna is using a radio.
Explanation:
Question 4 How many grams of LiOH are needed to make 100 ml of a 0.1 M solution?
Explanation:
0.24 grams of LiOH are needed to make 100 ml of a 0.1 M solution
3. Which of the following is NOT an assumption of the
kinetic-molecular theory?
a. Collisions between gas particles are elastic.
b. All the gas particles in a sample have the samel
velocity
c. A gas particle is not significantly attracted or
repelled by other gas particles.
d. All gases at a given temperature have the same aver-
age kinetic energy.