Answer:
[OH] = 6.31 * 10^-7 M
Explanation:
Mathematically;
pH + pOH = 14
Mathematically;
pH = -log [H3O+]
also;
pOH = -log [OH]
From the question; [H3O+] = 1.75 * 10^-8 M
pH = -log [1.75 * 10^-8]
pH = 7.76
since pH is normally given to 1 decimal place
we can say pH = 7.8
Now;
pH + pOH = 14
pOH = 14-7.8
pOH = 6.2
now pOH = -log [OH]
[OH] = -antilog 6.2
[OH] = 6.31 * 10^-7 M
Calcium carbonate, when heated, forms calcium oxide and carbon dioxide. 100grams of calcium carbonate will produce 56grams of calcium oxide. How many grams of carbon dioxide will it produce? Show working out
Answer:
It will produce 44 grams of carbon dioxide
Explanation:
Step 1: Data given
MAss of CaCO3 = 100 grams
Molar mass of CaCO3 = 100.09 g/mol
Mass of CaO produced = 56 grams
Molar mass of CaO = 56.08 g/mol
Step 2: The balanced equation
CaCO3 → CaO + CO2
Step 3: Calculate moles CaCO3
Moles CaCO3 = mass CaCO3 / molar mass CaCO3
Moles CaCO3 = 100 grams / 100.09 g/mol
Moles CaCO3 = 1.00 moles
Step 4: Calculate moles CaO
Moles CaO = 56 grams / 56.08 g/mol
Moles CaO = 1.00 moles
Step 5: Calculate moles CO2
For 1 mol CaCO3 we'll have 1 mol 1 mol CaO and 1 mol CO2
Step 6: Calculate mass CO2
Mass CO2 = moles CO2 * molar mass CO2
Mass CO2 = 1.00 moles * 44.0 g/mol
Mass CO2 = 44 grams
It will produce 44 grams of carbon dioxide
How does the mass and height of an object affect the gravitational potential energy?
Answer: The higher up an object an is the greater it’s gravitational potential energy. This is because a tree has more mass, so it needs to be given more gravitational potential energy to reach the same height. So a change in gravitational potential energy also depends on the mass of the object that is changing height
Explanation:
The gravitational potential energy (P.E) depends on the mass of the body and the height at which it travels, the two quantities will therefore dictate the work done on the object which is eventually the same as magnitude of the gravitational potential energy P.E.
It is assumed that gravitational pull acts toward the earth surface. The more the object move upward the more the work is done on the object to pull it down.
This work done is equal to the gravitational potential energy P.E which can be expressed as:
P.E = mgh
Where
m = mass of the body
g = gravitational field strength
h = height
We can have different masses of object at different heights, but gravitational field strength will always remain constant on earth.
Since the gravitational potential energy P.E depend on the mass of the body and the height at which it travels, the two quantities will therefore dictate the work done on the object which is eventually the same as magnitude of the gravitational potential energy P.E.
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If the temperature outside increases, but the amount of water vapor stays the same, what happens to the relative humidity? (50 points, please explain)
If the water vapor content remains the same and the temperature decreases, the relative humidity rises.
If the water vapor content remains the same and the temperature increases, the relative humidity falls.
This is because colder air doesn’t need as much moisture to become saturated as warmer air.
Hope this helps
Calculate the percent ionic, the percent covalent, and the bond length (in picometers) of a chemical bond between phosphorus and selenium.
Phosphorus—atomic radius: 109 pm; covalent radius: 106 pm; ionic radius: 212 pm.
Selenium—atomic radius: 122 pm; covalent radius: 116 pm; ionic radius: 198 pm.
98 percent ionic, 2 percent covalent, 410 pm
4 percent ionic, 96 percent covalent, 222 pm
2 percent ionic, 98 percent covalent, 222 pm
96 percent ionic, 4 percent covalent, 410 pm
Answer:
The correct option is;
4 percent ionic, 96 percent covalent, 222 pm
Explanation:
The parameters given are;
Phosphorus:
Atomic radius = 109 pm
Covalent radius = 106 pm
Ionic radius = 212 pm
Electronegativity of phosphorus = 2.19
Selenium:
Atomic radius = 122 pm
Covalent radius = 116 pm
Ionic radius = 198 pm
Electronegativity of selenium= 2.55
The percentage ionic character of the chemical bond between phosphorus and selenium is given by the relation;
Using Pauling's alternative electronegativity difference method, we have;
[tex]\% \, Ionic \ Character = \left [18\times (\bigtriangleup E.N.)^{1.4} \right ] \%[/tex]
Where:
Δ E.N. = Change in electronegativity = 2.55 - 2.19 = 0.36
Therefore;
[tex]\% \, Ionic \ Character = \left [18\times (0.36)^{1.4} \right ] \% = 4.3 \%[/tex]
Hence the percentage ionic character = 4.3% ≈ 4%
the percentage covalent character = (100 - 4.3)% = 95.7% ≈ 96%
The bond length for the covalent bond is found adding the covalent radii of both atoms as follows;
The bond length for the covalent bond = 106 pm + 116 pm = 222 pm.
The correct option is therefore, 4 percent ionic, 96 percent covalent, 222 pm.
Pls help me with this will mark brainliest
Answer:
Pulmonary circulation moves blood between the heart and the lungs. The oxygenated blood then flows back to the heart. Systemic circulation moves blood between the heart and the rest of the body. It sends oxygenated blood out to cells and returns deoxygenated blood to the heart
Explanation:
Which elements are diatomic?
Answer:The elements hydrogen, nitrogen, oxygen, fluorine, chlorine, bromine and iodine are diatomic elements
Definition of diatomic elements:Diatomic elements are special as the atoms that form it do not like to be alone. That is, you will never find a nitrogen or fluorine atom, for example, hanging out solo. Rather, these atoms will always be paired together because they need to pool resources to have enough electrons.
Answer:
H2, O2, N2, F2, Cl2, Br2, I2
Explanation:
These occur naturally has molecules of 2 atoms.
They are all gases except Br2, liquid and iodine which is solid.
What is a chemical solution and what are the names of its components?
Answer:
A chemical solution is defined as a homogeneous mixture of two or more substances. There are two components of chemical solution that include solute and solvent.
Solute is the component that get dissolved in another substance and solvent is the substance that dissolve solute.
For example: carbon dioxide in water. Where carbon-dioxide is solute and water is solvent.
A compound contains 34.5% calcium, 24.1% silicon and 41.4% oxygen by mass. What is its empirical formula?
[tex]empirical \: formula \\ = CaSiO3 \\ please \: see \: the \: attached \: picture \\ hope \: it \: helps[/tex]
Please can someone help I will mark brainiest!
Answer:
2Cl- ⇒ Cl ↓2+ 2e
Explanation: sorry if this is not what you were looking for.
Explain contribution of Mendleev for arrangement of elements in his periodic table
Answer:
Mendeleev arranged the elements in order of increasing relative atomic mass. When he did this he noted that the chemical properties of the elements and their compounds showed a periodic trend. He then arranged the elements by putting those with similar properties below each other into groups.
-- He left gaps for yet to be discovered elements
-- He switched the order of a few elements to keep the groups consistent
-- He was the first scientist to give the periodic law.
Which is the electron configuration for bromine?
Answer:
first answer
Explanation:
atomic number of bromine is 35
[tex]1{s}^{2} 2 {s}^{2} 2 {p}^{6} 3 {s}^{2} 3 {p}^{6} 3 {d}^{10} 4 {s}^{2} 4 {p}^{5} [/tex]
Answer:
1s22s22p63s23p64s23d104p5
Explanation:
;)
Where do you find the molar mass of an element
Answer:
Mass of a given chemical element or compound divided by the amount of substance.
(g/mol)
The pressure inside of a sealed tube if you raise the temperature go ______..
Answer:
The pressure will increase due ot expnasion of gasses in a closed sealed tube tube .
Explanation:
Answer:
The pressure inside of a sealed tube will increase if the temperature is raised.
Explanation:
When the temperature of the gas inside the sealed tube is raised, the particles within that tube will start to become faster and faster. Because they are going faster they collide with the sides of the tube faster, therefore increasing the pressure inside the sealed tube.
Hope this helps!
The name given to the substance formed when a liquid is miscible in another liquid.
Answer:
Solute
Explanation:
The diagram shows the setup of an experiment. The observations of the experiment are listed in the table below the diagram. A beaker filled three-fourths with a liquid labeled colorless silver nitrate solution is shown. A small strip is shown inside the beaker. The strip is labeled copper strip. The title of the image is Experimental Setup. Experimental Observations Observation Description 1 Copper strip became thinner 2 Gray particles were deposited on the edge of the strip Which of the following is the correct explanation for one of the given observations? (4 points) Observation 2 is a result of nitrate ions moving into the solution. Observation 2 is a result of silver ions moving into the solution. Observation 1 is a result of copper atoms losing two electrons. Observation 1 is a result of silver atoms losing one electron.
Answer:
The answer is Observation 1 is a result of copper atoms losing two electrons.
Explanation:
The electrons result in the color change of the copper strip, causing the gray particles to join onto the metal.
Answer:
C
Explanation:
Observation 1 is a result of the copper atoms losing two electrons. It came out as the right answer.
9.0 L of a gas at 25 oC expands to a volume of 25.0 L. What is the resulting temperature in Kelvin?
Answer:
Explanation:
H
How marly electrons are in an atom of elemental
sodium?
Answer: 11 Electrons
Explanation:
We know that the atomic number of sodium is 11. This tells us that sodium has 11 protons and because it is neutral it has 11 electrons.
Answer:
The sodium atom is left with a full outermost electron shell with eight electrons, and the outermost shell of the other atom is full as well.
Explanation:
The sodium atom now has a positive electrical charge of plus 1, and the other atom has a negative charge of minus 1. The two opposite charges attract, and the two atoms now form the molecule of a compound.
During a reaction, the enthalpy of the reactants and the products are not equal. What does this result in?
A. None of these
B. Absorption or release of energy
C. Change in chemical composition
D. Spin of electrons is reversed
The spin of electrons is reversed. Hence, option D is correct.
What is enthalpy?Enthalpy is the sum of the internal energy. and pressure times volume.
During a reaction, the enthalpy of the reactants and the products are not equal which means the spin of electrons is reversed.
Hence, option D is correct.
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Please answer number 5 ASAP
Answer: Hello mister i dont now your question
Explanation:
this is a multiple choice question. one of the answer from the option given is correct.Could you please help!!My sister needs help but she doesn't trust me '_' why am i even saying this, no one asked
6.What are the main
sources of water pollution?
a) Plastic, paper, metal
b) Snail in water
c) Agriculture, industry and community
C.
i cant explain why..................
What type of mixture is fog?
O A. A homogenous mixture of a solid in a gas
B. A heterogeneous mixture of a liquid in a gas
C. A homogenous mixture of a liquid in a gas
D. A heterogeneous mixture of a solid in a gas
Answer:
. A homogeneous mixture of a solid in a gas
The forces between water molecules are stronger
than the forces between ethanol molecules. Which
liquid would probably be most difficult for an insect
to walk on? Explain your answer.
Answer:
An insect would have an easier time walking on the surface of water than on the surface of ethanol.
Water's stronger intermolecular forces lead to higher surface tension.
Higher surface tension allows water to support the insect.
Answer:
An insect would have an easier time walking on the surface of water than on the surface of ethanol.
Water's stronger intermolecular forces lead to higher surface tension.
Higher surface tension allows water to support the insect.
Explanation:
The part of the atom involved in chemical bonding is the what
Why you cannot add 0.3 moles of calcium fluoride directly to 1L of water to make a 0.3 M
solution ?
need help ASAP!
Answer:
Because it's not soluble in water, need to be heated acidic solution
Explanation:
Calcium Fluoride Formula: CaF2 Comprises of Ca2+ and F−
H2O = Water H+ O2- OH-
Insoluble in water
In order to dissolve a salt, you have to break apart the ions and hydrate them via a solvent.
Need to read
HSAB concept( Pearson acid-base concept) is an initialism for "hard and soft (Lewis) acids and bases"
So F- is a Halogen which is a Hard Base
And OH- is a Hard base as well
And H- is a soft base
So soft acids react best with soft bases and hard acids react best with hard bases.
Bases don't react with other bases.
An elements mass number is made up of the number of ____ in the nucleus.
protons and neutrons
electrons and neutrons
protons and electrons
atoms and molecules
Answer:
The answer is protons and nuetrons
Explanation:
a student balanced the chemical equation for the reaction of magnesium with oxygen by writing Mg + O2 ----> MgO2. What is wrong with this equation?
Answer:
Explanation:
Magnesium when it oxidizes has a valence of 2.
Oxygen, when it mixes with something, has a valence of - 2
So Mg and O2 will form something, but what? The answer is MgO
Mg + O2 ===> MgO
To balance this equation, you need 2 Magnesiums on the right and 2 Oxygens also on the right. The left will need a two Magnesiums.
The balanced equation will be
2Mg + O2 ====> 2MgO
How will you test for the gas which is liberated when hcl reacts with an active metal ?
What would heating a sealed glass jar do?
O A. Increase the size of the gas molecules
B. Increase the number of gas molecules
C. Increase the pressure of the gas inside
D. Increase the volume of the gas inside
The right response is to raise the internal gas pressure. When a sealed glass jar is heated, the temperature of the gas within rises, causing the gas molecules to travel faster and collide with the jar's walls more often and with more force, increasing the gas's pressure.
What is gas molecule?Gas molecules are made up of atoms that are linked together. These interatomic connections function similarly to springs, connecting atoms of varying masses. This connection vibrates at a constant frequency known as the natural frequency. Atoms, molecules, and/or ions are all present in gases, liquids, and solids, but their behavior varies between the three phases. The graphic below depicts the tiny differences. A gas as seen via a microscope. A gas is a condition of stuff that does not have a set volume or form. Air, water vapor, and helium are examples of gases. A gas is a kind of stuff that does not have a defined volume or shape. To put it another way, a gas takes on the shape and volume of its container.
Here,
The correct answer is Increase the internal gas pressure as When a sealed glass jar is heated, the temperature of the gas within rises, forcing the gas molecules to travel faster and hit with the jar's walls more often and with more force, raising the gas's pressure.
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The pictures to the right, show two different models
of the atom. Type in the letter of your answer.
Which model best represents Dalton's atomic
theory?
Answer:
The pictures to the right, show two different models of the atom. Type in the letter of your answer.
Which model best represents Dalton’s atomic theory?
B
Which model best represents the modifications to the theory that Thomson’s results made necessary?
A
The model that represents Dalton's atomic model is the B model.
Dalton's Atomic TheoryDalton was a scientist who described how the atom is characterized, stating that the atom would be a massive and indestructible sphere, that is, it was not divided into subparticles (electrons, protons and neutrons).
Thus, model B is the most suitable according to Dalton's statements.
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S
Perform the following operation
and express the answer in
scientific notation.
1.248x10-2 : 7.8x10-7
[? ]x10
Answer: [tex]1.6\times 10^4[/tex]
Explanation:
Scientific notation is defined as the representation of expressing the numbers that are too big or too small and are represented in the decimal form with one digit before the decimal point times 10 raise to the power.
For example : 5000 is written as [tex]5.0\times 10^3[/tex]
In division , the result would contain the same number of significant digits as there in the least precise number , thus the answer would have 2 significant digits.
[tex]\frac{1.248\times 10^{-2}}{7.8\times 10^{-7}}=1.6\times 10^4[/tex]