Answer:
pOH = 3.18
Explanation:
The equilibrium of a weak base as NX3 is:
NX3(aq) + H2O(l) ⇄ HNX3⁺(aq) + OH-(aq)
Where the equilibrium constant, Kb, is:
Kb = 2.5x10⁻⁶ = [HNX3⁺] [OH-] / [NX3]
As both HNX3⁺ and OH- ions comes from the same equilibrium, their concentrations are the same, that is:
[HNX3⁺] = X
[OH-] = X
And: [NX3] = 0.175M:
2.5x10⁻⁶ = [X] [X] / [0.175M]
4.375x10⁻⁷ = X²
X = 6.61x10⁻⁴M = [OH-]
As pOH = -log [OH-]
pOH = 3.18PLZZ HELP!!!!!!! What is PH
What is the pH of an HCl solution if [H+] = 0.03?
A. 0.03
B. 1.5
C. 3.0
D. 3.5
Answer: B
Explanation:
1.5 :D
A liquid-fueled rocket engine has two liquids, usually called the fuel and the oxidizer. Which two liquids are most commonly used for this propellant?
Answer:
A liquid-fueled rocket has two liquids (liquids are good because of the density, they need less space than a gas to be stored), such that these liquids are called the fuel and the oxidizer.
These liquids are injected into a system that leads to a combustion chamber, where the liquids are mixed (we need to mix the fuel with the oxidizer to enable the combustion of the fuel) and burned to produce thrust.
Some common examples of oxidizers are liquid oxygen, which may be combined with fuels like liquid hydrogen, liquid methane, kerosene and hydrazine.
Other oxidizers are liquid fluorine (which also can be combined with the fuels liquid hydrogen and hydrazine), nitrogen tetroxide (which can be combined whit kerosene, hydrazine and other fuels) and FLOX-70, which can only be combined with kerosene.
The "most commonly used" may depend on the country and the type of liquid propellant ( petroleum, cryogens, and hypergols)
Such that the most common oxidizer may be liquid oxygen, and the most common fuel the kerosene.
Give me an example of electrons. in your own words.
Answer:
Electrons are the negative particles that are part of an atom
Explanation:
It’s short sorry
Which describes the titration graph when a strong acid is titrated by a weak base?
It begins at a low pH and has an equivalence point of 7.
It begins at a low pH and has an equivalence point less than 7.
It begins at a high pH and has an equivalence point of 7.
It begins at a high pH and has an equivalence point greater than 7.
Answer:
the answer is b edg 2021
Explanation:
it just is
who discovered electron
Answer: Electricity
Answer:
J.J Thomas in 1897
What is the source of solar energy? electricity . solar panels the sun None of the above
Answer:
The Sun
Explanation:
Solar power is energy from the sun that is converted into thermal or electrical energy.
Answer:
The sun
Explanation:
The sun is the main source of solar energy.
How much 2 M HBr is needed to neutralize 380 mL of 0.1 M NH4OH?
Answer:
19ml
Explanation:
trust me
How many moles are present in 2.45×10²³ molecules of CH4 ? Show your work!!!
The number of moles of CH4 present in 2.45 × 10²³ molecules is 0.41 moles.
How to calculate number of moles?The number of moles of a substance can be calculated by dividing the number of molecules by Avogadro's number.
no. of moles = no of molecules ÷ 6.02 × 10²³
According to this question, 2.45×10²³ molecules of CH4 are given. The number of moles is calculated as follows:
no of moles = 2.45 × 10²³ ÷ 6.02 × 10²³
no of moles = 2.45/6.02
no of moles = 0.41moles
Therefore, the number of moles of CH4 present in 2.45 × 10²³ molecules is 0.41 moles.
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What is the standard cell notation of a galvanic cell made with zinc and gold?
A. Zn2+(aq) | Zn(s) || Au(s) | Au+(aq)
B. Au(s)| Aut(aq) || Zn2+(aq) | Zn(s)
C. Aut (aq)| Au(s) || Zn(s) | Zn2+(aq)
D. Zn(s) | Zn2+ (aq) || Aut(aq) | Au(s)
Answer:
D
Explanation:
is the answer A or B?
Answer:
Letter DHope I helped!♥ ♥ ♥ ♥ ♥ ♥ ♥ ♥ ♥ ♥ ♥ ♥
1. Which is true for any element?
A. Atomic number = number of protons + number of electrons
B. Atomic number = nun number of protons
C. Atomic number = number of protons + number of neutrons
D. Atomic number = nun number of protons, electrons, and neutrons
2 C5H5 + Fe = Fe(C5H5)2
What is the percentage by mass of copper in copper oxide (CuO)?
Answer:
79.89%
Explanation:
Copper has a molar mass of 63.55
Oxygen has a molar mass of 16.00
If you add these you get 79.55
To get the mass percent of copper divide copper by the whole. 63.55/79.55*100= 79.89%
Which best describes global CO2 emissions?
O A. The amount of CO2 released by humans has increased over the
last 200 years.
B. There are no fuels that release CO2 when burned.
C. Humans have reduced the amount of CO2 in the atmosphere.
D. Humans have stopped releasing CO2 into the atmosphere.
Which best describes global cO2 emission
Answer:
The amount of CO2 released by humans has increased over the
last 200 years.
Hope it helps!!!
Answer:
A. The amount of CO2 released by humans has increased over the
last 200 years.
11 The cross section compares the densities of different Earth layers. Which Earth layer is most dense?
Answer:
b
Explanation:
i took the quiz
Given the equation:
Zn + 2HCl → ZnCl2 + H2
How many moles of HCl would be required to
produce a total of 2 moles of H2?
Answer:
4 moles of HCl will be required to produce 2 moles of H2.
Explanation:
A balanced chemical equation gives the stoichiometric ration of moles of reactants required to produce a certain number of moles of products. The ratio of moles of reactants to moles of products is known as the mole ratio and is constant for a given chemical reaction.
In the given balanced equation of reaction shown below:
Zn + 2HCl → ZnCl2 + H2
The mole ratio of HCl and H2 is 2:1. This means that in this reaction between Zinc metal and hydrochoric acid to produc zinc chloride and hydrogen gas, every two moles of hydrochloric acid used in the reaction will result in the production of one mole of hydrogen gas.
Therefore for two moles of H2 to be obtained from the reaction, twice the number of moles of HCl is required.
Moles of HCl required = 2 × 2 moles = 4 moles of HCl.
The Alliance to Save Energy seeks to increase energy efficiency through _______.
a.
petitioning consumers to change their habits
b.
lobbying for policy changes
c.
reducing greenhouse gases
d.
increased spending on consumer goods
Please select the best answer from the choices provided
A
B
C
D
Answer:
B.) Lobbying for policy changes
The Alliance to Save Energy seeks to increase energy efficiency through lobbying for policy changes and the correct option is option B.
What is Alliance to Save energy?The Alliance to Save Energy (ASE) is a nonprofit organization formed by industrial, technological, environmental and consumer leaders. It promotes energy efficiency across the world through research, education and advocacy.
Their mission is to improve energy productivity by:
Leading bipartisan initiatives that drive technological innovation and energy efficiency across all sectors of the economy, through policy advocacy, education, communications, and research.Convening and engaging in diverse public private partnerships, collaborative efforts and strategic alliances to optimize resources and expand our sphere of influence.Therefore, The Alliance to Save Energy seeks to increase energy efficiency through lobbying for policy changes and the correct option is option B.
Learn more about Alliance to Save energy, here:
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_____H2 + _____O2 _____H2O
How many grams of water will you make from 7 moles of H2?
Answer:
126 g of H₂O
Explanation:
Firstly, we complete the equation:
2H₂ + O₂ → 2H₂O
If we have 7 moles of hydrogen, we assume, the oxygen is in excess.
Ratio is 2:2.
2 moles of hydrogen can produce 2 moles of water
Then, 7 moles of H₂ must produce 7 moles of water.
We convert moles to mass → 7 mol . 18 g/mol = 126 g
What is the molecular formula for this molecule? a
Answer:
In a molecular formula, it states the total number of atoms of each element in a molecule.
Explanation:
May someone assist, please...? I don't know how to do chemistry work...
1) How many mL of 5.00M CaSO4 solution must be
diluted with water to prepare 500.0 mL of 0.900M CaSO4?
2) 20.0 mL of a stock solution of NaOH is diluted with water to prepare 150.0mL of 1.50 M NaOH solution.
Calculate the Molarity of the stock NaOH solution?
3) 12.00 mL of 3.50 M NaOH solution is diluted with 88.0 mL of water.
What is the concentration of sodium hydroxide in the diluted solution?
4) 9.0 mL of 8.0 M HCl solution is diluted with water to prepare 0.50 M HCl solution. What is the final volume of this solution?
Answer:
1) 90.0 mL
2) 11.25 M
3) 0.477 M
4) 144 mL
Explanation:
The main formula that will be used for all these calculations is:
C₁V₁ = C₂V₂
C stands for concentration and V stands for volume and the subscripts 1 and 2 indicate an initial concentration or volume and a final concentration or volume.
For each problem, it's best to start by figuring out what you have and what you need to find. Figure out if you're looking for an initial value or a final value.
1) We need to find the initial volume. So, take what values you have and plug them in and then solve for whatever variable:
5.00 M · V₁ = 500.0mL · 0.900 M - divide by 5.00
C₁ = 90.0 mL
2) This time we're finding the initial concentration:
20.0mL · C₁ = 150.0mL · 1.50 M - divide by 20.0mL
C₂ = 11.25 M
3) Now we're finding the final concentration:
12.00mL · 3.50 M = 88.0mL · C₂ - divide by 88.0mL
C₂ = 0.477 M
4) Finally, we're looking for the final volume:
9.0mL · 8.0 M = 0.50 M · V₂ - divide by 0.50 M
V₂ = 144mL
Which of the following is not a reason for extinction?
a change in climate
a change in predation rate
the ability to breed successfully
loss of habitat
Answer:
the ability to breed successfully
Explanation:
Answer:
the ability to breed successfully
Explanation:
the more offspring's an organism has, the less chance of extinction would happen. I hope that helped bestie
Will give brainliest please help!!
Answer:
D. The energy level of the electron.
Explanation:
There are four quantum numbers which are used to describe the movement and paths or positon of each electron within an atom. Quantum numbers can be used to determine the electronic configuration of atoms and the most likely location of the atom's electrons. Quantum numbers are also used in determining other characteristics of atoms, such as ionization energy and the atomic radius.
The four quantum numbers are namely, principal, azimuthal, magnetic and spin quantum numbers.
Principal quantum numbers are denoted by the symbol ‘n’. They describe the principal electron shell or energy level the atom.The value of the principal quantum number are positive integer values that is equal to or greater than one. The value n = 1 represents the innermost electron shell of an atom, which corresponds to the lowest energy state of an electron. The larger the values of 'n' the greater the energy level and the farther the electron is from the nucleus.
This tool is used to measure
Answer:
C. volume
Explanation:
What is reproduction?
What relates moles of 1 substance to another in a chemical reaction?
Answer:
Chemical reactions list reactants and products in molar amounts, not just molecular amounts. We can use the coefficients of a balanced chemical equation to relate moles of one substance in the reaction to moles of other substances
Explanation:
Which of the following effect increases the solubility of Ca(OH)2?
O Adding an acidic solution
O Adding KOH
O Adding solid CaCl,
O Adding solid NaOH
O Adding CaCO3
Answer:
adding an acidic solution
Explanation:
Strong acids dissociate completely in water and the H⁺ ions react with the OH⁻ ions to make H₂O. If we add an acid to our solution of Ca(OH)₂, the acid protons would react with some of the OH⁻ ions and drive the equilibrium to the right. More of the solid Ca(OH)₂ should dissolve.
Competition is rivalry between individuals for a particular resource.
Question 1 options:
True
False
Answer:
True
Explanation:
Competition is the act of competing with one another for a particular resource. An example is two animals quarrelling over a food or two people quarreling over who lost their money. Competing is a type of rivalry in which two people compete for one resource. The answer for this question is True.
The answer is TRUE. Competition is rivalry between individuals for a particular resource
Competition amongst individuals?
Competition can be described as an interaction between two individuals in which they both fight for the available resources in the environment.
For example, when there is limited source of food and water in an environment, the individuals or organisms present will struggle to take the available food in order to survive while those individuals that were unable to get this resource might end up dead as the available food is limited.
This also occurs in plants and they also compete for sunlight, food, water.
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Which model shows a way that large molecules can enter a cell without using the cell's energy? Outside the cell O A Cell membrane Vacuole 1 2 Inside the cell В.
Answer:
its B
Explanation:
I took the test and its that passage way thing. (tell me if this works for you! it will but just wanna make sure!)
I need help with this question!!
Answer:
Fossil fuels..........
Mary is standing on a train moving east at 10 km per hour. Alicia is sitting on a train that passes in the opposite direction at 30 km per hour. From Mary's point of view, how fast is Alicia moving?
Help