Write the electron configuration for Br, with 35 protons and 35 electrons.
Answer:
2 8 8 8 8 1
Explanation:
Hydrofluoric acid (HF) can be prepared according to the following equation:
CaF2 + H2SO4 2 HF + CaSO4.
How many grams of HF can be prepared from 75.0 g of H2SO4 and 63.0 g of CaF2?
In the above problem, which reactant is limiting and which is in excess?
Given the balanced equation:
( Reaction type : double replacement)
CaF2 + H2SO4 → CaSO4 + 2HFI
We can determine the number of grams prepared from the quantity of 75.0 H2SO4, and 63.0g of CaF2 by converting these grams to moles per substance.
This can be done by evaluating the atomic mass of each element of the substance, and totaling it to find the molecular mass.
For H2SO4 or hydrogen sulfate it's molecular mass is the sum of the quantity of atomic mass per element. H×2 + S×1 + O×4 = ≈1.01×2 + ≈32.06×1 + ≈16×4 = 2.02 + 32.06 + 64 = 98.08 u (Dalton's or Da) or g / mol.
For CaF2 or calcium fluoride, it's molecular mass adds 1 atomic mass of calcium and 2 atomic masses of fluoride due to the number of atoms.
Ca×1 + F×2 = ≈40.07×1 + ≈19×2 = 40.08 + 38 = 78.07 u (Da or Dalton's) or g / mol.
The limiting reactant in the given balanced reaction is sulphuric acid. The mass of HF produced from 75 g of H₂SO₄ is 30 g.
What is limiting reactant?The limiting reactant in a species is the reactant which is fewer in amount and thus determine the yield of the product.
In the given reaction, one mole of calcium fluoride reacts with one mole of sulphuric acid to give two moles of HF. The molar mass of calcium fluoride CaF₂ is 78 g/mol the weight taken here is 63 g. Thus number of moles is 63/78 = 0.87 moles.
The molar mass of sulphuric acid H₂SO₄ is 100g/mol. The weight taken here is 75 g and thus, number of moles is 75/100 = 0.75 moles. One mole of calcium fluoride need one mole of H₂SO₄ . Thus 0.87 neede 0.87 moles of H₂SO₄ . But here we have only 0.75. Thus it is the limiting reactant.
As per the reaction, one mole or 100 g of H₂SO₄ produce 2 moles or 40 g of HF (molar mass = 20 g/mol). Thus mass of HF produced from 75 g is calculated as follows:
mass of HF = (75 × 40)/100
= 30 g.
Hence, mass of HF produced in this reaction is 30 g.
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If 8.2 g of sodium ethanoate produced 560 cm3 of methane (at s.t.p.). which one of the following is the percentage yield of the reaction;
A 2.5
B 4.0
C 12.0
D 25.0
The percentage yield of the reaction : 25%
Further explanationC₂H₃NaO₂(CH₃COONa)- Sodium ethanoate(MW=82,0343 g/mol)
Reaction
CH₃COONa + NaOH⇒CH₄+Na₂CO₃
mol CH₃COONa :
[tex]\tt \dfrac{8.2}{82.0343}=0.1[/tex]
mol CH₄=mol CH₃COONa = 0.1
mass CH₄ (MW=16.04 g/mol) :
[tex]\tt 0.1\times 16.04=1.604~g[/tex]⇒ theoretical
mol of 560 cm³(0.56 L) of methane (⇒1 mol = 22.4 L at STP) :
[tex]\tt \dfrac{0.56}{22.4}=0.025~mol[/tex]
mass CH₄ :
[tex]\tt 0.025\times 16.04=0.401~g[/tex]
[tex]\tt \%yield=\dfrac{0.401}{1.604}\times 100\%=25\%[/tex]
5) If an atom has a positive charge what is it called?
Answer:
An atom that has a negative or positive charge it is called an ion.
Answer:
It''s called a Cation
Explanation:
What is the electron configuration for boron (B)?
Answer:
[He]2s2 2p1.
that is the answer have an amazing day. Remember your an amazing person for who you are.
When a liquid freezes into a solid, the particles of the substances *
lose energy
gain energy
move faster
disappear
Answer:
Lose energy
Explanation:
The molecules are moving from a liquid (molecules slide past one another) to a solid (molecules barely move) so are losing energy
A mixture of the gases neon and krypton is in a 2.00 L container with a pressure of 1.60 atm. The partial pressure of the neon is 0.40 atm. What is the partial pressure of the krypton?
Answer:
P(Kr) = 1.2 atm
Explanation:
According to Dalton law of partial pressure,
The total pressure inside container is equal to the sum of partial pressures of individual gases present in container.
Mathematical expression:
P(total) = P₁ + P₂ + P₃+ ............+Pₙ
Now we will solve this problem by using this law
Total pressure = 1.60 atm
Partial pressure of neon = 0.40 atm
Partial pressure of krypton = ?
Solution:
P(total) = P(Ne)+ P(Kr)
1.60 atm = 0.40 atm +P(Kr)
P(Kr) = 1.60 atm - 0.40 atm
P(Kr) = 1.2 atm
The partial pressure of Krypton in the mixture has been 1.2 atm.
Partial pressure can be defined as the pressure exerted by a single gas in the solution.
According to Dalton’s law of partial pressure, the total pressure of the gas has been the summation of the partial pressure of each gas present in the mixture.
Total pressure = Partial pressure of A + Partial pressure of B + Partial pressure of C……
The given mixture has been consisted of neon and krypton. The total pressure of the mixture has been:
Total pressure = Partial pressure of Ne + Partial pressure of Kr
The total pressure = 1.60 atm.
The partial pressure of Ne = 0.40 atm.
Substituting the values:
1.60 atm = 0.40 atm + Partial pressure of Kr
Partial pressure of Kr = 1.60 - 0.40 atm
Partial pressure of Kr = 1.2 atm.
The partial pressure of Krypton in the mixture has been 1.2 atm.
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Susana heats up a sample of red crystals. While the sample is being heated,a gas is released and a blue powder is left after heating. Is the sample of red crystals an element or compound?
Answer & Explanation:
Susana's red crystal sample is a compound because it was broken down into a gas and blue powder. It is not an element because elements cannot be broken down into simpler substances by ordinary means, such as heating.
Answer:
Susana's red crystal sample is a compound because it was broken down into a gas and blue powder. It is not an element because elements cannot be broken down into simpler substances by ordinary means, such as heating.
Explanation
Sample response form Edg
An experiment was conducted to determine the density of a rock sample. The table shows a partial record of the experiment.
Experimental Record
Mass of Rock
86.59
Volume of Water in the Graduated Cylinder 142.5 mL
?
What information should be recorded in the last row of the table?
Answer: the density of the rock
55.91g/ml
Explanation:
The density of the rock after it had being placed in the cylinder of water so the calculation should look like this:
Volume of water substract the mass of the rock:
And that is 142.5 ml - 86.59g =
Answer 55.91 g/ml
So the density of the rock is 55.91g/ml
plz help with this.....☺
Answer:
There is this property called CATENATION which is basically the tendency of the atoms to bind to eachother. It is the MOST in the carbon after that silicon.
So the answer should Carbon atoms bond together to form groups of compounds.
Which of the changes below would make Paul an effective interpersonal communicator?
I. Change his opening to a more calm and positive approach.
II. In his feedforward he should establish an appropriate timeframe and location.
III. He should add more criticism in his feedback.
IV. In the business section of his conversation he should include a list of everything Pat has
ever done wrong.
Answer:
i would say number 3 that was number 3
By changing his opening to a more calm and positive approach pauld can become a an effective interpersonal communicator.Thus, option A is correct.
What is interpersonal communication?Interpersonal communication is the way of communicating messages with each other. From person to person the way or tone of interpersonal communication will change.
We have to keep a good and polite behaviour to everyone when communicating with them. If we are going to criticize more it will hurt some people more than we expect.
To approach in a positive manner, we have to avoid prejudices and predictions and more expectation about others. But keep them in a polite manner in a very genuine friendship.
Interpersonal communication is important in any field especially in business field where, people have to gather , plan and contribute with each other. Hence Paul have to open more calm and positive approach.
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What volume do 4.96 moles of O2 occupy at STP?
Answer: Step 1: List the known quantities and plan the problem. Known. 4.96 moles O2; 1 mol = 22.4
Explanation: I hope that helped.
What happens in a double-replacement reaction?
A. An element replaces an element in another compound.
B. Two reactants combine to form one compound.
C. One compound separates into two or more products.
O D. The elements in two compounds switch places
Answer: D
Explanation: trust
Answer:
Explanation:
D
Which statement best describes scientific laws? A) Scientific laws are scientists' opinions of why events occur. B) Scientific laws are facts that describe observed reoccurring natural events. C)Scientific laws explain why natural events occur. D) Scientific laws were theories that have been proven to be true.
Answer:
Option B and D seem to be correct
Explanation:
As a scientific law is a statement which is bases on repeated experimental observations that describes some aspects of nature and also they are were theories that have been proven to be true as a theory become a law when the experiment agree with the theory and no contrary opinions so according to my studies , B and D options are seems to be correct.
The box in the above picture is falling from the top of a building to the ground. Two major forces are acting on the box as it falls. Which force is represented by the arrow labeled Q?
A.
the force of magnetism
B.
the force of gravity
C.
the net force of the object
D.
the force of air resistance
Answer:
I think it's B
Explanation:
apologies if I get this wrong
Answer:
The correct answer is B. The force of gravity.
Explanation:
Gravity affects all objects falling through the Earth's atmosphere. Gravity pulls down on a falling object.
( I got it on study Island as well )
In sexual reproduction, how many genes does an offspring receive for each trait ♀️
Answer:
Each parent's half of the genes acquired by the offspring. They have two of each chromosome and hence two alleles of each gene, and one acquired from each parent.
What two uses are used for oxygen?
Answer:
I think your lumgs and your heart but I could be tottaly wrong
which element in the alkali group will have the lowest first ionization energy?
Fluorine
Explanation:
F- has the lowest ionisation energy
first to answer correctly gets brainleist
Which of the following notations is the correct noble gas configuration for Li
Noble gas configuration for Li : [He]2s¹
Further explanationIn an atom, there are levels of energy in the shell and sub-shell
This energy level is expressed in the form of electron configurations.
Lithium with atomic number 3, then the electron configuration:
1s²2s¹
And for noble gas configuration or it can be called Condensed electron configurations :
[He]2s¹
Answer:
[He]2s¹
Explanation:
why is the moisture of cirrus clouds mostly in the solid state
Answer:
Wind is the horizontal movement of air, transporting energy transferred from the earth's surface as sensible and latent heat. Sensible heat is transferred by the processes of conduction and convection. Conduction transfers energy within a substance, and convection transfers energy through the vertical movement of the heated substance. Latent heat is the transfer of energy by transforming the substance itself. As you recall, water has the ability to exist as liquid, gas or solid. The transformation from liquid to gas is called evaporation; the reverse process, from gas to liquid, is called condensation; from liquid to solid is known as solidification (freezing); and from solid to liquid, fusion (melting). Water can also be transformed directly from solid to gas (sublimation), or the reverse, through a process called deposition. We will see these various processes in the formation of clouds.
Explanation:
if I did not give answer then i hope i at least helped!
Calculate the frequency of a wave that is 4.3 x 10^-11 m the speed of light 5 points
is 3x10^8 m/s *
1 Add file
PLEASE HELP
Why do clothes stick together when coming out of a dryer? And do the clothes start off as neutral?
here is what came up when i searched it up:
"The attraction between protons and electrons can also make clothes stick together in the dryer. When you dry clothes in the dryer, different fabrics rub together, and electrons from a cotton sock (for instance) may rub off onto a polyester shirt."
Sometimes, clothes can get stuck together after they come out of a dryer because of static electricity.
No, clothes may not start off as neutral. Whether clothes have static charges before going into the dryer depends on different things.
Why do clothes stick together when coming out of a dryer?Static electricity happens when certain things touch and create an uneven amount of electrons. This can cause one material to have a positive charge and the other to have a negative charge. When clothes move and touch each other in a dryer, this rubbing can cause static electricity.
If the clothes are cleaned and dried correctly, they should have no charge or be evenly charged.
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calculate the number of neutrons in potassium-40.
Considering the definiton of atomic number and atomic mass, the number of neutrons of the potassium is 21.
All atoms are composed of a central nucleus in which there are particles with a positive electric charge, the protons, and a neutral charge, the neutrons, around which other particles with a negative electric charge, which are electrons, move.
Atoms of different elements have different amounts of protons. The atomic number (which is identified by the letter Z) indicates the amount of protons that is present in the nucleus of an atom. This number is then responsible for defining the electronic configuration of the atom and the chemical properties of the element.
On the other side, the atomic mass (A) is defined as the sum of number of protons and number of neutrons:
Atomic mass = Number of protons + Number of neutrons
In this case, the potassium (K) elements has atomic number 19. That means, the number of of protons is equal to 19. And the atomic mass is 40. So, the number of neutrons is calculated as:
40= 19 + Number of neutrons
Solving:
Number of neutrons= 40 - 19
Number of neutrons= 21
Hence, the number of neutrons of the potassium is 21.
Learn more:
https://brainly.com/question/5527493?referrer=searchResultsbrainly.com/question/11837355?referrer=searchResults brainly.com/question/1758023Liquid Nitrogen’s temperature is minus what degress
Answer:
-320f
Explanation:
another term sometimes used for the celsius scale
Answer:
Explanation:
Centigrade
The radioactivity of U-235 is of low intensity. Why then were the people of Hiroshima exposed to high intensity radiation in the days and months after the atomic bomb was dropped?
Answer:
Explanation:
What occurred then is as a result of nuclear fission. This occurs as the Uranium-235 split into two smaller nuclei while releasing high energy neutrons. These neutrons bombard existing U-235 in the atmosphere and this reaction continue in a spontaneous manner until a chain reaction is formed of U-235, whose fall out fills the environment. This process was what led to people been exposed to high intensity radiation in the days and months after the atomic bomb was dropped.
A sector of a circle has an area of 132m². if the angle of the sector is 105,°,calculate the radius of the circle
please help fast
I WILL MARK YOU AS BRAINLIEST
Answer:
c
Explanation:
all the atoms must be balanced.
A bulldozer does 15,000 J of work lifting dirt 15 m up to get it out of a hole. How much force did the bulldozer use to accomplish this task?
Answer:
The answer is 3000 NExplanation:
The amount of force can be found by using the formula
[tex]f = \frac{w}{d} \\ [/tex]
w is the workdone
d is the distance
From the question we have
[tex]f = \frac{15000}{5} \\ [/tex]
We have the final answer as
3000 NHope this helps you