Answer:
1. 1.72 moles of potassium.
2. All of the answers are true
3. Are used up during a reaction
Explanation:
Recall that the number of moles is obtained from;
Number of moles= Mass of potassium/ molar mass of potassium
Mass of potassium= 67 g
Molar mass of potassium= 39 gmol-1
Number of moles of K= 67 g/ 39 gmol-1
Number of moles = 1.72 moles of potassium.
2. When we look at all the options, we will realize that all the options are true. The rate of reaction doubles for each 10°C rise in temperature, increasing reactant concentration increases particle collision and ultimately increases the rate of reaction. Rate of reaction deals with rate of disappearance of reactants or rate of appearance of products.
3. Catalysts remain unchanged in a chemical reaction because they do not actually participate in the reaction. Hence they are not used up in any chemical reaction.
Potassium atoms contribute one eletron to metallic bonding,but calcium atoms contribute two eletrons .Explain which metal is likely to be harder
Answer:
potassium is likely to be harder
Explanation:
because whenan atom loss electron they can form particle ion acquare stable a arrangement that loos electron can transfer to another which that also to acquaire stable
discharge by the combination of Nitrogen and oxygen
Answer:
NO2
Explanation:
N = Nitrogen
O = Oxygen
Answer:
NO. 2.
is the answer
hopes this helps
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:
scientists often work on projects for a long time and fail to see sources of error in their research. Which process allows an outside expert to look at the scientist’s project and point to sources of error?
Answer:
Replication
Explanation:
In science, the work of a scientist is regarded as authentic if other experts in other places can follow the same steps as he/she claimed to follow and arrive at the same result.
For example, a scientist in California, United States of America may carry out a research and publish his findings. Another scientist in Christchurch New Zealand following exactly the same procedure is expected to arrive at the same results as the original researcher if there were no errors in the work.
However, where there are disparities in results, the scientist in Newzealand may discover errors that were unknown to the original researcher in the united States. The New Zealand scientist was carrying out a process known as 'replication'. That is, repeating a scientific research in order to obtain the same results thereby validating the research.
Why does the structure of the plasma membrane make this type of transport necessary for fluids
Answer: because the phospholipid bilayer formed by these interactions makes a good barrier between the interior and exterior of the cell, because water and other polar or charged substances cannot easily cross the hydrophobic core of the membrane.
Explanation:
Which of these pulls denser rocks towards Earth's center?
1.thermal energy
2.gravity
3.radiation
Answer:
Gravity pulls denser rocks down toward Earth's center. This causes less dense rocks and magma to move upward toward the surface.
Answer:
Gravity boo
Explanation:
How do greenhouse gases such as CO2 and N2O contribute to an increase in Earth’s atmospheric temperature?
A.
Greenhouse gases interact with infrared photons and reflect them back to Earth’s surface.
B.
Greenhouse gases chemically react with one another, releasing heat in the process.
C.
Greenhouse gases agitate visible light photons, increasing the photons’ temperature and motion energy.
D.
Greenhouse gases generate internal heat through radioactive decay, similar to the core of Earth.
Answer:
The answer is A
Explanation:
The earth naturally maintains the heat energy balance by absorbing a sufficient amount of sunlight energy by the terrestrial land and then reverting back the excess sunlight energy back to the space. The increase in abundance of greenhouse gases in the atmosphere results in absorption of sunlight energy which contains infrared photons this is responsible for increasing the global temperature levels hence, responsible for global warming. These infrared photons are reflected to the earth surface instead of sending back to the space. This is responsible for disturbing the heat balance.
Greenhouse gases interact with infrared photons and reflect them back to earth’s surface, hence option A is correct.
How does greenhouse gases rise in earth’s atmosphere?The burning of fossil fuels, logging of forests, and raising of livestock all have a rising impact on the climate and temperature of the planet.
This increases the greenhouse effect and causes global warming by adding a significant amount of greenhouse gases to those that are already present in the atmosphere.
The earth naturally maintains the balance of heat energy by receiving enough solar energy through the terrestrial land and then returning any excess energy to space.
Therefore, greenhouse gases such as CO₂ and N₂O interact with infrared photons and reflect them back to earth’s surface.
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Which group in the periodic table contains the three elements with the highest
electrical conductivities?
OA) Group 8
B) Group 12
C) Group 11
D) Group 7
Answer:
Group 12
Explanation:
Group 12 is also called a transition metal group. This group in the periodic table lies in between the groups or tables. These metals are classified as the transition metal in the table.
These metals are found from the group number 3 to 12. In the periodic table, These transition elements are ductile and malleable. These metal conduct heat and electricity.
These elements are generally called dense and less to react to the alkaline metal. Iron, copper-silver, gold is the most important transition metal.
Answer:
Group 11
Explanation:
Pf
Which statement accurately describes the movement of Earth’s plates due to convection currents?
Answer:
Volcanic eruptions.
a. 24.5 g of ammonia NH3 = how many moles of ammonia?
.b How many molecules of ammonia is that from 22.a.?
rainwater is slightly acidic.why?
Answer:
Rainwater is slightly acidic because...Water reacts with carbon dioxide to form carbonic acid. Due to high carbon dioxide emission in oceans, it explains why sea waters are acidic. Carbonic acid then breaks down into hydrogen ions and hydro carbonates ions. The hydrogen ion raises the water pH and, thus, causes the rainwater to be slightly acidic.
Answer:
Explanation:
rainfall is slightly acidic because of the presence of dissolved carbonic acid. ... The gases of sulfur oxides and nitrogen oxides are chemically converted into sulfuric and nitric acids.
the vessel in which electrolysis takes place is called
PLEASE GUYS ANSWER IT
What is the definition of a scientific theory
A) A method of learning that emphasizes reason as the way to understand the world.
B) A brief statement that summarizes past observations and predicts future ones.
C) A model that explains the underlying reasons for observations and laws.
D) The equivalent of a scientific opinion which others may disagree with.
E) None of these.
Answer:
The correct answer to the following question will be Option C.
Explanation:
The theory seems to be the context within which findings are explained as well as possible predictions are made. This theoretical perspective discusses the factors behind the results as well as the laws.Theories have been used in scientific knowledge to give wide interpretations to accommodate observed facts in case the root reason is still yet to be found as well as characterized.So that Option C will be the right answer.
Why is John Dalton known as the originator of atomic theory?
Answer:
he thought of atoms first
Answer:
He was the first to be the one to propose that matter is made out of atoms. He also proved that the atoms are divisible in nature.
What is the molarity of a solution that contains 2 moles of KCl in 4 L of solution? a 2.0 M b 0.5 M c 0.25 M d 8.0 M
Answer:
A.) 2.0 M
Explanation:
Molarity=mole of solutes/Liters of solution so M=mol/L
2moles/4 L =2 M
65g of nitric acid are produced in a reaction. 2.5g of platinum are added to the reaction vessel at the start of the reaction to act as a catalyst. How much platinum will there be left in the vessel at the end of the reaction?
Answer:
2.5 g of platinum
Explanation:
Recall that a catalyst is a specie added to a reaction system to increase the rate of reaction. A catalyst does not participate in the chemical reaction hence it remains unchanged at the end of the chemical reaction. A catalyst merely provides an alternative reaction pathway by lowering the activation energy of the reaction system. Hence a catalysed reaction usually proceeds faster with less energy requirement than the uncatalysed reaction.
Since the catalyst does not participate in the reactions and remains unchanged at the end of the reaction, the mass of platinum will remain the same (2.5g). The mass can only change if a specie participates in the chemical reaction. Hence the answer.
2.5 g of platinum will there be left in the vessel at the end of the reaction
The following information should be considered:
Since the catalyst does not participate in the reactions and remains the same at the end of the reaction, the mass of platinum will remain the same (2.5g). The mass can only change in the case when a specie participates in the chemical reaction.learn more: https://brainly.com/question/2514933?referrer=searchResults
Level 3- How is tooth decay related to pH?How can it be prevented?
Answer:
A lower pH of the mouth creates bad bacteria that eventually lead to decay of the tooth.
It can be prevented by avoiding food that causes acidity.
Explanation:
Tooth decay is caused by the pH level in the mouth dropping below 5.5, meaning it is acidic. It can be prevented by brushing your teeth as toothpaste is an alkali which will neutralise the pH level in your mouth.
Hope this helps
which of these methods could are used to separate an insoluble solid and soluble solid
Answer:
To separate an insoluble solid from a soluble solid: Mixing the mixture with water, filtering out the insoluble solid, and then evaporating the water to isolate the soluble solid.
Explanation:
Answer:
Mixing the mixture with water, filtering out the insoluble solid, and then evaporating the water to isolate the soluble solid
Napisz równania reakcji chemicznych w formie cząsteczkowej, jonowej i jonowej skróconej. Podkreśl wzory soli trudno rozpuszczalnych i podaj ich nazwy.
palmitynian potasu + chlorek magnezu
zapis cząsteczkowy reakcji...………………..
zapis jonowy...…………………….
zapis jonowy skrócony...……………….
nazwa soli trudno rozpuszczalnej...……………..
oleinian sodu + azotan (V) wapnia
zapis cząsteczkowy reakcji...………………..
zapis jonowy...…………………….
zapis jonowy skrócony...……………….
nazwa soli trudno rozpuszczalnej...……………..
Answer:idioma equivocado ????
Explanation:
Distillation is a _____________ separation technique.
chemical
physical
Answer:
Chemical
Explanation:
Because it's being done by chemical means
what is the best way to make a supersaturated solution?
A. cool the solution
B. Stir the solution
C. Heat the solution
D. Evaporate the solution
C.heat the solution
Which set of phrases best lists the characteristics of asexual reproduction?
one parent, offspring are not identical to the parent
one parent, offspring are identical to the parent
two parents, offspring are not identical to the parents
two parents, offspring are identical to the parents
I need this answer fast ASAP.
Answer:
one parent, offspring are identical to the parent
Explanation:
Answer:
one parent, offspring are identical to the parent
Explanation:
asexual reproduction is a form of reproduction that does not require two gametes to fuse. Asexual reproduction results in offspring that are known as stable clones, meaning that their genetic makeup is stable and doesn't change between generations
Respiration occurs in the __________
Respiration occurs in the mitochondria
Answer:
mitochondria
Explanation:
Respiration happens in the cells of plants, animals and humans, mainly inside mitochondria.
C2H5OH(l)+CH3COOH(l) → CH3COOC2H5(l)+H2O(l) If the yield of ethyl ethanoate obtained when 20.00 g of ethanol is reacted with excess ethanoic acid is 30.27 g, calculate the percentage yield
Answer:
The percentage yield is 79.12%
Explanation:
The first thing we need to calculate here is the theoretical yield of ethyl ethanoate that can be obtained from 20g of ethanol.
Since the mole ratio is 1:1, then this is quite straightforward.
What we need to obtain at first here is the number of theoretical moles of ethanol reacting.
That would be mass of ethanol/molar mass of ethanol
Molar mass of ethanol is 46g/mol
Thus the number of moles is 20/46 = 0.4348 mole
Like it is indicated earlier, since the number of moles are equal from the balanced equation, it also means that 0.4348 mole of ethylethanoate is produced
Now, we need to know the mass of ethyl ethanoate produced
The mass can be calculated by multiplying the number of moles by the molar mass
The molar mass of ethyl ethanoate is 88g/mol
So the mass of it produced = 0.4348 * 88 = 38.2624 or let’s just say 38.26
Thus, the percentage yield will be;
Actual yield/Theoretical yield * 100%
From the question, our actual yield is 30.27g while our calculated theoretical yield is 38.26g
= 30.27/38.26 * 100% = 79.12%
Twenty liters of NO gas react with excess oxygen. How many liters of NO2 gas are produced if the NO gas reacts completely?
Answer:
2O L
Explanation:
The balanced chemical equation is 2NO+O
2
→2NO
2
Thus, 2 moles of NO will produce 2 moles of NO
2
.
Also, the volume is directly proportional to the number of moles.
Therefore, 20 L of NO will produce 20×
2
2
=20 L of NO
2
There are ___________ forces of attraction between particles in the gas state. Use the following word bank to help you.
Answer:
Different
Explanation:
pls help as soon I will give brainlist
Answer:
1) Conditions necessary for rusting are:
a) Presence of atmospheric oxygen or air
b)Presence of water or moisture
2) For protecting the iron gate, we can paint it because the paint will coat it and protect it from atmospheric oxygen and water.
3) Magnesium, Carbon and Oxygen (MgCO₃)
to the
of the substances.
DONE
Answer
what do you mean?
Explanation:
im confused
Answer:
Sorry. I don't understand
Explanation:
The diagram shows Niels Bohr’s model of an atom.
A small green circle labeled Proton is surrounded by 4 concentric circles. The space inside the first concentric circle is labeled N = 1; the space between the first and second circle is labeled N + = 2; between the second and third N = 3, and between the third and fourth N = 4. Oblong gray shapes labeled Electron appear on the second and third concentric circles.
What happens when the electron moves from the first energy level to the second energy level?
Energy is absorbed, and an emission line is produced.
Energy is released, and an emission line is produced.
Energy is absorbed by the atom.
Energy is lost from the atom.
Answer:
Energy is absorbed by the atom.
Explanation:
The lifting force on an airplane's wing does which of the following?
O A. Increases gravity
O B. Increases with speed
O C. Decreases with speed
D. Overcomes drag
The lifting force on an airplane's wing Increases with speed.
What is lifting force?The lifting pressure, lifting force, or virtually lift is the sum of all of the forces on a body that forces it to transport perpendicular to the route of flow.
Drag and Thrust are all “mechanical forces.” A mechanical force is generated through the interplay between an item and a fluid (liquid or gas). Weight is a “field force.” A subject's pressure no longer has to be in physical contact with the item to have an impact on the object.
The lift equation states that carry L is identical to the carry coefficient Cl times the density r times half of the velocity V squared instances the wing region A. For given air conditions, form, and inclination of the item, we have to decide a value for Cl to determine the raise.
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