Answer:
0.64 molesExplanation:
To find the number of moles in a substance given it's number of entities we use the formula
[tex]n = \frac{N}{L} [/tex]
where n is the number of moles
N is the number of entities
L is the Avogadro's constant which is
6.02 × 10²³ entities
From the question we have
[tex]n = \frac{3.86 \times {10}^{23} }{6.02 \times {10}^{23} } = \frac{3.86}{6.02} \\ = 0.641196...[/tex]
We have the final answer as
0.64 molesHope this helps you
On the line provided, write the formula for the compound made by each of the following. (3 pts each) 20. Mgand NO3-1, 21. CIO3-1 and K 22. Ca and So4-2, 23. NH4+1 and SO4-2, 24. C2H30-1, ' and H 25. Hand CO, t
Answer:
20. Mg(NO3)2
21. KClO3
22. CaSO4
23. (NH4)2SO4
24. HC2H3O
25. CO is carbon dioxide, which is neutral and would not combine with a hydrogen ion. Did you mean H and CO3(2-)? That would be H2CO3 (carbonic acid)
Explanation:
You have to match the charges of the Cations and Anions.
which of the following are the correct formulas for potassium oxide and calcium oxide respectively
Explanation:
potassium oxide is K2O
calcium oxide is CaO
calcium oxide is used to make glass
potassium oxide is used in fertilizer
Where do living organisms obtain energy for cell processes?
A. When bonds form during cell processes, energy is absorbed.
B. When bonds form during cell processes, energy is released.
C. When bonds in food are broken, energy is released.
Answer:
(C) when bonds in food are broken, energy is released
The symbol for free energy is
a. DG.
b. DS.
c. DT.
d. DH.
Calculate the mass percent of hydrogen in 70 g of C4H8O3?
Answer:
7.14%
Explanation:
From the question,
percentage by mass hydrogen in C₄H₈O₃ (h) = mass of hydrogen present in C₄H₈O₃(m)/molar mass of C₄H₈O₃ (m')
h = (m'/m)×100..................... Equation 1
Given: m' = (14×4)+(1×8)+(16×3) = 56+8+48 = 112 g, m = (1×8) = 8 g
Substitute these values into equation 1
h = (8/112)×100
h = 7.14%.
Hence the percentage of hydrogen in 70 g of C₄H₈O₃ is 7.14%
6.An ice cube that has a mass of 20 g is in a sealed container. As the container is heated, the ice first melts, but eventually it changes to water vapor.
A)The temperature at which the ice melts is ____________________.
B) Compare the motion of the particles in each state
Answer:
See explanation
Explanation:
a) Every substance melts at a particular temperature known as the melting point of the substance. The melting point of ice is 0°C. Hence ice melts at 0°C.
b) There are three states of matter; solid liquid and gas. The particles of matter in each stage of matter possess varying degrees of freedom.
In the solid state, the intermolecular forces between the particles of water that compose ice are very strong. Hence the particles do not translate, they only vibrate or rotate about their mean positions.
In the liquid state, the magnitude of intermolecular interaction is less than that of the solids hence the molecules can translate but not with a high kinetic energy.
In the gaseous state, there is a minimum intermolecular interaction between particles theoretically hence the particles are really free to move about with a very high kinetic energy.
If carbon is in an animal is it:
A. Abiotic matter
B. Biotic matter
C. Energy storage molecules
D. Carbon dioxide
I WILL MARK BRAINLIEST IF YOU HELP!
Do not guess or give me a file or I will report you!!
Answer:
It is A
Explanation:
Abiotic matter
Why is NH3 not considered a base under the Arrhenius definition of acids and bases?
SELECT AN ANSWER
a. It does not react with acids.
b. NH3(aq) does not contain OH- ions.
c. NH3 is considered a base under the Arrhenius definition, but not under the Bronsted-Lowry definition.
d. It does not cause a color change when mixed with an acid-base (pH) indicator.
Answer:
b. NH3(aq) does not contain OH- ions.
Explanation:
According to Arrhenius in his definition, a base is a substance that has the ability to increase the hydroxyll ion (OH-) of an aqueous solution. In other words, Arrhenius bases dissociates into OH- when dissolved in water.
According to this question, ammonia (NH3) will not be considered an Arrhenius base because it does not contain OH-. This means that ammonia (NH3) cannot dissociate into hydroxyll ion when dissolved in water.
Explain using balanced chemical equations, the alkaline hydrolysis reaction of esters.
Answer:
The alkaline hydrolysis of ester is known as saponification. When ester is heated with aqueous NaOH, sodium salt of acid and alcohol are formed.
The process of saponification of an ester in an alkaline solution. Alcohol and sodium salt of acid are created when the bis heated with aqueous NaOH.
What is saponification ?Esters are converted into soap and alcohol through the process of saponification, which uses an aqueous alkali. Fatty acids, which are long-chain carboxylic acids, are the building blocks of soaps. Sodium stearate is a regular soap ingredient.
From the Latin sapo, which signifies soap, the reaction is known as a saponification. The term is derived from the fact that fats were once hydrolyzed into esters to produce soap.
Particularly in the food industry, saponification is significant because it makes it simpler to estimate the amount of free fatty acids present in a specific food product. The quantity of free fatty acid can be determined by measuring how much alkali was needed to neutralize the fat or oil.
Thus,the alkaline hydrolysis reaction of esters is called as saponification.
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what changes would you see in the colour of litmus paper in lemon,ash and blood
Answer:
Colour of litmus papers in lemon:
Blue litmus- Red
Red litmus- No change
Really sorry but don't know about others
Litmus paper indicator shows following color changes for lemon it is, blue litmus to red, for ash and blood it is red litmus to blue indicating their acidic nature in case of lemon and alkaline nature in case of ash and blood.
What is an indicator?Indicator is defined as a chemical substance which is chemically a weak acid or a weak base which changes it's color depending upon the concentration of hydrogen ions present in the solution.They dissociate slightly in water to produce ions.
These are generally derived from plant pigments and are of slightly acidic or basic in nature.There are three types of indicators:
1) natural indicators
2) synthetic indicators
3) olfactory indicators.
These are mainly used in determination of end point of titrations. Every indicator has it's pH range in which it can perform effectively.These are usually organic compounds.
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Whats the name?!?!?!??!?!?!?!?!?!?!!?!?!?!??!?!?!?!
What is the benefit of adding sodium hydroxide and sulfuric acid?
Answer:
When sodium hydroxide react with sulphuric acid they form Sodium sulphate and water. The reactants is base and an acid, which leads to neutralization process and yields a salt .
Answered by The One and only #Queen
2 NaClO3→ 2 NaCl + 3 O2
How many moles of O2 are produced when 40g of NaCl are formed?
Answer:
75.6
Explanation:
For each of the following, predict the complete, balanced chemical equation for the reaction that occurs when they are mixed. Make sure to label the states.
1. HNO3 & NaOH
2. Sr(OH)2 & HI
..
Answer:
1. The balanced chemical reaction is:
[tex]HNO_3(aq)+NaOH(aq)\rightarrow NaNO_3(aq)+H_2O(l)[/tex]
2. The balanced chemical reaction is:
[tex]2HI(aq)+Sr(OH)_2(aq)\rightarrow SrI_2(aq)+2H_2O(l)[/tex]
Explanation:
Hello there!
In this case, according to the given chemical reactions, it is necessary to keep in mind the cations and anions are switched around as a result of the bonds rearrangement in these neutralization reactions; therefore, we can proceed as follows:
1. The balanced chemical reaction is:
[tex]HNO_3(aq)+NaOH(aq)\rightarrow NaNO_3(aq)+H_2O(l)[/tex]
Because all atoms are in the same amount at each side of the equation and the resulting salt is soluble.
2. The balanced chemical reaction is:
[tex]2HI(aq)+Sr(OH)_2(aq)\rightarrow SrI_2(aq)+2H_2O(l)[/tex]
Because all atoms are in the same amount at each side of the equation and the resulting salt is soluble.
Best regards!
A mixture of gaseous reactants is put into a cylinder, where a chemical reaction turns them into gaseous products. The cylinder has a piston that moves in or out, as necessary, to keep a constant pressure on the mixture of . The cylinder is also submerged in a large insulated water bath. (See sketch at right.) From previous experiments, this chemical reaction is known to release of energy. The position of the piston is monitored, and it is determined from this data that the system does of work on the piston during the reaction.
Answer:
It is exothermic in nature.
Explanation:
(1) The reaction is exothermic in nature because it releases heat energy.
(2) Yes, the temperature of the water go up as the reaction releases heat energy and the temperature cool down as the heat energy is completely removed from the water.
(3) The piston move in when the pressure in the cylinder decreases and the piston move out when increase of pressure occur.
(4) As the outside movement of piston occurs, so we can say that the gas mixture does work on its surroundings.
(5) The system released 244 kJ of energy, in which only 150 kJ went into the water, then the difference must be the work done by the system on its surroundings.
W = (244 - 150) kJ = 94 kJ
Which statement is true about fossils?
a.Only the remains of animals, and not plant, can be made into a fossil.
b.To officially be a fossil, the remains of an entire organism must be found.
c.The remains of an organism that lived 500 years ago is called a fossil.
d.A fossil is any trace of prehistoric life.
Answer:
d, the remains of an organism have to be 10,000 years old to be classified as a fossile:)
Answer:
(d)
Explanation:took the quiz
what is your experience about water pollution
Answer:
water pollution is a process in which water gets polluted due to discharge of city sewage and industrial waste. I was suffering through the water born disease when I drank the contaminated water. The sources of water becomes dirty. It makes environment unbalanced. People suffer from different water born disease when they drink polluted water.
Pls help ASAP ! Identify the following reaction: H2 + O2 → H2O
Group of answer choices
synthesis reaction
decomposition reaction
single replacement reaction
double replacement reaction
Answer:
Synthesis Reaction
Explanation:
Here we see H2 and O2 are being combined H2O. Synthesis reactions are where we see a combination to make a single product.
So here it'd be A + B =AB
2Na(s)+Cl2(g)→2NaCl(s)
Decomposition would be the break down of a compound into 2, the opposite of synthesis.
AB = A + B
2HgO(s)→2Hg(l)+O2(g)
Single replacement is where 1 element replaces another in a reaction, or switches place with 1 element.
AY + B = A + BY
2 HCl(aq) + Zn(s) → ZnCl2(aq) + H2(g)
Double replacement is similar but 2 elements are switch/replaced.
AY + BX = AX + BY
CuCl2(aq) + 2 AgNO3(aq) → Cu(NO3)2(aq) + 2 AgCl(s)
please answer's these scientist answer's
A scientist observes that the leg bones of cats are similar to the bones in the wings of bats. The scientist concludes the two species share a common ancestor. Which describes why the scientist drew that conclusion?
1. developmental patterns
2. DNA
3. fossil evidence
4 .structural data
Bald eagles might lay up to five eggs at a time, but only one hatchling usually survives. Which feature of natural selection is this an example of?
1 .adaptation
2. genetic variation
3. overproduction
4. selection
By which method the following mixture can be separated?(i)mixture of colours (ii) Minerals oil.
Answer:
mixture of colours answer
Which of the following apply to gases. Select all that apply.
Answer:
kindly give options
Explanation:
Can somebody please help me!!
Answer:
acceleration
pls dont report me
What is the mean of magnetic susceptibilty?
Answer:
Magnetic susceptibility is the degree to which a material can be magnetized in an external magnetic field. If the ratio between the induced magnetization and the inducing field is expressed per unit volume, volume susceptibility (k) is defined as.
Explanation:
good luck
what is the xonclusion of separating acetone and water by simple and fractional distillation
Answer:
In conclusion, acetone was determined to be the unknown used in the simple distillation and acetone- water was separated successfully by fractional distillation. Introduction Distillation is the chief technique used to separate and purify liquids.
PLEASEEEE HELLPPP I CANT FAILL PLSS
Can somebody please help me!!!!
Answer:
Friston to energy
Explanation:
Friction to Energy as its a energy stooping the object form moving
Do you think baking a cake is or is not a chemical reaction
Answer:
yes
Explanation:
its an endothermic chemical reaction
Answer:
It is a chemical reaction because you cannot get back the original ingredients. if you can get the original ingredients back, it would be a physical change.
Hope this helped you out!!
Plz I need helpppppp
What's the wavelength in meters of an electron traveling at 9.5 x 10^7 m/s? The mass of an electron is 9.11 x 10^-28 g.
Select one:
a. 7.66 x 10-15 m
b.7.66 x 10-12 m
c. 3.47 x 1027 m
d. 3.47 x 1030 m
Answer:
where:
• A is the wavelength in m.
• h = 6.626 x 10-34Js is Planck's
constant.
• m is the mass of the particle, such as the electron, in kg. The particle must have a mass for this relation to work.
• v is the forward velocity of the particle, in m/s.
Hence, the wavelength is:
6.626 x 10-34J.s
(9.1094 × 10 −³¹kg) (5 × 10³m/s)
We know that 1 J 1 kg. m²/s². So:
6.626 × 10-³4 g · m² / ø
9.1094 x 10 - 31) (5 x 105 m/s)
= 1.455 x 10-9 m
=
= 1.455 nm
Part A. Classify each of these soluble solutes as a strong electrolyte, a weak electrolyte, or a nonelectrolyte. Solutes Formula Nitric acid HNO3 Potassium hydroxide KOH Formic acid HCOOH Ethyl amine CH3CH2NH2 Sodium bromide NaBr Butanol C4H9OH Sucrose C12H22O11
Part B. Enter a molecular equation for the reaction that occurs between aqueous HBr and aqueous LiOH.
Answer:
1. Strong electrolytes = Nitric acid HNO3,Potassium hydroxide KOH, Sodium bromide NaBr
Weak electrolytes = Formic acid HCOOH Ethyl amine CH3CH2NH2, Butanol C4H9OH
Non-electrolyte = Sucrose C12H22O11
2. The reaction between aqueous HBr and aqueous LiOH is shown innthe equation below:
HBr + LiOH ----> NaBr + H₂O
Explanation:
Electrolytes are substances that when in molten state or in aqueous solution dissociate into ions both positively-charged and negatively-charged ions known as actions and anions, which are then able conduct electricity.
Strong electrolytes are aqueous or molten solutions of compounds which ionize completely to produce anions and actions. Ionic compounds such as organic salts, acids and bases are strong electrolytes.
Weak electrolytes only ionize partially, that is, they produce few ions. Some organic salts, acids and bases are weak elctrolytes
From the compounds given above;
Strong electrolytes = Nitric acid HNO3,Potassium hydroxide KOH, Sodium bromide NaBr
Weak electrolytes = Formic acid HCOOH Ethyl amine CH3CH2NH2, Butanol C4H9OH
Non-electrolyte = Sucrose C12H22O11
2. The reaction between aqueous HBr and aqueous LiOH is shown innthe equation below:
HBr + LiOH ----> NaBr + H₂O