During which change of state do atoms lose energy?

A. sublimation
B. freezing
C. boiling
D. melting

Answers

Answer 1

Answer:

B. freezing

Explanation:

During freezing, atoms lose energy. In this process, the molecules lose heat energy and they cool down. This reduces randomness of the matter.

In sublimation, heat is added to a matter, the molecules are agitated and their entropy increases. Boiling and melting are similar in that these processes heat is supplied. Then the particles are agitated and the molecules will tend to move apart more rapidly.
Answer 2

Answer:

B)Freezing

Explanation:

just took the test edge 2021


Related Questions

Hydrazine reacts with 2,4-pentanedione to yield 3,5-dimethylpyrazole. Including protonations and deprotonations, the reaction takes 12 steps. Write out the mechanism on a sheet of paper and then draw the structure of the product of step 9.

Answers

Answer:

Explanation:

From the given information:

We explained the reaction mechanism of 2,4-pentanedione with hydrazine to yield 3,5-dimethylpyrazole as shown below;

At the initial stage, the carbonyl oxygen gains a proton, increasing the carbonyl carbon's electrophilicity. After that, the carbonyl carbon is being attacked by hydrazine. Then, the process proceeds with the species formed where removal of a proton takes place. Similarly, hydroxyl oxygen gains a proton. After that, the water molecule is being removed, and further rearrangement of an electron occurs at the site of nitrogen in hydrazine.

From species formed, the removal of a proton takes place. Finally, all step is being repeated to yield the final product known as 3,5 - dimethylpyrazole.

which 2 letters have the most kinetic energy

Answers

Answer:

X and Z

Explanation:

See attachment for complete question...

Your question illustrates kinetic energy as it relates to height (according to the attachment)

Kinetic energy increases with a decrease in height.

So, from the attachment...

W and Y are at higher heights.

While X and Z are at lowest heights

By the analysis above, kinetic energy would be at highest at X and then Z.

Hence, the answer to the question is X and Z.

How do I know if something is an acid so I can avoid eating it?

Answers

Answer:

i feel like it will have an acid smell

when the tempature of the enviroment changes, the body tempature of a reptile

Answers

The reptile's body temperature rises when the external temperature rises. When the temperature drops, so does his body temperature. If a reptile feels cold because the external temperatures have made his blood cold, he'll lie in the sun to warm up.

hope this helps!!

The rate constant for a certain reaction is measured at two different temperatures:

Temperature K
376.0°C 4.8 x 10^8
280°C 2.3 x 10^8

Assuming the rate constant obeys the Arrhenius equation, calculate the activation energy for this reaction. Round your answer to significant digits.

Answers

Answer: 22.78KJ/ mol

Explanation:

The computation of activation energy [tex]E_0[/tex] follows by formula:

[tex]\ln (\dfrac{K_2}{K_1}) = (\dfrac{E_a }{ R}) (\dfrac{1}{T_1} -\dfrac{ 1}{T_2})[/tex]

Given:[tex]T_1 = 376.0^{\circ}C =376+273K= 649 K[/tex]

[tex]K_1 = 4.8 \times10^8[/tex]

[tex]T_2 = 280.0^{\circ}C = 273+280K=553 K ,\ \ \ K_2 = 2.3 \times 10^8[/tex]

[tex]\ln(\dfrac{2.3 \times10^8 }{ 4.8 \times 10^8}) = (\dfrac{E_a }{ 8.314}) (\dfrac{1}{649} - \dfrac{1}{553})\\\\\Rightarrow\ \ln(0.479) = (\dfrac{E_a }{ 8.314}) (-\dfrac{96}{358897})\\\\\Rightarrow\ -0.73605468= (\dfrac{E_a }{ 8.314}) (-\dfrac{96}{358897})\\\\\Rightarrow\E_a=-0.73605468\times 8.314\times\dfrac{-358897}{96}=22878.033\\\\\Rightarrow\E_a=22878.033\ J/mol=22.78 KJ /mol[/tex]

Hence, the activation energy for this reaction =22.78KJ/ mol

If the molar absorptivities of HIn and In- were determined at a wavelength corresponding to an isosbestic point, how would they compare in value

Answers

Answer:

A Weak acid indicator has general formulae HIn- and base has In-.

When constructed a plot determining wavelength equilibrium reached according to the equation HIn(aq) + H2O(l) ↔ In-(aq) + H3O+(aq)

HIn(aq) is the acid, that has a different color from the base In-(aq). When the pH is low, the concentration of the hydronium ion H3O+ is high and equilibrium is toward the left, producing the color A.

At high pH, the concentration of H3O+ is low, so equilibrium tends toward the right side of the equation and color B is displayed

4) How many moles are in each elemental sample?
a. 9.01 g Be
b. 42.03 g P
c. 71.90 g CI

Answers

Answer:

1 mole

The first step is to calculate the molar mass (gram formula weight) of MgCl2. Molar mass = (24.31 + 2 × 35.45) = 95.21 g mol–1 i.e. 95.21 g of MgCl2 is exactly 1 mole

Which of the following is not present in an atom? (1 point) Electron Element Neutron Proton

Answers

Answer:

Element is not present in an atom

Answer:

element

Explanation:

how do you find an unknown element

Answers

what is the question you're asking??

Answer:

There are two properties that can be used to identify an element: the atomic number or the number of protons in an atom. The number of neutrons and number of electrons are frequently equal to the number of protons, but can vary depending on the atom in question.

Calculate the concentration of 45.0 mL of a phosphoric acid solution that neutralized 20.8 mL of 0.532 M sodium hydroxide. Assume complete ionization of the acid.

Answers

Answer:

0.0820M H₃PO₄

Explanation:

THe phosphoric acid, H₃PO₄ reacts with sodium hydroxide, NaOH, thus:

H₃PO₄ + 3NaOH → Na₃PO₄ + 3H₂O

The moles of NaOH used to neutralize the acid are:

Moles NaOH:

20.8mL = 0.0208L * (0.532mol / L) = 0.0111 moles NaOH.

That means moles of phosphoric acid in the solutionare:

0.0111 moles NaOH * (1mole H₃PO₄ / 3 moles NaOH) =

0.00369 moles H₃PO₄

These moles are in 45.0mL = 0.045L. The molar concentration of the solution are:

0.00369 moles H₃PO₄ / 0.045L =

0.0820M H₃PO₄

What is the equilibrium expression for the following reaction: N2 (g) 3 H2 (g) rightwards harpoon over leftwards harpoon with blank on top 2 NH3 (g)

Answers

Answer:

[tex]Kp = \frac{P_{NH_{3}} ^{2} }{P_{N_{2}} ^{}P_{H_{2}} ^{3} }[/tex]

Explanation:

For the reaction at equilibrium:

N₂ (g) + 3 H₂(g) ⇄ 2 NH₃ (g)

Since this is an equilibrium in the gas phase, the equilibrium expression is obtained from the partial pressures (P) of the products (NH₃) and reactants (N₂ and H₂) raisen to their stoichiometric coefficients:

[tex]Kp = \frac{P_{NH_{3}} ^{2} }{P_{N_{2}} ^{}P_{H_{2}} ^{3} }[/tex]

g Part A A Hofmann degradation of a primary amine forms an alkene that gives butanal and 2-methylpropanal upon ozonolysis and workup under reducing conditions. Identify the amine.

Answers

Answer:

 

Explanation:

When the primary amine undergoes Hofmann degradation it forms an Alkene

In this case the alkenes have undergone ozonolysis and has formed two products as butanal and 2-methyl propanal

when we revert back from these aldehydes to alkene we observed the alkene formed will be "2-methyl hept-3-ene " this alkene is the Hofmann product of that primary amine

upon addition of this alkene we observe the primary amine formed is

4-amino-2-methylheptane

A compound has a molar mass of 100 g/mol and the percent composition (by mass) of 65.45% C, 5.45% H, and 29.09% O. Determine the empirical formula and the molecular formula.

Answers

Answer:

Empirical formula: C3H30

Molecular formula: C6H6O2

Explanation:

The empirical formula can be calculated thus:

65.45% C - 65.45g

5.45% H - 5.45g

29.09% O - 29.09g

We convert each mass to mole by dividing by their respective atomic mass:

C = 65.45/12 = 5.45mol

H = 5.45/1 = 5.45mol

O =29.09/16 = 1.82mol

Next, we divide each mole value by the smallest value;

C = 5.45mol/1.82 = 2.99

H = 5.45mol/1.82 = 2.99

O = 1.82mol/1.82 = 1

Approximately, the empirical ratio of C, H and O is 3:3:1 i.e. C3H3O

Molecular formula is calculated thus:

(C3H3O)n = 100g/mol

{12(3) + 1(3) + 16}n = 100

(36+3+16)n = 100

(55)n = 100

n = 100/55

n = 1.82

n = 2

Molecular formula= (C3H3O)2

C6H6O2

Ammonium perchlorate is the solid rocket fuel used by the U.S. Space Shuttle. It reacts with itself to produce nitrogen gas , chlorine gas , oxygen gas , water , and a great deal of energy. What mass of oxygen gas is produced by the reaction of of ammonium perchlorate

Answers

Answer:

2.9 g

Explanation:

The computation of the mass of oxygen gas produced is shown below:

As we know that

[tex]2NH_4ClO_4 \rightarrow N_2 + Cl_2 + 2O_2 + 4H_2O[/tex]

Now

The [tex]NH_4ClO_4[/tex] presented in 9.6g = 9.6 g/117.49 g/mol  

And, the mole ratio between the [tex]NH_4ClO_4 : H_2O[/tex] is 1 : 2

The moles of [tex]H_2O[/tex] produced is 2 × 9.6 g/117.49 g/mol

So,

Mass of H2O produced is

= 18.015 g/mol × 2 × 9.6 g/117.49 g/mol

= 2.94 g

The interaction of water droplets in rain with carbon dioxide that is naturally present in the atmosphere causes rain water to be slightly acidic because CO2 is an acidic anhydride. As a result, pure clean rain has a pH of about 5.7. What are the hydrogen ion and hydroxide ion concentration in this rain water

Answers

Answer:

Explanation:

 pH = 5.7

- log [ H⁺ ] = 5.7

[ H⁻ ] = 10⁻⁵°⁷ M

= 2 x 10⁻⁶ M

[ H⁺ ] x [ OH⁻ ] = 10⁻¹⁴

2  x 10⁻⁶ x [ OH⁻ ] = 10⁻¹⁴

[ OH⁻ ] = .5 x 10⁻⁸ M

= 5 x 10⁻⁹ M

Choose the reaction that represents the combustion of liquid C6H14?
a. C6H12O2(l) + 8 O2(g) → 6 C(s) + 6 H2O(g)
b. 6 C(s) + 7O2(g) + C6H14(l) → C6H14O2(aq) + 6CO2(g)
c. 6 C(s) + 6 H2(g) + 19 O2(g) → C6H14(l)
d. 2C6H14(l) + 19 O2(g) → 12 CO2(g) + 14 H2O(g)
HELP!!!!

Answers

Answer:

D. It's the only one with C6H14 on the reactant side.

Explanation:

The atoms of which element will form cations?
A. selenium
B. neon
C. copper
D. iodine

Answers

Answer Copper, copper is a type of metal, so it can form cations

The atoms of element will form cations is Copper as to get the stable electronic configuration.

What are cations?

Cations are those species which carries possitive charge on it and produced by any element by lossing of their outermost electrons.

An atom will form cation to get the stable outermost configuration.

Selenium belongs from the oxygen group and in the outermost shell 6 electrons are present, so it shows the negative oxidation state as it accepts the two electron to get the stable configuration and form an anion.Neon belongs from the noble gas group which already have stable configuration, so it does not form any cation or anion.Iodine belongs from the halogen groups, and in the outermost shell 7 electrons are present, so it shows the negative oxidation state as it accepts the one electron to get the stable configuration and form an anion.Copper is a transition metal atom and it has 4s¹3d¹⁰ electronic configuration, so it will loss 1 electron from the outermost shell and will form cation.

Hence option (C) is correct i.e. Copper.

To know more about cations, visit the below link:

https://brainly.com/question/14309645

A student filled a graduated cylinder with water to the 15.0 mL mark she placed a metal object with a mass of 33.65g into the cylinder when the object was completely submerged in the water the water level rose to 18.3mL what is the density of the object

Answers

Answer:

The answer is 10.2 g/mL

Explanation:

The density of a substance can be found by using the formula

[tex]density = \frac{mass}{volume} \\ [/tex]

From the question

volume = final volume of water - initial volume of water

volume = 18.3 -15 = 3.3 mL

We have

[tex]density = \frac{33.65}{3.3} \\ = 10.19696969...[/tex]

We have the final answer as

10.2 g/mL

Hope this helps you

State yes no whether each of the following orbital diagrams conforms to the rules governing electron configuration if not explain what is wrong with the diagram

Answers

Answer:yes,no,no,yes

For ethane (C2H6), what is the correct framework of the Lewis structure?

The central atoms consist of two hydrogens.

The central atoms consist of two hydrogens and one carbon.

The central atoms consist of one hydrogen and one carbon.

The central atoms consist of two carbons.

Answers

Answer: The answer is D. The central atoms consist of two carbons.

Explanation:

Answer:

The central atoms consist of two carbons

Explanation:

Took the test! hope this helps!

- On a test, Helena is defining energy. Which must she include in order to get her answer marked correct?
○making objects more compact
O the ability to do work
O carrying through matter and space
O the bonds of atoms ​

Answers

Answer: Option 2, The ability to do work.

Explanation: Edge

Energy can be defined as:

B. the ability to do work, It can of many forms.

What is Energy?

Energy is the capacity of an item to take care of business. It might exist in potential, motor, warm, electrical, substance, atomic, or other different structures. As per the work-energy hypothesis, the work done is put away in the energy of the body.

Thus, option B is correct.

Find more information about Energy here:

brainly.com/question/13881533

Based on these descriptions, write a balanced equation and the corresponding Kc expression for each reversible reaction.

a. Carbonyl fluoride, COF2(g), decomposes into gaseous carbon dioxide and gaseous carbon tetrafluoride.
b. Copper metal displaces Silver(I) Ion from aqueous solution , producing silver metal and an aqueous solution of copper(II) ion.
c. Peroxodisulfate ion , S2O82- , oxides iron (II) ion to iron (III) ion in aqueous solution and it is itself reduced to sulfate ion.

Answers

Answer:

See full explanation.

Explanation:

Hello.

In this case, since we apply the law of mass action in order to write the equilibrium expression for each chemical reaction, we proceed as follows:

a. The reaction is:

[tex]2COF_2(g)\rightleftharpoons CO_2(g)+CF_4(g)[/tex]

And the equilibrium expression:

[tex]Kc=\frac{[CO_2][CF_4]}{[COF_2]^2}[/tex]

Since all the species are in gaseous phase they are included on the equilibrium expression.

b. The reaction is:

[tex]Cu(s)+Ag^+(aq)\rightleftharpoons Ag(s)+Cu^{2+}(aq)[/tex]

And the equilibrium expression:

[tex]Kc=\frac{Cu^{2+}}{Ag^+}[/tex]

Since only copper (II) ions and silver (I) ions are in aqueous phase.

c. The reaction is redox and it turns out:

[tex](S_2O_8)^{2-}+Fe^{2+}\rightleftharpoons Fe^{3+}+(SO_4)^{2-}\\\\S_2^{7+}+2e^-\rightarrow 2S^{6+}\\\\2\times (Fe^{2+}\rightarrow Fe^{3+}+1e^-)\\\\\\(S_2O_8)^{2-}(aq)+2Fe^{2+}(aq)\rightleftharpoons 2Fe^{3+}(aq)+2(SO_4)^{2-}(aq)[/tex]

And the equilibrium expression:

[tex]Kc=\frac{[Fe^{3+}]^2[(SO_4)^{2-}]^2}{[(S_2O_8)^{2-}][Fe^{2+}]^2}[/tex]

Since all the species are in aqueous phase.

I have 5.33 moles of helium gas at 1.56 atm and a temperature of 25 ° C. What is the volume of my helium sample? 

Answers

Answer:

V = 83.6 L

Explanation:

Given data:

Number of moles of He = 5.33 mol

Pressure of gas = 1.56 atm

Temperature of gas = 25°C

Volume of sample = ?

Solution:

Formula:

PV = nRT

P= Pressure

V = volume

n = number of moles

R = general gas constant = 0.0821 atm.L/ mol.K  

T = temperature in kelvin

Now we will convert the temperature.

25+273 = 298 K

Now we will put the values in formula.

1.56 atm × V = 5.33 mol ×  0.0821 atm.L/ mol.K  × 298 K

1.56 atm × V = 130.4 atm.L

V = 130.4 atm.L/1.56 atm

V = 83.6 L

Why does the 4s sublevel fill up before the 3d sublevel? What principle is that based on?

Answers

According to the Aufbau principle, the 4s orbital is filled first instead of the 3d orbital

Further explanation

Each electron shell and its orbitals have a specific energy level.

The farther the shell is from the atomic nucleus, the higher the energy level.

This energy level is expressed in the form of electron configurations.

Writing electron configurations starts from the lowest to the highest sub-shell energy level. There are 4 sub shell in the shell of an atom, namely s, p, d and f.

Charging electrons in the subshell uses the following sequence:

1s², 2s², 2p⁶, 3s², 3p⁶, 4s², 3d¹⁰, 4p⁶, 5s², 4d¹⁰, 5p⁶, 6s², etc.

According to Aufbau, electrons occupy orbitals of the lowest energy level  

So the 4s orbital has a lower energy level than the 3d orbital, so the electrons fill the 4s orbital first

Can someone answer #1 for me please I’ll gift extra points! ☺️

Answers

GREETINGS!

The system here is chloroplast, so the boundary of the system would be cell cell membrane. Input will be nutrients, output waste and process photosynthesis

HOPE IT HELPS!

How many Joules are required to change 30.0g ofice at -20°C to steam at 140°C? There are a few steps you should follow using the following given
information
• The specific heat of ice is 2.108 J/g*°C
• The specific heat of water is 4.18 J/g*°C
• The specific heat of steam is 2.010 J/g*°C
• Hf for H2O = 334 334 J/g
• Hv for H2O = 2260 J/g

Answers

Answer:

Q = 10118.4 j

Explanation:

Given data:

Mass of ice = 30.0 g

Initial temperature of ice = -20°C

Final temperature = 140°C

Energy required = ?

Solution:

The specific heat of ice is 2.108 J/g*°C

Formula:

Q = m.c. ΔT

Q = amount of heat absorbed or released

m = mass of given substance

c = specific heat capacity of substance

ΔT = change in temperature

ΔT = 140°C -  (-20°C)

ΔT = 160°C

Q = 30.0 g× 2.108 J/g°C ×160°C

Q = 10118.4 j

Calcium oxide reacts with water in a combination reaction to produce calcium hydroxide. A 4.50-g sample of CaO is reacted with 4.34 g of H2O. How many grams of the excess reagent remain after the reaction is complete

Answers

Answer:

2.88 g

Explanation:

First, let us look at the balanced equation of the reaction:

[tex]CaO(s) + H_2O (l) --> Ca(OH)_2(s)[/tex]

From the equation, 1 mole of CaO reacts with 1 mole of H2O to produce 1 mole of [tex]Ca(OH)_2[/tex].

mole = mass/molar mass

4.50 g of CaO = 4.50/56.08 = 0.08 mole

4.34 g of H2O = 4.34/18.02 = 0.24 mole

The ratio of moles of CaO and H2O should be 1:1, hence, H2O is in excess.

Excess mole of H2O = 0.24 - 0.08 = 0.16 mole

mass of 0.16 mole of H2O = mole x molar mass = 0.16 x 18.02 = 2.88 g

Therefore, 2.88 g of the excess reagent (water) would remain after the reaction is complete.

please help!! chemistry question

Answers

Answer:

9

Explanation:

Answer:

9

because i studied this

a half-eaten apple turns brown which of these is evidence a chemical change took place

A.th3e apple is softer

b.the apple changed color

C.half the apple was eaten

D.the apple is warmer \

Answers

Answer:

the apple changed color

Explanation:

cause when it changes to brown it means the apple is no longer edible

many fruits with just having contact with the air it may change color like apple

B. The apple changed color

Bruh have you not eaten an apple before

Which of the following questions about the flu is a scientific question?
A. Is a flu shot effective in preventing the flu?
B. Is public fear of the flu out of control?
C. Is the benefit of drugs for the flu higher than the cost?
D. Who should receive a flu shot if there is not enough flu vaccine for
everyone?

Answers

The correct answer is A. This is because they are asking if the flu shot is necessary and effective to work to prevent the flu. We automatically know B is not the answer because the question is very unnecessary and does not sound like it could be a scientific question. C can’t be it because it’s talking about if the shot is beneficial because of the cost. It also can’t be D because it definitely does not make sense for there not to be a vaccine available for the people who need it for the flu. In this case the best option would be A.

Answer:

A is the correct answer

Explanation:

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