If a system's internal energy increases by 250 kJ after the addition of375 kJ of energy as heat, what was the value ofthe work in the process?
(A) -625 kJ
(B) -125 kJ
(C) 125 kJ
(D) 625 kJ

Answers

Answer 1

Answer:

(B) -125 kJ

Explanation:

Going by the First Law of Thermodynamics it states that"

"A system can do work and increase it's internal energy provided we supply heat."

ΔU= q+w-----------1

where U= the internal heat

           q= the quantity of heat added or removed from the system

            w= the work done

Given

ΔU= 250kJ

q= 375kJ

from equation 1 make w subject of the formula we have

w= ΔU-q

w= 250-350

w= -125kJ


Related Questions

How do balanced equations demonstrate the law of conservation of mass?​

Answers

Answer:

Every chemical equation adheres to the law of conservation of mass, which states that matter cannot be created or destroyed. ... When an equal number of atoms of an element is present on both sides of a chemical equation, the equation is balanced.

Explanation:

so have a great day

17. What is the correct empirical formula for H4C408?
A
H2C204
B HCO2
C
HCO4
D
H2C202

Answers

Answer:

B

Explanation:

by simlfying it you get HCO2

What does a useful scientific explanation include ??

Answers

Answer: scientific explanation

Explanation:

A really good scientific explanation should do two main things: It should explain all the observations and data we have. It should allow us to make testable predictions that we can check using future experiments.

Magnesium has a density of 1.738 g/cmº at 25°C. What is the mass of a block of
magnesium that has a volume of 743 cm??

Answers

Answer:

87.50g(1cm^3/1.1738g)=50.345 cm^3

Explanation:

volume units id in cubic centimeters

which event would most likely lead to a thunderstorm HELP GIVING BRAINLIEST

Answers

Warm moist air jaisjsisksusjisjud

Answer:

A

Explanation:

i got right

A paint chip is placed in ethanol and curls what type of paint is it

Answers

Answer:

it is probably acrylic or latex

Explanation:

There are two types of chemical compound one is covalent compound and other is ionic compound, covalent compound formed by sharing of electron and ionic compound formed by complete transfer of electron. Therefore, the type of paint is  acrylic or latex.

What is chemical Compound?

Chemical Compound is a combination of molecule, Molecule forms by combination of element and element forms by combination of atoms in fixed proportion.

An ionic compound is a metal and nonmetal combined compound.  Ionic compound are very hard. They have high melting and boiling point because of strong ion bond.  If the chip remains flat when put in ethanol, it is probably an oil-based paint. If the chip curls, it is probably acrylic or latex. So, The type of paint is  acrylic or latex.

Therefore, the type of paint is  acrylic or latex.

To learn more about chemical compound, here:

brainly.com/question/26487468

#SPJ2

Please help this affects my grade a lot and im confused

Double Replacement/Combustion I need to find the product of each one
zinc oxide + Cobalt(III) nitrite
Calcium hydroxide + phosphoric acid
Copper(I) dichromate + Iron(III) arsenate
Hydrochloric acid + aluminum hydroxide

Answers

1 ) Cobalt(II) nitrate react with nitrate zinc(II) to produce cobalt(III)-zinc oxide, nitrogen dioxide and oxygen  

2Co(NO3)2 + Zn(NO3)2 → Co2ZnO4 + 6NO2 + O2

2) Calcium hydroxide react with phosphoric acid to produce calcium, hydrogen phosphate and water

Ca(OH)2 + H3PO4 → CaHPO4 + 2H2O

3) Copper(II) dichromate will react with Iron(III) arsenate to form Copper(II) Arsenate and Iron(III) dichromate

3Cr2CuO7 + 2AsFeO4 → Cu3(AsO4)2 + Fe2(Cr2O7)3

Reaction Type : Double Displacement

4) aluminium hydroxide and hydrochloric acid react to form aluminium chloride and water

Al(OH)3 + 3HCl → AlCl3 + 3H2O

a) Calculate the standard reaction entropy for the combustion of methane to carbon dioxide and liquid water at 298 K. b) Calculate the standard reaction entropy for the hydrolysis of liquid water to form oxygen and hydrogen gas. c) Do your results in (a) and (b) agree with the general rule that reaction entropies are positive if there is a net formation of gas in a reaction, and negative if the is a net reduction of gas?

Answers

Answer: (a) [tex]\Delta S^{0}[/tex] = - 242.2J/K.mol

              (b) [tex]\Delta S^{0}[/tex] = 163.34J/K.mol

              (c) Yes

Explanation: Entropy is the measure of randomness or disorder of a system. Standard Entropy has the symbol [tex]S^{0}[/tex].

Mathematically, Entropy is defined as

[tex]\Delta S^{0}=\Sigma S^{0}(products)-\Sigma S^{0}(reagents)[/tex]

Each substance has its own entropy value.

(a) Combustion of Methane:

[tex]CH_{4}+2O_{2}[/tex] ⇒ [tex]CO_{2}+2H_{2}O[/tex]

Using standard entropy table, entropy will be:

[tex]\Sigma S^{0}(products)=214+2(69.91)[/tex] = 353.8

[tex]\Sigma S^{0}=186.264+2(205.138)[/tex] = 596.54

[tex]\Delta S^{0}=[/tex] 353.8 - 596.54

[tex]\Delta S^{0}=[/tex] - 242.2

Standard Entropy for combustion of methane is [tex]\Delta S^{0}=[/tex] - 242.2 J/K.mol.

(b) Hydrolysis of Water:

[tex]H_{2}O_{(l)}[/tex] ⇒ [tex]H_{2}_{(g)}+1/2O_{2}_{(g)}[/tex]

[tex]\Sigma S^{0}(products)=130.684+0.5(205.138)[/tex] = 233.253

[tex]\Sigma S^{0}(reagents)=69.91[/tex]

[tex]\Delta S^{0}=[/tex] 233.253 - 69.91

[tex]\Delta S^{0}=[/tex] +163.34

Standard Entropy for hydrolysis of water is [tex]\Delta S^{0}=[/tex] + 163.34 J/K.mol

(c) Yes, the results prove the general rule: Reactions Entropies are positive for net formation of gas and negative for net reduction of gas. This happens because, as entropy is the measure of disorder, the entropy for gases are greater than for liquids and solids. So, when there is formation of a gas, Entropy increases and when there isn't, entropy decreases.

how many moles of NO are formed from 2.5 moles of NO2 if there is plenty of water present

Answers

Moles of NO formed : 0.833

Further explanation

Given

2.5 moles of NO2

Required

moles of NO formed

Solution

Reaction

3 NO₂(g) + H₂O(l) = 2 HNO₃(aq) + NO(g)

The reaction coefficient in a chemical equation shows the mole ratio of the compounds in the reactants and products

From the equation, mol ratio of NO₂ and NO = 3 : 1, so moles of NO :

[tex]\tt moles~NO=\dfrac{1}{3}\times 2.5\\\\moles~NO=0.833[/tex]

Someone plz help me write notes (images attached)

Answers

Answer:

I'm not going to give you notes but I'm going to give you a tip for notes take what you think is the most important thing about the text and basically paraphrase it into your own words if that helps

A particle that travels around the nucleus of an atom in orbitals is called a(n)
quark.
proton.
neutron.
electron.

Answers

Electrons travel around the nucleus atom

Answer:

The electrons of an atom travel around the nucleus like a solar system or cloud. The protons and neutrons are both inside of the nucleus that the electrons travel around.

The answer is D, electrons!!

In the reaction C + O2 → CO2, 18 g of carbon react with oxygen to produce 72 g of carbon dioxide. What mass of oxygen would be needed in the reaction?

18 g
54 g
72 g
90 g

Answers

Answer:

54g of O2 reacted in the reaction

Answer:

54g

Explanation:

a wooden block with a mass of 2.0kg starts from at the top of an inclined plane and ends with a force of 25N at the bottom what was the rate of acceleration of the block

Answers

Answer:

Force F = 20N .

Mass m = 2.0 kg

Initial velocity u = 0

acceleration, a = 10m/s  

2

 

t = 1 sec.

Now Refer to the attachment, See the free body diagram of the block.

Force works on the block:-

Weight, W = mg

W = 2 × 10

W = 20N (which is Downward)  

Normal force N = mg cos37

N = 20 × 0.80  

N = 16 N. (perpendicular & upward to the plane )

Here Applied Force, P = 20N (which is down along the plane)

Now For Final Speed, We know the formula:-

v = u + at

v = 0 + 10 × 1

v = 10 m/s

the Distance travelled s = ut + 0.5 at×t

s = 0 + 0.5 ×10×1×1

s = 5 m.

Now,

(a)     So work done by the force of gravity in 1 sec. = F × d

             ⇒20 N × 5m      

             ⇒100 J.

(b) Here the weight act as downward, so distance travelled in downward.

             ⇒5 × sin37

             ⇒5 × 0.6  

             ⇒3 m.

 

so work done by gravity,

               ⇒20 N × 3 m

              ⇒60 J.

(c) Now, work done by all the forces  

               ⇒change in Kinetic energy

  ⇒

2

1  m(v2

−u  2

)

⇒0.5×2.0×(10  2

−0  2  )

⇒ 100 J.

⇒W.D by frictional force  

                 = work was done by all forces -( work was done by Normal force + work done by applied force + work done by gravity )  

                 = 100 J - (100 + 60 +0 )

                 = 100 - 1

     Hope this helps you≅        

           

Which of the following statements is true about exothermic reactions?

Answers

Answer:

An Exothermic Reaction , gives off more heat, and a little energy to its surroundings.

this can helps us figure out that the answer is , C, More heat is given off into its products.

Explanation:

Suppose you wish to determine the order of the reaction. You initially measure a rate, r0, given some arbitrary concentration of reactants. You then proceed to double the amount of A in the reaction (keeping B the same) and find that the rate is now 2r0. In a reciprocal experiment, you double the amount of B (A same as initial) in the reaction and measure a rate of 8r0. What is the order of this reaction

Answers

Answer:

See explanation

Explanation:

Now taking A, we can see that if we double the amount of A while keeping the amount of B constant, the rate of reaction doubles, hence we can write;

2^n = 2^1

hence n =1

For B, when the amount of B is doubled while keeping the amount of A constant, the rate of reaction increases eight times. Hence we can write;

2^n = 8

2^n = 2^3

n=3

Hence this reaction has an overall order of 1 + 3 = 4

So we can write;

rate =k[A] [B]^3

how dose dissolving sugar in water show that matter is made up of particles

Answers

Answer:

When sugar dissolves, the sugar particles separate from each other and mix with the water particles. When the sugar particles separate, the smaller water particles fit into the spaces between the larger sugar particles. The water and sugar particles are attracted to each other, so they move closer together when they mix.

Explanation:

:  )

Which is a pure substance?

They are chemically bonded together.
They can be classified as pure substances.
They have fixed ratios between their components.
They can be separated by physical processes.

Answers

Answer: C. They have fixed ratios between their components.

Please help, it’s much appreciated



If the hydrogen ion concentration,
[H+], in a solution is 2.65 x 10-2 M,
what is [OH-]?

Answers

Answer: acidic

Explanation:

Answer:

3.77 x 10^-13 M

Explanation:

HELPPPPPP

is this
1:conduction
2:radiation
3:convection

Answers

Answer:

Radiation

Explanation:

Sun rays shine on earth. Thats radiation.

Which material would get electrons from the source to the load the fastest

Answers

Answer:

Copper

Explanation:

Because copper conducts a lot of electricity, and gets the most electrons


Can someone help me I only have 5 minutes left.

Answers

Graph 4. Graph 4 is the answer but I need 20 characters

someone on this planet please help me with this vocab

Answers

Answer:

1 - concentrated solution

2- dilute solution

3- solubility

4- saturated solution

5- supersaturated solution

6- unsaturated solution

7- acid

8- base

9- corrosive

10- indicator

Explanation:

the formula of calcium oxide is CaO. What is the formula of the ionic compound containing calium abd sulfate ions

Answers

Answer:

[tex]CaS[/tex]

Explanation:

Hello!

In this case, since calcium's oxidation state when forming ionic bonds is +2 and sulfur's oxidation state when bonding those bonds is -2, for the required formula we write:

[tex]Ca^{2+}S^{2-}[/tex]

Now, since they have the same charge number, we infer the ionic compound formed when they bond is calcium sulfide:

[tex]CaS[/tex]

Best regards!

Which element has the highest electronegativity?

Answers

Answer:

fluorine

Explanation:

has the highest electronegativity?

1
MS-LS1-1, MS-LS1-2
Structure and
Function of Cells
-, -
1. Which of the following is not stated in the cell
theory?
A. Cells are the basic unit of structure and
function in all living things.
B. Animal cells are generally more complex
than plant cells.
C. All living things are composed of cells.
D. All cells are produced from other cells.
Ok

Answers

Number b, because nothing mentions that:))

Which event would most likely lead to a thunderstorm g i v i n g b r a i n l e s i t HELP
--

Answers

Answer:

A

Explanation:

hope it helps

Answer:

A

Explanation:

I got right

Pure sodium metal reacts violently with water according to the equation below
Na + H2O - NaO + H2
17 mol
If 0.75 mol of Na is placed in 500 g of
H,O how many moles of hydrogen
gas will be produced?
0.75 mol
28 mol
1.5 mol

Answers

Answer:

0.75 mol

Explanation:

Given data:

Number of moles of Na = 0.75 mol

Mass of water = 500 g

Moles of hydrogen gas produced = ?

Solution:

Chemical equation:

Na + H₂O   →      NaO + H₂

Number of moles of water:

Number of moles = mass/molar mass

Number of moles = 500 g/ 18 g/mol

Number of moles = 27.8 mol

now we will compare the moles of hydrogen gas with both reactant.

                   Na         :          H₂

                    1            :          1

                  0.75       :         0.75

                 H₂O        :          H₂

                   1            :           1

               27.8          :         27.8

sodium will act as limiting reactant it produced small number of moles of hydrogen gas as compared to water.

Thus, number of moles of hydrogen gas are 0.75 mol.

HELPPP PLEASEEE

is this
1: radiation
2: conduction
3: convection

Answers

Number 2: Conduction.

This is an example of #2, conduction.

Conduction is the process where heat energy is transmitted through collisions between atoms or molecules.

Solids, liquids and gases are all
considered to be forms of matter.
Each of these take up space and also
exhibit what other significant
characteristic?
A. color
B. smell
C. texture
B. mass

Answers

Answer:

mass

Explanation:

hope this helps you!!

I want to say texture but I’m not 100%

how is the strength of an acid affected by the number of hydrogen ions it contains​

Answers

More the no. of hydrogen ions more is the solution acidic.

pH means the power of hydrogen that determines the concentration of hydrogen ions or the level of acidiy or basicity of a solution.

so more the hydrogen ions more will be the Power of Hydrogen (pH) and thus more wil be the acidity.

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