What are chemical equations used to represent?​

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.

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.

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

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.

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

Answer:

Radiation

Explanation:

Sun rays shine on earth. Thats radiation.

Answer:

54g of O2 reacted in the reaction

Answer:

54g

Explanation:

Answer:

gas to liquid

Explanation:

think of water vapor condensing on glass when you breathe on it for a while.

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

This is an example of #2, conduction.

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

Moles of NO formed : 0.833

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]

Answer:

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

Explanation:

volume units id in cubic centimeters

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

Answer:

fluorine

Explanation:

has the highest electronegativity?

Answer: acidic

Explanation:

Answer:

3.77 x 10^-13 M

Explanation:

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:

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

Answer:

mass

Explanation:

hope this helps you!!

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!!

Answer:

A

Explanation:

hope it helps

Answer:

A

Explanation:

I got right

Answer:

Copper

Explanation:

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

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.

Answer:

Solid

Explanation:

In solid there are strong intermolecular forces present as compared to liquid and gas. This is why solid are in more packed form as compared to liquid and gas. In liquid and gas intermolecular forces are week that's why molecules are away from each other and occupy more space.

Properties of gases:

Molecule of gases randomly move everywhere and occupy all available space.

Gases don't have definite volume and shape and take the shape and volume of container in which it present.

Their densities are very low as compared to the liquid and solids.

Gas molecules are at long distance from each other therefore by applying pressure gases can be compressed.

The very weak inter molecular forces are present between gas molecules.

Properties of Liquid:

Liquid have definite volume but don't have definite shape.

Their densities are high as compared to the gases but low as compared to the solids.

In liquid, molecules are close to each other and have greater inter molecular forces as compared to the gas molecules.

Properties of solids:

Solids have definite volume and shape.

In solids molecules are tightly pack and very close to each other.

Their melting and boiling point are every high.

The densities of solids are also very high as compared to the liquid and gas.

There are very strong inter molecular forces are present between solid molecules.

Answer:

A: Solid

Explanation:

Correct with Acellus

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≅        

Answer:

B

Explanation:

by simlfying it you get HCO2

Answer:

Roman numeral notation indicates charge of ion when element commonly forms more than one ion. For example, iron(II) has a 2+ charge; iron(III) a 3+ charge.

Explanation:

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:

:  )

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.