*explain your answer for brainliest
Aluminum reacts with chlorine gas to produce aluminum chloride according to the following equation.


Al + Cl2 → AlCl3


Which of the following fractions can be used for the mole ratio to determine the mass of Cl2 from a known mass of AlCl3?


two over one

three over two

one over two

two over three

It is in the center and everything surrounds it

This is false. An alcohol does indeed have a polar C-O single bond, but what we should really be focusing on is the extraordinarily polar O-H single bond. When oxygen, fluorine, or nitrogen is bound to a hydrogen atom, there is a small (but not negligible) charge separation, where the eletronegative N, O, or F has a partial negative charge, and the H has a partial positive charge. Water has two O-H single bonds in it (structure is H-O-H). The partially negative charge on the O of the water molecule (specifically around the lone pair) can become attracted either a neighboring water molecule's partially positive H atom, or an alcohol's partially positive H atom. This is weak (and partially covalent) attraction is called a hydrogen bond. This is stronger than a typical dipole-dipole attraction (as would be seen between neighboring C-O single bonds), and much stronger than dispersion forces (between any two atoms). When the solvent (water) and the solute (the alcohol) both exhibit similar intermolecular forces (hydrogen bonding being the most important in this case), they can mix completely in all proportions (i.e. they are miscible) in water.

Answer:

Explanation:

Took test got it right.

Explanation: A thermochemical equation is a balanced chemical equation which require an enthalpy change.

A balanced equation is the equation in which number of atoms on reactant side is same as the number of atoms on product side.

A thermochemical equation for [tex]CaCl_2+H_2O[/tex] is:

[tex]CaCl_2+2H_2O\rightarrow Ca(OH)_2+2HCl+heat[/tex]

Here, heat is released in the reaction hence, it is a type of exothermic reaction.

A thermochemical equation for [tex]NH_4NO_3+H_2O[/tex] is:

[tex]NH_4NO_3+heat\overset{water}{\rightarrow} NH_4^++NO_3^-[/tex]

Here, heat is absorbed in the reaction hence,it is a type of endothermic reaction.

Answer:

D) is the correct answer on usatestprep

Explanation:

Answer:

C It dictates that the number of atoms of each element must be the same on both sides of a chemical equation.  

Step-by-step explanation:

Atoms have mass, so they can neither be destroyed nor created.

Thus, the number of atoms of each element must be the same on both sides of a balanced chemical equation.  

A is wrong. Molecules consist of different numbers of atoms, and it is atoms that must be conserved.

B is wrong. the Law of conservation of Mass applies to all chemical reactions.

D is wrong. If the reaction proceeds, the mass of reactants must decrease as they are converted to products.

Answer:

The correct answer is option C.

Explanation:

Law of conservation of mass states that mass can neither be created nor be destroyed but it can only be transformed from one form to another form.  

This also means that total mass on the reactant side must be equal to the total mass on the product side that also means the number of atoms of each element must be the same on both sides of a chemical equation.

For example:

[tex]2H_2+O_2\rightarrow 2H_2O[/tex]

Number of hydrogen and oxygen atoms on both sides are equal.

Answer: Photoelectric is characterized by or involving the emission of electrons from a surface by the action of light.

Photoelectric effect is the emission of electrons when a radiation of frequency higher than the threshold frequency falls on the surface of an element. The substance which undergoes photoelectric effect is called as photoelectric.

Ground state is the state representing the lowest energy  state.

Excited state is the state which represents a high energy state.

An electron in ground state absorbs energy to move to the excited state.

density = mass/volume

Answer:

Why is volleyball considered to be such a good aerobic exercise?

Explanation:

The moles of KClO₃  that were consumed  is  0.343  moles

    calculation

2KClO₃ →  2KCl +3O₂

 step  1: find the  moles    KCl

moles   = mass÷ molar mass

 25.6 g÷74.55 g/mol =0.343  moles

Step 2 : use the  mole  ratio to determine    the  moles  KClO₃

  from  equation above KClO₃ : KCl  is 2:2  =1:1

     therefore   the  moles  KClO₃  = 0.343  moles

1.) The modern atomic theory has been updated over the years..

the correct option is:

C. The changes make the theory stronger because it has been tested and edited multiple times, making it more durable.        

2. In Rutherfords experiment,Based on Thomson's plum pudding model of the atom, what did Rutherford expect to happen;

A. All the alpha particles would be deflected by the foil because of the even distribution of mass and charge throughout the atom.

According to Thomson's plum pudding model of the atom the positive and negative charges are evenly distributed.

Changes in atomic theory show its strength through rigorous testing and refinement, and Rutherford's experiment disproved the plum pudding model by showing atoms have a dense nucleus since not all alpha particles passed straight through the gold foil.

1. The changes in the modern atomic theory illustrate the dynamic nature of scientific exploration. Option C is the correct answer, as these changes make the theory stronger because it has been tested and edited multiple times, making it more durable. Scientific theories evolve over time through experimentation and observation, and the ability to adapt and refine a theory in the light of new evidence is a sign of its robustness.

Regarding Rutherford's famous experiment, based on Thomson's plum pudding model of the atom, Rutherford expected that the alpha particles would pass essentially straight through the foil with only slight deflection. This is because the plum pudding model posited that atoms had an even distribution of mass and charge.

2. The correct answer is Option B: All the alpha particles would pass straight through the foil because of the even distribution of mass and charge throughout the atom. However, the unexpected result of alpha particles being deflected at large angles or even straight back led to the conclusion that Thomson's model was incorrect and that atoms have a dense, positively charged nucleus at their center.

Answer:

4.563 times more energy.  

Step-by-step explanation:

The ionization energy of hydrogen is 1312.0 kJ·mol⁻¹.

The second ionization energy of Li (the first ionization energy of Li⁺) is 7298.1 kJ·mol⁻¹.

Ratio = 7298.1/1312.0

Ratio = 5.563

The ionization energy of Li⁺ is 5.563 times as much as, or 4.563 times more than, the ionization energy of H.

Answer:

ΔH = -22 kcal

Step-by-step explanation:

N₂(g) + 3H₂(g) ⇌ 2NH₃(g) + 22 000 cal

Energy is on the right-hand side of the equation, so it is being released by the system.

The thermodynamic convention is that energy going out of a system is negative. Thus,

ΔH = -22 000 cal     Convert to kilocalories

ΔH = -22 kcal

A and B are both wrong, because you divide by 1000 to convert calories to kilocalories.

C is wrong, because the sign must be negative for an exothermic reaction.

The enthalpy change (ΔH) for the reaction N2(g) + 3H2(g) → 2NH3(g), which releases 22,000 calories, is -22,000 kcal.

The question is asking for the enthalpy change (ΔH) of the reaction where nitrogen gas (N2(g)) reacts with hydrogen gas (3H2(g)) to form ammonia (2NH3(g)). The enthalpy change is given in calories, and the options are either positive or negative, indicating an endothermic or exothermic reaction, respectively. The reaction as provided shows that it releases 22,000 cal, which means it's exothermic and ΔH should be negative. Therefore, the value of ΔH for the reaction N2(g) + 3H2(g) → 2NH3(g) is -22,000 kcal.

True

Answer:

true

Explanation:

took test!

Final answer:

Sodium acetate (NaCH₃CO₂) is a basic salt formed from the reaction of acetic acid, a weak acid, with NaOH, a strong base. It reacts with water to produce hydroxide ions, causing the solution to be slightly basic.

Explanation:

When acetic acid, a weak acid, reacts with NaOH, a strong base, the resulting product is a salt called sodium acetate (NaCH₃CO₂). This compound is considered a basic salt due to the hydrolysis of the acetate ion in water. The acetate ion (C₂H₃O₂⁻) reacts with water to produce hydroxide ions (OH⁻), which make the solution slightly basic. In the process, sodium acetate (NaC₂H₃O₂) is formed along with water. The equation for this neutralization reaction is:

CH₃CO₂H (aq) + NaOH (aq) → NaCH₃CO₂ (aq) + H₂O (aq)

Answer:

C) Synthetic rubber has different monomers than natural rubber

Explanation:

Hello,

In this case, since statements A and B are correct due to the abundance of natural rubber and that both of them have the same properties making then suitable for several applications specially in the production of tires, belts, hoses, footwear and others, chemically, the best statement is C since the main monomers associated with synthetic rubber are derived from the petroleum byproducts such as styrene-butadiene whose condensation lead to the polymer forming the rubber. However, natural rubber is based on the isoprene (2-methyl-1,3-butadiene) as the promoting monomer whose polymerization lead to its formation.

Best regards.

Hey there!

The Buoyant force is going to be equal to the weight of the water displaced and it would be like this 100 L(9.8 N/L) = 980 N.

Hope this helped and mind marking me brainliest. Thank you!

A CH₄ molecule has four C-H bonds. Each of the C-H bonds is weakly polar. However, the molecule has a tetrahedral shape. The shape itself is symmetric.

As a result, charges on the four C-H bonds have a symmetric distribution. They cancel out within the molecule. Overall, the molecule is nonpolar.

The correct statement describing the charge distribution and the polarity of a [tex]{\text{C}}{{\text{H}}_{\text{4}}}[/tex] molecule is as follows:

[tex]\boxed{{\text{The charge distribution is symmetrical and the molecule is nonpolar}}}[/tex].

Further Explanation:

The most important factor in determining the polarity of a bond is the difference in the electronegativity values of the bonded atoms. If there is an electronegativity difference between the bonded atoms, the molecule is said to be polar and vice-versa.

Another factor that plays a significant role in governing the bond polarity is symmetry. If a molecule has symmetry or symmetrical charge distribution, it is said to be nonpolar due to the cancellation of the individual dipole moments present in the molecule and vice-versa.

 consists of one carbon atom and four hydrogen atoms. In this molecule, carbon acts as the central atom and four hydrogen atoms are placed around it in symmetrical positions so the net dipole moment becomes zero. As a result, this molecule is non-polar and has a symmetrical charge distribution (For structure, refer to the attached image).

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Answer details:

Grade: High School

Chapter: Ionic and covalent compounds

Subject: Chemistry

Keywords: polar, nonpolar, symmetry, dipole moment, zero, symmetrical charge distribution, carbon, hydrogen, CH4.

Caffeine has the following percent composition: carbon 49.48%, hydrogen 5.19%, oxygen 16.48% and nitrogen 28.85%. Its molecular weight is 194.19 g/mol.

The percent composition of carbon in caffeine (C8H10N4O2) is calculated by dividing the total mass of carbon in one mole of the substance by its molar mass and multiplying by 100, which equals 49.48%.

The student has asked for the percent composition of carbon in caffeine, with the molecular formula C₈H₁₀N₄O₂. To calculate the percent composition, we first need to determine the molar mass of caffeine using the atomic masses of carbon (C), hydrogen (H), nitrogen (N), and oxygen (O). Then, we calculate the percentage by dividing the total mass of carbon in one mole of caffeine by the molar mass of caffeine and multiply by 100.

To calculate the percent composition of carbon in caffeine:

From the balanced equation  3 moles of oxygen are produced from 2 molecules of potassium chlorate.

So the number of moles of oxygen from 1 mole of chlorate = 3/2 = 1.5.

By proportion  the number of moles produced from 6 moles of  the chlorate =

= 6 * 1.5  = 9 moles  (answer).

Considering the reaction stoichiometry, the correct answer is the last option: the total number of moles of O₂ produced by the decomposition of 6.0 moles of potassium chlorate is 9 moles.

The balanced reaction is:

2 KClO₃ → 2 KCl + 3 O₂

By reaction stoichiometry (that is, the relationship between the amount of reagents and products in a chemical reaction), the following amounts of moles of each compound participate in the reaction:

Then you can apply the following rule of three: if by stoichiometry 2 moles of KClO₃ produce 3 moles of O₂, 6 moles of KClO₃ will produce how many moles of O₂?

[tex]amount of moles of O_{2}=\frac{6 moles of KClO_{3} x 3moles of O_{2}}{2moles of KClO_{3} }[/tex]

amount of moles of O₂= 9 moles

Finally, the correct answer is the last option: the total number of moles of O₂ produced by the decomposition of 6.0 moles of potassium chlorate is 9 moles.

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(a) A material that can be melted and reformed at a low temperature.

1)ionic solid      

2) molecular solid  

3)metallic solid  

4)covalent network solid

(b) A material that can be drawn into long, thin wires.  

1)ionic solid  

2)molecular solid  

3)metallic solid

4)covalent network solid

(c) A material that conducts electricity when molten.

1)ionic solid  

2)molecular solid  

3)metallic solid  

4)covalent network solid  

(d) An extremely hard material that is non-conductive.

1)ionic solid  

2)molecular solid  

3)metallic solid  

4)covalent network solid

Answer:

A- molecular solid

B-metallic solid

C-ionic solid

D-covalent network solid

Explanation:

A molecular solid is held together by weak vanderwaals forces. It can be melted easily but reformed at low temperature when the kinetic energy of molecules is sufficiently reduced. An ionic solid is a network of oppositely charged ions linked together into a three dimensional rigid network. The ions are immobile hence it cannot conduct electricity in the solid state. When the solid melts, the ions become free hence it can now conduct electricity. Metals can be drawn into wire (ductility), this is a fundamental property of metals. Covalent network solid are hard and often have no free valence electrons e.g diamond. They do not conduct electricity

We must to know:

Cm = molarity = niu / Vs, when the niu = no. of moles and Vs = Volume of solution

the no. niu = mass / molecular mass of substance

molecular mass of C8H8 = 12x8+8x1 = 104 g/mol

=> niu = 1,5 / 104 = 0,0144 moles C8H8

=> Cm = 0,0144/0,225 = 0,06 mol/L

Cmm = molality = niu (C8H8) / mass of solvent (kg)

=> p = mass / V => mass (solvent) = p x V

=> 225 x 1,02 = 229,5 g solvent = 0,2295 kg solvent

=> Cmm = 0,0144 / 0,229,5 = 0,063

Answers:

a. 0.064 mol/L; b. 0.063 mol/kg

Explanation:

a. Molar concentration

c = moles/litres

=====

Moles = 1.5 × 1/104.15

Moles = 0.0144 mol

=====

Litres = 225. × 1/1000

Litres = 0.225. L

=====

c = 0.0144/0.225.

c = 0.064 mol·L⁻¹

===============

b. Molal concentration

b = moles of solute/kilograms of solvent

=====

Mass of solvent = 225. × 1.02/1

Mass of solvent = 229.5 g      Convert to kilograms

Mass of solvent = 0.2295 kg

=====

b = 0.0144/0.2295

b = 0.063 mol/kg

A chemical reaction absorbs energy which means it is endothermic reaction.

The reaction is endothermic if the energy of products is more than the energy of reactants.

The energy of products is more means that the bond energy of products is more than the bond energy of reactants.

so breaking of bond needs energy which is greater than the energy released in making of new bonds.

Enthalpy of reaction = Bond energy of reactants - Bond energy of products.

Answer:

its all of them

Explanation:

i got it off of edmentum

False, photons emit ir in other ways.

Answer : The maximum number of grams of [tex]PH_3[/tex] formed is, 8.955 g

Solution : Given,

Mass of phosphorous = 8.2 g

Mass of hydrogen = 4 g

Molar mass of [tex]P_4[/tex] = 123.6 g/mole

Molar mass of [tex]H_2[/tex] = 2.016 g/mole

Molar mass of [tex]PH_3[/tex] = 33.924 g/mole

The balanced chemical reaction is,

[tex]P_4(s)+6H_2(g)\rightarrow 4PH_3(g)[/tex]

First we have to calculate the moles [tex]P_4[/tex] and [tex]H_2[/tex]

[tex]\text{ Moles of }P_4=\frac{\text{ Mass of }P_4}{\text{ Molar mass of }P_4}=\frac{8.2g}{123.6g/mole}=0.066moles[/tex]

[tex]\text{ Moles of }H_2=\frac{\text{ Mass of }H_2}{\text{ Molar mass of }H_2}=\frac{4g}{2.016g/mole}=1.98moles[/tex]

From the reaction, we conclude that

1 mole of [tex]P_4[/tex] react with 6 moles of [tex]H_2[/tex]

0.066 moles of [tex]P_4[/tex] react with [tex]6\times 0.066=0.396[/tex] moles of [tex]H_2[/tex]

That means the [tex]H_2[/tex] is in excess amount and [tex]P_4[/tex] is in limited amount.

Now we have to calculate the moles of [tex]PH_3[/tex].

As, 1 mole of [tex]P_4[/tex] react to give 4 moles of [tex]PH_3[/tex]

So, 0.066 moles of [tex]P_4[/tex] react to give [tex]4\times 0.066=0.264[/tex] moles of [tex]PH_3[/tex]

Now we have to calculate the mass of [tex]PH_3[/tex]

[tex]\text{ Mass of }PH_3=\text{ Moles of }PH_3\times \text{ Molar mass of }PH_3[/tex]

[tex]\text{ Mass of }PH_3=(0.264moles)\times (33.924g/mole)=8.955g[/tex]

Therefore, the maximum number of grams of [tex]PH_3[/tex] formed is, 8.955 g

You might be referring to alkali metals.

Alkali metals are in group 1 of the periodic table.

Alkali metals have a silvery color. Like nearly all main group metals, they reflect light from the entire visible spectrum.

Each of the group 1 atom have one single valence electron. Removing that electron is easy. They are one electron away from the nearest noble gas element. Removing that extra electron will give the atom an empty valence shell. The atom gains stability through that process.

Alkali metals will readily lose its electrons to non-metals such as oxygen, chlorine, and fluorine. They react with water to form a base and hydrogen gas- hence the name alkali. They are too reactive to exist in nature as metals. That's one of the reasons why power packs containing lithium (an alkali metal) should not be cut open at home. They might catch fire when exposed to the air and have a good chance of creating an explosion.

Alkali metals have low m.p. and b.p. among all the metals. They are easy to cut under room temperature. The softness (a.k.a. malleability), melting point, and boiling point of a metal depends on the strength of the bond between its atoms. Each of the group 1 alkali metal atom has one single electron, whereas metals like aluminum have three. Metallic bonds between alkali metal atoms are much weaker than those between aluminum atoms. As a result, it takes less energy to pull alkali metal atoms apart. They are easier to melt, boil, or cut than metals from other groups. For example, it is possible to tear a chunk of sodium but not iron apart by hand.

Alkali metals are likely to be less dense than any other metals on the periodic table. Elements from the same period have an equal number of electron shells. Alkali metals have less protons per atom than elements from the rest of the period. They weakly attract their electron shells and have a large atomic and ionic radius. An alkali metal will have a lofty structure, while metals to the right of the period are more tightly packed.  Alkali metals will have less mass per unit space and have a lower density. For example, typical power banks contain lithium ions rather than nickel. Lithium is lighter than nickel; it allows the battery pack to store more energy per unit mass.

Alkali metals are silvery, soft, highly reactive elements with low melting and boiling points, and are found in Group 1 of the periodic table. These include lithium, sodium, potassium, rubidium, cesium, and francium.

The silvery metals that are soft, highly reactive, and too reactive to be found free in nature, characterized by low melting and boiling temperatures, and low densities, are known as alkali metals. These elements make up Group 1 of the periodic table and include lithium (Li), sodium (Na), potassium (K), rubidium (Rb), cesium (Cs), and francium (Fr). Alkali metals react rapidly with water to form hydroxides and hydrogen gas, and they must be stored under oil to prevent reactions with moisture and oxygen from the air.

Their reactivity is due to having one electron in their outermost energy level, which they can easily lose to form positive ions with a charge of +1.

Answer: hydrogen atom of a polarized molecule bonds with an electro negative atom.

Explanation:

Hydrogen bonds are special type of dipole dipole forces which are formed when hydrogen bonds with an electro negative element. Hydrogen bonds are strongest type of bonds .Example: Bond between Oxygen of one water molecule to the hydrogen of another water molecule as shown in the image below.

Covalent bonds are formed by sharing of electrons among non metals.

Ionic bond is formed by transfer of electrons between metals and non metals.

Answer : The volume of neon gas will be, 7.99 liters.

Explanation : Given,

Mass of argon (Ar) gas = 27.1 g

Molar mass of argon = 39.95 g/mole

Volume of argon gas = 4.21 L

Moles of neon (Ne) gas = 1.29 mole

First we have to calculate the moles of argon gas.

[tex]\text{Moles of }Ar=\frac{\text{Mass of }Ar}{\text{Molar mass of }Ar}=\frac{27.1g}{39.95g/mole}=0.68moles[/tex]

Now we have to calculate the volume of neon gas.

According to the Avogadro's law, the volume of gas is directly proportional to the number of moles of gas at same pressure and temperature. That means,

[tex]V\propto n[/tex]

or,

[tex]\frac{V_1}{V_2}=\frac{n_1}{n_2}[/tex]

where,

[tex]V_1[/tex] = volume of argon gas

[tex]V_2[/tex] = volume of neon gas

[tex]n_1[/tex] = number of moles of argon gas

[tex]n_2[/tex] = number of moles of neon gas

Now we put all the given values in this formula, we get

[tex]\frac{4.21L}{V_2}=\frac{0.68mole}{1.29mole}[/tex]

[tex]V_2=7.99L[/tex]

Therefore, the volume of neon gas will be, 7.99 liters.

The unknown substance that Melinda is encountering in her experiment is most likely a metal, based on its ability to reflect light, warm up in the hand, flatten upon impact, and conduct electricity. These are all characteristic properties of metals.

Based on the properties of the substance highlighted by Melinda - the ability to reflect light, warm up in the hand, flatten out when hit with a hammer, and conduct electricity - it suggests that she is dealing with a metal. These are standard characteristics of metals, which are usually shiny (reflect light), malleable (can be flattened), conductive to heat and electricity, and are known to warm up when handled due to their conductivity.

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Answer:- 6.91 kj of heat is needed.

Solution:- We have solid ethanol at -135 degree C and wants to calculate the heat required to convert it to -50 degree C liquid ethanol.

Melting point of ethanol is -114 degree C. So, it is a three step process. In the first step, -135 degree C solid ethanol changes to -114 degree C solid ethanol.

In second step, -114 degree C solid ethanol melts to -114 degree C liquid ethanol. In third step, -114 degree C liquid changes to -50 degree C liquid.

for the first and third step, there is a change in temperature and so we use the equation, [tex]Q=ms\Delta T[/tex]

where, Q is the heat energy, m is mass in grams, s is specific heat capacity in joule per gram per degree C and [tex]\Delta T[/tex] is the change in temperature.

For second step, there is a phase change so the equation used is, [tex]Q=m\Delta H_f_u_s[/tex]

where [tex]\Delta H_f_u_s[/tex] is the enthalpy of fusion.

Let's do the calculations for the first step:-

[tex]\Delta T[/tex] = -114-(-135) = 21 degree C

m = 25.0 g

s = 0.97 J per g per degree C

[tex]Q_1=25.0g(0.97\frac{J}{g.^0C})(21^0C)[/tex]

[tex]Q_1[/tex] = 509.25 J

let's convert this J to kj

[tex]509.25J(\frac{1kj}{1000J})[/tex]

= 0.509 kj

For the second step we need the moles of ethanol as the enthalpy of fusion is given in kj per mol. Molar mass of ethanol is 46.07 g per mol.

[tex]25.0g(\frac{1mol}{46.07g})[/tex]

= 0.543 mol

[tex]Q_2=0.543mol(\frac{5.02kj}{mol})[/tex]

[tex]Q_2[/tex] = 2.72 kj

For the third step, [tex]\Delta T[/tex] = -50 -(-114) = 64 degree C

[tex]Q_3=25.0g(2.3\frac{J}{g.^0C})(64^0C)[/tex]

[tex]Q_3[/tex] = 3680 J

[tex]3680J(\frac{1kj}{1000J})[/tex]

= 3.68 kj

total Q = [tex]Q_1+Q_2+Q_3[/tex]

total Q = 0.509 kj + 2.72 kj + 3.68 kj

total Q = 6.909 kj

this could be round to 6.91 kj.

So, 6.91 kj of heat is needed to convert -135 degree C solid ethanol to -50 degree C ethanol.

Final answer:

To convert 25.0 g of solid ethanol at -135°C to liquid ethanol at -50°C, approximately 9.161 kJ of heat is needed. This involves heating the solid, melting it, and then heating the liquid to the final temperature.

Explanation:

To calculate the heat needed to convert 25.0 g of solid ethanol at -135°C to liquid ethanol at -50°C, three steps are involved:

Calculate the heat required to raise the temperature of solid ethanol from -135°C to its melting point at -114°C.

Calculate the heat absorbed when solid ethanol melts at -114°C.

Calculate the heat required to raise the temperature of liquid ethanol from -114°C to -50°C.

Using the specific heat of solid ethanol (0.97 J/g·K) for the first part:

q1 = mass x specific_heat_solid x ∆T_solid = 25.0 g x 0.97 J/g·K x (114 K) = 2763 J or 2.763 kJ

For the phase change at the melting point:

q2 = moles x enthalpy_fusion = (25.0 g / 46.07 g/mol) x 5.02 kJ/mol = 2.718 kJ

Finally, for the temperature increase of the liquid phase, using its specific heat:

q3 = mass x specific_heat_liquid x ∆T_liquid = 25.0 g x 2.3 J/g·K x (64 K) = 3680 J or 3.680 kJ

The total heat (q_total) is the sum of q1, q2, and q3:

q_total = q1 + q2 + q3 = 2.763 kJ + 2.718 kJ + 3.680 kJ = 9.161 kJ

So, approximately 9.161 kJ of heat is needed to convert 25.0 g of solid ethanol at -135°C to liquid ethanol at -50°C.

I am not sure if this is what you are looking for, I have done a bit searching.

1 mol = 6..20 x 103 particles (atoms, molecules, formula units)

1 mol = molar mass/formula mass (Periodic Table)

1 mo = 22.4 L for a ga at STP

The three mole equalities are 1 mole = 6.20 x 103 particles,1 mole = molar mass/formula mass 1 mole = 22.4 L for a gas at STP.

Mole is defined as the unit of amount of substance . It is the quantity measure of amount of substance of how many elementary particles are present in a given substance.

It is defined as exactly 6.022×10²³ elementary entities. The elementary entity can be a molecule, atom ion depending on the type of substance. Amount of elementary entities in a mole is called as Avogadro's number.

It is widely used in chemistry as a suitable way for expressing amounts of reactants and products.For the practical purposes, mass of one mole of compound in grams is approximately equal to mass of one molecule of compound measured in Daltons. Molar mass has units of gram per mole . In case of molecules, where molar mass  in grams present in one mole  of atoms is its atomic mass.

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BaO..........................

The other reactant in the given reaction is [tex]\boxed{{\text{BaO}}}[/tex].

Further explanation:

A chemical reaction involves the rearrangement of the constituents of reactants to form new substances called products. Chemical reactions can be classified into the following five types:

1. Combination reactions

The chemical reactions where the combination of two or more reactants yields a single product are known as combination reactions. These are normally exothermic in nature.

Examples of combination reactions are as follows:

(a) [tex]{{\text{H}}_2} + {\text{C}}{{\text{l}}_2} \to {\text{2HCl}}[/tex]  

(b) [tex]{\text{CaO}} + {{\text{H}}_2}{\text{O}} \to {\text{Ca}}{\left( {{\text{OH}}} \right)_2}[/tex]  

2. Decomposition reactions

In these types of reactions, two or more products are produced from a single reactant. These are usually endothermic in nature.

Examples of decomposition reactions are as follows:

(a) [tex]2{{\text{H}}_2}{{\text{O}}_2} \to 2{{\text{H}}_2}{\text{O}} + {{\text{O}}_2}[/tex]  

(b) [tex]2{\text{NaCl}} \to {\text{2Na + C}}{{\text{l}}_2}[/tex]  

3. Displacement reactions

In these reactions, one of the reactants replaces another one due to its high reactivity. These reactions are also called replacement reactions.

Examples of displacement reactions are as follows:

(a) [tex]{\text{Cu}} + {\text{AgN}}{{\text{O}}_3} \to {\text{Ag}} + {\text{Cu}}{\left( {{\text{N}}{{\text{O}}_3}} \right)_2}[/tex]  

(b) [tex]{\text{C}}{{\text{l}}_2} + {\text{KBr}} \to {\text{B}}{{\text{r}}_2} + {\text{KCl}}[/tex]  

4. Double displacement reactions

In these reactions, ions of two compounds interchange with each other to form the product.

Examples of double displacement reactions are as follows:

(a) [tex]{\text{N}}{{\text{a}}_2}{\text{S}} + {\text{HCl}} \to {\text{NaCl}} + {{\text{H}}_2}{\text{S}}[/tex]  

(b) [tex]2{\text{KOH}} + {\text{Cu}}{\left( {{\text{N}}{{\text{O}}_{\text{3}}}} \right)_2} \to 2{\text{KN}}{{\text{O}}_3} + {\text{Cu}}{\left( {{\text{OH}}} \right)_2}[/tex]  

5. Combustion reactions

These reactions occur when hydrocarbons are burnt in the presence of oxygen. Here, carbon dioxide and water are produced.

Example of combustion reactions are as follows:

(a) [tex]{\text{C}}{{\text{H}}_4} + {{\text{O}}_2} \to {\text{C}}{{\text{O}}_2} + {{\text{H}}_2}{\text{O}}[/tex]  

(b) [tex]{{\text{C}}_{10}}{{\text{H}}_{14}} + 12{{\text{O}}_2} \to 10{\text{C}}{{\text{O}}_2} + 4{{\text{H}}_2}{\text{O}}[/tex]  

One of the reactants is [tex]{{\text{H}}_{\text{2}}}{\text{O}}[/tex] and the given reaction is a combination reaction. When BaO reacts with [tex]{{\text{H}}_{\text{2}}}{\text{O}}[/tex], it produces [tex]{\text{Ba}}{\left( {{\text{OH}}} \right)_{\text{2}}}[/tex]. The reaction occurs as follows:

 [tex]{\text{BaO}} + {{\text{H}}_{\text{2}}}{\text{O}} \to {\text{Ba}}{\left( {{\text{OH}}} \right)_{\text{2}}}[/tex]

Therefore the other reactant in the given reaction is found to be BaO.

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Answer details:

Grade: High School

Chapter: Chemical reaction and equation

Subject: Chemistry

Keywords: types of reactions, combination reaction, decomposition reaction, double displacement reaction, combustion reaction, BaO, H2O, Ba(OH)2, reactants, products.