"a sample of helium gas at 27.0 °c and 4.20 atm pressure is cooled in the same container to a temperature of -73.0 °c. what is the new pressure?"

im not sure wow super hard question

Can you please send me whole question picture to better assist you.

Thank you

When 10 g of diethyl ether is converted to vapor at its boiling point, approximately 2.12 kJ of heat is absorbed. This is calculated by first determining the number of moles in 10g of diethyl ether and then multiplying that by the given heat of vaporization.

To calculate the heat absorbed during the vaporization of diethyl ether, we first need to know the number of moles of diethyl ether. The molar mass of diethyl ether (C4H10O) is approximately 74 g/mol. So, 10 g of diethyl ether equates to roughly 0.135 moles (10g / 74g/mol).

Given that the heat of vaporization (δHvap) for diethyl ether is 15.7 kJ/mol, the total heat absorbed can be calculated by multiplying the number of moles by the heat of vaporization. Therefore, total heat absorbed would be approximately 2.12 kJ (0.135 moles * 15.7 kJ/mol).

So, when 10 g of diethyl ether is converted to vapor at its boiling point, approximately 2.12 kJ of heat is absorbed.

https://brainly.com/question/33393699

#SPJ3

To vaporize 10 g of diethyl ether at its boiling point, approximately 2.12 kJ of heat is absorbed. Thus, option C is correct answer.

To find the amount of heat absorbed when 10 g of diethyl ether (C₄H₁₀O) is vaporized, we need to use the enthalpy of vaporization ([tex]\Delta H_{vap}[/tex]) and the molar mass of diethyl ether.

First, calculate the molar mass of diethyl ether (C₄H₁₀O):

Next, determine the number of moles of diethyl ether in 10 g:

Given the enthalpy of vaporization, [tex]\Delta H_{vap}[/tex], is 15.7 kJ/mol, calculate the total heat absorbed using the formula:

Therefore, option c) about 2.12 kJ of heat is absorbed when 10 g of diethyl ether is vaporized at its boiling point of 34.6°C.

The complete question is as follows:

When 10 g of diethyl ether is converted to vapor at its boiling point, how much heat is absorbed? (C₄H₁₀O, [tex]\Delta H_{vap}[/tex] = 15.7 kJ/mol, boiling point: 34.6°C)

A. 20 KJ

B. 0.2 KJ

С. 2.12 kJ

D. 200 KJ

C) The higher number of molecules increases the number of collisions that will occur with the reactants.

Hope this helps!!

Increasing the concentration of a solution leads to a higher rate of reaction due to an increased number of collisions between the reactant molecules.

The correct statement that explains why the rate of reaction increases when the concentration of a solution is increased is option C) The higher number of molecules increases the number of collisions that will occur with the reactants.

When the concentration of a solution increases, there are more particles of the reactants in the same volume. This means that there are more molecules available to collide with each other, leading to an increased chance of successful collisions and a higher rate of reaction.

For example, if you have a solution containing a high concentration of hydrochloric acid and you add more reactant particles, such as magnesium chips, to the solution, there will be more collisions between the hydrochloric acid molecules and the magnesium particles, resulting in a faster reaction.

https://brainly.com/question/8592296

#SPJ3

To calculate the equilibrium constant at 25°C for the given reaction, use the information from the standard reduction potentials given in the question. Write the half-reactions and use the Nernst equation to calculate the cell potential. Then, calculate the equilibrium constant using the relation ΔG = -RTlnK.

To calculate the equilibrium constant at 25°C for the given reaction, we need to use the information from the standard reduction potentials given in the question. We can first write the half-reactions for the species involved in the reaction:

Then, we can use the Nernst equation to calculate the cell potential for the reaction:

E = E0 - (0.0592/n) * log(Q)

Where:

By calculating the cell potential and using the equation ΔG = -nFEcell, where ΔG is the change in Gibbs free energy, F is Faraday's constant, and Ecell is the cell potential, we can then calculate the equilibrium constant K using the relation ΔG = -RTlnK.

By substituting the values into the equations and calculating, we can find the equilibrium constant for the given reaction at 25°C.

Final answer:

To calculate the equilibrium constant for a redox reaction, one must balance the half-reactions, find the standard potentials for both, and then use these values with the Nernst equation and the relationship between free energy and the equilibrium constant.

Explanation:

To calculate the equilibrium constant at 25 °C for the redox reaction given, we need to use the standard reduction potentials of each half-reaction. First, we balance the half-reactions for each species involved.

For MnO⁴⁻ reduction to Mn²⁺:

MnO⁴⁻(aq) + 8H⁺⁺(aq) + 5e⁻ → Mn²⁺(aq) + 4H₂O(l)

For Cl⁻ oxidation to Cl₂:

2Cl⁻(aq) - 2e⁻ → Cl₂(g)

After balancing, we use the Nernst equation to find the standard cell potential (E° cell) by subtracting the standard reduction potential of the anode (E° anode) from the cathode (E° cathode).

E° cell = E° cathode - E° anode

Then, the equilibrium constant (K) is related to the standard cell potential by the following equation, where n is the number of moles of electrons transferred and F is the Faraday constant:

ΔG° = -nFE° cell

And the standard free energy change (ΔG°) is related to the equilibrium constant (K) by the equation:

ΔG° = -RTlnK

Combining these equations and solving for K gives us:

lnK = nFE° cell / RT

By using the standard reduction potentials from the appendix and plugging in the values for n, F, R (the universal gas constant), and T (temperature in Kelvin), we can calculate K.

This approach allows us to understand the spontaneity and the composition of the equilibrium mixture for the reaction in question, providing valuable insights into the chemical process at equilibrium.

The heavy particles all passed straight through the foil, because the atoms are mostly empty space.

Answer is third choice

Answer:  Some of the heavy particles bounced off the foil, because there is a dense, positive area in the atom.

Explanation:

In Rutherford's experiment, he took a gold foil and bombarded it with alpha particles which carry positive charge. He thought that the alpha particles will pass straight through the foil, but to his surprise, many of them passed through, some of them deflected their path and a few of them bounced back.

From this he concluded that in an atom, there exist a small positive charge in the center. Due to this positive charge, the alpha particles deflected their path and some of them bounced straight back their path.

Thus he concluded that there is a dense, positive area in the atom.

Answer:

Explanation:

The law of partial pressures states that, in a mixture of gases, the total pressure of the mixture is equal to the sum of the individual pressures of each gas, as if each gas were alone in the mixture.

So:

They are called earth alkali metals. Elements in groups 3 through 12 have many useful properties and are called transition metals. Elements in group 17 are known as “salt formers”. They are called halogens.

mark me brainliest please!

Group 17 elements, known as halogens, include fluorine, chlorine, bromine, iodine, and astatine. Derived from Greek for "salt forming," they are highly reactive and commonly found in nature as halide salts.

The elements in Group 17 are known as the halogens, a term derived from the Greek words for "salt forming." They include fluorine, chlorine, bromine, iodine, and astatine. Halogens have a distinctive chemical property; they react readily with metals to form compounds like sodium chloride and calcium chloride. Because of their reactivity with alkali metals and alkaline earth metals, they can form a wide range of halide salts.

The elements of Group 17 are characterized by having the general electron configuration ns²np⁵ with seven valence electrons, making them highly reactive as they are one electron short of having a full outer shell. While these elements do not occur freely in nature due to their reactivity, they are abundantly found as halide salts such as those in the mineral fluorspar, which consists mainly of calcium fluoride.

Answer:

Air masses move and meet

Explanation:

The formation, movement, and collision of the air masses is one of the biggest and most noticeable changer of the weather conditions, be it locally, regionally, or globally. The air masses are constantly on the move, with the basic rule being - the heavier, denser air masses move toward the less dense, lighter air masses. Once they come in contact, the denser, heavier air masses push upward or backward the less dense, lighter air masses. The properties of the air masses depend on the place they have formed, so they can be dry, wet, cold, warm, and they are able to change the weather conditions literary in several minutes.

Answer:

Air masses move and meet

Explanation:

Answer:

[tex]\boxed{\text{c) NH$_{3}$; hydrogen bonding}}[/tex]

Explanation:

For each of these molecules, you must determine their VSEPR structure and then identify the strongest intermolecular forces.

Remember that water is a highly polar molecule.

a) CH₄

  Electron geometry: tetrahedral

Molecular geometry: tetrahedral

          Bond polarity: C-H bond nonpolar

  Molecular polarity: nonpolar

        Strongest IMF: London dispersion forces

 Solubility in water: low

A nonpolar molecule is insoluble in a polar solvent.

b) CCl₄

  Electron geometry: tetrahedral

Molecular geometry: tetrahedral

          Bond polarity: C-Cl bond nonpolar

  Molecular polarity: nonpolar (symmetrical molecule. All bond dipoles cancel)

        Strongest IMF: London dispersion forces

 Solubility in water: low

A nonpolar molecule is insoluble in a polar solvent.

d) PH₃

  Electron geometry: tetrahedral

Molecular geometry: trigonal pyramidal

          Bond polarity: P-H bonds are polar

  Molecular polarity: polar (all P-H bond dipoles point towards P)

         Strongest IMF: dipole-dipole

  Solubility in water: soluble

A polar molecule is soluble in a polar solvent.

c) NH₃

  Electron geometry: tetrahedral

Molecular geometry: trigonal pyramidal

          Bond polarity: N-H bonds are highly polar

  Molecular polarity:  highly polar (all N-H bond dipoles point towards N)

         Strongest IMF: hydrogen bonding

  Solubility in water: highly soluble

NH₃ is so polar that it can form hydrogen bonds with water.

[tex]\boxed{\textbf{The compound with the greatest solubility in water is NH$_{3}$}}[/tex]

Answer:

The correct answer is  [tex]NH_{3}[/tex].

Explanation:

The electron geometry of the [tex]NH_{3}[/tex] is tetrahedral and the molecular geometry is a trigonal pyramid.

The [tex]NH_{3}[/tex] has the strongest intramolecular hydrogen bond, which makes them a highly polar molecule.

The polarity is directly proportional to the solubility of the compound in the water.

Therefore,[tex]NH_{3}[/tex]  has the greatest solubility.

For more information, refer to the link:-

https://brainly.com/question/16461135?referrer=searchResults

Limiting reactant is the answer

Answer: i really       dont know srry

Explanation:

Answer:

D) 1/2

Explanation:

Using Ideal gas equation for same mole of gas as

[tex] \frac {{P_1}\times {V_1}}{T_1}=\frac {{P_2}\times {V_2}}{T_2}[/tex]

Given,

P₂ = 4P₁

T₂ = 2T₁

Using above equation as:

[tex] \frac {{P_1}\times {V_1}}{T_1}=\frac {{P_2}\times {V_2}}{T_2}[/tex]

[tex] \frac {{P_1}\times {V_1}}{T_1}=\frac {{4\times P_1}\times {V_2}}{2\times T_1}[/tex]

[tex]V_2=\frac{1}{2}\times V_1[/tex]

The volume change by half of the original.

¹/₂

Given:

Question:

By what factor does the volume of the sample change?

The Process:

We use an equation of state for an ideal gas:  

[tex]\boxed{\boxed{ \ \frac{pV}{T} = constant \ }}[/tex]

For the same amount of substances in two states, the equations for state-1 and state-2 are as follows:

[tex]\boxed{ \ \frac{p_2V_2}{T_2} = \frac{p_1V_1}{T_1} \ }[/tex]

Let us use the equation above to see the relationship between volumes. Enter all the information in the equation.

[tex]\boxed{ \ \frac{4p_1V_2}{2T_1} = \frac{p_1V_1}{T_1} \ }[/tex]

[tex]\boxed{ \ \frac{4V_2}{2} = V_1} \ }[/tex]

[tex]\boxed{ \ 2V_2 = V_1} \ }[/tex]

[tex]\boxed{ \ V_2 = \frac{1}{2}V_1} \ }[/tex]

Thus by factor ¹/₂, the volume of the sample will change.

- - - - - - - - - -

Notes

[tex]\boxed{ \ \frac{pV}{nT} = R \ } \rightarrow \boxed{ \ pV = nRT \ }[/tex]

n = moles of ideal gas

R = the molar gas constant (in J mol⁻¹ K⁻¹)

Keywords: the pressure of a gas sample, an ideal gas, volume, constant, moles, equation of state , quadrupled, the absolute temperature, doubled, by what factor, change

Final answer:

A base is a compound that increases the concentration of hydroxide ions (OH-) in aqueous solution, according to the Arrhenius definition, which also states an acid increases the concentration of hydrogen ions (H+) in an aqueous solution.

Explanation:

A compound which contributes hydroxide ions (OH-) or increases the OH- concentration when dissolved in water is called a base. This definition aligns with the Arrhenius theory, formulated in 1884 by Svante Arrhenius. According to the Arrhenius definition, an acid is a substance that increases the concentration of hydrogen ions (H+) in an aqueous solution, while a base is a substance that increases the concentration of hydroxide ions in an aqueous solution.

An Arrhenius base is typically recognized by its ability to dissociate and release OH- ions into the solution, which can raise the pH level, making the solution more basic. For example, when sodium hydroxide (NaOH) is dissolved in water, it dissociates into Na+ and OH- ions, thereby increasing the hydroxide ion concentration in the solution.

Answer:

Explanation:

The nucleus of an atom is consituted by protons and neutrons. The electrons are out of (surrounding) the nucleus.

The elements are uniquely identified by the atomic number, which is the number of protons.

Since, the mass of the electrons is barely 1 / 1840 times the mass of the protons or neutrons, the mass of the atoms is approximated to the mass of protons and neutrons. The relative mass of neutrons and protons is practically 1.

So, the mass number of an atom is the sum of the protons and neutrons.

The symbols and equation used are:

Hence, to calculate the number of neutrons, N, you solve from that equation:

Which means that to calculate the number of neutrons you subtract the atomic number from the mass number.

To calculate the number of neutrons in an atom, subtract the atomic number (number of protons) from the mass number (total number of protons and neutrons). You can find these numbers on the periodic table for each element.

In order to calculate the number of neutrons in an atom, you must subtract the atomic number from the mass number. The atomic number (Z) represents the number of protons in an atom's nucleus and defines the identity of that atom. For instance, an atom with six protons is the element carbon with the atomic number 6. The mass number (A), on the other hand, is the total number of protons and neutrons in an atom. So, the formula to calculate the number of neutrons is A - Z = number of neutrons.

For example, let's take the element Fe (Iron). Iron has an atomic number of 26, indicating it has 26 protons. Its atomic mass is typically around 56. To find the number of neutrons, simply subtract the atomic number from the mass number: 56 - 26 = 30. Therefore, a typical atom of iron has 30 neutrons.

https://brainly.com/question/13058354

#SPJ3

Answer:

0.643 mol.

Explanation:

where, P is the pressure of the gas in atm (P = 4.0 atm).  

V is the volume of the gas in L (V = 4000 mL = 4.0 L).  

n is the no. of moles of the gas in mol (n = ??? mol).

R is the general gas constant (R = 0.0821 L.atm/mol.K),  

T is the temperature of the gas in K (T = 30ºC + 273 = 303 K).

∴ n = PV/RT = (4.0 atm)(4.0 L)/(0.0821 L.atm/mol.K)(303 K) = 0.643 mol.

Answer:

818.2 g.

Explanation:

M = (no. of moles of NaCl)/(Volume of the solution (L))

M = 2.0 M.

no. of moles of NaCl = ??? mol,

Volume of the solution = 7.0 L.

∴ (2.0 M) = (no. of moles of NaCl)/(7.0 L)

∴ (no. of moles of NaCl) = (2.0 M)*(7.0 L) = 14.0 mol.

no. of moles of NaCl = mass/molar mass

∴ mass of NaCl = (no. of moles of NaCl)*(molar mass) = (14.0 mol)*(58.44 g/mol) = 818.2 g.

Answer:

[tex]\boxed{\text{18.2 kJ}}[/tex]

Explanation:

The formula for the heat involved is  

[tex]q = m\Delta_{\text{f}}\text{H}[/tex]

Data:

m = 115 g

[tex]\Delta_{\text{f}}\text{H} = \text{158.3 J/g}[/tex]

Calculation:

[tex]q = \text{115 g} \times \dfrac{\text{158.3 J}}{\text{1 g}}\\\\q = \text{18 200 J} = \textbf{18.2 kJ}}\\\\\text{It takes }\boxed{\textbf{18.2 kJ}} \text{ to melt the p-xylene}[/tex]

Answer:

CoCl₃ > Li₂SO₄ > NH₄I.

Explanation:

ΔTf = i.Kf.m,

where, ΔTf is the depression in freezing point.

i is the van 't Hoff factor.

Kf is the molal depression constant of water.

m is the molality of the solution.

(1) Li₂SO₄:

i for Li₂SO₄ = no. of particles produced when the substance is dissolved/no. of original particle = 3/1 = 3.

∴ ΔTb for (Li₂SO₄) = i.Kb.m = (3)(Kf)(m) = 3(Kf)(m).

(2) NH₄I:

i for NH₄I = no. of particles produced when the substance is dissolved/no. of original particle = 2/1 = 2.

∴ ΔTb for (NH₄I) = i.Kb.m = (2)(Kf)(m) = 2(Kf)(m).

(3) CoCl₃:

i for CoCl₃ = no. of particles produced when the substance is dissolved/no. of original particle = 4/1 = 4.

∴ ΔTb for (CoCl₃) = i.Kb.m = (4)(Kf)(m) = 4(Kf)(m).

CoCl₃ > Li₂SO₄ > NH₄I.

Answer:

344.02 g.

Explanation:

no. of moles (n) = mass/molar mass

no. of moles Al(OH)₃ = 4.41 mol & molar mass of Al(OH)₃ = 78.01 g/mol.

∴ mass = no. of moles * molar mass = (4.41 mol)*(78.01 g/mol) = 344.02 g.

What does q stand for?

Answer : The 'q' for this reaction is, 328 J

Explanation :

First we have to calculate the moles of [tex]NaOH[/tex] and [tex]NaHCO_2[/tex].

[tex]\text{Moles of }NaOH=\text{Molarity of }NaOH\times \text{Volume of solution}=0.200mole/L\times 0.04L=0.008mole[/tex]

[tex]\text{Moles of }NaHCO_2=\text{Molarity of }NaHCO_2\times \text{Volume of solution}=0.100mole/L\times 0.2L=0.02mole[/tex]

From this we conclude that, the moles of [tex]NaOH[/tex] are less than moles of [tex]NaHCO_3[/tex]. So, the limiting reactant is, NaOH.

Now we have to calculate the 'q' for this reaction.

The balanced chemical reaction will be,

[tex]OH^-+HCO_3^-\rightarrow CO_3^{2-}+H_2O[/tex]

The expression used for 'q' of this reaction is:

[tex]q=n(\Delta H_f^o\text{ of product})-n(\Delta H_f^o\text{ of reactant})[/tex]

[tex]q=n[(\Delta H_f^o\text{ of }CO_3^{2-})+(\Delta H_f^o\text{ of }H_2O)]-n[(\Delta H_f^o\text{ of }HCO_3^-)+(\Delta H_f^o\text{ of }OH^-)][/tex]

where,

n = number of moles of limiting reactant = 0.008 mole

At room temperature,

[tex]\Delta H_f^o\text{ of }CO_3^{2-}[/tex] = -677 kJ/mole

[tex]\Delta H_f^o\text{ of }H_2O[/tex] = -286 kJ/mole

[tex]\Delta H_f^o\text{ of }HCO_3^-[/tex] = -692 kJ/mole

[tex]\Delta H_f^o\text{ of }OH^-[/tex] = -230 kJ/mole

Now put all the given values in the above expression, we get:

[tex]q=0.008mole[(-677kJ/mole)+(-286kJ/mole)]-0.008mole[(-692kJ/mole)+(-230kJ/mole)][/tex]

[tex]q=0.328kJ=328J[/tex]      (conversion used : 1 kJ = 1000 J)

Therefore, the 'q' for this reaction is, 328 J

Answer:

S₂(s) + C(s) → CS₂(s).

Explanation:

S₂(s) + C(s) → CS₂(s).

1 mol of S₂(s) reacts with 1 mol of charcoal (C(s)) to produce 1 mol of CS₂(s).

Answer:

Explanation:

The innermost electron shell is the lowest principal energy level, i.e n = 1.

For n = 1 there is only one orbital, the 1s orbital.

As stated by the Pauli's exculsion principle an orbital may have a maximum of two electrons, and they have opposed spins.

Then, the innermost electron shell has just one orbital and, in consequence, can hold up to 2 elecrons.

The innermost electron shell of an atom can hold up to two electrons.

The innermost electron shell of an atom, also known as the first shell or K-shell, can indeed hold a maximum of 2 electrons. This is often based on the quantum mechanical model of the atom, where the electrons are organized into various shells and subshells.

In addition to this, the first shell consists of only one subshell, called the 1s subshell, which accommodates a maximum of 2 electrons. The distribution of electrons in shells and subshells is a fundamental aspect of atomic structure and determines the chemical properties of elements, as well as their interactions in chemical reactions and bonding.

Answer:

[tex]\boxed{\text{C. 11.2 L}}[/tex]

Explanation:

The pressure is constant, so we can use Charles' Law to calculate the volume.

[tex]\dfrac{V_{1}}{T_{1}} = \dfrac{V_{2}}{T_{2}}[/tex]

Data:

V₁ = 22.4 L; T₁ = 273.15 K

V₂ = ?;         T₂ = 136.58 K

Calculations:

[tex]\dfrac{ 22.4}{273.15} = \dfrac{ V_{2}}{136.58}\\\\0.082 00 = \dfrac{ V_{2}}{136.58}\\\\V_{2} =0.082 00 \times 136.58 = \boxed{\textbf{11.2 L}}[/tex]

Answer:

The last option:

Explanation:

1) Word equation

2) Chemical (molecular) equation

3) Ionization reactions

Write the dissociation of the soluble ionic compounds:

4) Total ionic equation:

5) Net ionic equation

You must cancel the spectator ions, which are those ions that are repeated in both reactant and product sides, i.e. NO₃⁻. They are name spectator because they do not participate (change) during the reaction.

And that is the last choice of the list.

A chemical equation that depicts the aqueous electrolytes as dissociated ions is an ionic equation.  The ionic equation is shown by [tex]\rm NH_{3} (aq) + H^{+} (aq) \rightarrow NH_{4}^{+} (aq).[/tex]

The ionic equation is the depiction of the ions of the compounds or the substances involved in the reaction.

The word equation for the aqueous ammonia with nitric acid can be shown as,

[tex]\text{Ammonia (aq) + nitric acid} \rightarrow \text{Ammonium nitrate (aq)}[/tex]

Its molecular reaction can be shown as,

[tex]\rm NH_{3} (aq) + HNO_{3} (aq) \rightarrow NH_{4} NO_{3}[/tex]

The dissociation of the ions can be shown as,

[tex]\rm HNO_{3} \rightarrow H^{+} + NO_{3}^{-}[/tex]

[tex]\rm NH_{4} NO_{3} \rightarrow NH_{4}^{+} + NO_{3}^{-}[/tex]

The total ionic reaction will be,

[tex]\rm NH_{3} (aq) + H^{+} (aq) + NO_{3}^{+}(aq) \rightarrow NH_{4}^{+}(aq) + NO_{3}^{-} (aq)[/tex]

The total net ionic reaction can be shown as,

[tex]\rm NH_{3} (aq) + H^{+} (aq) \rightarrow NH_{4}^{+} (aq)[/tex]

Therefore, option D. [tex]\rm NH_{3} (aq) + H^{+} (aq) \rightarrow NH_{4}^{+} (aq)[/tex] is the net ionic reaction.

Learn more about the ionic reactions here:

https://brainly.com/question/1503814

Answer:

Explanation:

Water molecule is H₂O, which means that there is one oxygen atom per each water molecule.

The balanced chemical equation that represents this is:

The stoichiometric coefficents 1 for O₂ (g) and 2 for H₂O (g) means that two molecules of oxygen are required to produce two molecules of water.

STP stands for standard temperature and pressure. Those conditions are 273.15 K (0 °C, 32 °F) and 100 KPa of absolute pressure.

That means that the reaction is carried out at constant temperature and pressure.

Then, since the  ideal gas law states that the at constant pressure and temperature the volume occupied by the gases is proportional to the number of particles (atoms or molecules), the molecular stoichiometric ratio of 1 molecule of O₂ (g) to 2 molecules for H₂O (g) is equivalent to the volumetric ratio 1 liter of O₂ to 2 liters of H₂O:

Hence, you conclude that 1 liter of oxygen is required to produce 2 liters of water, at STP.

Answer:

D; constructive; mountains

Answer:

D.) Constructive , Mountains

Explanation:

I got it right in study island

Answer:

1. Percentage composition O in CO₂ is 72.7%

2.Percentage composition of O in N₂O₅ is 74.1%

Explanation:

How to calculate percentage composition

I. Calculate the molar mass of the compound by summing up the atomic masses of the elements that makes up the compound

II. The percentage composition of the element is derieved by dividing the atomic mass of the atoms by the molar mass of the compound

III. Now express this ratio as a percentage.

1. Percentage composition of Oxygen in CO₂:

Molar mass of CO₂

Atomic mass of C = 12gmol⁻¹

Atomic mass of O = 16gmol⁻¹

Note: We have two atoms of Oxygen

Molar mass = [12 + (2x16)]gmol⁻¹

= (12 + 32)gmol⁻¹

= 44gmol⁻¹

Percentage composition O in CO₂

= (2x16)/44 x 100

= 32/44 x 100

= 0.727 x 100

= 72.7%

Percentage composition O in CO₂ is 72.7%

2. The percentage composition of O in N₂O₅

Atomic mass of N = 14gmol⁻¹

Atomic mass of O = 16gmol⁻¹

Molar mass of N₂O₅ = [(2x14) + (5x16)]gmol⁻¹

= (28 + 80)gmol⁻¹

= 108gmol⁻¹

Percentage composition of O in N₂O₅

= (5x16)/108 x 100

= 80/108 x 100

= 0.741 x 100

= 74.1%

Percentage composition of O in N₂O₅ is 74.1%

Note: Percentage composition is expressed as a percentage.

Final answer:

The percent composition of oxygen in CO2 is approximately 72.7%, and in dinitrogen pentoxide, it is approximately 74.1%. This is calculated by dividing the mass of oxygen in each molecule by the total molar mass of the molecule and then multiplying by 100%.

Explanation:

Percent Composition of Oxygen in Compounds

The percent composition of an element in a compound represents the mass percentage of that element in the total mass of the compound. To calculate the percent composition of oxygen in CO2 (carbon dioxide) and dinitrogen pentoxide, we need to look at the molar masses of these compounds and the elements within them.

CO2:

Carbon dioxide is composed of one carbon atom and two oxygen atoms. The molar mass of carbon is 12.01 g/mol and oxygen is 16.00 g/mol. Hence, the molar mass of CO2 equals 44.01 g/mol (12.01 + (16.00 × 2)). The mass of oxygen in CO2 is 32.00 g/mol, which we get from (16.00 × 2). To find the percent composition of oxygen in CO2, we divide the mass of oxygen by the molar mass of CO2 and multiply by 100%.

Percent composition of O in CO2 = (32.00 g/mol / 44.01 g/mol) × 100% ≈ 72.7%

Dinitrogen Pentoxide:

Dinitrogen pentoxide consists of two nitrogen atoms and five oxygen atoms. To calculate the percent composition of oxygen, we first find the molar mass of N2O5, which is 108.01 g/mol (14.01 × 2 + 16.00 × 5). The mass of oxygen in N2O5 is 80.00 g/mol, from (16.00 × 5). The percent composition of oxygen is then calculated as follows:

Percent composition of O in N2O5 = (80.00 g/mol / 108.01 g/mol) × 100% ≈ 74.1%

The boiling point of a 0.1 mole glucose in 200 ml water solution is approximately 100.255°C at 1 atm, after calculating the molality as 0.5 m and applying the molal boiling point elevation constant for water of 0.51°C/m.

The question asks: What is the boiling point of a solution of .1 mole of glucose in 200 ml of water? To calculate this, we need to first determine the molality (m) of the glucose solution since we have the molal boiling point elevation constant (Kb) for water, which is 0.51°C/m.

The molality (m) is calculated by the number of moles of solute per kilogram of solvent (water in this case). Given that 0.1 mole of glucose is dissolved in 200 ml (or 0.2 kg) of water, the solution's molality would be 0.5 m (0.1 mole / 0.2 kg). Since the constant Kb is 0.51°C/m, the boiling point elevation would be 0.5 m x 0.51°C/m = 0.255°C.

The normal boiling point of water is 100°C at 1 atm. We add the boiling point elevation to this to get the boiling point of the glucose solution: 100°C + 0.255°C = 100.255°C. Therefore, the boiling point of the given glucose solution would be approximately 100.255°C at 1 atm.

Answer:

False

Explanation:

In chemistry, trigonal planar is a molecular geometry model with one atom at the center and three atoms at the corners of an equilateral triangle, called peripheral atoms, all in one plane. In an ideal trigonal planar species, all three ligands are identical and all bond angles are 120°.

Meaning there shouldn't be any lone pair.

Look up "Structure of a trigonal planar molecule" for a visual

So it is false.