Using VSEPR model, how is the molecular arrangement about the central atom (molecular geometry) for XeF4?

Answer:

Mixtures can be physically separated by using methods that use differences in physical properties to separate the components of the mixture, such as evaporation, distillation, filtration and chromatography.

Explanation:

You are very much welcom

Answer:

stirring. because it will mixup together

Answer:

A practical pursuit of alchemy was the development of metallurgy practices.

Explanation:

As alchemists always tried to turn various metals into other things, metalworking techniques were developed even though their experiments were often unsuccessful.

Answer: developing metalworking techniques

Explanation:

trust it!!

Answer:

in real-world conditions

Explanation:

Answer:

333.6 atm

Explanation:

The following data were obtained from the question:

Mole of O2 (nO2) = 3.96 moles

Mole of N2 (nN2) = 7.49 moles

Mole of CO2 (nCO2) = 1.19 moles

Total pressure = 563 mmHg

Partial pressure of N2 =..?

Next, we shall determine the total number of mole in the container.

This can be obtained as follow:

Mole of O2 (nO2) = 3.96 moles

Mole of N2 (nN2) = 7.49 moles

Mole of CO2 (nCO2) = 1.19 moles

Total mole =?

Total mole = nO2 + nN2 + nCO2

Total mole = 3.96 + 7.49 + 1.19

Total mole = 12.64 moles

Next, we shall determine the mole fraction of N2.

This can be obtained as follow:

Mole fraction = mole of substance/total mole

Mole of N2 (nN2) = 7.49 moles

Total mole = 12.64 moles

Mole fraction of N2 =?

Mole fraction of N2 = 7.49/12.64

Finally, we shall determine the partial pressure of N2.

This can be obtained as follow:

Mole fraction of N2 = 7.49/12.64

Total pressure = 563 mmHg

Partial pressure of N2 =..?

Partial pressure = mole fraction x total pressure

Partial pressure of N2 = 7.49/12.64 x 563

Partial pressure of N2 = 333.6 atm

The, the partial pressure of nitrogen, N2 is 333.6 atm

Answer:

90.3 kJ/mol

Explanation:

Let's consider the following thermochemical equation.

2 NO(g) + O₂(g) → 2 NO₂(g)  ∆H°rxn = –114.2 kJ

We can find the standard enthalpy of formation for NO using the following expression.

∆H°rxn = 2 mol × ΔH°f(NO₂(g)) - 2 mol × ΔH°f(NO(g)) - 1 mol × ΔH°f(O₂(g))

∆H°rxn = 2 mol × ΔH°f(NO₂(g)) - 2 mol × ΔH°f(NO(g)) - 1 mol × 0 kJ/mol

∆H°rxn = 2 mol × ΔH°f(NO₂(g)) - 2 mol × ΔH°f(NO(g))

ΔH°f(NO(g)) = (2 mol × ΔH°f(NO₂(g)) - ∆H°rxn) / 2 mol

ΔH°f(NO(g)) = (2 mol × 33.2 kJ/mol + 114.2 kJ) / 2 mol

ΔH°f(NO(g)) = 90.3 kJ/mol

Answer:

the final volume of the gas is [tex]V_2[/tex] = 1311.5 mL

Explanation:

Given that:

a sample gas has an initial volume of 61.5 mL

The workdone = 130.1 J

Pressure = 783 torr

The objective is to determine the final volume of the gas.

Since the process does 130.1 J of work on its surroundings at a constant pressure of 783 Torr. Then, the pressure is external.

Converting the external pressure to atm ; we have

External Pressure [tex]P_{ext}[/tex]:

[tex]P_{ext} = 783 \ torr \times \dfrac{1 \ atm}{760 \ torr}[/tex]

[tex]P_{ext} = 1.03 \ atm[/tex]

The workdone W = [tex]P_{ext}[/tex]V

The change in volume ΔV= [tex]\dfrac{W}{P_{ext}}[/tex]

ΔV = [tex]\dfrac{130.1 \ J \times \dfrac{1 \ L \ atm}{ 101.325 \ J} }{1.03 \ atm }[/tex]

ΔV = [tex]\dfrac{1.28398717 }{1.03 }[/tex]

ΔV = 1.25 L

ΔV = 1250 mL

Recall that the initial  volume = 61.5 mL

The change in volume V is [tex]\Delta V = V_2 -V_1[/tex]

[tex]- V_2= - \Delta V -V_1[/tex]

multiply through by (-), we have:

[tex]V_2= \Delta V+V_1[/tex]

[tex]V_2[/tex] =  1250 mL + 61.5 mL

[tex]V_2[/tex] = 1311.5 mL

∴ the final volume of the gas is [tex]V_2[/tex] = 1311.5 mL

The final volume of the gas when the volume of 61.5 mL should be 1311.5 mL.

Since

a sample gas has an initial volume of 61.5 mL

The workdone = 130.1 J

Pressure = 783 torr

So, here the external pressure should be

= 783 * 1 / 760

= 1.03 atm

Now the change in volume is

= 130.1 J * 1 / 101.325 J / 1.03
= 1250 mL

Now the change in volume should be

= 1250 + 61.5

= 1311.5 mL

hence, The final volume of the gas when the volume of 61.5 mL should be 1311.5 mL.

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Answer:

[See Below]

Explanation:

13 cm.

Answer:

Pressure, P = 15.4 lb/in²

Explanation:

Given that,

Force applied, F = 26.4 lb

Area of cross section, A = 1.71 in²

To find,

Pressure.

Solution,

Pressure is equal to force per unit area of cross section.

[tex]P=\dfrac{F}{A}\\\\P=\dfrac{26.4\ lb}{1.71\ in^2}\\\\P=15.43\ lb/in^2\\\\P=15.43\ Pa[/tex]

Hence, the correct option is (a) "15.4 lb/in²".

Answer:

Reactants: K = 2, S = 1, Co = 1, Cl = 2; Products: K = 2, S = 1, Co = 1, Cl = 2

Explanation:

The reaction is a double replacement reaction so the anions (Cl⁻ and S²⁻) switch places.

1 K₂S + 1 CoCl₂ ⇒ 2 KCl +  1 CoS (balanced chemical equation)

On the reactants and products side, K = 2, S = 1, Co = 1, and Cl = 2.

Hope that helps.

Answer:

C

Explanation:

Atomic radius generally increases as we move down a group and from left to right across a period

Answer:

The correct answer is b. Negative

Explanation:

An electrolytic cell is based on a reduction- oxidation reaction which is non spontaneous. That means that the standard cell potencial (Eº) is negative. For this reason, an electrical potential must be applied in order to force the reaction. Conversely, a galvanic cell is based on a spontaneous redox reaction, so the galvanic cell produces electrical energy.

Answer:

Increase in pressure

Explanation:

The rise in temperature will increase the pressure of the gas.

Answer:

increase is ur answer

hope it helps u

plz mark as brainlist

Answer: When silver is exposed to sulfur-containing gases in the air, it discolours and then darkens as it reacts with the gas to form a surface layer of tarnish. This process is called tarnishing.

Hope this helped :)

Answer:

The Lewis structure for CO2 is O = C = O rather than  O ≡ C - O because of the covalent nature of the bonds that makes CO2 a polar molecule and to become stable it is important to fill valence shell of both atoms equally.

CO2 can not be written as O ≡ C - O because then there will be one non-paired electron in the oxygen atom that can disturb the stability of CO2.

Answer:

a) 1.269 × 10^-7 m

b) This wavelength occurs in the ultraviolet region of the electromagnetic spectrum

Explanation:

The energy required to break the bond= energy of the incident photon

E= 941 × 10^3/6.02 × 10^23 = 1.56 ×10^ -18 J

From

E= hc/λ

h= Plank's constant

c= speed of light

λ= wavelength of incident photon

λ= hc/E

λ= 6.6 ×10^-34 × 3 ×10^8/1.56 ×10^ -18 J

λ= 1.269 × 10^-7 m

b) This wavelength occurs in the ultraviolet region of the electromagnetic spectrum

Answer:

The correct answer is option D, that is, magic numbers.

Explanation:

The magic number in nuclear physics refers to the number of nucleons, that is, either neutrons or protons, distinctly, such that their alignment results in the formation of complete shells within the nucleus of the atom. As a consequence, atomic nuclei comprising a magic number of neutrons or protons are much more stable in comparison to other nuclei.  

The seven most broadly known magic numbers are 2,8,20,28,50,85 and 126.  

Answer:

on each side of the salt bridge, which is represented by a double vertical line

Explanation:

While writing a cell notation, the general convention is; anode || cathode. The anode and the cathode are separated by a double line. The anode is written on the lefthand side while the cathode is written on the righthand side.

The cell notation is a shorthand representation of a cell, hence any electrochemical cell can easily be produced based on its cell diagram.

Answer:

Communication between scientists increased.

Technological advancements were made.

Explanation:

The options:

Metalworkers began using new metals.

 Communication between scientists increased.

 The American Civil War started.

 Technological advancements were made.

The reasons the number of known elements more than double by 1861 would be because technological advancements have been made and communication between scientists increased.

With the advancement in technology, more equipment become available and research became more sophisticated leading to new discoveries. The new discoveries would not have made much difference if they are not adequately communicated to other scientists.  

Answer:

See the answer below

Explanation:

From the illustration;

1 chain = 20.1 meters

1 talent = 30.2 kg

The map says the treasure chest was buried 27 chains due west and 3 chains deep under the ground.

27 x 20.1 = 542.7 meters.

3 x 20.1 = 60.3 meters

This means that one would need to travel 542.7 meters due west from the US Capitol and dig 60.3 meters under the ground in order to locate the treasure chest.

The treasure chest has 50 talents of gold:

50 x 30.2 = 1,510 kg of gold.

Answer:

B. Ionic

Explanation:

RbCl is ionic compound formed from the combination of rubidium (a strongly electropositive element) and chlorine (a strongly electronegative element).

The transfer of an electron from rubidium to chlorine leads to the formation of two oppositely charged ions Rb⁺ and Cl⁻.

In a solid crystal of RbCl, the major intermolecular forces of attraction are electrostatic forces of attraction between oppositely charged ions in the molecules of the crystalline solid.

Ion-dipole attraction only occur when the solid is dissolved in a polar molecule like water. Dispersion forces as well as dipole-dipole forces, though present are weak forces and contribute very little to intermolecular attraction. Hydrogen bonding is not present as there are no hydrogen atoms in solid RbCl.

The dominant (strongest) type of intermolecular force present in RbCl(s) is ionic force (Option B).

In conclusion, the dominant (strongest) type of intermolecular force present in RbCl(s) is ionic force (Option B).

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Answer:

burning of paper

melting of lead

Answer:

d- activating a glow stick

Explanation:

Glow sticks produce light through a chemical reaction.

Answer: 89.345

Explanation:

Answer:

quantity of heat=mc*theta

=25*0.930(76-25)

=25*0.930*51

=1185.75J

=11.9kJ

Answer:

1.19kJ

Explanation:

The heat can be calculated using the specific heat capacity, mass, and the change in temperature.

q=mxcxΔT=(25.0g)×(0.930Jg⋅∘C)×(76.0−25.0∘C)=1186J

Finally, the heat can be converted from J into kJ using the metric conversion factor.

1186J×1kJ1000J=1.19kJ

Answer:

pH after the addition of NaOH is 4.37

Explanation:

When the amount of the weak acid = Amount of the conjugate base (As in the problem) pH = pKa. That means pKa of benzoic buffer is 4.19.

Now, to solve the pH of the buffer we need to use H-H equation for benzoic buffer:

pH = pKa + log [Benzoate] / [Benzoic acid]

pH = 4.19+ log [Benzoate] / [Benzoic acid]

You can take [] concentrations as the moles of both species.

When you add NaOH to the buffer, it reacts with benzoic acid producing more sodium benzoate and water, thus:

NaOH + Benzoic Acid → Sodium benzoate + Water.

Before the reaction, moles of benzoic acid and sodium benzoate were:

500.0mL = 0.500L × (0.10mol / L) = 0.050 moles

After the reaction, 0.010 moles of Benzoic acid are consumed and the same 0.010 moles of sodium benzoate are produced. That means moles of both species after reaction are:

[Benzoate] = 0.050 moles + 0.010 moles = 0.060 moles

[Benzoic acid] = 0.050 moles - 0.010 moles = 0.040 moles

Replacing in H-H equation:

pH = 4.19+ log [Benzoate] / [Benzoic acid]

pH = 4.19+ log [0.060mol] / [0.040mol]

pH = 4.37

Answer : Option C is correct -- a ketone and an ether

Explanation:

It should be noted that Ketone and ether are the compound on the right that contain two functional groups. an aldehyde and an ether, an aldehyde and an alcohol, a ketone and an ester, and also a carboxylic acid and an ether don't contain two functional groups on the right.

Answer:

Percent yield = 70.8%

Explanation:

Equation of the reaction:

Al2O3 + 3C ----> 2Al + 3CO

From the reaction equation, 1 mole of Aluminum oxide produces 2 moles of Aluminum when reacted with 3 moles of carbon.

Molar mass of Aluminum oxide = 102 g; molar mass of Aluminum = 27 g; molar mass of C = 12

3 moles of C = 36 g

2 moles Al = 54 g

102 g of Al2O3 reacts with 36 g of C

60 g of Al2O3 will react with (36/102) × 60 g of C = 21.2 g of C

Therefore, Al2O3 is the limiting reactant while C is in excess.

102 g of Al2O3 produces 54 g of Al

60 g of Al2O3 will produce (54/102) × 60 of Al = 31.8 g of Al

Percent yield = (actual yield/ theoretical yield) × 100%

Percent yield = (22.5 g / 31.8 g) × 100%

Percent yield = 70.8 %

Answer:

like, plasmas have no fixed shape or volume, and are less dense then solid or liquids but unlike ordinary gases, plasma are made up of atoms in which some or all of the electrons have been stripped away and positively charged nuclei, called ions, roem freely

Answer:

much greater

Explanation:

Binding energy of a nucleus is the energy evolved in the formation of a nucleus from free protons and neutrons. It is also defined as the energy that binds nucleons together in the nucleus of an atom.

The nuclear binding energy is far greater than the chemical energy stored in chemical bonds. Nuclear energy is the greatest source of energy which could be exploited to achieve various ends.

Answer:

A. Neutral salts.  (7, 2)

B. Acidic salts.  (4, 6)

C. Basic salts. (1, 3, 5)

Explanation:

We must know where, do the ions come from. If they come from a weak acid or base, they can make hydrolysis in water, so OH⁻ and H⁺ are given to medium.

1. LiF → Li⁺ + F⁻

F⁻  +  H₂O  ⇄  HF + OH⁻

F⁻ can make the hydrolysis, and it gives OH⁻. Salt is basic.

2. SrBr₂ → Sr²⁺  + 2Br⁻

Both are weak and they can not hydrolyse. This salt is neutral.

3. NH₄CN →  NH₄⁺  + CN⁻

Both ions are strong, so they can make the hydrolysis. The thing is, while the ammonium gives protons, the cyanide give hydroxides. To determine how's the salt, we need to compare the Ka and Kb.

NH₄⁺  +  H₂O ⇄  NH₃  +  H₃O⁺   Ka = 5.7×10⁻¹⁰

CN⁻  + H₂O ⇄  HCN  +  OH⁻     Kb = 1.61×10⁻⁵

As  Kb > Ka, pH is basic.

If Ka > Kb, pH would be acidic.

4. NH₄Br →  NH₄  + Br⁻

Br⁻ does not hydrolize. The ammonium cation, reacts in water to give protons to medium that's why the salt will be acidic.

NH₄⁺  +  H₂O ⇄  NH₃  +  H₃O⁺   Ka

5.  KCN →  K⁺  + CN⁻

K⁺ does not hydrolize. The cyanide anion, reacts in water to give hydroxides to medium that's why the salt will be basic.

CN⁻  + H₂O ⇄  HCN  +  OH⁻     Kb

6. NH₄ClO₄ →  NH₄⁺  + ClO₄⁻

ClO₄⁻ comes from the perchlroric acid (a strong acid). It does not hydrolyze

NH₄⁺  +  H₂O ⇄  NH₃  +  H₃O⁺   Ka

Ammonium gives H⁺ to medium so the salt is acidic.

7. LiNO₃ → Li⁺  + NO₃⁻

Both ions does not make hydrolysis. They come from a strong base and a strong acid, so they are the conjugate weak acid and base, respectively.

The salt in this case, will be neutral.