When stirred in 30°C water, 5 g of powdered potassium bromide, KBr, dissolves faster than 5 g of large crystals of potassium bromide. Which of the following best explains why the powdered KBr dissolves faster?
A. Potassium ions and bromide ions in the powder are smaller than potassium ions and bromide ions in the large crystals.
B. Powdered potassium bromide exposes more surface area to water molecules than large crystals of potassium bromide.
C. Fewer potassium ions and bromide ions have been separated from each other in the powder than in the crystals.
D. Powdered potassium bromide is less dense than large crystals of potassium bromide.

Answer:

The most stable conformation of the following compound has

A. An axial methyl group and an axial ethyl group.

B. An axial methyl group and an equatorial ethyl group.

C. An axial tert-butyl group.

D. An equatorial methyl group and an equatorial ethyl group.

E. An equatorial methyl group and an axial ethyl group.

Explanation:

The most stable conformation in the cyclohexane ring is the one in which both the substituents are in the equatorial position.

Among the given options,

option D  An equatorial methyl group and an equatorial ethyl group.

When the substituents in the cyclohexane ring are in equatorial positions then, the steric repulsions will be reduced.

Answer is option D.

Answer:

The molar mass is the mass of a given chemical element or chemical compound (g) divided by the amount of substance(mol) .

Explanation:

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Explanation:

3 The questions refer to the substances in the table.

Melting point/°C

Boiling point/°C

A

-259

-253

Explanation:

2. [tex]2C_2H_6 + 7O_2 \rightarrow 4CO_2 + 6H_2O[/tex]

First, we need to find the number of moles of [tex]CO_2[/tex] at 300K and 1.5 atm using the ideal gas law:

[tex]n= \dfrac{PV}{RT}= \dfrac{(1.5\:\text {atm})(33\:L)}{(0.082\:\text{L-atm/mol-K})(300K)}[/tex]

[tex]=2.0\:\text{mol}\:CO_2[/tex]

Now use the molar ratios to find the number of moles of ethane to produce this much [tex]CO_2[/tex].

[tex]2.0\:\text{mol}\:CO_2 \times \left(\dfrac{2\:\text{mol}\:C_2H_6}{4\:\text{mol}\:CO_2}\right)[/tex]

[tex]=1.0\:\text{mol}\:C_2H_6[/tex]

Finally, convert this amount to grams using its molar mass:

[tex]1.0\:\text {mol}\:C_2H_6 \times \left(\dfrac{30.07\:\text g\:C_2H_6}{1\:\text{mol}\:C_2H_6} \right)[/tex]

[tex]=30.1\:g\:C_2H_6[/tex]

3. [tex]3Zn + 2H_3PO_4 \rightarrow 3H_2 + Zn_3(PO_4)_2[/tex]

Convert 75 g Zn into moles:

[tex]75\:\text g\:Zn \times \left(\dfrac{65.38\:\text g\:Zn}{1\:\text{mol}\:Zn}\right)=1.1\:\text{mol}\:Zn[/tex]

Then use the molar ratios to find the amount of H2 produced.

[tex]1.1\:\text{mol}\:Zn \times \left(\dfrac{3\:\text{mol}\:H_2}{3\:\text{mol}\:Zn}\right)=1.1\:\text{mol}\:H_2[/tex]

Now use the ideal gas law [tex]PV=nRT[/tex] to find the volume of H2 produced at 23°C and 4 atm:

[tex]V= \dfrac{nRT}{P}= \dfrac{(1.1\:\text{mol}\:H_2)(0.082\:\text{L-atm/mol-K})(296K)}{4\:\text{atm}}[/tex]

[tex]=8.9\:\text L\:H_2[/tex]

Answer:

Compound A, C8H10, absorbed 3 equivalents of H2 on catalytic hydrogenation over a Pd/C catalyst to give B (C8H16). On ozonolysis, compound A gave, among other things, a ketone which was identified as cyclopentanone. On treatment with NaNH2 in NH3, followed by addition of iodomethane, compound A gave a new hydrocarbon, C (C9H12). Draw the structure of Compound A and Compound B.

Explanation:

The degree of unsaturation in the given compound A  C8H10 is:

DU= (Cn+1)-Hn/2 -Xn/2 +Nn/2

DU=(8+1)-10/2

    =9-5

    =4

So, the given compound has either three double bonds and a ring or four double bonds or four rings.

Given,

compound A C8H10 absorbed three equivalents of H2 on catalytic hydrogenation that means compound A has three double bonds or it has one double bond and one triple bond.

The structure of compounds A, B and C along with the entire reaction is shown below:

Answer:

2.11×10²³ atoms.

Explanation:

From the question given above, the following data were obtained:

Mass of Ne = 7 g

Number of atoms =?

Recall:

1 mole of Ne = 6.02×10²³ atoms

1 mole of Ne = 20 g

Thus,

20 g of Ne = 6.02×10²³ atoms

Finally, we shall determine the number of atoms in 7 g of Ne. This can be obtained as follow:

20 g of Ne = 6.02×10²³ atoms

Therefore,

7 g of Ne = (7 × 6.02×10²³) / 20

7 g of Ne = 2.11×10²³ atoms

Thus, 7 g of Ne contains 2.11×10²³ atoms.

Explanation:

this is a single Replacement Reaction, so Na and Cl will form a bond.

Answer:

V = 364500 L, 476.748 yard³

Explanation:

Given that,

The dimensions of a room are 10 meters wide by 15 meters long and 8.0 ft high.

l = 10 m, b = 15 m, h = 8 ft = 2.43 m

The volume of the room is :

V = lbh

So,

V = 10×15×2.43

V = 364.5 m³

As 1 m³ = 1000 L

364.5 m³ = 364500 L

Also, 1 m³ = 1.30795 yard³

364.5 m³ = 476.748 yard³

Hence, this is the required solution.

Answer:

NAF IS AN IONIC COMPOUND

Explanation:

Answer:

Explanation:

CO2 is a covalent bonding. It is something from the middle of the periodic table bonded with something on the right of the periodic table. It is not ionic.

NH3 is also covalent. The H bonds with the N and the H has properties that resemble both the metals and non metals. That's why it is on both the left and right sides of the periodic table. In this case, it is more non metallic than metallic. Since Nitrogen is on the right side of the table, you have a situation where 2 nonmetals are bonding. It is not ionic.

The answer is NaF. Sodium is on the left side of the periodic table and F is on the right side. That's what it takes to get an ionic bond.

Answer:

NF3< H2S< H2O< He

Explanation:

The average speed of a gas depends on the relative molecular mass of the gas. Lighter gases have a greater average speed and move faster than heavier gases.

Hence, we need to arrange these gases listed in the question in order of decreasing molecular mass in order to obtain the order of increasing Urms assuming equivalent amounts and all gases are at the same temperature and pressure.

Hence; NF3< H2S< H2O< He

Answer:

b. 0.27 M ammonia + 0.38 M ammonium nitrate.

Explanation:

Hello there!

In this case, according to the given information, it turns out possible for us to bear to mind the fact that buffest must be prepared by using either of the following pairs:

weak acid/conjugate base

weak base/conjugate acid

So that the pH might be set constant. In such a way, since a. shows two salts, c. a strong acid with a neutral base, d, shows two acids and e. a strong base with a neutral base, we infer the correct buffer is b. 0.27 M ammonia + 0.38 M ammonium nitrate because it has a weak base (ammonia) and its conjugate acid, ammonium.

Regards!

Answer:

a. Extract reconstituted 3-nitroaniline out of the aqueous layer: Dichloromethane.

b. Extract benzoic acid into the aqueous layer: 5% NaOH.

c. Extract aniline into the aqueous layer: 5% HCl.

d. Reconstitute aniline from aqueous layer: 6M NaOH.

Explanation:

Each of the answers is explained as follows:

a. Extract reconstituted 3-nitroaniline out of the aqueous layer: Dichloromethane.

Dichloromethane is an organochloride chemical and CH2Cl2 is its formula. It is commonly employed as a solvent since it is a colorless, volatile liquid with a sweet, chloroform-like odor. It is polar and miscible with numerous organic solvents, despite not being miscible with water.

b. Extract benzoic acid into the aqueous layer: 5% NaOH.

According to the Mass by Volume percentage concept, 5% NaOH solution (W/V) indicates 5g of NaOH dissolved in 100ml of water.

c. Extract aniline into the aqueous layer: 5% HCl.

Hydrochloric acid (HCl) is a common acid found in the human body as well as in laboratories, and it is a key component of stomach acid.

As a result, 5% HCl solution is made by mixing 8.26 mL concentrated HCl with roughly 50 mL distilled water, stirring well, and then adding water up to 100 mL.

d. Reconstitute aniline from aqueous layer: 6M NaOH.

6M NaOH refer to 6 moles in 1L MW (NaOH). Therefore, 6 moles of NaOH are dissolved in 1 liter of H2O to make a 6M NaOH solution. Because NaOH has a molar mass of 39.9997 g/mol, we'll need 240 g NaOH (39.997 x 6) in 1L of H2O to make a 6M solution.

Answer:

978 J

General Formulas and Concepts:

Thermodynamics

Specific Heat Formula: q = mcΔT

Explanation:

Step 1: Define

[Given] c = 4.18 J/g K

[Given] m = 6.00 g

[Given] ΔT = 75.0 °C - 36.0 °C = 39.0 °C

[Solve] q

Step 2: Find q

Step 3: Check

Follow sig fig rules and round. We are given 3 sig figs.

978.12 J ≈ 978 J

Answer:

I don't remember this topic very well.

Explanation:

if we want to increase 1C° of 1 gram water. we must use 4.18 joules energy that 75-36= 39 C° for 6 gram H2O we should use 6*39*(4.18) joules

Answer:

It is always less than the theoretical yield.

Answer:

c it does not change the energy state

Explanation:

Answer:

NaCl

Explanation:

[tex]na + cl > nacl[/tex]

This is also a salt

Answer:

Explanation:

Diels-Alder reactions are cyclo-additional reactions between conjugated dienes and a dienophile (a substituted alkene compound for example acrylic acid) to produce a ring structure of cyclohexene compounds.

From the image attached below, we will see the reaction between 2,3-dimethylbuta-1,3-diene which is a conjugated diene with acrylic acid to produce a Diel-Alder adduct as the product.  From the reaction, a single new π-bond and two σ-bonds are produced.

Answer: [tex]NH_4^+[/tex] is an acid, [tex]CN^-[/tex] is a base, [tex]NH_3[/tex] is conjugate base and [tex]HCN[/tex] is conjugate acid

Explanation:

According to Bronsted and Lowry's theory:

An acid is defined as a proton donor while a base is defined as a proton acceptor.

In a chemical reaction, an acid loses a proton to form a conjugate base while a base accepts a proton to form conjugate acid.

For the given chemical reaction:

[tex]NH_4^+(aq)+CN^-(aq)\rightleftharpoons HCN(aq)+NH_3(aq)[/tex]

[tex]NH_4^+[/tex] is losing a proton thus it is an acid to form [tex]NH_3[/tex] which is its conjugate base

[tex]CN^-[/tex] is gaining a proton thus it is a base to form [tex]HCN[/tex] which is its conjugate acid

Hence, [tex]NH_4^+[/tex] is an acid, [tex]CN^-[/tex] is a base, [tex]NH_3[/tex] is conjugate base and [tex]HCN[/tex] is conjugate acid

Answer: The molecule [tex]CH_{3}-CH_{3}[/tex] is expected to have a dipole moment of zero.

Explanation:

The product of magnitude of the charge calculated in electrostatic units is called dipole moment.

Formula for dipole moment is as follows.

Dipole moment = Charge (in esu) [tex]\times[/tex] distance (in cm)

Non-polar molecules have zero dipole moment.

For example, [tex]CH_{3}-CH_{3}[/tex] is a non-polar molecule so its dipole moment is zero.

[tex]H_{2}C=O[/tex] is a polar molecule so it will have dipole moment.

[tex]CH_{2}Cl_{2}[/tex] is a polar molecule so it will have dipole moment.

[tex]NH_{3}[/tex] has nitrogen atom as more electronegative than hydrogen atom. So, net dipole moment will be in the direction of nitrogen atom.

Thus, we can conclude that the molecule [tex]CH_{3}-CH_{3}[/tex] is expected to have a dipole moment of zero.

Answer:

What kind of chemical reaction occurs when fossil fuels and biomass are burned? What is produced in addition to energy?

What is acid rain? Which fossil fuel causes acid rain? What are the chemical reactions that produce the acid?

Difference Between Biomass and Fossil Fuels

In terms of environmental impact, what’s the difference between natural gas, coal, and biomass? Consider both carbon dioxide (CO2) emissions and acid rain.

What’s the difference between nonrenewable and renewable energy sources? Is biomass a renewable energy source?

What’s a new discovery that makes it easier to use biomass as an energy source?

Comparing Biomass with Other Renewable Energy Sources

What are the pros and cons of several renewable energy sources? Renewable energy sources include biomass, wind power, hydropower, solar power, and geothermal power.

Making Recommendations for Energy Choices

Which renewable energy sources should be developed in your area, and why? Consider abundance of the energy source, ease of setup in your area, and cost.

Review the seven questions. Write a few sentences summarizing what you already know about these topics.

Explanation:

Answer:

Alkanes

Cycloalkanes

Ring flip

Lower

Angle

Equatorial

Axial

Explanation:

For alkanes, the general molecular formula is CnH2n+2 while for cycloalkanes, the general molecular formula is CnH2n.

The cycloalkanes could undergo a ring flip in which axial and equatorial hydrogen atoms are interconverted.

The lower energy conformation of alkanes is the anti conformation and not the gauche conformation due to steric strain.

When the bond angle in alkanes deviate from the ideal 109.5°, an angle strain has occurred.

For bulky groups, the equatorial position his preferred since it has more room than the axial position.

Answer:

2–methylbutane

Explanation:

To name the compound given above, the following must be obtained:

1. Determine the longest continuous carbon chain. This gives the parent name of the compound.

2. Determine the substituent group attached.

3. Determine the position of the substituent group by giving it the lowest possible count..

4. Combine the above to obtain the name of the compound.

With the above information, we can name the compound as follow:

1. The longest continuous carbon chain of the compound is 4. Thus, the parent name is butane.

2. The substituent group attached to the compound is methyl (–CH₃).

3. The methyl (–CH₃) group is located at carbon 2 (i.e counting from the left side).

4. The name of the compound is:

2–methylbutane

Explanation:

Sublimation is the conversion between the solid and the gaseous phases of matter, with no intermediate liquid stage

Answer:

Molarity: 0.092M

Molality: 0.090m

Explanation:

Molarity, M, is defined as the moles of solute (In this case, C14H12 -Molar mass: 180.25g/mol-) in 1L of solution.

The molality, m, are moles of solute per kg of solvent.

Molarity:

Moles solute:

7.9g * (1mol/180.25g) = 0.04383 moles

Liters solution:

475mL = 0.475L

Molarity: 0.04383 moles / 0.475L = 0.092M

Molality:

kg solvent:

475mL * (1.03g/mL) = 489.25g = 0.48925kg

Molality:

0.04383 moles / 0.48925kg = 0.090m

Answer:

carbohydrates are simple sugars which can be broken down to form 3 sugars.

which are , (maltose) (fructose) & (glucose)

Answer:

Option B

Explanation:

From the question we are told that:

Equation

[tex]EX_4+Y_2->EX_3Y+XY[/tex]

Bond enthalpies are:

 [tex]Y-Y 109 kJ/mol,[/tex]

[tex]X-Y 123.1 kJ/mol[/tex]  

[tex]E-Y 290 kJ/mol.[/tex]

Generally the equation for the energy used to break E-X and Y-Y is mathematically given by

 [tex]E_2=109+x[/tex]

Therefore

Total Energy Liberated is

 [tex]E_T=E_1+E_2[/tex]

 [tex]E_T=413.1+109+x[/tex]

 [tex]E_T=304.1-x[/tex]

Since

  [tex]E_T+E_I[/tex]

Therefore

 [tex]304.1-x=243.6[/tex]

 [tex]x=60.5kJ/mol[/tex]

Option B

Answer:

c

Explanation:

it is because the chemical reaction will have the exposure to all the minerals with Microsoft word

Answer:

no halbo ingles

Explanation: