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Answer:

one mole of water (6.022 x 10 23 molecules) has a mass of 18.02 g. One mol of NaCl (6.02 x1023 formulas) has a mass of 58.44 g.

Explanation:

• The mole (or mol) represents a certain number of objects.

• SI def.: the amount of a substance that contains the same

number of entities as there are atoms in 12 g of carbon-12.

• Exactly 12 g of carbon-12 contains 6.022 x 10 23 atoms.

• One mole of H 2O molecules

contains 6.022 x 10 23 molecules.

• 1 mole contains 6.022 x 10 23 entities (Avogadro’s number)

• One mole of NaCl contains 6.022 x 10 23 NaCl formula units.

• Use the mole quantity to count formulas by weighing them.

• Mass of a mole of particles = mass of 1 particle x 6.022 x 1023

Mass of 1 H atom: 1.008 amu x 1.661 x10-24 g/amu = 1.674 x10-24 g

Mass of 1 mole of H atoms:

1.674 x10-24g/H atom x 6.022 x1023H atoms = 1.008 g  

• The mass of an atom in amu is numerically the same

as the mass of one mole of atoms of the element in grams.

• One atom of sulfur has a mass of 32.07 amu;

one mole of S atoms has a mass of 32.07 g

Answer:

a. 1.12 L

Explanation:

Step 1: Write the balanced equation for the photosynthesis

6 CO₂(g) + 6 H₂O(l) ⇒ C₆H₁₂O₆(s) + 6 O₂(g)

Step 2: Calculate the moles corresponding to 2.20 g of CO₂

The molar mass of CO₂ is 44.01 g/mol.

2.20 g × 1 mol/44.01 g = 0.0500 mol

Step 3: Calculate the moles of O₂ produced

The molar ratio of CO₂ to O₂ is 6:6. The moles of O₂ produced are 6/6 × 0.0500 mol = 0.0500 mol

Step 4: Calculate the volume occupied by 0.0500 moles of O₂ at STP

At STP, 1 mole of O₂ occupies 22.4 L.

0.0500 mol × 22.4 L/1 mol = 1.12 L

Answer:

electric charge

Explanation:

Charged particles are deflected in an electric or a magnetic field. The particles discovered by J.J. Thomson were charged particles.

When these charged particles are passed through electric and magnetic fields, deflection occurs depending on the nature of the charge.

A positive charge is deflected towards the negative part of an electric field or the south pole of a magnetic field.

A negative charge is selected towards the positive end of an electric field or the north pole of a magnetic field.

Answer:

The order of reactivity towards electrophilic susbtitution is shown below:

a. anisole > ethylbenzene>benzene>chlorobenzene>nitrobenzene

b. p-cresol>p-xylene>toluene>benzene

c.Phenol>propylbenzene>benzene>benzoic acid

d.p-chloromethylbenzene>p-methylnitrobenzene> 2-chloro-1-methyl-4-nitrobenzene> 1-methyl-2,4-dinitrobenzene

Explanation:

Electron donating groups favor the electrophilic substitution reactions at ortho and para positions of the benzene ring.

For example: -OH, -OCH3, -NH2, Alkyl groups favor electrophilic aromatic substitution in benzene.

The -I (negative inductive effect) groups, electron-withdrawing groups deactivate the benzene ring towards electrophilic aromatic substitution.

Examples: -NO2, -SO3H, halide groups, Carboxylic acid groups, carbonyl gropus.

The number of replaceable electrons in an atom is called its valency.

Examples

Thanks !

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Answer:

the combining capacity if an atom is know as valency.

the property of an element that determines the number of other atimd with an aton if the element can combine.

Answer:

See explanation and Image attached

Explanation:

The preparation of triphenylmethanol occurs as shown in the image attached to this answer.

The first step is the nucleophillic reaction of the phenyl magnesium bromide with the carbonyl group.

Reaction of the second molecule of phenyl magnesium bromide with the product yields triphenyl methoxide ion. Reaction with acid yields the triphenylmethanol product which is extracted into the organic phase.

The triphenylmethanol product can be purified by recrystallization.

Answer:

is this question or you just asking I can't understand.

Answer:

Option D. 17.5

Explanation:

Equiibrium is: CO + 2H₂  ⇄  CH₃OH

1 mol of CO is in equibrium with 2 moles of hydrogen in order to make, methanol.

Initially we have 0.42 moles of CO and 0.42 moles of H₂

If 0.29 moles of CO remained, (0.42 - 0.29) = 0.13 moles have reacted.

So in the equilibrium we may have:

0.29 moles of CO, and (0.42 - 0.13 . 2) = 0.16 moles of H₂

Ratio is 1:2, if 0.13 moles of CO haved reacted, (0.13 . 2) moles have reacted of hydrogen

Finally 0.13 moles of methanol, are found after the equilibrium reach the end.

Let's make expression for KC: [Methanol] / [CO] . [Hydrogen]²

0.13 / (0.29 . 0.16²)

Kc = 17.5

Answer:

Low value for copper recovery

Explanation:

The percentage recovery is obtained from;

Percent recovery = amount of substance you actually collected / amount of substance you were supposed to collect × 100

Note that the fact that some of the copper nitrate solution splashed out of the beaker means that some amount copper has been lost from the system. This loss of copper leads to a lower value of copper recovered from solution.

Answer:

[tex]x=54g[/tex]

Explanation:

From the question we are told that:

Content of Sterling silver:

Let x be sterling silver

Silver [tex]S=0.9x[/tex]

Copper [tex]C=0.1x[/tex]

Total  silver available [tex]T=48.3[/tex]

Generally the equation for Total amount to be made is mathematically given by

[tex]T=\frac{x*90}{100}[/tex]

[tex]x=\frac{48.3*100}{90}[/tex]

[tex]x=54g[/tex]

Answer:

23

Explanation:

Answer:

1.28 M

Explanation:

Step 1: Given data

Mass of luminol (solute): 17.0 g

Volume of water: 75.0 mL (this is also the volume of solution)

Step 2: Calculate the moles corresponding to 17.0 g of luminol

The molar mass of luminol is 177.16 g/mol.

17.0 g × 1 mol/177.16 g = 0.0960 mol

Step 3: Calculate the molarity of the solution

We will use the definition of molarity

M = moles of solute / liters of solution

M = 0.0960 mol / 0.0750 L = 1.28 M

Answer:

M of HNO₃ is 0.119M

Explanation:

A basic concept of titration is that in equivalence point:

mmoles of acid = mmoles of base

We have data from base and we only have data from volume of acid.

In a case our titration is a strong acid against a strong base.

We apply formula:

M of acid . Vol of acid = M of base . Vol of base

M of acid . 21.8 mL = 0.137M . 19 mL

M of acid = (0.137M . 19 mL) / 21.8 mL

M of acid = 0.119 M

When we neutralize all the titrant we reach the equivalence point.

At this point, pH = 7

2HNO₃  +  Ca(OH)₂ → Ca(NO₃)₂ +  2H₂O

Explanation:

since hydrochloric acid is an acid and calcium hydroxide is a base, we know that this is an acid base reaction. The ions will then dissociatiate and bond with one another.

Answer:

"They established the laws of planetary motion"

Explanation:

Mr. Kepler was the astronomer who came up with the "Laws of Planetary Motion."

 9 is the element Florine

Florine has 9 electrons as well as the 9 protons that determine its atomic number.

The ground state configuration is the lowest energy configuration.

Answer:

See Explanations

Explanation:

pH =-log[H₃O⁺] = -log[H⁺]

pOH = -log[OH⁻]

For weak acids [H⁺] = SqrRt(Ka·[Acid])

For weak bases [OH⁻] = SqrRt(Kb·[Base])

pH + pOH = 14

__________________________________________

A. Given 0.18M CH₃NH₂; Kb = (4.4 x 10⁻⁴)* => pH = 11.95

CH₃NH₂ + H₂O => CH₃NH₃OH ⇄ CH₃NH₃⁺ + OH⁻;

[OH⁻]  = SqrRt(Kb·[weak base]) = SqrRt(4.4 x 10⁻⁴ x 0.18)M = 8.97 x 10⁻³M

=> pOH = -log[OH⁻] = -log(8.93x10⁻³) = -(-2.05) = 2.05

=> pH = 14 - pOH = 14 - 2.05 = 11.95.

*Kb values for most ammonia derivatives in water can be found online by searching 'Kb-values for weak bases'. Kb-values for methyl amine and methylammonium chloride are both 4.4x10⁻⁴.

___________________________________________________

B. Given 0.18M CH₃NH₃Cl

In water ... CH₃NH₃Cl => CH₃NH₃⁺ + Cl⁻; Kb(CH₃NH₃Cl) = 4.4 x 10⁻⁴

Cl⁻ + H₂O => No Rxn (i.e.; no hydrolysis occurs) ... Cl⁻ does not react with H₂O.

Hydrolysis Reaction of Methylammonium Ion:

CH₃NH₃⁺ + H₂O => CH₃NH₄OH ⇄ CH₃NH₄⁺ + OH⁻

Ka' x Kb = Kw => Ka' = Kw/Kb = 10⁻¹⁴/4.4 x 10⁻⁴ = 2.27 x 10⁻¹¹                                   Ka' = [CH₃NH₄⁺][OH⁻]/[CH₃NH₄OH] = (x)(x)/(0.18M) = (x²/0.18M) = 2.27 x 10⁻¹¹ => x = [OH⁻] = SqrRt(2.27x10⁻¹¹ x 0.18)M = 2.02 x 10⁻⁶M => pOH = -log(2.02 x 10⁻⁶) = -(-5.69) = 5.69 => pH = 14 - pOH = 14 - 5.69 = 8.31.

*note => the general nature of halide interactions would increase acidity (lower pH) of the halogenated compound.

C. A mixture of 0.18M CH₃NH₂ and 0.18M CH₃NH₃Cl          

Mixture of 0.18M CH₃NH₂ + 0.18M CH₃NH₃Cl

In Water ...

=> 0.18M CH₃NH₃OH + 0.18M CH₃NH₃Cl

=> 0.18M CH₃NH₃⁺ + 0.1M OH⁻ + 0.18M CH₃NH₃⁺ + 0.18M Cl⁻

=> 0.36M CH₃NH₃⁺ + 0.18M OH⁻ + 0.18M Cl⁻

-----------------------------------------------------------

Ka'(CH₃NH₃⁺) x Kb(CH₃NH₂) = Kw => Ka'(CH₃NH₃⁺) = Kw/Kb(CH₃NH₂)

=> Ka'(CH₃NH₃⁺) = (10⁻¹⁴/4.4x10⁻⁴) = 2.27x10⁻¹¹

----------------------------------------------------------

From the 0.36M CH₃NH₃⁺

=>       CH₃NH₃⁺ + H₂O  ⇄ CH₃NH₄⁺ + OH⁻

C(eq)   0.36M        ----              x             x     (<= at equilibrium after mixing)

Ka'(CH₃NH₃⁺) = [CH₃NH₄⁺][OH⁻]/[CH₃NH₃⁺] = x²/(0.36M)

=> x = [OH⁻] = SqrRt(Ka'(CH₃NH₃⁺)·0.36M) = SqrRt(2.27x10⁻¹¹/0.36) = 0.0126M

=> Total [OH⁻] = 0.0126M + 0.18M = 0.1926M from hydrolysis process

=> final solution mix is therefore, 0.1926M in OH⁻ + 0.18M in Cl⁻

--------------------------------------------------------

∴pH = -log[H⁺] = -log(5.192x10⁻¹⁴) = -(-13.29) = 13.29 for solution mix

The acid and base dissociation constant and the 0.18 M of CH₃NH₂ and

CH₃NH₃Cl and the mixture give the following approximate values;

A. The pH value of the 0.18 M CH₃NH₂ is 11.93

B. The pH value of the 0.18 M CH₃NH₃Cl is 5.69

C. The pH value of the mixture is 10.644

A. 0.18 M CH₃NH₂

The solution is presented as follows;

CH₃NH₂ + H₂O → CH₃NH₃⁺ + OH⁻

Let x represent the number of moles of CH₃NH₃⁺ and OH⁻ produced, we

have;

The number of moles of CH₃NH₂ remaining = 0.18 - x

Which gives;

[tex]K_b = \mathbf{\dfrac{[CH_3NH_3^+][OH^-]}{[CH_3NH_2]}}[/tex]

[tex]K_b[/tex] for CH₃NH₂ = 4.167 × 10⁻⁴

Therefore;

[tex]4.167 \times 10^{-4} = \mathbf{\dfrac{x \times x}{0.18 - x}}[/tex]

4.167 × 10⁻⁴ × (0.18 - x) = x²

4.167 × 10⁻⁴ × (0.18 - x) - x² = 0

Which gives;

x = [OH⁻] = 8.455 × 10⁻³

pH = 14 + log[OH⁻]

Which gives;

pH = 14 + log(8.455 × 10⁻³) ≈ 11.93

B.  0.18 M CH₃NH₃Cl

The solution is presented as follows;

CH₃NH₃⁺ → CH₃NH₂ + H⁺

Let x represent the number of moles of CH₃NH₂ and H⁺ produced,

respectively, we have;

The number of moles of CH₃NH₃⁺ remaining = 0.18 - x

Which gives;

[tex]K_a = \mathbf{\dfrac{[CH_3NH_2][H^+]}{[CH_3NH_3^+]}}[/tex]

Kₐ for CH₃NH₃Cl = 2.27 × 10⁻¹¹

Therefore;

[tex]2.27\times 10^{-11} = \dfrac{x \times x}{0.18 - x}[/tex]

2.27 × 10⁻¹¹ × (0.18 - x) = x²

2.27 × 10⁻¹¹ × (0.18 - x) - x² = 0

Which gives;

x = [H⁺] ≈ 2.02 × 10⁻⁶

pH = -log[H⁺]

Which gives;

pH = -log(2.02 × 10⁻⁶) ≈ 5.69

C. For the mixture of 0.18 M CH₃NH₂ and 0.18 M of CH₃NH₃Cl, we have;

Based on the Henderson-Hasselbalch equation, we have;

[tex]pH = \mathbf{ pKa + log\dfrac{[Conjugate \ base]}{[acid ]}}[/tex]

Which gives;

[tex]pH = -log\left(2.27 \times 10^{-11} \right)+ log\dfrac{0.18}{0.18} \approx \underline{10.644}[/tex]

Learn more about Henderson-Hasselbalch equation here:

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[tex]\boxed{\sf {AlCl_3\atop Aluminium\:Chloride}+{H_2\atop Hydrogen}\longrightarrow {Al\atop Aluminium}+{HCl\atop Hydrochloric\:acid}}[/tex]

Balanced Equation:-

[tex]\boxed{\sf {2AlCl_3\atop Aluminium\:Chloride}+{3H_2\atop Hydrogen}\longrightarrow {2Al\atop Aluminium}+{6HCl\atop Hydrochloric\:acid}}[/tex]

Answer:

pH = 3.02

Explanation:

Acetic Acid is a weak acid (HOAc) that ionizes only ~1.5% as follows:

HOAc ⇄ H⁺ + OAc⁻.

In pure water the hydronium ion concentration [H⁺] equals the acetate ion concentration [OAc⁻] and can be determined* using the formula [H⁺] = [OAc⁻] = SqrRt(Ka·[acid]) = SqrRt(1.8x10⁻⁵ x 0.0500)M = 9.5x10⁻⁴M.

By definition, pH = -log[H⁺] = -log(9.5x10⁻⁴) = 3.02

______________________________________________________

*This formula can be used to determine the [H⁺] & [Anion⁻] concentrations for any weak acid in pure water given its Ka-value and the molar concentration of acid in solution.

Answer:

F 64.6 percent of carbon may be

Answer:

[tex]\lambda=3451*10^{10}m[/tex]

Explanation:

From the question we are told that:

Energy state [tex]e=3.50 eV[/tex]

Time [tex]t=2ms[/tex]

Generally the equation for energy of Photon is mathematically given by

[tex]E=e-e_0[/tex]

[tex]E=3.6*10^{-19}J[/tex]

[tex]E=5.7*10^{-19}J[/tex]

Generally the equation for Wave-length of Photon is mathematically given by

[tex]\lambda=\frac{hc}{E}[/tex]

[tex]\lambda=\frac{6.626*10^{-34}*3*10^8}{5.76*10^{-19}}[/tex]

[tex]\lambda=3451*10^{10}m[/tex]

Answer: The question wants you to determine the energy that the incoming photon must have in order to allow the electron that absorbs it to jump from  

n

i

=

2

to  

n

f

=

6

.

A good starting point here will be to calculate the energy of the photon emitted when the electron falls from  

n

i

=

6

to  

n

f

=

2

by using the Rydberg equation.

1

λ

=

R

⋅

(

1

n

2

f

−

1

n

2

i

)

Here

λ

si the wavelength of the emittted photon

R

is the Rydberg constant, equal to  

1.097

⋅

10

7

m

−

1

Plug in your values to find

1

λ

=

1.097

⋅

10

7

.

m

−

1

⋅

(

1

2

2

−

1

6

2

)

1

λ

=

2.4378

⋅

10

6

.

m

−

1

This means that you have

λ

=

4.10

⋅

10

−

7

.

m

So, you know that when an electron falls from  

n

i

=

6

to  

n

f

=

2

, a photon of wavelength  

410 nm

is emitted. This implies that in order for the electron to jump from  

n

i

=

2

to  

n

f

=

6

, it must absorb a photon of the same wavelength.

To find the energy of this photon, you can use the Planck - Einstein relation, which looks like this

E

=

h

⋅

c

λ

Here

E

is the energy of the photon

h

is Planck's constant, equal to  

6.626

⋅

10

−

34

.

J s

c

is the speed of light in a vacuum, usually given as  

3

⋅

10

8

.

m s

−

1

As you can see, this equation shows you that the energy of the photon is inversely proportional to its wavelength, which, of course, implies that it is directly proportional to its frequency.

Plug in the wavelength of the photon in meters to find its energy

E

=

6.626

⋅

10

−

34

.

J

s

⋅

3

⋅

10

8

m

s

−

1

4.10

⋅

10

−

7

m

E

=

4.85

⋅

10

−

19

.

J

−−−−−−−−−−−−−−−−−  

I'll leave the answer rounded to three sig figs.

So, you can say that in a hydrogen atom, an electron located on  

n

i

=

2

that absorbs a photon of energy  

4.85

⋅

10

−

19

J

can make the jump to  

n

f

=

6

.

Explanation:

Answer:

The mole ratio of AgNO3 to Ag2SO4 IS 2:1 .0.657 g Ag2SO4 x 1 mol / 312 g = 0.00211 mol Ag2SO4.

0.00211 mol Ag2SO4 x 2 mol AgNO3 / 1 mol Ag2SO4 = 0.00421 mol AgNO3

0.00421 mol AgNO3 x 1 L / 0.123 mol AgNO3 = 0.0342 L = 34.2 mL of AgNO3 solution.Therefore,34.2ml of 0.123M AgNO3 will be required.

Answer:

Explanation:

From the given information:

The surface area of the can = (30 × 20 × 2) +(20× 15 × 2) +(30 × 15 × 2)

= 1200 + 600 + 900

= 2700 cm²

Since 1 inch² = 0.155 inch²

The surface area in inches² = 2700 × 0.155 inch²

= 418.5 inches²

The total force can be determined by using the expression:

Force = Pressure ×Area

Force = 14.7 psi ×  418.5 inches²

Force = 6151.95 lbs

Yes, the gasoline can will be able to withstand the force.

Answer:

The molar mass is "185.44 g/mol".

Explanation:

According to the question,

The moles of NaOH will be:

= [tex]\frac{0.315}{1000}\times 25.72[/tex]

= [tex]8.1018\times 10^{-3} \ moles[/tex]

Number of moles of an acid will be:

= [tex]\frac{8.1018\times 10^{-3}}{3}[/tex]

= [tex]2.7006\times 10^{-3} \ moles[/tex]

We know that,

⇒ [tex]Moles = \frac{Mass}{Molar \ mass}[/tex]

hence,

Molar mass of unknown acid will be:

= [tex]\frac{Mass \ in \ g}{Moles}[/tex]

= [tex]\frac{0.5008}{2.7006\times 10^{-3}}[/tex]

= [tex]185.44 \ g/mol[/tex]

We know

[tex]\boxed{\Large{\sf M_1V_1=M_2V_2}}[/tex]

[tex]\\ \Large\sf\longmapsto M_2=\dfrac{M_1V_1}{V_2}[/tex]

[tex]\\ \Large\sf\longmapsto M_2=\dfrac{3(75)}{250}[/tex]

[tex]\\ \Large\sf\longmapsto M_2=\dfrac{225}{250}[/tex]

[tex]\\ \Large\sf\longmapsto M_2=0.9M[/tex]

Answer:

Mass 1=3M

Mass 2=?

Volume1=75mL

Volume2=250mL

By using molarity formula:

mass1*volume 1=mass2*volume 2

3M*75=mass2*250

mass2=225/250

mass2:0.9M

Hello There!

Hope that helps you!

~Just a felicitous girlie

#HaveASplendidDay

[tex]SilentNature[/tex]

Answer:

495 J

Explanation:

When the hot pot was set on the counter to cool, heat energy was lost from the pot. Note that according to the first law of thermodynamics, heat is neither created nor destroyed.

This implies that, the heat energy lost from the pot must be gained by the surrounding air. Therefore, if 495 J of energy is lost from the pot, then 495 J of energy is gained by the surrounding air.

Answer:

HCl contain a polar covalent bond because H is more electropositive than Cl and Cl is more electronegative than H, resulting in a dipole moment

Answer:

There must be a complete circuit to allow electrons to flow. Oxidation happens at the anode. Reduction happens at the cathode.

Explanation:

Select all that are true for both a voltaic cell and an electrolytic cell.

There must be a complete circuit to allow electrons to flow. YES. This is true for both cells.

The redox reaction is spontaneous. NO. This is only true for the voltaic cell.

Oxidation happens at the anode. YES. This is true for both cells.

Reduction happens at the cathode. YES. This is true for both cells.

The redox reaction is non-spontaneous. NO. This is only true for the electrolytic cell.

The statements that have been true for both voltaic and electrolytic cells are:

Option A: There must be a complete circuit to allow electrons to flow.

Option C: Oxidation happens at the anode.

Option D: Reduction happens at the cathode.

The electrolytic cells are the one that converts electrical energy into chemical energy. Voltaic cells convert chemical energy into electrical energy.

From the given options, the best-suited option for both electrolytic and voltaic cells are:

The statements that have been true for both voltaic and electrolytic cells are, Option A, C, and D.

For more information about the electrolytic and voltaic cell, refer to the link:

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