You decide to focus on pickling cucumbers. The cucumbers that you have are all approximately 12 cm in length and 3 cm in diameter. If the diffusion coefficient for H+ ions in cucumbers is the same as in water, 7 x 10-5 cm2/sec, how long will it take for the protons to reach the center of the cucumbers? Enter your answer in minutes without including the units.

Answer: The new molarity is 2.4 M

Explanation:

According to the dilution law,

[tex]C_1V_1=C_2V_2[/tex]

where,

[tex]C_1[/tex] = concentration of pure solution = 3 M

[tex]V_1[/tex] = volume of pure solution = 200 ml

[tex]C_2[/tex] = concentration of diluted solution= ?

[tex]V_2[/tex] = volume of diluted solution= 250 ml

Putting in the values:

[tex]3M\times 200ml=M_2\times 250ml[/tex]

[tex]M_2=2.4M[/tex]

Thus the new molarity is 2.4 M

Answer:

[tex]1.56 \,\,mol/L[/tex]

Explanation:

Molarity of the solution measures number of moles of a solute per litre of solution.

Molarity = volume of solution in litres/number of moles of solute dissolved in solution

Volume of solution in litres = 0.86 L

Also, 1.34 mole sample of LiCl dissolves in water

So,

Molarity of the Solution = [tex]\frac{1.34}{0.86}=1.56 \,\,mol/L[/tex]

Answer:

Koverall [NO]^2 [Br2]

Balanced chemical reaction equation;

2NO + Br2 ⇄2NOBr

Explanation:

Consider the first step in the reaction;

NO(g) + Br2(g) ⇄ NOBr2(g) fast

The second step is the slower rate determining step

NOBr2(g) + NO(g) ⇄ 2NOBr(g)

Given that k1= [NOBr2]/[NO] [Br2]

k2= [NOBr2] [NO]

The concentration of the intermediate is now;

[NOBr2]= k1[NO][Br2]

It then follows that overall rate of reaction is

Rate= k1k2[NO]^2 [Br2]

Since k1k2=Koverall

Rate= Koverall [NO]^2 [Br2]

Answer:

NOBr_2(g)+NO(g)----> 2NOBr(g)

Explanation:

Answer retrieved from ALEKS

The molar mass of fructose will be "180 g/mol". To understand the calculation check below.

According to the question,

Fructose mass = 1.8 g

Water's mass = 0.100 kg

Molal freezing point depression constant, [tex]K_f[/tex] = 1.86°C/m

Freezing point change, Δ[tex]T_f[/tex] = 0.186°C

Freezing point constant, [tex]K_f[/tex] = 1.86°C/m

We know the relation,

→ Δ[tex]T_f[/tex] = i × [tex]K_f[/tex] × m

or,

         = i × [tex]K_f[/tex] × [tex]\frac{Fructose \ mass}{Fructose \ molar \ mass\times Solvent's \ mass}[/tex]

By substituting the values, we get

0.186 = 1 × 1.86 × [tex]\frac{1.8}{Fructose \ molar \ mass\times 0.100}[/tex]

By applying cross-multiplication,

Molar mass = 180 g/mol

Thus the above approach is right.          

Find out more information about molar mass here:

https://brainly.com/question/24727597

A 1.8 g mass of fructose is added to 0.100 kg of water and it is found that the freezing point has decreased by 0.186 °C. The molar mass of fructose is 180 g/mol.

Given:

ΔTf = 0.186 °C

Kf = 1.86 °C kg/mol

m = mass of fructose/mass of water

mass of fructose = 1.8 g

mass of water = 0.100 kg = 100 g

Use the equation:

ΔTf = Kf mi

Where:

ΔTf is the change in freezing point (in °C)

Kf is the cryoscopic constant of water (in °C kg/mol)

m is the molality of the solute (in mol/kg)

i is the van't Hoff factor

m = (mass of fructose) / (mass of water)

m = 1.8 g / 100 g

m = 0.018 mol/kg

Rearrange the equation to solve for the molar mass (M):

ΔTf = Kfmi

Substitute the values in the above equation:

0.186 = 1.86 × 0.018 × 1 / M

By applying cross multiplication,

Molar mass (M) = 180 g/mol

To learn more about the molar mass, follow the link:

https://brainly.com/question/12127540

#SPJ6

Answer:

See figure 1

Explanation:

On this case we have a base (methylamine) and an acid (2-methyl propanoic acid). When we have an acid and a base an acid-base reaction will take place, on this specific case we will produce an ammonium carboxylate salt.

Now the question is: ¿These compounds can react by a nucleophile acyl substitution reaction? in other words ¿These compounds can produce an amide?

Due to the nature of the compounds (base and acid), the nucleophile (methylamine) doesn't have the ability to attack the carbon of the carbonyl group due to his basicity. The methylamine will react with the acid-producing a positive charge on the nitrogen and with this charge, the methylamine loses all his nucleophilicity.

I hope it helps!

Answer:

A Reaction

3. Pt(NO₃)₂(aq) + Cu(s)

4. Cr(s) + H₂SO₄(aq)

B Non Reaction

1. Mn(s) + Ca(NO₃)₂(aq)

2. KOH(aq) +  Fe(s)

Y > Q > W > Z > X

Explanation:

The first question is whether a reaction will occur base on the chemical equation below.

1. Mn(s) + Ca(NO₃)₂(aq)

2. KOH(aq) +  Fe(s)

3. Pt(NO₃)₂(aq) + Cu(s)

4. Cr(s) + H₂SO₄(aq)

Firstly, some element are more reactive than others , base on this criteria element can be arranged  base on it reactivity .

1. Mn(s) + Ca(NO₃)₂(aq)

This reaction will not occur because Mn cannot displace Ca in it compound. Usually, more reactive element displaces less reactive element.

2. KOH(aq) +  Fe(s)

The reaction will not occur since Iron is less reactive and lower in the reactivity series than potassium . So iron won't be able to displace potassium.

3. Pt(NO₃)₂(aq) + Cu(s)

Copper is more reactive than platinum so it will displace platinum easily . The reaction will definitely occur.

4. Cr(s) + H₂SO₄(aq)

Chromium is higher up in the reactivity series than hydrogen so, it will definitely displace hydrogen in it compound . The reaction will occur in this case.

Base on the reaction

Q + W+ Reaction occurs

Since the reaction occurred element Q is more reactive as it displace element w from it compound.  

X + Z+ No reaction

No reaction occurred because element x is less reactive than z therefore, it cannot displace z from it compound.

W + Z+ Reaction occurs

Element w is more reactive than z as it displaces z form it compound.

Q+ + Y Reaction occurs

Element Y is more reactive than element  Q as it displaces Q from it compound.

Therefore, the  order of reactivity from the most reactive to the least reactive will be Y > Q > W > Z > X

A. The beakers in which a chemical reaction will occur:

3. Pt(NO₃)₂(aq) + Cu(s)

4. Cr(s) + H₂SO₄(aq)

B. The beakers in which there is no reaction:

1. Mn(s) + Ca(NO₃)₂(aq)

2. KOH(aq) +  Fe(s)

C. The elements from most reactive to least reactive is:

Y > Q > W > Z > X

A.

1. Mn(s) + Ca(NO₃)₂(aq)

2. KOH(aq) +  Fe(s)

3. Pt(NO₃)₂(aq) + Cu(s)

4. Cr(s) + H₂SO₄(aq)

Elements can be arranged on the basis of reactivity:

1. Mn(s) + Ca(NO₃)₂(aq)

This reaction will not occur because Mn cannot displace Ca in it compound. Usually, more reactive element displaces less reactive element.

2. KOH(aq) +  Fe(s)

The reaction will not occur since Iron is less reactive and lower in the reactivity series than potassium . So iron won't be able to displace potassium.

3. Pt(NO₃)₂(aq) + Cu(s)

Copper is more reactive than platinum so it will displace platinum easily . The reaction will definitely occur.

4. Cr(s) + H₂SO₄(aq)

Chromium is higher up in the reactivity series than hydrogen so, it will definitely displace hydrogen in it compound . The reaction will occur in this case.

According to reactions:

Q + W→ Reaction occurs

Since the reaction occurred element Q is more reactive as it displace element w from it compound.  

X + Z →No reaction

No reaction occurred because element X is less reactive than Z therefore, it cannot displace z from it compound.

W + Z→ Reaction occurs

Element W is more reactive than Z as it displaces Z form it compound.

Q + Y →Reaction occurs

Element Y is more reactive than element Q as it displaces Q from it compound.

Thus, the order of reactivity from the most reactive to the least reactive will be: Y > Q > W > Z > X

Find more information about Reactivity series here:

brainly.com/question/17469010

Answer:

See explanation below

Explanation:

In this case, let's see both molecules per separate:

In the case of SeO₂ the central atom would be the Se. The Se has oxidation states of 2+, and 4+. In this molecule it's working with the 4+, while oxygen is working with the 2- state. Now, how do we know that Se is working with that state?, simply, let's do an equation for it. We know that this molecule has a formal charge of 0, so:

Se = x

O = -2

x + (-2)*2 = 0

x - 4 = 0

x = +4.

Therefore, Selenium is working with +4 state, the only way to bond this molecule is with a covalent bond, and in the case of the oxygen will be with double bond. See picture below.

In the case of CO₂ happens something similar. Carbon is working with +4 state, so in order to stabilize the charges, it has to be bonded with double bonds with both oxygens. The picture below shows.

Answer and Explanation:

7.40 becomes lower or shorter than the pKa of functional groups or chains of all the 3 amino acids respectively Lys, His, as well as Asp, although since pH provided throughout the statement. However, all of the covalent chains or bonds of the three compounds or acids (amino) will serve a purpose in the pro-toned pattern.

The pH during which everyone's binding sites will mostly keep track of customer for someone's comparison is:

Lys:

[tex]pH > 10.53[/tex]

His:

[tex]pH > 6.00[/tex]

Asp:

[tex]pH > 3.65[/tex]

Answer:

(i)The compression factor is 1.12

(ii) The molar volume of the gas is 2.68 L/mol

Since the compression factor is greater than 1, the attractive forces are dominating.

Explanation: Please see the attachments below

Answer: Boyle's law states that pressure and volume are inversely related because the product of pressure and volume is approximately constant.

Explanation:

In each of the given values product of P and V, that is, PV remains constant. As according to Boyle's law, at constant temperature the pressure will be inversely proportional to volume of the gas.

Mathematically,    [tex]P \propto \frac{1}{V}[/tex]

or,            PV = k

where,   k = Proportionality constant

              P = pressure of gas

              V = volume of gas

Product of values will only remain constant when pressure is inversely proportional to volume.

Therefore, we can conclude that Boyle's law states that pressure and volume are inversely related because the product of pressure and volume is approximately constant.

Boyle's law mentioned that pressure and volume should be inversely related since the product of pressure and volume is approximately constant.

According to this law, at a constant temperature, the pressure should be inversely proportional to the volume of the gas.

PV = k

Here

k = Proportionality constant

P = Pressure

V = volume of gas

So based on this we can conclude that Boyle's law mentioned that pressure and volume should be inversely related since the product of pressure and volume is approximately constant.

Learn more about volume here: https://brainly.com/question/21960832

Answer:

Explanation:

CH₃C(CH₃)=CH-CH₂-CH₃ ( 2 - methylpent-2-ene)

Cl₂ ⇒ Cl⁺ + Cl⁻

Cl⁺( electrophile)

CH₃C(CH₃)=CH-CH₂-CH₃  + Cl⁺ ( electrophile)  ⇒ CH₃C⁺(CH₃)-C(Cl)H-CH₂-CH₃ (  intermediate )

CH₃C⁺(CH₃)-C(Cl)H-CH₂-CH₃ + Cl⁻  ⇒ CH₃CCl(CH₃)-C(Cl)H-CH₂-CH₃ ( final product )

It is electrophilic addition reaction.

Complete Question

The complete question is shown on the first uploaded image  

Answer:

The density is  [tex]\rho = 21.1 \ g/cm^3[/tex]

Explanation:

From the question we are told that

      The lattice constant is  [tex]a = 0.387 nm = 0.387 *10^{-9} \ m[/tex]

Generally the volume of the unit cell is  [tex]V = a^3[/tex]

                                                             =>   [tex]V = [0.387 *10^{-9}]^2[/tex]

                                                                   [tex]V = 5.796 *10^{-29} \ m^3[/tex]

Converting to  [tex]cm^3[/tex]   We have  [tex]5.796 *10^{-29} * 1000000 = 5.796 *10^{-23} cm^3[/tex]

The molar mass of Tungsten is constant with a value  [tex]Z = 184 g/mol[/tex]

One mole of Tungsten contains  [tex]6.022*10^{23}[/tex] unit cells

    Where [tex]6.022*10^{23}[/tex]  is  a constant for the number of atom in one mole of a substance(Tungsten) which is known as Avogadro's constant

      Now for FCC distance  the number of atom per unit cell  is  n =  4

               Mass of Tungsten (M) =  [tex]= \frac{Z * n }{1 \ mole \ of \ Tungsten}[/tex]

=>              Mass of Tungsten (M) =  [tex]= \frac{184 * 4 }{6.023*10^{23}}[/tex]

=>              Mass of Tungsten (M) =  [tex]= 1.222*10^{-21} \ g[/tex]

 Now  

      The density of  Tungsten is  

                  [tex]\rho = \frac{M}{V}[/tex]

substituting values

                [tex]\rho = \frac{1.222*10^{-21}}{5.796*10^{-23}}[/tex]

                [tex]\rho = 21.1 \ g/cm^3[/tex]

Answer:

THE FINAL TEMPERATURE OF THE LIQUID SAMPLE  IS 30.45 DEGREE CELSIUS

Explanation:

Mass of the liquid sample = 1424 g

Initail temperature = 30 degree C

Heat evolved = 1560 J

Specific heat of the liquid = 2.44 J/g degree C

Final temperature = unknown

Since the heat evolved by a substance is the product of the mass, specific heat capacity and the change in temperature of the sample

Heat = Mass * Specific heat * change in temp.

                                       H = m c (T2-T1)

Re-arranging the formula by making T2 (final temperature) the subject of the equation, we have:

         T2= H/ m c + T1

So therefore, introducing the value of the variables and solving for T2, we have:

T2 = 1560 / 1424 * 2.44 + 30

T2 = 1560 / 3474.56 + 30

T2 = 0.4487 + 30

T2 = 30.4487 degree C

The final temperature of the liquid sample is approximately 30.45 degree C

Answer: 0.424 J/g°C

Explanation:

For this problem, we would have to manipulate the equaiton for heat, q=mCT. Specific heat is the C in the equation. Since we are looking for specific heat, we manipulate the equation so that it says C=.

[tex]C=\frac{q}{m(deltaT)}[/tex]

*I didn't know how to type in delta so I just wrote the word delta, but pretend you see a Δ.

Now that we have our equation, we can plug in our values and solve.

[tex]C=\frac{181J}{(38.8g)(36-25°C)}[/tex]

*Please ignore the capital A in the equation. It pops up every time I type in the ° sign.

[tex]C=0.424J/g°C[/tex]

Answer: the enthalpy of reaction is, -155 kJ

Explanation:-

According to Hess’s law of constant heat summation, the heat absorbed or evolved in a given chemical equation is the same whether the process occurs in one step or several steps.

According to this law, the chemical equation can be treated as ordinary algebraic expression and can be added or subtracted to yield the required equation. That means the enthalpy change of the overall reaction is the sum of the enthalpy changes of the intermediate reactions.

The final reaction is:

[tex]CH_4(g)+2O_2(g)\rightarrow CO_2(g)+2H_2O(l)[/tex]    [tex]\Delta H_{rxn}=?[/tex]

The intermediate balanced chemical reaction will be,

(1) [tex]CH_4(g)+O_2(g)\rightarrow CH_2O(g)+H_2O(g)[/tex]     [tex]\Delta H_1=-284kJ[/tex]

(2) [tex]CH_2O(g)+O_2(g)\rightarrow CO_2(g)+H_2O(g)[/tex]    [tex]\Delta H_2=-527kJ[/tex]

(3) [tex]H_2O(l)\rightarrow H_2O(g)[/tex]    [tex]\Delta H_3=44.0kJ[/tex]

Now multiplying (3) by 2 and adding all the equations, we get :

[tex]\Delta H_{rxn}=\Delta H_1+\Delta H_2+2\times \Delta H_3[/tex]

[tex]\Delta H_{rxn}=(-284)+(-527)+2\times (44)[/tex]

[tex]\Delta H_{rxn}=-155kJ[/tex]

Therefore, the enthalpy of reaction is, -155 kJ

Answer:

Acid base titration curves shows the pH at equivalence point

Explanation:

Since the images were not shown, I will proceed to give a general description of the following acid-base titration curves:

In a strong acid-strong base titration, the acid and base will react to form a neutral solution. At the equivalence point of the reaction, hydronium (H+) and hydroxide (OH-) ions will react to form water, leading to a pH of 7.

The titration curve reflects the strengths of the corresponding acid and base. If one reagent is a weak acid or base and the other is a strong acid or base, the titration curve is irregular, and the pH shifts less with small additions of titrant near the equivalence point.

Polyprotic acids are able to donate more than one proton per acid molecule, in contrast to monoprotic acids that only donate one proton per molecule. In the titration curve of a polyptotic acid and a strong base, The curve starts at a higher pH than a titration curve of a strong base. There is always a steep climb in pH before the first midpoint. Gradually, the pH increases until it passes the midpoint; Right before the equivalence point there is a very sharp increase in pH.

Answer:

awzsexdrcftvgybhunimoknljbkhvjgchfx

Explanation:

Answer:

THE STANDARD ENTHALPY OF FORMATION OF AMMONIA GAS IS 293.75kJ OF HEAT.

Explanation:

To solve this question, you must first write out the equation for the reaction.

Equation:

N2 (g) + 3H2(g) <-------> 2NH3(g)

So therefore, when 50 g of N2 reacts, 164.5 kJ of Heat was liberated.

First equate the number of moles of Nitrogen and ammonia gas

1 mole of N2 produces 2 moles of ammonia

Calculate the molar mass of each variables:

Molar mass of N2 = 14*2 = 28 g/mol

Molar mass of ammonia = ( 14 + 1*3) = 17 g/mol

So, 1 mole of N2 = 2 moles of NH3

28 g/mol of N2 = 17 * 2 g/mol of NH3

If 50 g of nitrogen was used to react with excess hydrogen, the mass of ammonia formed is;

28 g of N2 = 34 g/mol of NH3

50 g of N2 = ( 50 * 34 / 28 ) g of NH3

= 1700 / 28

= 60 .71 g of ammonia.

At standard conditions, 34 g of ammonia will liberate 164.5 kJ of heat. What amonut would be generated by 60.71 g of ammonia?

34 g of ammonia = 164.5 kJ of heat

60.71 g of ammonia = ( 60.71 * 164.5  / 34) kJ of heat

= 9987.5 / 34

= 293.75 kJ of heat.

In other words, the standard enthalpy of formulation for ammonia gas is 293.75 kJ of heat.

The question is incomplete, here is the complete question:

Steam reforming of methane [tex](CH_4)[/tex] produces "synthesis gas," a mixture of carbon monoxide gas and hydrogen gas, which is the starting point for many important industrial chemical syntheses. An industrial chemist studying this reaction fills a 125 L tank with 20 mol of methane gas and 10 mol of water vapor at 38 degrees celsius. He then raises the temperature, and when the mixture has come to equilibrium measures the amount of hydrogen gas to be 18 mol . Calculate the concentration equilibrium constant for the steam reforming of methane at the final temperature of the mixture. Round your answer to significant digits.

Answer: The equilibrium constant for the reaction is [tex]3.99\times 10^{-2}[/tex]

Explanation:

We are given:

Initial moles of methane gas = 20 moles

Initial moles of water vapor = 10 moles

Equilibrium moles of carbon monoxide = 18 moles

Volume of the tank = 125 L

The chemical equation for the reaction of methane and water vapor follows:

                       [tex]CH_4(g)+H_2O(g)\rightleftharpoons CO(g)+3H_2(g)[/tex]

Initial:                20             10

At eqllm:          20-x         10-x            x            3x

Evaluating the value of 'x':

[tex]\Rightarrow 3x=18\\x=6[/tex]

So, equilibrium moles of methane gas = (20 - x) = [20 - 6] = 14 mol

Equilibrium moles of water vapor = (10 - x) = [10 - 6] = 4 mol

Equilibrium moles of carbon monoxide gas = x = 6 mol

The expression of equilibrium constant for the above reaction follows:

[tex]K_{eq}=\frac{[H_2]^3[CO]}{[CH_4][H_2O]}[/tex]

We are given:

[tex][H_2]=\frac{18}{125}=0.144M[/tex]

[tex][CO]=\frac{6}{125}=0.048M[/tex]

[tex][CH_4]=\frac{14}{125}=0.112M[/tex]

[tex][H_2O]=\frac{4}{125}=0.032M[/tex]

Putting values in above expression, we get:

[tex]K_{eq}=\frac{(0.144)^3\times 0.048}{0.112\times 0.032}\\\\K_{eq}=3.99\times 10^{-2}[/tex]

Hence, the equilibrium constant for the reaction is [tex]3.99\times 10^{-2}[/tex]

Answer:

Explanation:

If the power of ten is positive, you move the decimal place to the right when converting  a number from scientific to standard notation

For example:

5.6894 * 10^9

10^9 is 1 with 9 zeros

5.6894 * 1000000000

5689400000.

it moved right

If the power of 10 is positive, move the decimal point to the left.

If the power of 10 is positive, move the decimal point to the right.

If the number being converted is greater than 10, move the decimal point to the left.

If the number being converted is greater than 10, move the decimal point to the right.

This is option 2

The correct answer is if the power of 10 is positive, move the decimal point to the right.

A frequently-used floating-point system in which integers are expressed as products of a number between 1 and 10 multiplied by a power of 10.

Learn more about scientific notation here:-

https://brainly.com/question/2890945

#SPJ2

Answer:

Calcium

Explanation:

We must first put down the reaction equation as this will serve as a guide in solving the question.

M(s) + S(s) -----> MS(s)

According to the reaction equation; 1 mole of metal reacts with 1 mole of sulphur. Hence 0.09 moles of sulphur reacts with 0.09 moles of metal.

Now recall that;

Number of moles (n) = mass(m)/ molar mass(M)

Since

mass of metal reacted= 3.6g

Number of moles of metal= 0.09 moles

Then;

Making molar mass of metal the subject of the formula;

Molar mass of metal = mass of metal / number of moles of metal

Molar mass of metal = 3.6g /0.09 moles

Molar mass of metal= 40 gmol-1

The metal having a molar mass of 40gmol-1 is calcium, therefore the metal is calcium.

Answer:

AT THE END OF 80% DISSOLUTION, THE PRESSURE OF NO2 HAS CHANGED FROM 99kPa TO 139.97kPa

Explanation:

P1 = 99 kPa

P2 = unknown

From the reaction,

2 mole of NO2 will produce 2 mole of NO

We can also say that 1 mole of NO2 will produce 1 mole of NO

At 56.6 % of NO2, 0.566 mole of NO2 will be consumed

At STP, 1 mole of  a substance will occupy 22.4 dm3 volume

0.566 mole will occupy ( 22.4 * 0.566 / 1) dm3 volume

= 39.58 dm3 volume

V1 = 39.56 dm3

At the new percent of 80%, 0.80 mole of NO2 will be consumed

Since, 1 mole = 22.4 dm3

0.80 mole = (22.4 / 0.80) dm3

= 28 dm3

V2 = 28 dm3

Using the equation of Boyle's law which shows the relationship between pressure and volume of a given mass of gas at constant temperature, we have:

P1 V1 = P2 V2

Re-arranging to make P2 the subject of formula:

P2 = P1V1 / V2

P2 = 99 kPa * 39.56 / 28

P2 = 3916.44 kPa / 28

P2 = 139.87 kPa

So at 80 % dissociation of NO2, the pressure has changed from 99 kPa to 139.97 kPa.

Answer:

H2 is the limiting reactant.

Explanation:

From the diagram above:

H2 => White ball

O2 => Red ball

Before the reaction

H2 => White ball => 10

O2 => Red ball => 7

After the reaction

H2O => White and red ball => 10

O2 => 2

From the simple illustration above, we can see that all the H2 were used up in the reaction but there are left over of O2.

This simply means that H2 is the limiting reactant as all of it is used up in the reaction while O2 is the excess reactant as there are leftover.

Answer:

Answer:

56°

Explanation:

First calculate [tex]a:[/tex]

[tex]a=2 R \sqrt{2}=2(0.1246) \sqrt{2}=0.352 \mathrm{nm}[/tex]

The interplanar spacing can be calculated from:

[tex]d_{111}=\frac{a}{\sqrt{1^{2}+1^{2}+1^{2}}}=\frac{0.352}{\sqrt{3}}=0.203 \mathrm{nm}[/tex]

The diffraction angle is determined from:

[tex]\sin \theta=\frac{n \lambda}{2 d_{111}}=\frac{1(0.1927)}{2(0.2035)}=0.476[/tex]

Solve for [tex]\theta[/tex]

[tex]\theta=\sin ^{-1}(0.476)=28^{\circ}[/tex]

The diffraction angle is:

[tex]2 \theta=2\left(28^{\circ}\right)=56^{\circ}[/tex]

Answer:

1. Q = 8.66 KJ

2. Q = 7.58 Kcal

3. Q = 0.71 KJ

4. Q = 24.31 Kcal

Explanation:

1. The quantity of heat absorbed can be determined by:

       Q = mcΔθ

where: Q is the quantity of heat absorbed or released, m is the mass of the substance, c is the specific heat capacity of water = 4.2 j/g[tex]^{0}C[/tex] and Δθ is the change in temperature.

           = 45.2 × 4.2  × (76.9 - 31.3)

           = 8656.704

∴       Q = 8.66 KJ

The quantity of heat absorbed is 8.66 KJ.

2. Q = mcΔθ + mL

Where L is the latent heat of fusion of ice = 334 J.

       = m(cΔθ + L)

       = 72.1(4.2 × 25.2 + 334)

   Q = 31712.464 J

       = 7579.466 calories

The total heat released is 7.58 Kcal.

3. Q = mcΔθ

      = 55.5 × 0.129 × (123.4 - 24.6)

     = 707.3586

The quantity of heat required to increase the temperature of gold is 0.71 KJ.

4. Q = mL

Where: L is the specific latent heat of vaporization = 533 calories.

     Q  = 45.6 × 533

      = 24304.8

The quantity of heat required to change water to steam is 24.31 Kcal.

Answer:

C = 2.24x10⁻⁴ M

Explanation:

The concentration of iron in Uncle Wilbur's runoff can be calculated using Beer-Lambert law:

[tex] A = \epsilon*C*l [/tex]   (1)

Where:

A: is the absorbance of the compound

ε: is the molar absorptivity of the compound

C: is the concentration of the compound

l: is the optical path length

Since the runoff sample exhibited the same absorbance as the reference sample, we can find the concentration using equation (1):      

[tex] \epsilon*C_{1}*l_{1} = \epsilon*C_{2}*l_{2} [/tex]    (2)

Where:

Subscripst 1 and 2 refer to Uncle Wilbur's runoff and to reference sample, respectively.

l₁ = 2.41 cm

l₂ = 1.00 cm

We can find C₂ as follows:

[tex] C_{2} = \frac{C_{2i}*V_{i}}{V_{f}} [/tex]    (3)

Where:

[tex]C_{2i}[/tex]: is the initial concentration of the reference sample = 6.74x10⁻⁴ M

[tex]V_{i}[/tex]: is the initial volume = 10.0 mL

[tex]V_{f}[/tex]: is the final volume = 50.0 mL

[tex] C_{2} = \frac{6.74 \cdot 10^{-4} M*10.0 mL}{50.0 mL} = 1.35 \cdot 10^{-4} M [/tex]

Now, we can find C₁ using equation (2):

[tex] C_{1} = \frac{C_{2}*l_{2}}{l_{1}} = \frac{1.35 \cdot 10^{-4} M*1.00 cm}{2.41 cm} = 5.60 \cdot 10^{-5} M [/tex]

Finally, since the runoff solution was diluted to 100.0 mL, the initial concentration can be calculated using equation (3) for [tex]C_{1i}[/tex]:

[tex]C_{1i} = \frac{C_{1}*V_{f}}{V_{i}} = \frac{5.60 \cdot 10^{-5} M*100.0 mL}{25.0 mL} = 2.24 \cdot 10^{-4} M[/tex]

Therefore, the concentration of iron in Uncle Wilbur's runoff is 2.24x10⁻⁴ M.

I hope it helps you!

Answer:

N-Type Semiconductor

Explanation:

Answer:

Option C

Explanation:

Consider the ionic equation of this chemical equation. We are given barium chloride and silver nitrate as the reactants, and silver chloride and barium nitrate as the products. We can thus conclude that the ionic equation ( not balanced yet ) should be as follows -

Ba( 2 + ) + Cl ( - ) + Ag ( + ) + NO3 ( - ) ------> AgCl + Ba( 2 + ) + NO3( - )

As you can see these compounds are present in aqueous solutions, and are thus dissociated.

______________________________________________________

Now let us take a look at the number of elements on the reactant and product sides, and balance this chemical equation out -

Ba( 2 + ) + 2Cl ( - ) + 2Ag ( + ) + 2NO3 ( - ) ------> 2AgCl + Ba( 2 + ) + 2NO3( - )

Solution = Option C!

Answer:

5.28 moles of NaOH.

Explanation:

Step 1:

Determination of the number of mole in

375.4 g of any Na2S04.

Molar mass of Na2SO4 = (2x23) + 32 + (16x4) = 142g

Mass of Na2SO4 = 375.4g

Number of mole of Na2SO4 =..?

Mole = Mass /Molar Mass

Number of mole of Na2SO4 = 375.4/142 = 2.64 moles

Step 2:

The balanced equation for the reaction.

H2SO4 + 2NaOH —> Na2SO4 + 2H2O

Step 3:

Determination of the number of mole of NaOH needed for the reaction.

From the balanced equation above,

2 moles of NaOH reacted to produce 1 mole of Na2SO4.

Therefore, Xmol of NaOH will react to produce 2.64 moles of Na2SO4 i.e

Xmol of NaOH = 2 x 2.64

Xmol of NaOH = 5.28 moles

Therefore, 5.28 moles of NaOH is needed for the reaction.

Answer:

See figure 1.

Explanation:

In this case have to take into account that all structures must have the formula: [tex]C_7H_16[/tex]. If we remember the general formula for alkanes: [tex]C_nH_2_n_+_2[/tex] if we have "7" carbons (n=7) we will have 16 hydrogens.  Therefore all the structures that fit with this formula are alkanes.