According to Beer's law a. the absorbance is proportional to the reciprocal of the concentration. b. the absorbance is proportional to the concentration. c. the absorbance is proportional to the square of the concentration.

Answer:

309.1K

Explanation:

Step 1: Convert the flown heat to Joule

We will use the relationship 1 kJ = 1,000 J.

[tex]69.0kJ \times \frac{1,000J}{1kJ} = 69.0 \times 10^{3} J[/tex]

Step 2: Convert the mass of water to gram

We will use the relationship 1 kg = 1,000 g.

[tex]8.10 kg \times \frac{1,000g}{1kg} = 8.10 \times 10^{3} g[/tex]

Step 3: Convert the initial temperature to Kelvin

We will use the following expression.

K = °C + 273.15 = 33.9°C + 273.15 = 307.1 K

Step 4: Calculate the final temperature

We will use the following expression.

[tex]Q = c \times m \times (T_f - T_i)[/tex]

where,

[tex]T_f = \frac{Q}{c \times m} + T_i = \frac{69.0 \times 10^{3}J }{4.18J/g.K \times 8.10 \times 10^{3}g} + 307.1K = 309.1K[/tex]

Answer:

Final pressure is 1.42atm

Explanation:

Based on Gay-Lussac's law, pressure of a gas is directely proportional to its absolute temperature. The equation of this law is:

P₁T₂ = P₂T₁

Where P is pressure and T is absolute temperature of 1, initial state and 2, final state of the gas.

In the problem, initial conditions are Standard Temperature and Pressure, STP, that are 1 atm and 273.15K.

If the final temperature is 115°C = 388.15K (115°C + 273.15 = 388.15K), using Gay-Lussac's law:

P₁T₂ = P₂T₁

1atmₓ388.15K = P₂ₓ273.15K

1.42atm = P₂

Answer:

[tex]4BaCO_3(s)\rightarrow 4BaO(s)+4CO_2(g)\ \ \ ;\ \ \ \Delta H=2651.2kJ[/tex]

Explanation:

Hello,

In this case, in order to answer to the requirement, we first should invert the given reaction since it is the formation of barium carbonate and we need its decomposition:

[tex]BaCO_3(s)\rightarrow BaO(s)+CO_2(g)[/tex]

Thereby, the enthalpy of reaction is inverted, to positive since it is the contrary reaction:

[tex]\Delta H=662.8kJ[/tex]

Nevertheless, we need to specify it for the formation of 4 moles of carbon dioxide it means:

[tex]4BaCO_3(s)\rightarrow 4BaO(s)+4CO_2(g)\\\Delta H=662.8kJ*4[/tex]

Which finally results in the following thermochemical expression:

[tex]4BaCO_3(s)\rightarrow 4BaO(s)+4CO_2(g)\ \ \ ;\ \ \ \Delta H=2651.2kJ[/tex]

Regards.

Answer:

OH⁻ < NH₃ < HCO₃⁻ < H₂O < NH₄⁺ < H₂CO₃

Explanation:

We can do some rough calculations to find the approximate pH values of these solutions.

H₂CO₃

Kₐ ≈ 10⁻⁶

[tex]\text{H}^{+} = \sqrt{K_{\text{a}}c} = \sqrt{10^{-6} \times 10^{-1}} = \sqrt{10^{-7}} = 10^{-3.5}\\\text{pH} = -\log (10^{-3.5}) = \mathbf{3.5}[/tex]

NH₄⁺

Kb of NH₃ ≈ 10⁻⁵

Kₐ of NH₄⁺ ≈ 10⁻⁹

[tex]\text{H}^{+} = \sqrt{K_{\text{a}}c} = \sqrt{10^{-9} \times 10^{-1}} = \sqrt{10^{-10}} = 10^{-5}\\\text{pH} = -\log (10^{-5}) = \mathbf{5}[/tex]

OH⁻

Strong base

[OH⁻] = 10⁻¹

pOH = 1

pH = 14 - 1 = 13

HCO₃⁻

Salt of dibasic acid

K₁ ≈ 10⁻⁶; K₂ ≈ 10⁻¹⁰

[tex]{\text{H}^{+}} = \sqrt{K_{1}K_{2}} = \sqrt{10^{-6}\times 10^{-10}} = \sqrt{10^{-16}} = 10^{-8}\\\text{pH} = -\log (10^{-8}) = \mathbf{8}[/tex]

NH₃

Kb ≈ 10⁻⁵

[tex]\text{OH}^{-} = \sqrt{K_{\text{b}}c} = \sqrt{10^{-5} \times 10^{-1}} = \sqrt{10^{-6}} = 10^{-3}\\\text{pOH} = -\log (10^{-3}) = 3[/tex]

pOH = 14 - 3 = 11

H₂O

Neutral. pH = 7

Order from lowest [H₃O⁺] to highest [H₃O⁺]:

      OH⁻ < NH₃ < HCO₃⁻ < H₂O < NH₄⁺ < H₂CO₃  

pH   1 3        11          8            7         5           3.5

Answer:

0.83 g

Explanation:

Step 1: Write the balanced equation

Fe + CuSO₄ ⇒ Cu + FeSO₄

Step 2: Calculate the moles corresponding to 0.75 g of Fe

The molar mass of Fe is 55.85 g/mol.

[tex]0.75g \times \frac{1mol}{55.85g} = 0.013 mol[/tex]

Step 3: Calculate the moles of Cu produced from 0.013 moles of Fe

The molar ratio of Fe to Cu is 1:1. The moles of Cu produced are 1/1 × 0.013 mol = 0.013 mol.

Step 4: Calculate the mass corresponding to 0.013 moles of Cu

The molar mass of Cu is 63.55 g/mol.

[tex]0.013mol \times \frac{63.55g}{mol} = 0.83 g[/tex]

Answer:

If 0.75 grams of iron (Fe) react, 0.85 grams of copper (Cu) will be produced.

Explanation:

You know the following balanced reaction:

Fe + CuSO₄ ⇒ Cu + FeSO₄

By stoichiometry of the reaction (that is, the relationship between the amount of reagents and products in a chemical reaction), the following quantities react and are produced:

Being:

the molar mass of the compounds participating in the reaction is:

Then, by stoichiometry of the reaction, the amounts of reagent and product that participate in the reaction are:

Then you can apply a rule of three as follows: if 55.85 grams of Fe produces 63.54 grams of Cu, 0.75 grams of Fe how much mass of Cu does it produce?

[tex]mass of Cu=\frac{0.75 grams of Fe*63.54 grams of Cu}{55.85 grams of Fe}[/tex]

mass of Cu= 0.85 grams

If 0.75 grams of iron (Fe) react, 0.85 grams of copper (Cu) will be produced.

Answer: products; reactants

Explanation: as the endothermic reactions are tye one which absorbs energy

Answer:

4.2g of gasoline

Explanation:

In the problem, you need to give energy to the cup from the combustion of gasoline. The energy you need to give is:

Qcup + QWater + QCopper

As you need to increase (110ºC - 21ºC = 89º = Increase 89K) 89K, the Qcup is:

Qcup = 89K × (47J/K) = 4183J.

You can find Qwater using its specific heat, C (4.18Jg⁻¹K⁻¹), its mass (450mL = 450g) and the change of temperature, 89K:

QWater = CₓmₓΔT

QWater = 4.184Jg⁻¹K⁻¹ ₓ 450g×89K

QWater = 167569J

And Q of Copper, QCu, could be obtained in the same way (Specific heat Cu: 0.387 J/g⁻¹K⁻¹:

QCu = CₓmₓΔT

QCu = 0.387 J/g⁻¹K⁻¹ₓ850gₓ89K

QCu = 29277J

Thus, total heat you need is:

Q = Qcup + QWater + QCopper

Q = 4183J + 167569J + 29277J

Q = 201029J = 201kJ

The combustion of gasoline (Octane) produce 47.8kJ/g (Its heat of combustion). that means to produce 201kJ of energy you require:

201kJ × (1g / 47.8kJ) =

Answer:

we will use universal gas law

Explanation:

First, convert torr to atm

[tex]\frac{677}{760} = 0.89[/tex]

[tex]PV = \frac{mass}{molar mass} R T[/tex]

[tex]0.125 * 0.89 = \frac{0.281}{molar mass} * 0.082 * (26 +273)[/tex]

Molar mass = 61.9

Note: I converted Celsius to kelvin and mL to L

Answer:

THE EMPIRICAL FORMULA FOR THE UNKNOWN COMPOUND IS C7H9O

Explanation:

The empirical formula for the unknown compound can be obtained by following the processes below:

1 . Write out the percentage composition of the individual elements in the compound

C = 75.68 %

H = 8.80 %

O = 15.52 %

2. Divide the percentage composition by the atomic masses of the elements

C = 75 .68 / 12 = 6.3066

H = 8.80 / 1 = 8.8000

O = 15.52 / 16 = 0.9700

3. Divide the individual results by the lowest values

C = 6.3066 / 0.9700 = 6.5016

H = 8.8000 / 0.9700 = 9.0722

O = 0.9700 / 0.9700 = 1

4. Round up the values to the whole number

C = 7

H = 9

O = 1

5 Write out the empirical formula for the compound

C7H90

In conclusion, the empirical formula for the unknown compound is therefore C7H9O

Answer:

Specific heat of calcium carbonate(C) = 0.82 (Approx)

Explanation:

Given:

Energy absorbs (q) = 85 J

Change in temperature (Δt) = 34.9 - 21 = 13.9°C  

Mass of calcium carbonate = 7.47 g

Find:

Specific heat of calcium carbonate(C)

Computation:

Specific heat of calcium carbonate(C) = q / m(Δt)

Specific heat of calcium carbonate(C) = 85 / (7.47)(13.9)

Specific heat of calcium carbonate(C) = 85 / 103.833

Specific heat of calcium carbonate(C) = 0.8186

Specific heat of calcium carbonate(C) = 0.82 (Approx)

The third energy level will hold 18​ electrons. Hence, option (D) is correct.

The electrons surrounding an atom are located in regions around the nucleus called “energy levels”.

An energy level represents the 3-dimensional space surrounding the nucleus where electrons are most likely to be.

The general formula is that the nth shell can hold up to 2(n²) electrons in principle.

Therefore, The third energy level will hold 18​ electrons. Hence, option (D) is correct.

Learn more about Energy level here ;

https://brainly.com/question/17396431

#SPJ2

Answer:

The volume of the balloon after 38.0 hours is 99.55 L

Explanation:

Given;

volume of helium in the weather balloon, V = 110 L

initial mole of the gas, n = 4 mol

the rate leak of the gas, dn/dt = 10 mmol/hr

After 38.0 hours, the moles of the gas lost = 38hr x 10 x 10⁻³ mol/hr = 0.38 mol

the moles of the gas lost = 0.38 mol

Number of moles of helium in balloon after 38.0 hours = 4 mol - 0.38 mol

                                                                                            = 3.62 mol

Volume of helium in balloon after 38.0 hours ;

[tex]= 110(L) (\frac{3.62 \ mol}{4 \ mol} )\\\\= 99.55 \ L[/tex]

Therefore, the volume of the balloon after 38.0 hours is 99.55 L

Answer:

2500 Calories IS REQUIRED TO HEAT 50 g OF WATER FROM 25 C TO 75 C

Explanation:

Specific heat of water = 1 cal/gC

Mass = 50 g

Temperature change = 75 C - 25 C = 50 C

How many calories are required to heat the 50 g of water?

Heat = mass * specific heat * temperature change

Heat = 50 * 1 * 50

Heat = 2500 Calories

In other words, 2500 calories is required to heat 50 g of water from 25 C to 75 C.

Answer:

Sn2 mechanism reaction

Explanation:

In this case, we have a primary substrate (1-bromo-3,3-dimethylbutane). Because the leaving group "Br" is bonded to a primary carbon. Additionally, the nucleophile will come from the "NaI" (sodium iodide). This is an ionic compound, so, in solution, a cation and an anion would be produced. The anion [tex]I^-[/tex] would be the nucleophile.

Due to the primary substrate, we will have an Sn2 reaction. So, the attack of the nucleophile and the removal of the leaving group will take place in 1 step. Producing a "transition state" and finally and the final product (1-iodo-3,3-dimethylbutane).

See figure 1

I hope it helps!

Explanation:

0.08206 L atm mol-1K-1

pv=nRT

Px213 x10^-³ = 0.0150 x 0.08206 x 323

px213 x10^-³ = 0.398

p = 0.398/213 x10^-³

p = 1.87 x 10^-6atm

p = 0.0014mmHg

please brainliest

Answer:

[tex]V=980L[/tex]

Explanation:

Hello,

In this case, we have a concentration that is per unit of deciliters, therefore, we need to convert it to litre basis:

[tex]3.48\frac{g}{dL} *\frac{1L}{10dL}=0.348\frac{g}{L}[/tex]

Then, to compute the volume we use the given mass to obtain:

[tex]V=\frac{341g}{0.348g/L}\\ \\V=980L[/tex]

Best regards.

Answer:

(D) CuCl2 and Na2CO3.

Explanation:

Hello,

In this case, we can represent the aqueous-phase reaction of D as shown below:

[tex]CuCl_2(aq)+Na_2CO_3(aq)\rightarrow CuCO_3(s)+2NaCl(aq)[/tex]

Such precipitation of copper (II) carbonate is shown off due to its tiny solubility of 8.41x10⁻⁵ mol/L or 0.0157 g/L in water. It means that only 0.0157 grams of cupper (II) carbonate are soluble in 1 liter of water. Moreover, copper salts tend to be greenish, for that reason it is a green-colored precipitate.

Unlike the aforementioned case, the other ones do not produce colored precipitates even when barium acetate and barium carbonate are not too soluble but they are colorless. On the other hand even when copper (II) acetate is colored, it is slightly soluble in water.

Best regards.

Answer:

a change in temperature would be observed(ΔH is -ve)

Explanation:

Hydrochloric acid react with sodium hydroxide to give salt(sodium chloride) and water

HCl(aq) + NaOH(aq) =====> NaCl(aq) + H2O(l)

There would be no notable change since sodium chloride dissolved in water but there would be a change in temperature.

Since neutralization is exothermic(heat is evolved), therefore ΔH is negative

Answer:

Explanation:

equilibrium constant

Kc = [ C ]² / [ A ] [ B ]

= .5² / .2  x 3

= .4167

Let moles of A to be added be n

concentration of A unreacted becomes .2 + n M

increase of product C by .2 M will require use of A  and B be .1 M

So unreacted A = .2 + n - .1 = n + .1

Kc = [ C ]² / [ A ] [ B ]

.4167 = .7² / ( n + .1 ) ( 3 - .1 )

n + .1 = .4

n = . 3 moles .

So .3 moles of A to be added .

Answer:

en español por favor

Explanation:

no seeeed perdona

Answer:

C₈H₈O₃  

Explanation:

The empirical formula is the simplest whole-number ratio of atoms in a compound.

The ratio of atoms is the same as the ratio of moles.

So, our job is to calculate the molar ratio of C:H:O.

Assume 100 g of the compound.

1. Calculate the mass of each element.

Then we have 63.15 g C, 5.30 g H, and 31.55 g O.

2. Calculate the moles of each element

[tex]\text{Moles of C} = \text{63.15 g C} \times \dfrac{\text{1 mol C}}{\text{12.01 g C}} = \text{5.258 mol C}\\\\\text{Moles of H} = \text{5.30 g H} \times \dfrac{\text{1 mol H}}{\text{1.008 g H }} = \text{5.258 mol H}\\\\\text{Moles of O} = \text{31.55 g O} \times \dfrac{\text{1 mol O}}{\text{16.00 g O }} = \text{1.972 mol O}[/tex]

3. Calculate the molar ratio of the elements

Divide each number by the smallest number of moles

C:H:O = 5.258:5.258:1.972 = 2.667:2.666:1

4. Multiply by a number to make each ratio close to an integer

Multiply the ratios by three.

2.667:2.666:1 = 8.000:8.000:3 ≈ 8:8:3

5. Write the empirical formula

EF = C₈H₈O₃

The correct answer is C. Surface craters

Explanation:

Short-term environmental changes involve temporary changes and effects in the ecosystem, which are mainly minor. In the case of a small asteroid or comet, this will likely lead to surface craters or changes in the surface of the impact zone. This is because the craters and asteroids impact the surface at hight speed. Also, because this is a minor event it might lead to the death of some organisms but not the extinction of these and it is not expected this has major effects such as changes in weather. Thus, the short-term effect that this will most likely cause is "surface craters."

Answer:

surface

Explanation:

The given question is incomplete, the complete question is:

Calculating an equilibrium constant from a partial equilibrium... Steam reforming of methane (CH) 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 25.0L tank with 8.0 mol of methane gas and 1.9 mol of water vapor, and when the mixture has come to equilibrium measures the amount of carbon monoxide gas to be 1.5 mol. Calculate the concentration equilibrium constant for the steam reforming of methane at the final temperature of the mixture. Round your answer to 2 significant digits.

Answer:

The correct answer is 2.47.

Explanation:

Based on the given information, the equation for the synthesis gas is,  

CH₄ (g) + H₂O (g) ⇔ CO (g) + 3H₂ (g)

Based on the given information, 25.0 L is the volume of the tank, the concentration of CH₄ is 8.0 mol, the concentration of water vapor is 1.9 mol, and the concentration of CO gas is 1.5 mol.  

Therefore, 25 L of the solution comprise 8.0 mole of CH₄. So, 1 L of the solution will comprise 8.0 / 25 mole CH₄,  

= 0.32 mole of CH₄

Thus, the concentration of CH₄ or [CH₄] will be 0.32 mole/L or 0.32 M.  

Similarly, the concentration of H₂O or [H₂O] will be 1.9/25 = 0.076 M

and [CO] is 1.5/25 = 0.06 M

The concentration equilibrium constant for the steam will be,  

Kc = [CO] pH₂ / [CH₄] [H₂O] (Here pH₂ is the partial pressure of H₂)

Now lets us assume that the reaction has taken place in a constant atmospheric pressure, therefore, pH₂ will be equal to 1.  

= 0.06 M/0.32 M × 0.076 M  

= 2.47  

Answer:

Following are the answer to this question:

Explanation:

The structure of the S molecular formula [tex]C_7H_{14}O_2[/tex] defined in the attachment file.

Please find the attachment file.

Answer:

See attached picture.

Explanation:

Hello,

In this case, given the IUPAC name, we can infer we have a seven-carbon carboxylic acid that has a bromine at the fifth carbon, an isopropyl at the fourth carbon and the carboxyl functional group (COOH) at the first carbon, thus, on the attached document, you will find the correct structure.

Best regards.

Answer:  13.9 g of [tex]H_2O[/tex] will be produced from the given mass of oxygen

Explanation:

To calculate the moles :

[tex]\text{Moles of solute}=\frac{\text{given mass}}{\text{Molar Mass}}[/tex]    

[tex]\text{Moles of} O_2=\frac{28.8g}{32.00g/mol}=0.900moles[/tex]

The balanced chemical reaction is:

[tex]4NIO_2(g)+7O_2(g)\rightarrow 4NO_2(g)+6H_2O(g)[/tex]

According to stoichiometry :

7 moles of [tex]O_2[/tex] produce =  6 moles of [tex]H_2O[/tex]

Thus 0.900 moles of [tex]O_2[/tex] will produce =[tex]\frac{6}{7}\times 0.900=0.771moles[/tex]  of [tex]H_2O[/tex]

Mass of [tex]H_2O=moles\times {\text {Molar mass}}=0.771moles\times 18.02g/mol=13.9g[/tex]

Thus 13.9 g of [tex]H_2O[/tex] will be produced from the given mass of oxygen

Answer:

D.  0.385 J/(gi°C)

Explanation:

Heat = mC(T2-T1)

1540 = 200.0 (C)(40 - 20)

C = 0.385 J / g C

The heat capacity of a system is defined as the amount of heat required to raise the temperature through 1°C. It is denoted by C. The specific heat capacity of copper is 0.385 J/(gi°C). The correct option is D.

The specific heat capacity or specific heat of a substance is defined as the amount of heat required to raise the temperature of 1 gram of the substance through 1°C. It is usually denoted by c.

Heat capacity is an extensive property. The heat needed to raise the temperature of a sample of mass 'm' having  specific heat capacity 'c' from T₁ to T₂ is given as:

q = mc (T₂ -  T₁)

1540 = 200.0 × c (40.0 - 20.0)

c= 1540 / 200.0 × 20

c = 0.385 J/g°C

Thus the correct option is D.

To know more about specific heat capacity, visit;

https://brainly.com/question/27991746

#SPJ7

Answer:

Methyl ethyl ketone

Explanation:

Compound 'A' forms phenyl hydrazone, so it must be a carbonyl compound.  Since it also gives a negative iodoform test, so it can't be an aldehyde.  

'A' on reduction gives propane. So, it must be butanone.  Ketone reacts with phenyl hydrazine to form phenyl hydrazone but gives a negative iodoform test.

Thus, the correct answer is - Methyl ethyl ketone

Answer:

Hey there!

CS2) Carbon Disulfide.

PBr3) Phosphorus Tribromide

NO) Nitric Oxide

CF4) Carbon Tetrafluoride

P2O5) Phosphorus Pentoxide

Let me know if this helps :)

Answer:

NaClO + CH₃COOH ----> HClO + CH3CO- + Na

Explanation:

This reaction occurs between the combination of a salt and an acid, that is, an oxide-reduction reaction