4
The work done when a gas is compressed in a cylinder is 338 J. At the same time,
it absorbs 142 J of heat from the surroundings. Compute the change in energy of
the system.

Answer:

[tex]Kc=\frac{[HI]^2}{[I_2][H_2]}[/tex]

Explanation:

Hello there!

In this case, for these equilibrium problems it is firstly necessary to know the balanced reaction at equilibrium:

H2((g) + I2(g) ⇋ 2HI(g)

Next, by means of the law of mass action, it turns out possible for us to write the required and correct expression for the equilibrium constant by considering the concentrations and the coefficients in the aforementioned reaction:

[tex]Kc=\frac{[HI]^2}{[I_2][H_2]}[/tex]

Best regards!

Answer: The percentage of potassium iodide in the sample is 2.63 %.

Explanation:

The chemical equation for the reaction of iodide ions with bromine gas follows:

[tex]I^-+3Br_2+3H_2O\rightarrow 6Br^-+IO_3^-+6H^+[/tex]                (i)

The chemical equation for the reaction of iodate ions with barium ions follows:

[tex]Ba^{2+}+2IO_3^-\rightarrow Ba(IO_3)_2[/tex]                 ......(ii)

To calculate the number of moles, we use the equation:

[tex]\text{Number of moles}=\frac{\text{Given mass}}{\text{Molar mass}}[/tex]

Given mass of barium iodate = 0.0596 g

Molar mass of barium iodate = 487.13 g/mol

Using equation 1:

[tex]\text{Moles of barium iodate}=\frac{0.0596 g}{487.13 g/mol}\\\\\text{Moles of barium iodate}=1.22\times 10^{-4} moles[/tex]

By Stoichiometry of the reaction (ii):

1 mole of barium iodate is produced by 2 moles of iodate ions

So, [tex]1.22\times 10^{-4} moles[/tex] of barium iodate will be produced by [tex]\frac{2}{1}\times 1.22\times 10^{-4} =2.44\times 10^{-4}moles[/tex] of iodate ions

By the stoichiometry of the reaction (i):

1 mole of iodate ions are produced by 1 moles of iodine ions

So, [tex]2.44\times 10^{-4} moles[/tex] of iodate ions will be produced by [tex]\frac{1}{1}\times 2.44\times 10^{-4} =2.44\times 10^{-4}moles[/tex] of iodine ions

Moles of potassium iodide = Moles of iodide ions = [tex]2.44\times 10^{-4}[/tex]

Since, the molar mass of potassium iodide = 166 g/mol

Using equation 1:

[tex]\text{Mass of potassium iodide}=2.44\times 10^{-4}mol\times 166 g/mol\\\\\text{Mass of potassium iodide}=0.0405 g[/tex]

To calculate the percentage by mass of a substance, the equation used is:

[tex]\text{Percent by mass}=\frac{\text{Mass of a substance}}{\text{Mass of solution}}\times 100[/tex]

Mass of a solution = 1.54 g

Mass of potassium iodide = 0.0405 g

Using above equation:

[tex]\text{Percent potassium iodide}=\frac{0.0405 g}{1.54g}\times 100\\\\\text{Percent potassium iodide}=2.63\%[/tex]

Hence, the percentage of potassium iodide in the sample is 2.63 %.

Expressing the results of potassium iodide in percentage = 2.63%

The chemical reaction of iodine ions with Bromine gas can be expressed as :

I⁻  + 3Br₂  + 3H₂O  -- > 6Br⁻ + IO₃ + 6H⁺ ----- ( 1 )

Chemical reaction between iodate ions with barium ions  can be expressed as :  Ba²⁺  + 2IO⁻₃ ------> Ba ( IO₃ )₂   --------- ( 2 )

Step 1 : Calculate the number of Barium iodate moles

mass of Barium iodate = 0.0596 g

molar mass of Barium iodate = 487.13 g/mol

from equation ( 1 )

moles of Barium iodate = ( 0.0596 ) / ( 487.13 ) = 1.22 * 10⁻⁴ moles

also from equation ( 1 ) the moles of potassium iodide = moles of iodide ions

= 2.44 * 10⁻⁴

molar mass of potassium iodide = 166 g/mol

Next step : Determine the mass of potassium iodide

moles of potassium * molar mass

= 2.44 * 10⁻⁴  * 166 g/mol  = 0.0405 g

Final step : Determine the percentage of potassium iodide in the solution

Percentage = ( mass of potassium iodide / mass of solution ) * 100

                   = ( 0.0405 / 1.54 ) * 100

                   = 2.63%

Hence we can conclude that potassium iodide in percentage = 2.63%

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Answer:

[tex]74.5gCO_2[/tex]

Explanation:

Hello there!

In this case, for the described reaction, it is possible to realize there is a 13:8 mole ratio between oxygen (O2) and carbon dioxide (CO2); moreover, since the molar mass of the former is 32.00 g/mol and that of latter is 44.01 g/mol, the produced mass of the required product turns out to be:

[tex]88gO_2*\frac{1molO_2}{32.00gO_2}*\frac{8molCO_2}{13molO_2}*\frac{44.01gCO_2}{1molCO_2} \\\\=74.5gCO_2[/tex]

Best regards!

Answer:

As gas is compressed, the individual molecules begin to move in each others way creating a very repulsive force. It acts to oppose any further volume decrease. At very close distances, all molecules repel each other as their electron clouds emerge.

Explanation:

Answer:

NO is the limiting reagent.  

In this reaction 0.886 mole of NO2 is produced

Explanation:

The chemical equation for this reaction is  

2NO(g) + O2(g) → 2NO2(g)

In this limiting reagent reaction, 2 moles of NO reacts with one mole of O2  to produce 2 mole of 2NO2

0.886 mole of NO * (2 mole of NO2/2 mole of NO) = 0.886 mole of NO2

0.503 mole of O2 * (1 mole of NO2/1 mole of O2) = 1.01 mole of NO2

Hence, NO is the limiting reagent.  

In this reaction 0.886 mole of NO2 is produced

Answer:NH3 + H2O <==> NH4+ + OH-

0.10 x 0.013 = 0.0013 M (this is the hydroxide concentration)

Kw = [H+] [H-]

1.00 x 10^-14 = (x) (0.0013)

x = 7.7 x 10^-12 M

Explanation:

Answer:

2nd option

Explanation:

Answer:

[tex]Q=-407kJ[/tex]

Explanation:

Hello there!

In this case, considering that the heat has two forms, sensible (variable temperature) and latent (constant temperature), we can notice that phase changes account for latent heat as the temperature remains the same. In such a way, given the enthalpy of vaporization of water, 40.67 kJ/mol, the enthalpy of condensation (reverse process) is the negative value, -40.67 kJ/mol; therefore, the associated latent heat would be:

[tex]Q=180g*\frac{1mol}{18.02g} *-40.67\frac{kJ}{mol} \\\\Q=-407kJ[/tex]

Best regards!

The answer is

C) -407 kJ d

Answer:

i think the answer is c.

Explanation:

Answer:

The answers to your questions are given below.

Explanation:

__ NaBr + CaF₂ —> __ NaF + CaBr₂

The above equation can be balance as follow:

NaBr + CaF₂ —> NaF + CaBr₂

There are 2 atoms of F on the left side and 1 atom on the right side. It can be balance by writing 2 before NaF as shown below:

NaBr + CaF₂ —> 2NaF + CaBr₂

There are 2 atoms of Na on the right side and 1 atom on the left side. It can be balance by writing 2 before NaBr as shown below:

2NaBr + CaF₂ —> 2NaF + CaBr₂

Now, the equation is balanced.

Atom >>>> Reactant >>>> Product

Na >>>>>> 2 >>>>>>>>>>> 2

Br >>>>>>> 2 >>>>>>>>>>> 2

Ca >>>>>> 1 >>>>>>>>>>>> 1

F >>>>>>> 2 >>>>>>>>>>>> 2

Answer:

12

Explanation:

Boyles law

P1 (.36)

V1(28.3)

P2(.85)

V2(?)

P1*V1=P2*V2

plug it in, and you get 12

Answer:

C. 1-ethyl, 3-methylcyclohexane

(Photo for proof at the bottom.)

Explanation:

The 1-ethyl is because you start numbering from the longest branch, towards the next closest branch. Prefix "eth-" means two, there are 2 carbons in the longest branch. 3-methyl is because the next branch is at number 3, and prefix "meth-" means 1, there is 1 carbon in that chain. "Cyclo" in cyclohexane means the skeletal model is shaped like a ring, and the "hexane" means there are 6 carbons in the ring. Prefix "hex" means 6.

Here's a photo of the unit review on Edge. Refer to the 2nd attachment for a visualization.

Please click the heart if this helped.

Answer:

C. 1-ethyl,3-methylcyclohexane

Explanation:

Answer:

c. uracil

Explanation:

uracil is not found in DNA. the missing base would be thymine

Answer: [tex]2NH_3(g)+2O_2(g)\rightarrow N_2O(g)+3H_2O(l)+684kJ[/tex]

Explanation:

The skeletal thermochemical equation for the reaction is:

[tex]NH_3(g)+O_2(g)\rightarrow N_2O(g)+H_2O(l)+342kJ[/tex]

The balanced  thermochemical equation for the reaction is:

[tex]2NH_3(g)+2O_2(g)\rightarrow N_2O(g)+3H_2O(l)+684kJ[/tex]

When 1 mole of [tex]NH_3[/tex] reacts with oxygen , heat released = 342 kJ

Thus when 2 moles of [tex]NH_3[/tex] reacts with oxygen , heat released = [tex]\frac{2}{1}\times 342 kJ=684kJ[/tex]

Answer:

[tex]a=1.134\frac{m}{s^2}[/tex]

Explanation:

Hello there!

In this case, by considering the physical definition of force in terms of mass and acceleration:

[tex]F=m*a[/tex]

Given the generated force and the involved mass, we can compute the required acceleration as shown below:

[tex]a=\frac{F}{m}\\\\a=\frac{2552N}{114kg}[/tex]

Yet it is necessary to break out Newtons to:

[tex]a=\frac{2552\frac{kg*m}{s^2} }{114kg}\\\\a=1.134\frac{m}{s^2}[/tex]

Best regards!

The concentration of SO42- ions in the final solution is 0.01 mol L-1.

The neutralisation reaction between sulfuric acid (H2SO4) and sodium hydroxide (NaOH) requires the use of a chemical equation that is balanced:

H2SO4 + NaOH = Na2SO4 + 2H2O

We may deduce from the balanced equation that one mole of H2SO4 reacts with one mole of Na2SO4, meaning that the amount of SO42- ions produced is equal to the amount of H2SO4 utilised.

We may determine how many moles of H2SO4 were used by calculating the amount of 0.05 M H2SO4 solution needed to neutralise 25 mL of NaOH solution:

H2SO4 moles are equal to the product of the volume of H2SO4 (in L) and the concentration of H2SO4 (in mol L-1): 0.03214 L 0.05 mol L-1 = 0.001607 mol

The formation of SO42- ions results in the same amount of moles as the
The resulting solution contains the following amounts of SO42- ions per mole of H2SO4 used:

Moles of SO42- ions/volume of solution (in L) = 0.001607 mol/(0.025 L + 0.03214 L) = 0.01 mol L-1; concentration of SO42- ions (in mol L-1)

As a result, the final solution contains 0.01 mol L-1 of SO42- ions.

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Answer:

As of right now (4-7-2021), the physical science requirement for the SLP certificate must be met by completing coursework in the areas of either chemistry or physics.

Answer: 1. The empirical formula is [tex]PNF_2[/tex]  

2. The molecular formula is [tex]PNF_2[/tex]

Explanation:

If percentage are given then we are taking total mass is 100 grams.

So, the mass of each element is equal to the percentage given.

Mass of P = 37.32 g

Mass of N = 16.88 g

Mass of F = 45.79 g

Step 1 : convert given masses into moles.

Moles of P =[tex]\frac{\text{ given mass of P}}{\text{ molar mass of P}}= \frac{37.32g}{31g/mole}=1.20moles[/tex]

Moles of N =[tex]\frac{\text{ given mass of N}}{\text{ molar mass of N}}= \frac{16.88g}{14g/mole}=1.20moles[/tex]

Moles of F =[tex]\frac{\text{ given mass of F}}{\text{ molar mass of F}}= \frac{45.79g}{19g/mole}=2.41moles[/tex]

Step 2 : For the mole ratio, divide each value of moles by the smallest number of moles calculated.

For P = [tex]\frac{1.20}{1.20}=1[/tex]

For N = [tex]\frac{1.20}{1.20}=1[/tex]

For F =[tex]\frac{2.41}{1.20}=2[/tex]

The ratio of P: N: F= 1: 1: 2  

Hence the empirical formula is [tex]PNF_2[/tex]

The empirical weight of [tex]PNF_2[/tex]= 1(31)+1(14)+2(19)= 82.98 g.

The molecular weight = 82.98 g/mole

Now we have to calculate the molecular formula.

[tex]n=\frac{\text{Molecular weight}}{\text{Equivalent weight}}=\frac{82.98}{82.98}=1[/tex]

The molecular formula will be=[tex]1\times PNF_2=PNF_2[/tex]

Answer:

coal

Explanation:

Explanation:

c)The new kinetic energy of each gas particle is the sum of the kinetic energy that each particle is traveling with.

Answer:

Scientists know that today the Earth's magnetic field is powered by the solidification of the planet's liquid iron core. The cooling and crystallization of the core stirs up the surrounding liquid iron, creating powerful electric currents that generate a magnetic field stretching far out into space.

Answer:

80 ml

Explanation:

From the question,

Applying Dilution formular

MV = mv................... Equation 1

Where M = Molarity of Kl before dilution, V = Volume of Kl before dilution, m = molarity of Kl after dilution, v = volume of Kl after dilution.

make V the subject of the equation

V = mv/M............. Equation 2

Given: m = 1.00 M, v = 200 ml, M = 2.50 M

Substitute these values into equation 2

V = (1.00×200)/2.50

V = 80 ml