A sample of calcium fluoride was decomposed into the constituent elements. Write a balanced chemical equation for the decomposition reaction. If the sample produced 294 mg of calcium, how many g of fluorine were formed

Answer:

The entropy change of carbon dioxide = 0.719 kJ/k

Explanation:

Given:

1.5 m - 3 insulated rigid tank contains 2.7 kg of carbon dioxide at 100 kPa

The objective is to determine the entropy change of carbon dioxide

Formula used:

ΔS=

Solution:

On considering,

[tex]C_{P} =0.846 kJ/kg K\\C_V=0.657 kJ/kg k\\[/tex]

ΔS=[tex]mc_{v} lu\frac{p_{2} }{P_{1} }[/tex]

On substituting the values,

ΔS=[tex]2.7*0.657lu\frac{150}{100}[/tex]

ΔS=0.719 kJ/k

The entropy change is "0.719 kJ/K".

Given values are:

Mass of tank,

Pressure,

Rised pressure,

Assumption of constant specific heat is,

As we know the formula,

→ [tex]\Delta S = mC_v \ ln(\frac{P_2}{P_1} )[/tex]

         [tex]= (2.7)(0.657) \ ln (\frac{150}{100} )[/tex]

         [tex]= 1.7739\times 0.4055[/tex]

         [tex]= 0.7193 \ kJ/K[/tex]

Thus above answer is right.

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Answer:

Bohr Model is the correct answer

Answer:

Electron -Cloud Model

Explanation:

Just took the quiz got 100%

Answer: The mass in [tex]3.75 \times 10^{21}[/tex] atoms of zinc is 0.405 g.

Explanation:

Given: Atoms of zinc = [tex]3.75 \times 10^{21}[/tex]

It is known that 1 mole of every substance contains [tex]6.022 \times 10^{23}[/tex] atoms. So, the number of moles in given number of atoms is as follows.

[tex]Moles = \frac{3.75 \times 10^{21}}{6.022 \times 10^{23}}\\= 0.622 \times 10^{-2}\\= 0.0062 mol[/tex]

As moles is the mass of a substance divided by its molar mass. So, mass of zinc (molar mass = 65.39 g/mol) is calculated as follows.

[tex]Moles = \frac{mass}{molar mass}\\0.0062 mol = \frac{mass}{65.39 g}\\mass = 0.405 g[/tex]

Thus, we can conclude that the mass in [tex]3.75 \times 10^{21}[/tex] atoms of zinc is 0.405 g.

Answer:

The solution is 0.450 M. How many mL are needed?

- 0.667 mL

Explanation:

Answer:

Molecules of O₂F₂ = mass of O₂F₂ × (1 mole O₂F₂ / 70 g O₂F₂) × (6.02 × 10²³ molecules / one mole of O₂F₂)

Explanation:

The Avogadros constant gives the the number of specified entities in one mole of a substance. One mole of any substance contains 6.02 × 10²³ particles. Therefore, one mole of O₂F₂ contains 6.02 × 10²³ molecules.

Also, the molar mass of a substance is the mass in grams of one mole of that substance. It is obtained by summing the relative atomic masses of all the atoms of the elements in the substance. For O₂F₂, the molar mass = (2 × 16 + 2 × 19) g/mol = 70 g/mol

Converting to molecules of O₂F₂;

To convert from grams of a substance to molecules of that substance, multiply by the ratio of one mole and mass of one mole, and then by the number of molecules per mole.

Molecules of A = mass of A × (1 mole / mass of one mole) × (6.02 × 10²³ molecules / 1 mole)

Therefore,Molecules of O₂F₂ = mass of O₂F₂ × (1 mole O₂F₂ / 70 g O₂F₂) × (6.02 × 10²³ molecules /one mole of O₂F₂)

Answer:

E = hv

Explanation:

Energy = planck constant × frequency

Answer:

14

73%

Explanation:

The mean Number of years worked :

. (sum of service years) / employees in the

(8+13+15+3+13+28+4+12+4+26+29+3+10+3+17+13+15+15+23+13+12+1+14+14+17+16+7+27+18+24) /

(417 / 30)

= 13.9 years

= 14 years

The percentage of employees who have worked for atleast 10 years :

Number of employees with service years ≥ 10 years = 22 employees

Total number of employees

Percentage (%) = (22 / 30= * 100% = 0.7333 * 100% = 73.33% = 73%

Answer:

heat rate= 1281W

length = 15.8m

Explanation:

we have this data to answer this question with

Tmi = 85 degrees

Tmo = 35 degrees

Ts = 25 dgrees

flow rate = 25 degrees

using engine oil property from table a-5

Tm = Tmo - TMi/2 = 333k

u =0.522x10⁻²

k = 0.26

pr = 51.3

cp = 2562 J/kg.k

mcp(Tmo-Tmi) =

0.01 x 2562(35-85)

= 1281 W

we find the change in Tim

= [(35-25)-(85-25)]/ln[(35-25)/(85-25)]

= -50/ln0.167

= -50/-1.78976

= 27.9°c

we finf the required reynold number

4x0.01/πx0.003x0.522x10⁻²

= 0.04/0.00004921

= 812.8

= 813

we find approximate correlation

NuD = hd/k

NuD = 3.66

3.66 = 0.003D/0.26

cross multiply

0.003D = 3.66x0.26

D = 3.66x0.26/0.003

= 317.2

As = 1281/317x27.9

= 0.145

As = πDL

L = As/πD

= 0.145/π0.003

= 0.145/0.009429

L = 15.378

Answer:

The appropriate answer is "1.96 mol".

Explanation:

The given values are:

Volume,

V = 26.5 L

Pressure,

P = 1.7 atm

Temperature,

T = 280 K

Now,

The number of moles (n) will be:

= [tex]\frac{PV}{RT}[/tex]

By substituting the values, we get

= [tex]\frac{1.7\times 26.5}{0.0821\times 280}[/tex]

= [tex]\frac{45.05}{22.988}[/tex]

= [tex]1.96 \ mol[/tex]

Answer:

high melting point

Explanation:

The filament of a bulb is often heated to very high temperatures as the bulb is in operation.

Many times, electric bulbs may have to be on for a whole day and they may reach temperatures that are outrageously high in the process.

The material of the filament must have a very high melting point so that it doesn't melt while the bulb is still in operation.

Answer:

Actually the answer is High Vapor pressure

Explanation:

Answer:

21.6 g

Explanation:

The reaction that takes place is:

First we convert the given masses of both reactants into moles, using their respective molar masses:

0.6 moles of CH₄ would react completely with (2 * 0.6) 1.2 moles of O₂. As there are more O₂ moles than required, O₂ is the reactant in excess and CH₄ is the limiting reactant.

Now we calculate how many moles of water are produced, using the number of moles of the limiting reactant:

Finally we convert 1.2 moles of water into grams, using its molar mass:

Answer:

It is equal to the total mass of the products.

Explanation:

Hope this helps :)

Answer: A bromine radical is more stable than chlorine radical, so it is less reactive and more choosy.

Explanation:

A chlorine atom being more electronegative in nature is able to attract a hydrogen atom more readily towards itself as compared to a bromine atom.

Since bromine is less electronegative in nature so bromine will be more selective as a hydrogen abstracting agent. As a result, bromine radical is more stable in nature than chlorine radical.

Thus, we can conclude that bromine radical is more stable than chlorine radical, so it is less reactive and more choosy.

Answer:

[tex] This\:may\: help[/tex]

Answer:

(1) Write down the chemical reaction in the form of word equation,keeping reactants on left hand side and products on right hand side.

(2) Write symbol and formula of all reactants and products in word equation. (3) Balance the equation by multiplying the symbols and formula by smallest possible figures.

The question is incomplete, the complete question is:

A chemist measures the amount of iodine solid produced during an experiment. He finds that 8.31 g of iodine solid is produced. Calculate the number of moles of iodine solid produced. Round your answer to the correct number of significant digits.

Answer: The number of moles of solid iodine produced is 0.0327 moles

Explanation:

The number of moles is defined as the ratio of the mass of a substance to its molar mass.  The equation used is:

[tex]\text{Number of moles}=\frac{\text{Given mass}}{\text{Molar mass}}[/tex] ......(1)

Given mass of solid iodine = 8.31 g

Molar mass of solid iodine = 253.8089 g/mol

Plugging values in equation 1:

[tex]\text{Moles of solid iodine}=\frac{8.31g}{253.8089g/mol}=0.0327mol[/tex]

Hence, the number of moles of solid iodine produced is 0.0327 moles

Explanation:

4 tctcgcgcgctctchvvyctctc

Answer:

The answer would be B, putting thermal energy into something means you're adding heat into it.

Answer:

c

Explanation:

its c because it has multiple mixture blueberries flower water and others thats why i says c

Answer:

Explanation:

This is a halogenation reaction i.e substitution or replacement of a single or more than a single hydrogen atom in the organic alkane compound with the halogen(here it is chlorine).

The chlorination of 1-chloro-2,2,3,3-tetramethylpentane under UV light resulted in the formation of five (5) dichloro derivatives which are shown in the image attached below.

Also, the compounds containing a stereocenter (i.e a location within the compound composing of various substituents in which the interchangeability of these substituents has the tendency of resulting into a stereoisomer) are indicated with an asterisk in the image below.

From the image below:

compound 1 ⇒  1,1-dichloro-2,2,3,3-tetramethylpentane = 2° C

∴

The given relative reactivity rate for 2°  = 3.6x

For compound 2 ⇒  1,4-dichloro-2,2,3,3-tetramethylpentane = 2°  = 3.6x

For compound 3 ⇒ 1,5-dichloro-2,2,3,3-tetramethylpentane = 1°  = 1x

For compound 4 ⇒ 1-chloro-2-chloromethyl-2,3,3-trimethylpentane

= 1°  = 1x

For compound 5 ⇒ 1-chloro-3-chloromethyl-2,2,3-trimethylpentane

= 1°  = 1x

As such, we have:

2(3.6x) + 3(1x) = 100

7.2x + 3x = 100

10.2x = 100

x = 100/10.2

x = 9.803°

∴

For compound (1) = 3.6(9.803) = 35.3%

For compound (2) = 3.6(9.803) = 35.3%

For compound (3) = 1(9.803) = 9.803°%

For compound (4) = 1(9.803) = 9.803°%

For compound (5) = 1(9.803) = 9.803°%

Answer:

The number of moles of H₃PO₄ that reacted is 0.000343 moles

Note: Some data is missing. Data from the attachment is used for the calculationsinnthe explanation below.

Explanation:

The reaction is a neutralization reaction between NaOH and H₃PO₄. The equation of the reaction is given as follows:

3 NaOH + H₃PO₄ ---> Na₃PO₄ + 3 H₂O

The molarity of the NaOH solution is 0.238 mol/L.

Average volume of NaOH used during the titration to arrive to endpoint = (4.6 + 3.9 + 4.5) mL / 3 = 4.33 mL

Molarity is defined ratio of the number of moles of solute to the volume of solution. Mathematically, molarity = number of moles/volume in Litres

Number of moles of NaOH reacted = 0.238 mol/L × (4.33mL × 1 L/1000 mL)

Number of moles of NaOH = 0.00103 moles

From the equation of the reaction, 3 moles of NaOH reacts with 1 mole of H₃PO₄

0.00103 moles of NaOH will react with 0.00103 x 1/3 moles of H₃PO₄ = 0.000343 moles of H₃PO₄.

Therefore, number of moles of H₃PO₄ that reacted is 0.000343 moles

As the gas expands on the surrounding, work is done by the system.

Therefore, W= -279J

Absorbtion of heat,q= +216J

∆U=q+W = (216-279)J= -63J

Answer:

n = 0.0814 mol

Explanation:

Given mass, m = 35.7g

The molar mass of Tin(IV) bromate, M = 438.33 g/mol

We need to find the number of moles of bromine. We know that,

No. of moles = given mass/molar mass

So,

[tex]n=\dfrac{35.7}{438.33}\\\\n=0.0814\ mol[/tex]

So, there are 0.0814 moles of bromine in 35.7g of  Tin(IV) bromate.

Answer:

liquefied petroleum gas

LPG is prepared by refining natural gas. it is made by refining crude oil or from extracted natural gas streams as they emerge from the ground.

Answer:

Less stable

Explanation:

When an exothermic reaction occurs, the reactants have a greater energy level than the outputs. The products, in other respects, are more stable than that of the reactants.

The outcomes of an exothermic reaction have a lower energy to react. The enthalpy of a process is the difference between some of the activation energy and the power of the products. 

Answer: In order for a substitution reaction to take place, at a minimum, loss of a leaving group and nucleophilic attack are needed.

Explanation:

When one group in a molecule is replaced by another one then it is called a substitution reaction.

For a substitution reaction reaction to occur at a minimum, it is necessary to have a leaving group that helps in creating a carbocation and hence a nucleophile can easily attack.

For example, [tex]CH_{4} + Cl_{2} + h\nu \rightarrow CH_{3}Cl + HCl[/tex]

Thus, we can conclude that in order for a substitution reaction to take place, at a minimum, loss of a leaving group and nucleophilic attack are needed.

Answer:

The sample should be diluted

Explanation:

According to Beer Lambert's law, the absorbance of a sample depends on the concentration of the sample.

Hence, if the concentration of the sample is very high, the spectrophotometer will also report a very high value of absorbance.

When this is the case, the sample should simply be diluted and the readings are taken again using the spectrophotometer.

Answer:

4.00 is the pH of the mixture

Explanation:

The ethyl amine reacts with HNO3 as follows:

C2H5NH2 + HNO3 → C2H5NH3⁺ + NO3⁻

To solve this question we need to find the moles of ethyl amine and the moles of HNO3:

Moles C2H5NH2:

0.0500L * (0.100mol/L) = 0.00500 moles ethyl amine

Moles HNO3:

0.201L * (0.025mol/L) = 0.005025 moles HNO3

That means HNO3 is in excess. The moles in excess are:

0.005025 moles HNO3 - 0.00500 moles ethyl amine =

2.5x10⁻⁵ moles HNO₃

In 50 + 201mL = 251mL = 0.251L:

2.5x10⁻⁵ moles HNO₃ / 0.251L = 9.96x10⁻⁵M = [H+]

As pH = -log [H+]

pH = -log 9.96x10⁻⁵M

pH = 4.00 is the pH of the mixture

Answer:

The answer is

-control rods

Answer:

B. Control Rods.... via A P E X

Answer:

) Making a sandwich To prepare a liquid sample to IR analysis, firstly place a drop of the liquid on the face of a highly polished salt plate (such as NaCl, AgCl or KBr), then place a second plate on top of the first plate so as to spread the liquid in a thin layer between the plates, and clamps the plates together.