Q5. A 1.35 m solution of NaCl in water is prepared. What is the mole fraction of
the NaOCI? 0.0237

Answer:

265hs+24.464536b+16o

Explanation:

265hs+16o+9b(2.718282)

=265hs+16o+24.464536b

=265hs+24.464536b+16o

This question is describing an spectrophotometry experiment in which the concentration of copper(II) ions has to be determined when 2.50 g of a copper-rich penny is reacted with 50.0 mL of nitric acid. In addition, the absorbance of a sample of the solution turned out to be 0.12 at 635 nm, so that the concentration was estimated as 12.8 g/L.

First of all, we must recall the Beer's law that can be written as follows:

[tex]A=ebC[/tex]

Whereas A is the absorbance of the sample, e the molar absorptivity, b the cuvette's path and C the concentration. However, this problem is not providing sufficient information to calculate the required concentration, however, similar absorbance experiments have graphed (absorbance vs concentration) calibration curves exhibiting trendlines as the one shown below:

[tex]y=0.009647x-0.003655[/tex]

Thus, since y stands for the absorbance and x for the concentration but in g/L not M (mol/L) for those experiments, we can set y equal to 0.12 so we solve for x as the concentration of the copper(II) ions in the sample:

[tex]y=0.009647x-0.003655\\\\x=\frac{0.12+0.003655}{0.009647}\\\\x=12.8g/L[/tex]

Nevertheless, it would be great if you come up with your own trendline, having clear the units for the absorbance vs concentration graph and thus double check your results because the data was not enough for the time being.

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Answer:

c.boron-11

Explanation:

The atomic mass of boron is 10.81 u.

And 10.81 u is a lot closer to 11u than it is to 10u, so there must be more of boron-11.

To convince you fully, we can also do a simple calculation to find the exact proportion of boron-11 using the following formula:

(10u)(x)+(11u)(1−x)100%=10.81u

Where u is the unit for atomic mass and x is the proportion of boron-10 out of the total boron abundance which is 100%.

Solving for x we get:

11u−ux=10.81u

0.19u=ux

x=0.19

1−x=0.81

And thus the abundance of boron-11 is roughly 81%.

Answer:

Water will generally require more energy for a phase change compared to a similar substance without hydrogen bonds.

Explanation:

The number of moles of the solute in the solution is the product of its volume and molarity. The number of moles of copper sulphate in 0.500 L of 2.30 M solution is 1.15 moles.

Molarity of a solution is the common term used to represent the concentration of a solution. It is the ratio of its number of moles of solute to the volume of solution in liters.

Molarity = no.of moles/volume in L.

Molarity is a temperature dependant quantity.

The given solution has a volume of 0.500 L.

molarity of copper sulphate solution = 2.30 M

Thus, number of moles of copper sulphate solute dissolved in 0.50 L of water is calculated by multiplying the volume with molarity.

No. of. moles of copper sulphate = molarity × volume

= 0.500 L × 2.30 M = 1.15 moles.

Therefore, there will be 1.15 moles of copper sulphate in the solution.

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Easy!!

2+17=19

#hope that helps

Answer:

To find the answer you may

2+17=19

Explanation:

so that is the answer I'm sorry,to not give all the solutions

Answer:

The basis for incomplete combustion is that instead of carbon dioxide being produced alongside water, carbon monoxide and carbon is produced instead, the carbon being released as soot. That handily sets the products up for the equation.

And combustion is simply a reaction between a fuel, in this case, methanol and oxygen.

The chemical formula for methanol is CH3OH. Simply write the reactants and products as a chemical equation and balance it, and you have the equation.

Explanation:

Answer:

D. 17,190 years old

Answer:

your question is not very clear but I think the answer is either

Primary (non-rechargeable)

Secondary (rechargeable) or

Lithium-ion battery.

Rechargeable li-ion button cell.

Answer: B. strontium

Explanation: This is due to electrons being further away from the nucleus in strontium.

Considering the Dalton's partial pressure, the correct answer is option a.: the total pressure of the mixture is 1.86 atm.

The pressure exerted by a particular gas in a mixture is known as its partial pressure. So, Dalton's law states that the total pressure of a gas mixture is equal to the sum of the pressures that each gas would exert if it were alone:

[tex]P_{T} =P_{1} +P_{2} +...+P_{n}[/tex]

where n is the amount of gases present in the sample.

This relationship is due to the assumption that there are no attractive forces between the gases.

In this case, a mixture contains 220 mmHg of CO, 350 mmHg of Ne and 840 mmHg of He. The total pressure of the mixture can be calculated as:

[tex]P_{T} =P_{CO} +P_{Ne} +P_{He}[/tex]

[tex]P_{T} =220 mmHg +350 mmHg+840 mmHg[/tex]

Solving:

[tex]P_{T}[/tex]= 1410 mmHg

Being 760 mmHg=1 atm, then:

[tex]P_{T}=1410 mmHgx\frac{1 atm}{760 mmHg}[/tex]

Solving:

[tex]P_{T}[/tex]= 1.86 atm

Finally, the correct answer is option a.: the total pressure of the mixture is 1.86 atm.

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bcz the defination of matter is that

anything which occupy space

Hence , option a is correct

Answer:

A. increase

Explanation:

the smaller the size of the ionic compounds, the more closer they get packed together. This means electrostatic attraction also increases, which means the ionic bonds gets stronger...therefore increases the melting point

Answer:

Thermosphere

Explanation:

More specifically the ionosphere, since the ionosphere is the lower part of the thermosphere.

Hope this helps!

Answer:

A compound is something like atoms coming together as a team, and a mixture is 2 or more substances mixing together.

Explanation:

Answer:

Explanation:

7A 0.2

7B cork

7C  Yes because the lighter it is the more likely it will float

7D  Density is one of the fundamental scientific principles of life. It can describe any everyday object. Despite its significance, students often struggle to understand what it really is. Density is a measurement of how much space or volume is packed in an object or substance.

8   property means a characteristic or trait that you can use to describe matter by observation, measurement, or combination.

By decomposing 157g of NaCl, approximately 1.35 moles of chlorine can be produced.

To determine the number of moles of chlorine that could be produced by decomposing 157g of NaCl, we need to use the molar mass of NaCl and apply stoichiometry.

The molar mass of NaCl is the sum of the atomic masses of sodium (Na) and chlorine (Cl), which is approximately 22.99 g/mol + 35.45 g/mol = 58.44 g/mol.

Now, we can calculate the number of moles of NaCl:

Moles of NaCl = Mass of NaCl / Molar mass of NaCl

Moles of NaCl = 157 g / 58.44 g/mol

Moles of NaCl ≈ 2.69 mol

According to the balanced equation 2NaCl → 2Na + Cl₂, we can see that for every 2 moles of NaCl, we produce 1 mole of Cl₂.

Therefore, using the stoichiometric ratio, we can calculate the number of moles of chlorine produced:

Moles of Cl₂ = (Moles of NaCl / 2) × 1

Moles of Cl₂ = 2.69 mol / 2

Moles of Cl₂ ≈ 1.35 mol

Thus, by decomposing 157g of NaCl, approximately 1.35 moles of chlorine can be produced.

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solid.................

Answer:

b solid

Explanation:

i know for a fact

An experiment that would show that intramolecular forces are stronger than intermolecular forces will be heating a block of ice in a sealed container then allowing it to change to steam.

Intramolecular forces are the forces of attraction that hold atoms together within a molecule. Intramolecular forces require a high amount of energy to splits atoms or molecules in a chemical bonding.

Intermolecular forces are weaker forces of attraction that occur between molecules. They require lesser energy to splits molecules compared to intramolecular forces.

An experiment that would show that intramolecular forces are stronger than intermolecular forces will be heating a block of ice in a sealed container then allowing it to change to steam.

In the process, the energy required to change the state from ice to steam water is more than intermolecular forces.

Thus, we can conclude that this experiment shows that the intramolecular forces are stronger than the intermolecular forces.

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Answer: This would be C.) 70%

Explanation:

Answer:

African?

Explanation:

The number of grams of ammonium nitrate (NH₄NO₃) it would take for all the barium hydroxide to react is 18.7g

First, we will write the balanced chemical equation for the reaction

The balanced chemical equation for the reaction is

Ba(OH)₂ + 2NH₄NO₃ → 2NH₄OH + Ba(NO₃)₂

This means, 1 mole of barium hydroxide is required to react with 2 moles of ammonium nitrate

Now, we will calculate the number of moles of barium hydroxide present.

Mass of barium hydroxide (Ba(OH)₂) = 20 g

Using the formula

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

Molar mass of Ba(OH)₂ = 171.34 g/mol

∴ Number of moles of Ba(OH)₂ present =[tex]\frac{20}{171.34}[/tex]

Number of moles of Ba(OH)₂ present = 0.116727 mole

Now,

Since 1 mole of barium hydroxide is required to react with 2 moles of ammonium nitrate

Then,

0.116727 mole of barium hydroxide will react with 2 × 0.116727 mole of ammonium nitrate

2 × 0.116727 = 0.233454 mole

∴ Number of moles of NH₄NO₃ required is 0.233454 mole

Now, for the mass of ammonium nitrate (NH₄NO₃) required

From the formula

Mass = Number of moles × Molar mass

Molar mass of NH₄NO₃ = 80.043 g/mol

∴ Mass of NH₄NO₃ required = 0.233454 × 80.043

Mass of NH₄NO₃ required = 18.68636 g

Mass of NH₄NO₃ required ≅ 18.7g

Hence, the number of grams of ammonium nitrate (NH₄NO₃) it would take for all the barium hydroxide to react is 18.7g

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Answer:

It increases the freezing point

Explanation:

The salt lowers the temperature at which water freezes. :)

1 mL = 0.815 g

11.2 mL = X

X = 11.2 × 0.815

= 9.128 g

mole = 9.128/58

= 0.157 mole

1 mole = 6.02 × 10^23 atoms

0.157 mol = x

X = 0.157/1 × 6.02 × 10^23

= 9.451 × 10^22 atoms of C

please to recheck answers to ensure they are correct

I really hope this helps

Answer:

The Sigma (σ) Bond

S-S Overlapping. In this kind of overlapping, one 's' orbital from each participating atom undergoes head-on overlapping along the internuclear axis. ...

S-P Overlapping. ...

P-P overlapping.

Answer:

4.002602

Explanation:

Seems Am Converting Between Grams Helium And Mole.

Answer:

1)  a) 2 C2H2 +  3O2 -->  2CO2 +  2H2O

b) Combustion Reaction

c) Bonds will be broken on the reactant side which will require energy.

d) It agrees with the law of conservation of mass because there are the same amount of molecules of each element on both sides of the equation, meaning mass was not created nor destroyed.

2) a) 2Na + Cl2 --> 2NaCl

        Synthesis

   b) 2Fe + O2 --> 2FeO

        Synthesis

Hope this helps!

Explanation:

To calculate the atoms of an element in a given molecule, we need to multiply stoichiometry by the number that is written on the foot of that element. Therefore, the balanced equation is

2 C[tex]_2[/tex]H[tex]_2[/tex]+  3O[tex]_2[/tex] [tex]\rightarrow[/tex] 2CO[tex]_2[/tex]+  2H[tex]_2[/tex]O

Balanced equation is the one in which the total number of atoms of a species on reactant side is equal to the total number of atoms on product side. The mass of the overall reaction should be conserved. There are so many types of chemical reaction reaction like combination reaction, displacement reaction.

a) 2 C[tex]_2[/tex]H[tex]_2[/tex]+  3O[tex]_2[/tex] [tex]\rightarrow[/tex] 2CO[tex]_2[/tex]+  2H[tex]_2[/tex]O is the balanced equation

b)Reaction is a Combustion Reaction

c) energy is required for the breaking of bond.

d) It agrees with the law of conservation of mass as the number  of atoms of each element on reactant and product side is same.

Therefore, the balanced equation is

2 C[tex]_2[/tex]H[tex]_2[/tex]+  3O[tex]_2[/tex] [tex]\rightarrow[/tex] 2CO[tex]_2[/tex]+  2H[tex]_2[/tex]O

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