Which statement is about population density

Answer:

[tex]0.175\; \rm mol \cdot L^{-1}[/tex].

Explanation:

Magnesium chloride and silver nitrate reacts at a [tex]2:1[/tex] ratio:

[tex]\rm MgCl_2\, (aq) + 2\, AgNO_3\, (aq) \to Mg(NO_3)_2 \, (aq) + 2\, AgCl\, (s)[/tex].

In reality, the nitrate ion from silver nitrate did not take part in this reaction at all. Consider the ionic equation for this very reaction:

[tex]\begin{aligned}& \rm Mg^{2+} + 2\, Cl^{-} + 2\, Ag^{+} + 2\, {NO_3}^{-} \\&\to \rm Mg^{2+} + 2\, {NO_3}^{-} + 2\, AgCl\, (s)\end{aligned}[/tex].

The precipitate silver chloride [tex]\rm AgCl[/tex] is insoluble in water and barely ionizes. Hence, [tex]\rm AgCl\![/tex] isn't rewritten as ions.

Net ionic equation:

[tex]\begin{aligned}& \rm Ag^{+} + Cl^{-} \to AgCl\, (s)\end{aligned}[/tex].

Calculate the initial quantity of nitrate ions in the mixture.

[tex]\begin{aligned}n(\text{initial}) &= c(\text{initial}) \cdot V(\text{initial}) \\ &= 0.25\; \rm mol \cdot L^{-1} \times 0.150\; \rm L \\ &= 0.0375\; \rm mol \end{aligned}[/tex].

Since nitrate ions [tex]\rm {NO_3}^{-}[/tex] do not take part in any reaction in this mixture, the quantity of this ion would stay the same.

[tex]n(\text{final}) = n(\text{initial}) = 0.0375\; \rm mol[/tex].

However, the volume of the new solution is twice that of the original nitrate solution. Hence, the concentration of nitrate ions in the new solution would be [tex](1/2)[/tex] of the concentration in the original solution.

[tex]\begin{aligned} c(\text{final}) &= \frac{n(\text{final})}{V(\text{final})} \\ &= \frac{0.0375\; \rm mol}{0.300\; \rm L} = 0.175\; \rm mol \cdot L^{-1}\end{aligned}[/tex].

Answer:

force exerted per unit area by gas particles as they strike the surfaces around them

Explanation:

According to the kinetic molecular theory, a gas is composed of molecules. The molecules of a gas are in constant random motion and collide frequently with each other as well as with the walls of the container.

Pressure is defined as force per unit area. The pressure of a gas is the force exerted per unit area by gas particles as they strike the surfaces around them hence the answer above.

Answer:

[tex]x=54g[/tex]

Explanation:

From the question we are told that:

Content of Sterling silver:

Let x be sterling silver

Silver [tex]S=0.9x[/tex]

Copper [tex]C=0.1x[/tex]

Total  silver available [tex]T=48.3[/tex]

Generally the equation for Total amount to be made is mathematically given by

[tex]T=\frac{x*90}{100}[/tex]

[tex]x=\frac{48.3*100}{90}[/tex]

[tex]x=54g[/tex]

Answer:

-800 kJ/mol

Explanation:

To solve the problem, we have to express the enthalpy of combustion (ΔHc) in kJ per mole (kJ/mol).

First, we have to calculate the moles of methane (CH₄) there are in 2.50 g of substance. For this, we divide the mass into the molecular weight Mw) of CH₄:

Mw(CH₄) = 12 g/mol C + (1 g/mol H x 4) = 16 g/mol

moles CH₄ = mass CH₄/Mw(CH₄)= 2.50 g/(16 g/mol) = 0.15625 mol CH₄

Now, we divide the heat released into the moles of CH₄ to obtain the enthalpy per mole of CH₄:

ΔHc = heat/mol CH₄ = 125 kJ/(0.15625 mol) = 800 kJ/mol

Therefore, the enthalpy of combustion of methane is -800 kJ/mol (the minus sign indicated that the heat is released).

Answer:

[tex]X=6[/tex]

Explanation:

From the question we are told that:

Energy levels [tex]n=4[/tex]

Generally, the equation for spectral lines is mathematically given by

 [tex]X=\frac{n(n-1)}{2}[/tex]

 [tex]X=\frac{4(4-1)}{2}[/tex]

 [tex]X=6[/tex]

Answer:

43) protein

44) oxidoreductase

Answer:

The molar mass of benzoic acid is 122.1 g/mol

The molar mass of hydrochloric acid = 36.5 g/mol

Explanation:

Benzoyl chloride is an organic compound with the molecular formula C₆H₅COCl. It is an acyl chloride since is it an organic derivative of a carboxylic acid. Acyl chlorides have the general molecular formula, R-COCl, where R is a side chain.

The R group of benzoyl chloride is the benzyl group C₆H₅. It reacts with water (hydrolysis) to produce hydrochloric acid and benzoic acid. The equation of the reaction is given below:

C₆H₅COCl + H₂O → C₆H₅CO₂H + HCl

The molar mass of benzoic acid as well as of hydrochloric acid is calculated from the sum of the masses of the atoms of the elements present in the compound thus:

Molar mass of carbon = 12.0107 g

Molar mass of hydrogen = 1.00784 g

Molar mass of oxygen = 15.999 g

Molar mass of chlorine = 35.453 g

Molar mass of benzoic acid, C₆H₅CO₂H containing 7 moles of atoms of carbon, 6 moles of atoms of hydrogen and 2 moles of atoms of oxygen = 7 × 12.0107 + 6 × 1.00784 + 2 × 15.999 = 122.1 g

Therefore, the molar mass of benzoic acid is 122.1 g/mol

Molar mass of hydrochloric acid, HCl, containing 1 mole of atoms of hydrogen and 1 mole of atoms of chlorine = 1 × 1.00784 + 1 × 35.453 = 36.5 g

Therefore, the molar mass of hydrochloric acid = 36.5 g/mol

Answer:

the quantum mechanical model VS. Neils Bohr of the atom

Explanation:

The Bohr model and quantum model are models that explain the structure of an atom. ... The key difference between Bohr and quantum model is that Bohr model states that electrons behave as particles whereas quantum model explains that the electron has both particle and wave behavior.

Answer:

B

Explanation:

Frequency and wavelength are inversely proportional

Answer:

As you know, one mole of any substance contains exactly

6.022

⋅

10

23

molecules of that substance - this is known as Avogadro's number.

Notice that you're dealing with more than

6.022

⋅

10

23

molecules of carbon dioxide, which means that you'll also be dealing with more than one mole of the compound.

More specifically, you'll have

1.5

⋅

10

26

molecules

⋅

1 mole CO

2

6.022

⋅

10

23

molecules

=

2.491

⋅

10

2

moles CO

2

Now, a substance's molar mass tells what the mass of one mole of that substance is. In carbon dioxide's case, its molar mass is equal to

44.01 g/mol

, which means that every mole of

CO

2

will have a mass of

44.01 g

.

In your case,

2.491

⋅

10

2

moles of

CO

2

would have a mass of

2.491

⋅

10

2

moles CO

2

⋅

44.01 g

1

mole CO

2

=

109.63 g

Rounded to two sig figs, the number of sig figs you have for the number of molecules of

CO

2

, the answer will be

m

C

O

2

=

110 g

The equilibrium constant K₁ = Equilbrium constant K₂.

The equilibrium constant, K, of a reaction, is defined as:

"The ratio between concentration of products powered to their reaction quotient and concentration of reactants powered to thier reaction quotient".

For the reaction:

aA + bB ⇄ cC + dD

The equilibrium constant, K, is:

[tex]K = \frac{[C]^c[D]^d}{[A]^a[B]^b}[/tex]

Now, assuming the reaction of the problem is 1:1:

A + B ⇄ C + D

[tex]K = \frac{[C][D]}{[A][B]}[/tex]

The concentrations of the reactants are directly proportional to the volume added. Thus, we can assume that concentration = Volume. Replacing for K₁ and K₂:

[tex]K_1 = \frac{[C][D]}{[10mL][10mL]} = K_1 = \frac{[C][D]}{100mL^2}[/tex]

In the same way:

[tex]K_2 = \frac{[C][D]}{[1mL][100mL]} = K_2 = \frac{[C][D]}{100mL^2}[/tex]

Thus, we can say:

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Answer:

True

Explanation:

Copper has the highest electrical conductivity rating of all non-precious metals: the electrical resistivity of copper = 16.78 nΩ•m at 20 °C. Specially-pure Oxygen-Free Electronic (OFE) copper is about 1% more conductive (i.e., achieves a minimum of 101% IACS).

True is the correct answer.

Answer:

3.6487g

CuCl2 moles reacted = (0.15×250)/1000

according to balanced chemical equation

precipitated Cu(OH)2 moles = Reacted CuCl2 moles

molar mass of Cu(OH)2 = 63.5+ (17+1)×2 = 97.5

mass of precipitate = (97.5 × 0.15×250)/1000

= 3.648g

Answer:

A white gelatinous precipitate is observed in each case.

Explanation:

Qualitative analysis in chemistry is mostly used to identify the ions present in a sample by adding certain reagents. The observation after adding the reagent often leads to an inference.

When NaOH is added to a solution containing Zn^2+ in drops, a white gelatinous precipitate is observed.

When NH3(aq) is added in drops to a solution containing Zn^2+, a white gelatinous precipitate is also observed.

Answer:

here's your answer

Explanation:

Molar mass of CH3CH2OH = 46.06844 g/mol

This compound is also known as Ethanol.

Convert grams CH3CH2OH to moles  or  moles CH3CH2OH to grams

Molecular weight calculation:

12.0107 + 1.00794*3 + 12.0107 + 1.00794*2 + 15.9994 + 1.00794

Percent composition by element  

Hydrogen H 1.00794 6 13.128%

Carbon C 12.0107 2 52.143%

Oxygen O 15.9994 1 34.730%

The mass percentage of C in CH₃CH₂OH is 52.14% (to two decimal places)

To calculate the mass percentage of C (Carbon) in CH₃CH₂OH (Ethanol),

First, we will determine the mass of CH₃CH₂OH

Molar mass of CH₃CH₂OH = 46.07 g/mol

Mass of C = 12.01 g/mol

Now, for the mass percentage of C in CH₃CH₂OH,

We will determine the ratio of the total mass of C to the mass of CH₃CH₂OH, and then multiply by 100%

Since we have 2C in CH₃CH₂OH

Then, total mass of C in CH₃CH₂OH = 2 × 12.01 g/mol = 24.02 g/mol

That is,

Mass percentage of C in CH₃CH₂OH = [tex]\frac{24.02}{46.07} \times 100\%[/tex]

Mass percentage of C in CH₃CH₂OH = 0.5213805 ×100%

Mass percentage of C in CH₃CH₂OH = 52.13805%

Mass percentage of C in CH₃CH₂OH ≅ 52.14%

Hence, the mass percentage of C in CH₃CH₂OH is 52.14% (to two decimal places)

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Answer:

duw8 Wert gsi

Explanation:

pues pues y 8y1rcuecisscfjfj3eoeu xv cihskdkkd HD jekifeuifkeñ elijo eh fh FC eh SSH DJ djdvheshdhs

The mass percent of antimony in the sulfide is 71.7% and the mass of Sb2S3 is 0.148 g.

Mass percent is defined as a way of expressing a concentration or describing a component in a particular mixture.

To calculate the mass percent of an element in a compound, divide the mass of the element in 1 mole of the compound by the molar mass of the compound and multiply the result by 100.

Mass percent = Mass of chemical / Total mass  of compound x 100

Mass of ore = 10 kg

% antimony in ore = 10.6%

                              = 10.6 / 100 = 0.106 g

Mass of antimony = 0.106 g

Mass percent = Mass of antimony / Mass of stibnite x 100

71.7% = 0.106 / X x 100

X = 0.106 x 1000 / 71.7 x 1000

  = 106 / 717 = 0.148 g

Thus, the mass percent of antimony in the sulfide is 71.7% and the mass of Sb2S3 is 0.148 g.

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Answer:

I don't know What can I do.

Answer:

Correct option is

A

Explanation:

The number of molecules of CO involves in the slowest step will be 0 because CO is not involve in the slowest step i.e. rate determing step.

Answer:

rrgggf in the world of the world of the world of the up the good morning I will take a user and pass it on the

Answer:

There are no options in this question, however, it can be answered based on general understanding

- The number of neutrons each isotope contain

Explanation:

Isotopes are atoms of an element with the same atomic number or number of protons but different mass number/atomic masses. Since isotopes have same proton numbers, they have similar chemical behavior or identity.

However, difference in atomic mass or mass number of the same atomic number indicates that the number of neutrons each isotope contain differs from one another. Hence, in two isotopes of chlorine given as follows: Cl-35 and Cl-37, the NUMBER OF NEUTRONS in each atom differentiates the two isotopes.

Cl-35 contains 18 neutrons while Cl-37 contains 20 neutrons.

Answer:

Solution given:

1 mole of KCl[tex]\rightarrow [/tex]22.4l

1 mole of KCl[tex]\rightarrow [/tex]74.55g

we have

0.14 mole of KCl[tex]\rightarrow [/tex]74.55*0.14=10.347g

74.55g of KCl[tex]\rightarrow [/tex]22.4l

10.347 g of KCl[tex]\rightarrow [/tex]22.4/74.55*10.347=3.11litre

volume of each solution contains 0.14 mol of KCl contain 3.11litre.

1 mol of any gas contains 22.4L of volume at STP

Volume of KCl:-

The correct answer is option c. Both A and B: An ion is a charged particle that is formed when an atom gains electrons or an atom loses electrons.

First you need to know the definition of ion. An ion is a molecule or atom that has a positive or negative electrical charge.

That is, an ion is an atom whose electric charge is not neutral. This charged particle can be positive or negative.  

Ionization is the chemical or physical process by which ions are produced. In this process, negatively charged ions are produced by gaining electrons and are known as anions.

The positively charged are produced by the loss of electrons and are known as cations.

In summary, an ion is a charged particle that is formed when  an atom gains electrons or an atom loses electrons, and they are known as cations and anions respectively.

The correct answer is both A and B.

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Answer:

Production of some products is highly concentrated in a few countries, China, the leading producer of wheat and ramie in 2013, produces 6% of the world's ramie fiber but only 17% of the world's wheat.

The name of the compound shown below is 1- pentene. The correct answer is option D.

A compound is a substance made up of two or more different elements chemically bonded together in a fixed ratio.

1-pentene is an unsaturated hydrocarbon with the chemical formula [tex]\rm C_5H_{10}[/tex]. It is an alkene, which means it contains a carbon-carbon double bond.

Therefore, option D. 1-pentene is the name of the compound shown.

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Answer:

Have you ever touched a fish? Most fish will feel a bit rough - due to their scales. Some, like sharks, will feel like sandpaper. Even fish with small, smoother scales will feel a bit like that. Amphibians don’t have scales, and most species will be wet to some degree - they have to keep their skin moist or they’ll die. A few groups, like toads and newts, have rougher skin, which is heavier and thicker, which allows them to retain moisture better away from water.

Functionally, the big thing about amphibian skin is that it is semi-permeable. Amphibians can breathe through their skin - all amphibians can get some oxygen through their skin, but some species of salamanders get all their oxygen that way - they have no lungs or gills. The skin can also allow water in - sort of like a paper towel. The bad thing is that other chemicals can pass through the skin, too - pollutants and other chemicals tend to affect amphibians far more than they do other groups.

Amphibians also shed their skin - fish do not. People don’t tend to see frogs shedding their skin often, though, since they eat it to regain nutrients and other resources in the skin.

Finally, since amphibian skin offers no defense against predators in the way that scales do, and limited barrier against disease the way non-amphibian skin does (shedding helps), the skin of many amphibians contain toxins, and some of them have anti-fungal properties (typically due to symbiotic bacteria). Many species have evolved chemical defenses in the skin, while others have glands that produce toxins that can be secreted outside of the skin.

The skin can withstand dessication more than the fish.

They have moist skin used as respiratory surface during deep sleep / hibernation.

They have moist skin due to secretion of mucus by glands under the skin.

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Answer:

Explanation:

True

Answer:

water, when the metastable state is reached, is cooled below the zero temperature. It freezes abruptly. this is called metastable. They are not at equilibrium per se; as at negative temperatures the only equilibrium state of water is ice.

Explanation:

Answer:

the answer should be B because elements do not tranform into other elements in a chemical reaction

am I right please?