PHMWMHW(14 points):))));)))))

Answer:

The main universal indicator is in the form of a solution and are thymol blue , methyl red , bromothymol blue and phenolphthalein this mixture is important because each component loses or gains protons depending upon the acidity of the solution being tested .

maybe this mighr help u

Answer:

D

Explanation:

Answer:

Molecular formulas describe the exact number and type of atoms in a single molecule of a compound. The constituent elements are represented by their chemical symbols, and the number of atoms of each element present in each molecule is shown as a subscript following that element's symbol

Answer:

your cool

Explanation:

owa owa owa owa owa bob

Answer:

Adding fluoride to the water supply reduces the incidence of tooth decay. Fluoride protects teeth from decay by demineralization and remineralization. Too much fluoride can lead to dental fluorosis or skeletal fluorosis, which can damage bones and joints.

Explanation:

N/A

Answer: since the sodium ion is Na+, and sulfate is SO4(2-), you'll need 2 sodiums for a sulfate, making sodium sulfate Na2SO4.

Explanation:

Answer: Imidogen

Explanation: I just looked it up.

Answer:

Imidogen

Explanation:

Answer:

pH = 2.46

Explanation:

Hello there!

In this case, since this neutralization reaction may be assumed to occur in a 1:1 mole ratio between the base and the strong acid, it is possible to write the following moles and volume-concentrations relationship for the equivalence point:

[tex]n_{acid}=n_{base}=n_{salt}[/tex]

Whereas the moles of the salt are computed as shown below:

[tex]n_{salt}=0.021L*0.68mol/L=0.01428mol[/tex]

So we can divide those moles by the total volume (0.021L+0.0066L=0.0276L) to obtain the concentration of the final salt:

[tex][salt]=0.01428mol/0.0276L=0.517M[/tex]

Now, we need to keep in mind that this is an acidic salt since the base is weak and the acid strong, so the determinant ionization is:

[tex]C_6H_5NH_3^++H_2O\rightleftharpoons C_6H_5NH_2+H_3O^+[/tex]

Whose equilibrium expression is:

[tex]Ka=\frac{[C_6H_5NH_2][H_3O^+]}{C_6H_5NH_3^+}[/tex]

Now, since the Kb of C6H5NH2 is 4.3 x 10^-10, its Ka is 2.326x10^-5 (Kw/Kb), we can also write:

[tex]2.326x10^{-5}=\frac{x^2}{0.517M}[/tex]

Whereas x is:

[tex]x=\sqrt{0.517*2.326x10^{-5}}\\\\x=3.47x10^-3[/tex]

Which also equals the concentration of hydrogen ions; therefore, the pH at the equivalence point is:

[tex]pH=-log(3.47x10^{-3})\\\\pH=2.46[/tex]

Regards!

Answer:

The answer is C!

Explanation:

Hope it helps

Answer D

Explanation: did the quiz ψ(｀∇´)ψ

Answer:

Arteries

Explanation:

Answer:         arteries.    :)

Explanation:

the top one is right trust me and i took the test.      :)

have agreat day.     :)

Answer:

0.3529moles

Explanation:

no of moles =mass ÷molar mass

molar mass =17+17

=34

12÷34

=0.3529moles

According to the mole concept, the number of moles of molecules in a 12.0-gram sample of Cl₂ is equal to 0.169  moles.

Mole is defined as the unit of amount of substance . It is the quantity measure of amount of substance of how many elementary particles are present in a given substance.

It is defined as exactly 6.022×10²³ elementary entities. The elementary entity can be a molecule, atom ion depending on the type of substance. Amount of elementary entities in a mole is called as Avogadro's number.

It is widely used in chemistry as a suitable way for expressing amounts of reactants and products.For the practical purposes, mass of one mole of compound in grams is approximately equal to mass of one molecule of compound measured in Daltons. Molar mass has units of gram per mole . In case of molecules, where molar mass  in grams present in one mole  of atoms is its atomic mass.Number of moles is mass/molar mass= 12/70.90=0.169 moles.

Learn more about mole,here:

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Answer:

phase change always has two phases in contact during the change. melting => solid & liquid; evaporation (boiling) => liquid & vapor. If only one phase is present, then phase change is not occurring. Also, when two phases are in contact, no temperature changes occur. Only the pure phase demonstrates temperature change when measured. Example, when ice is added to water, at thermal equilibrium (temp = 0°C) the water temp will not continue to change. Only when all the ice has melted will the water temperature demonstrate a measured temperature change.

Explanation:

Answer:

wool ,rubber and copper wire should be correct

Answer:

B. a difference in temperatures.

Explanation:

Conduction involves the transfer of electric charge or thermal energy due to the movement of particles. When the conduction relates to electric charge, it is known as electrical conduction while when it relates to thermal energy, it is known as heat conduction.

In the process of heat conduction, thermal energy is usually transferred from fast moving particles to slow moving particles during the collision of these particles.

Also, thermal energy is typically transferred between objects that has different degrees of temperature and materials (particles) that are directly in contact with each other but differ in their ability to accept or give up electrons.

In order for heat to flow there must be a difference in temperatures.

This ultimately implies that, the driving force responsible for heat to flow is a difference in temperature between the points from which heat originates and where heat is received.

Additionally, the higher the temperature difference, the greater would be the heat flow; which is usually from a high temperature level to a low temperature level.

Answer:

[tex]0.5594\ \text{L}[/tex]

Explanation:

Mol of NaI = 0.405 mol

Molarity of solution = 0.724 M

Molarity is given by

[tex]M=\dfrac{\text{mol}}{\text{Volume of solution in }NaI}\\\Rightarrow \text{Volume of solution in }NaI=\dfrac{0.405}{0.724}\\\Rightarrow \text{Volume of solution in }NaI=0.5594\ \text{L}[/tex]

The required volume is [tex]0.5594\ \text{L}[/tex].

Answer:

71.99100

Explanation:

The mass of oxygen equal to one mole of oxygen is 15.998 grams and the mass of one mole of hydrogen is 1.008 g. 15.998*4.5 = 71.99100

Answer:

Shorter

Explanation:

As a wavelength increases in size, its frequency, and energy (E) decrease. From these equations, you may realize that as the frequency increases, the wavelength gets shorter. As the frequency decreases, the wavelength gets longer. There are two basic types of waves: mechanical and electromagnetic.

Answer:

The stratosphere

Explanation:

Answer:

a. changes with temperature.

Explanation:

Hello there!

In this case, according to the thermodynamic definition of the equilibrium constant in terms of the Gibbs free energy of reaction and the temperature of the system:

[tex]lnK=-\frac{\Delta G}{RT}[/tex]

It is possible to figure out that the equilibrium constant varies as temperature does, not only on the aforementioned definition, but also in the Gibbs free energy as it is also temperature-dependent. Therefore, the appropriate answer is a. changes with temperature.

Best regards!

The question is incomplete. The complete question is :

A common "rule of thumb" for many reactions around room temperature is that the rate will double for each ten degree increase in temperature. Does the reaction you have studied seem to obey this rule? (Hint: Use your activation energy to calculate the ratio of rate constants at 300 and 310 Kelvin.)

Solutions :

If we consider the activation energy to be constant for the increase in 10 K temperature. (i.e. 300 K → 310 K), then the rate of the reaction will increase. This happens because of the change in the rate constant that leads to the change in overall rate of reaction.

Let's take :

[tex]$T_1=300 \ K$[/tex]

[tex]$T_2=310 \ K$[/tex]

The rate constant = [tex]$K_1 \text{ and } K_2$[/tex] respectively.

The activation energy and the Arhenius factor is same.

So by the arhenius equation,

[tex]$K_1 = Ae^{-\frac{E_a}{RT_1}}$[/tex]  and [tex]$K_2 = Ae^{-\frac{E_a}{RT_2}}$[/tex]

[tex]$\Rightarrow \frac{K_1}{K_2}= \frac{e^{-\frac{E_a}{RT_1}}}{e^{-\frac{E_a}{RT_2}}} $[/tex]

[tex]$\Rightarrow \frac{K_1}{K_2}= e^{-\frac{E_a}{R}\left(\frac{1}{T_1}-\frac{1}{T_2}\right)}$[/tex]

[tex]$\Rightarrow \ln \frac{K_1}{K_2}= - \frac{E_a}{R} \left(\frac{1}{T_1} -\frac{1}{T_2} \right)$[/tex]

[tex]$\Rightarrow \ln \frac{K_2}{K_1}= \frac{E_a}{R} \left(\frac{1}{T_1} -\frac{1}{T_2} \right)$[/tex]

Given, [tex]$E_a = 0.269$[/tex] J/mol

           R = 8.314 J/mol/K

[tex]$\Rightarrow \ln \frac{K_2}{K_1}= \frac{0.269}{8.314} \left(\frac{1}{300} -\frac{1}{310} \right)$[/tex]

[tex]$\Rightarrow \ln \frac{K_2}{K_1}= \frac{0.269}{8.314} \times \frac{10}{300 \times 310}$[/tex]

[tex]$\Rightarrow \ln \frac{K_2}{K_1}= 3.479 \times 10^{-6}$[/tex]

[tex]$\Rightarrow \frac{K_2}{K_1}= e^{3.479 \times 10^{-6}}$[/tex]

[tex]$\Rightarrow \frac{K_2}{K_1}= 1$[/tex]

∴ [tex]$K_2=K_1$[/tex]

So, no this reaction does not seem to follow the thumb rule as its activation energy is very low.

Answer:

Average mass of 6 apple  = 1 kg

Explanation:

Given:

Average mass of 5 dozen apple = 10 kg

Find:

Average mass of 6 apple

Computation:

Average mass of 6 apple  = [Average mass of 1 apple] x [6 apple]

Average mass of 6 apple  = [10/(12 x 5)] x [6]

Average mass of 6 apple  = 1 kg

Answer:

KCl and Ba(OH)₂.

Explanation:

Hello there!

In this case, since electrolytes are substances characterized by presence of covalent bonds between the atoms forming the compound, it is possible to realize that just KCl and Ba(OH)₂ as they are species composed by cations (K and Ba) and anions (OH and Cl); therefore, they have the capacity to get ionized in aqueous solution and thus transfer electricity when present.

Best regards!

The solution containing electrolytes is the flask of KCI and [tex]Ba(OH)_2[/tex].

The correct options are a and c.

An electrolyte is a medium that contains ions and conducts electricity through the movement of ions, but not electrons.

They are minerals present in the body, that are electrically charged.

Electrolytes help in maintaining the water balance in the body, and pH of the body.

The three primary electrolytes are sodium, potassium, and chloride.

Thus, the correct options are a, KCI, and b, [tex]Ba(OH)_2[/tex].

Learn more about electrolyte

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Answer: 9.46

Explanation: in LiOH solution concentration of OH- ions is 2.88·10^-5 M

And pOH = -log( 2.88·10^-5 M) = 4.54. Because PH + pOH = 14.00

Then pH = 14-4.54

Answer:

E. Enthalpy is an intensive property Is false.

Explanation:

The false or wrong option in this question is that Enthalpy is an intensive property.

To explain this, I would first explain an intensive property. An intensive property is one that does not depend on the quantity or the mass of matter. Examples are temperature and pressure.

But an extensive property is a property which depends on the mass and the quantity of the system. Enthalpy, volume are all extensive.

Answer:

COMMENSALISM

Explanation:

Commensalism refers to the relationship that exists between two different organism that belong to different species. In this relationship neither of the organisms are harmed while either of them is benefitted. The web made by the spider between the horns of the deer increases the probability of the spider to catch its prey. The random movement of the deer helps the spider and at the same time it do not harm the deer.

Answer:

It’s d

Explanation:

It’s d 100%

Answer:

helped

The number  of ml of isopropyl  alcohol  that are 1 pint (473 Ml)   is  331.1 Ml

  calculation

assume  that  the 1 pint  is in  a  container

  This implies  that the 1 pint (473 ml)  is  in 100 %  M/V

     what about 70 %(M/V)

that is  473 Ml  = 100 %

                  ?   =   70 %

by  cross  multiplication

   =  473 x70/100 = 331.1 Ml

Explanation:

Answer:

28g

Solution. Hence, 2 moles of nitrogen atoms weigh 28g.

Answer: The [tex]R_f[/tex] value is 0.664

Explanation:

Distance travelled by solvent front = (7.7-1.45)cm = 6.25 cm

Distance travelled by unknown = (5.6-1.45) cm = 4.15 cm

 The retention factor or the [tex]R_f[/tex] value is defined as the ratio of distance traveled by the unknown to the distance traveled by the solvent front.

[tex]R_f=\frac{\text {distance travelled by unknown}}{\text {distance travelled by solvent}}[/tex]

[tex]R_f=\frac{4.15}{6.25}=0.664[/tex]

Thus the [tex]R_f[/tex] value is 0.664