4. A puddle of coastal seawater, caught in a depression formed by some coastal rocks at high tide, begins to evaporate as the tide goes out. If the volume of a puddle decreases to 23% of its original volume, what is the sodium chloride concentration if it was initially 0.449 M?

Answer:

The Answer is B. Mass and distance

Explanation:

Trust me lol

Answer:mass and distance

Explanation:

Answer: There are [tex]2.29\times 10^{23}[/tex] formula units

Explanation:

According to avogadro's law, 1 mole of every substance occupies 22.4 L at STP and contains avogadro's number [tex]6.023\times 10^{23}[/tex] of particles.

To calculate the moles, we use the equation:

[tex]\text{Number of moles}=\frac{\text{Given mass}}{\text {Molar mass}}=\frac{36.0g}{95g/mol}=0.38moles[/tex]

1 mole of [tex]MgCl_2[/tex] contains = [tex]6.023\times 10^{23}[/tex] formula units

Thus 0.38 moles of [tex]MgCl_2[/tex] contains = [tex]\frac{6.023\times 10^{23}}{1}\times 0.38=2.29\times 10^{23}[/tex] formula units

Thus there are [tex]2.29\times 10^{23}[/tex] formula units

Answer:

1.418688 atm

Explanation:

(a)  Moles of PCl5 = mass / molar mass

                      =1.5 g / 208.22 g/mol

                     = 0.0072 moles

Also given,

T = 600 K

V = 0.500 L

Pressure of PCl5, P = nRT / V

                             = 0.0072 mol×0.0821 L-atm / (mol.K)×600 K / 0.500 L

                             = 0.709344 atm

(b)  PCl5(g) ⇄ PCl3(g) + Cl2(g)

Initial               0.965         0               0

Change               -x            +x             +x

Equilibrium (0.709344 -x)         x               x

K_p = 11.5 = x×x / (0.965 -x)

solving, we get x = 0.67027

So partial pressure of PCl5 at equilibrium = 0.709344 - 0.67027 = 0.039074 atm

(c)   Partial pressure of PCl3 = Cl2 = 0.709344 atm

So total pressure = 0.709344+0.039074+ 0.67027= 1.418688 atm

Answer and Explanation:

The water is a polar solvent which dissolves into the LiBr molecules and converts into [tex]Li^+[/tex] and [tex]Br^-[/tex] ions far from the solid also into the solution, when they are hydrated.

Now, the complete words are as given below:-

The [tex]K^+[/tex] and [tex]I^-[/tex] ions at the surface of the solid are pulled into the solution by the polar water molecules, where the hydration process surrounds separate ions with water molecules.

LiBr has been the ionic compound and has been dissociated in the water by the force of the polar water molecules. The water molecules that have been polar in nature exert the force onto the ionic compounds and help in the dissociation.

At the dissociation surface of the solid KI molecules, are pulled into the solution by the polar water molecules, where the hydration process surrounds ions and separates them with water molecules.

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Answer:

because according to the electron sea model they are good conductor of heat so,they can be used for cooking.

Answer:

21.88mL is the volume of base required for the titration.

Explanation:

For an acid-base titration trying to find the concentration of an acid, you must add a known quantity of the acid and titrate it with an standarized base.

If you know the moles of base you add to the acid solution, these moles are equal to moles of acid.

In the buret of the titration, initial volume is 1.94mL and final volume is 23.82mL. The volume you are adding is the difference between initial and final volume, that is:

23.82mL - 1.94mL

five oxygen molecules

step by step explanation.

according to the equation,one molecule of oxygen is enough to react with two carbon molecules thus 10 carbon molecules need 5oxygen molecules

Answer:

Explanation:

Partial pressure of oil = mole fraction of oil x total pressure

mole fraction of oil = mole of oil / mole of water + mole of oil

= mole of oil = mass of oil / molecular weight of oil

= 20 / 100 = .2

mole of water = 80 / 18

= 4.444

mole fraction of oil =  .2 / .2 + 4.444

= .2 / 4.644

Partial pressure of oil = mole fraction of oil x total pressure

= (.2 / 4.644 ) x 760 mm

= 32.73 mm Hg .

Answer:

Path A-B-D involves a catalyst and is slower than A-C-D

Explanation:

The diagram above illustrates both the catalyzed path and the uncatalyzed path of a chemical reaction.

The catalysed path is the path expressed with broken lines and the uncatalyzed path is the path expressed with thick small line as shown in the diagram above.

The catalyzed path has a higher activation energy than the uncatalyzed path.

Therefore, the catalyzed path will be slower that the uncatalyzed path because, the catalyzed path will require a higher energy to overcome the activation energy in order for the reaction to proceed to product.

On the other hand, the uncatalyzed path has a lower activation energy and a lesser amount of energy is needed to overcome it in order for the reaction to proceed to product.

Answer:

Slow combustion

Spontaneous combustion

Explosive combustion

Explanation:

-Slow combustion reactions: Occurs at low temperatures. Cellular respiration is an example.

-Spontaneous combustion reactions: Occurs suddenly without an outside heat source. The heat source is the result of oxidation.

-Explosive combustion reactions: Involves an oxidizing agent.

hopefully this helped :3

Answer:

Three types are: Rapid Combustion, Complete Combustion, and Spontaneous Combustion.

Explanation:

Note: there are more types! This is just three random ones I picked to list. Hope this helps! :)

Answer:

[tex]V_2 = 4.87 * 10^3[/tex]

Explanation:

This question is an illustration of ideal Gas Law;

The given parameters are as follows;

Initial Temperature = 25C

Initial Volume = 4.5 * 10³L

Required

Calculate the volume when temperature is 50C

NB: Pressure remains constant;

Ideal Gas Law states that;

[tex]PV = nRT[/tex]

The question states that the pressure is constant; this implies that the constant in the above formula are P, R and n

Divide both sides by PT

[tex]\frac{PV}{PT} = \frac{nRT}{PT}[/tex]

[tex]\frac{V}{T} = \frac{nR}{P}[/tex]

Represent [tex]\frac{nR}{P}[/tex] with k

[tex]\frac{V}{T} = k[/tex]

[tex]k = \frac{V_1}{T_1} = \frac{V_2}{T_2}[/tex]

At this point, we can solve for the required parameter using the following;

[tex]\frac{V_1}{T_1} = \frac{V_2}{T_2}[/tex]

Where V1 and V2 represent the initial & final volume and T1 and T2 represent the initial and final temperature;

From the given parameters;

V1 = 4.5 * 10³L

T1 = 25C

T2 = 50C

Convert temperatures to degree kelvin

V1 = 4.5 * 10³L

T1 = 25 +273 = 298K

T2 = 50 + 273 = 323K

Substitute values for V1, T1 and T2 in [tex]\frac{V_1}{T_1} = \frac{V_2}{T_2}[/tex]

[tex]\frac{4.5 * 10^3}{298} = \frac{V_2}{323}[/tex]

Multiply both sides by 323

[tex]323 * \frac{4.5 * 10^3}{298} = \frac{V_2}{323} * 323[/tex]

[tex]323 * \frac{4.5 * 10^3}{298} = V_2[/tex]

[tex]V_2 = 323 * \frac{4.5 * 10^3}{298}[/tex]

[tex]V_2 = \frac{323 * 4.5 * 10^3}{298}[/tex]

[tex]V_2 = \frac{1453.5 * 10^3}{298}[/tex]

[tex]V_2 = 4.87 * 10^3[/tex]

Hence, the final volume at 50C is [tex]V_2 = 4.87 * 10^3[/tex]

Answer:

Alumunium

Explanation:

Alumunium = [Ne] 3s² 3p¹

Ne = [He]2s²2p⁶

He = 1s

Alumunium = 1s 2s²2p⁶3s² 3p¹

Answer:

D

Explanation:

Answer:

NaCl in water; ion-dipole interaction

Explanation:

Sodium chloride is an ionic solid. Ionic solids dissolve in water due to ion dipole interaction. Ionic solids are composed of an ion pair which are strongly bound by electrostatic interaction between the oppositely charged ions in the solid state.

When an ionic substance is dissolved in water, the positive ion interacts with the negative end of the dipole in water while the negative ion interacts with the positive end of the dipole in water. Hence the ions are pulled apart by this ion-dipole interaction and the crystal structure of the solid collapses as the ionic solid dissolves in water.

Sodium chloride is an ionic solid. Interaction between the sodium ion and the negative end of the dipole in water as well as chloride ion and the positive end of the dipole in water leads to the dissolution of sodium chloride solid in water. This is the strongest solute-solvent interaction in the list.

When The strongest solute-solvent interactions and the interaction the correct option is A NaCl in water; ion-dipole interaction

Sodium chloride is an ionic solid. Ionic solids liquefy in water due to ion-dipole interaction. Ionic solids are formed of an ion team that is strongly bound by electrostatic interaction between the differently delegated ions in the solid-state.

When an ionic substance is disbanded in water, the positive ion interacts with the negative end of the dipole in the water while the opposing ion interacts with the positive end of the dipole in water. Therefore the ions are dragged apart by this ion-dipole interaction and also when the crystal configuration of the solid collapses as the ionic solid dissolves in water.

Sodium chloride is an ionic solid. The interchange between the sodium ion and the negative future of the dipole in water as well as the chloride ion and the positive end of the dipole in water leads to the abolishment of sodium chloride solid in water. This is the strongest solute-solvent exchange on the list.

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Answer:

The main component of natural gas is methane (CH4) at 60 to 90% followed by various combination of ethane, propane, and butane whose percentage can vary from 0 to 20% each. For each unit mass of alkanes, the combustion energy (energy released when the fuel reacts with oxygen) released is very high about 13 to 15 kcal/g, which is higher than even those generated by petrol or diesel. So, for heating or other energy generation purpose for household purposes, this source of energy is used.

The equation for combustion of methane is shown below. Upon combustion, carbondioxide and water is produced with simultaneous generation of heat which is the source of energy used for consumption.

CH4 + 2O2 --> CO2+ 2H2O + heat [ For methane, the combustion energy is ~ 6kcal/g]

As the CH2 units are increased in the alkanes, the combustion energy increases, for e.g., ethane has combustion energy of 7 kcal/g and propane has about 12 kcal/g.

Explanation:

Answer:

Mg²⁺

Explanation:

Electronic configuration = 1s22s22p6 (or [Ne] )

Charge = -2

This means the element has two extra electrons. So total electrons = 12.

The lement is Magnesium and the ion is Mg²⁺

Answer:

C. Grinding the solute down into tiny particles.

Explanation:

The dissolution of a solute has something to do with particle size. The size of solute particles usually determines how quickly a solute dissolves in a solvent. When large solute particles are introduced into the solvent, the large solute particles do not easily interact with solvent particles hence preventing easy dissolution in the solvent.

However, when the solute is ground into tiny particles, smaller solute particles interact more effectively with solvent particles hence dissolution is faster.

Therefore, tiny solute particles will dissolve faster in a solvent than a lump of solute. Summarily, small particle size enhances dissolution of a solute in the appropriate solvent.

Answer: stirring the solution vigorously

Grinding the solute down into tiny particles

gently heating the solution

Explanation:

A dissolution will proceed more readily when heated . Breaking up the solute as much as possible will aid in overcoming the solute-solute interaction, as will stirring the solution

Answer:

3d and 4th

Explanation:

Carbohydrates general formula (CH2O)n.

Not 1st one because it has NH2-group.

2nd - C3H6O4, also it is acid.

3d - C3H6O3

4th - C6H12O6

Among the given compounds only compound present in 3rd option is a carbohydrate.

Carbohydrates are the organic molecules which are made up of oxygen atom, carbon atom and hydrogen atom and general molecular formula of carbohydrates is CₙH₂ₙOₙ, where n is the number of atoms.

In the carbohydrate molecule, alcoholic group and aldehyde groups may present.

Hence compound C is carbohydrate.

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Answer:

Answer:

A) at the rod's geometrical center

Explanation:

Let us assume that the rod is replaced by water. And now this water volume is in translational and in rotational equilibrium.

Therefore, a net upward force must have been exerted by the surrounding liquid which acts at the center of mass of the water volume.

This force determines through the geometric center of the column of the cylindrical water  

Moreover, the force is also independent of submerged body into it

Hence, the first option is correct

Answer:

x = 86.908 amu

Explanation:

Average mass of isotope =  85.4678 amu

Rb-85 = 84.9117 amu, Percentage = 72.15% = 0.7215

Other isotope = x, Percentage = 100 - 72.15 = 27.85% = 0.2785

Average mass = (Percentage * Mass of Rb-85)  + (Percentage * Mass of Rb-87)

85.4678 = (0.7215 * 84.9117) + (0.2785 * x)

85.4678 = 61.2638 + 0.2785x

0.2785x = 24.204

x = 24.204 / 0.2785

x = 86.908 amu

86.908 amu

It is given that:

Average atomic mass of Rb = 85.4678 amu.

Also the mass of Rb-85 = 84.9117 amu and its Percentage = 72.15% = 0.7215

Let the mass of other isotope (Rb-87) = x

So, Percentage of other isotope (Rb-87) = 100 - 72.15 = 27.85% = 0.2785

Average mass = (Percentage * Mass of Rb-85)  + (Percentage * Mass of Rb-87)

85.4678 = (0.7215 * 84.9117) + (0.2785 * x)

85.4678 = 61.2638 + 0.2785x

0.2785 x = 24.204

x = 24.204 / 0.2785

x = 86.908 amu

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Answer:

Kinetic energy = 1/2mv²

where m is the mass

v = velocity

m = 5.31 × 10^-23 kg

v = 1.00 × 10^2 m/s

Kinetic energy = 1/2 × 5.31 × 10^-23 × ( 1.00 × 10^2)²

= 2.655 × 10^-19 Joules

Hope this helps

Answer:

E) Al³⁺

Explanation:

A reaction involving a gain of electrons is known as a reduction reaction because the oxidation number of the species gaining the electron is reduced.

In the given question, the oxidation number (charge) of particle accepting two electrons will decrease by 2. From the given options;

A. K is a neutral atom with oxidation number of 0. If is accepts two electrons, its oxidation number becomes -2.

K + 2e⁻  ----> K⁻²

B) Fe²⁺ has a charge of +2. If it accepts two electrons, its charge comes 0.

Fe⁺ + 2e⁻  ----> Fe

C) O²⁻ has a charge of -2. if it accepts two electrons, it will have a charge of -4.

O²⁻ + 2e⁻  ---->  O⁴⁻

D) Ne has a charge of zero. If it accepts two electrons, its charge becomes -2.

Ne + 2e⁻   ---->   Ne²⁻

E) Al³⁺ has a charge of +3. If it gains two electrons, its charge becomes +1.

Al³⁺ + 2e⁻   ---->   Al⁺

Answer:

Photon of light

Explanation:

According to Bohr's model of the atom, electrons in atoms are found in specific energy levels. These energy levels are called stationary states, an electrons does not radiate energy when it occupies any of these stationary states.

However, an electron may absorb energy and move from one energy level or stationary state to another. The energy difference between the two energy levels must correspond to the energy of the photon of light absorbed in order to make the transition possible.

Since electrons are generally unstable in excited states, the electron quickly jumps back to ground states and emits the excess energy absorbed. The frequency or wavelength of the emitted photon can now be measured and used to characterize the transition. This is the principle behind many spectrometric and spectrophotometric methods.

Answer:

[tex]=C_3H_4O_3[/tex]

Explanation:

When percentage composition is given, and asked for the empirical formula, it is simplest to  assume 100 g of material. Thus,

Mass C = 40.92 g.  Moles C = 40.92 g x 1 mole/12 g = 3.41 moles C

Mass H = 4.58 g.  Moles H = 4.58 g x 1 mole/1.0 g = 4.58 moles H

Mass O = 54.50 g.  Moles O = 54.50 g x 1 mole/16 g = 3.41 moles O

Now, we want to get the moles into whole numbers, so we begin by dividing all by the smallest, i.e. divide all values by 3.41.

Moles C = 3.41/3.41 = 1

Moles H = 4.58/3.41 = 1.34

Moles O = 3.41/3.41 = 1

Now, in order to get 1.34 to be a whole number we multiply it (and all others) by 3

Moles C = 1x3 = 3

Moles H = 1.34x3 = 4

Moles O = 1x3 = 3

Empirical Formula [tex]=C_3H_4O_3[/tex]

Answer:

Fermentation

Explanation:

Fermentation is the general term used to describe the process by which sugars such as glucose, starch or cellulose are converted to ethanol and carbon (iv) oxide. It is anaerobic process meaning that it occurs in the absence of air or in very low oxygen concentrations.

Yeast and other microorganisms ferment glucose into ethanol and carbon (iv) oxide with the help of the enzyme zymase. Polysaccharides such as starch and cellulose are first broken down into glucose by enzymes such as diastases, maltase and cellulase, before it is then converted into ethanol and carbon (iv) oxide.

The equation for the conversion of glucose to ethanol and carbon (iv) oxide is as follows:

C₆H₁₂O₆(aq) -----> 2C₂H₅OH(aq) + 2CO₂(g)

Answer:

61.54%

Explanation:

Hello,

To calculate the percent yield of a product, we express it as ratio between the actual yield to the theoretical yield multiplied by 100.

Percent yield = (actual yield / theoretical yield) × 100

Actual yield = 400mg

Theoretical yield = 650mg

Percent yield = (400 / 650) × 100

Percent yield = 0.6154 × 100

Percent yield = 61.54%

Percent yield of guaifenesin in the drug is 61.54%

Answer:

The pressure will be twice the initial pressure

Explanation:

Gay-Lussac's law states that the pressure of a gas is directely proportional to absolute temperature under constant volume. That is because vibrations of a gas increase when temperature increases, increasing the pressure of the gas.

That means if the temperature of a gas is doubled, the pressure will be twice the initial pressure.

Answer:

Ductility is the how stretchable a solid is under tension. If a solid is ductile, then it can be stretched into wire-like (think rubber band). Ductility is similar to malleability and physical components of solids.

Explanation:

Answer:

It's well Explained below.

Explanation:

First of Excess product of CaCO_3 would be produced due to the fact that there would not be enough CaCl_2 to react with Na_2•CO_3. The main purpose of having stoichiometric quantities is for us to know the correct amount or near the correct amount of each reactant in order to create a product that will be close to the theoretical amount and thus have a higher percent yield.

The number of moles of carbon atoms in 0.500 mol of ethane (C₂H₆) is equal to one mole.

A mole can be defined as a scientific unit that is utilized to calculate the quantities such as atoms, molecules, ions, or other particular particles. The mass of one mole of a given chemical element is atomic mass and that of 1 mole of a chemical compound is molar mass.

The number of entities found in one mole is equal to 6.023 × 10 ²³ which is known as Avogadro’s constant.

Given, the number of moles of C₂H₆ = 0.500 mole

One molecule of ethane has carbons = 2

One mole of ethane has moles of carbons = 2 moles

0.500 mol of ethane has moles of carbon atoms = 0.500×2 = 1 mol

Therefore, one mole of carbon atoms is present in 0.500 mol of ethane C₂H₆.

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