Which statement is true about the substances in a mixture?

They change their composition

They retain their chemical properties

They always consist of the same element

They are always in the same state of matter

Answer:

Kelvin

Explanation:

Final answer:

Charles's law requires temperatures to be in Kelvin, the absolute temperature scale, to accurately describe the relationship between a gas's volume and its temperature at constant pressure.

Explanation:

This gas law works only if the temperature is recorded in Kelvin units. Specifically, the gas law referred to here is Charles's law, which establishes a direct relationship between the volume of a gas and its temperature, given constant pressure and amount of gas. Kelvin is the absolute temperature scale used in this context because it starts at absolute zero, the theoretical point at which a gas would have no volume. To convert Celsius to Kelvin, the formula K = °C + 273 is used, ensuring that temperatures are in the appropriate scale for these calculations. Charles's law, along with others like Boyle's law, forms the foundation of our understanding of gas behavior under various conditions.

Answer:

D.) changes in the populations of the community

Explanation:

Any disruption of any ecosystem always leads to some changes, some minor ones, some dramatic ones. All of the organisms living in a particular ecosystem are adapted to live in the conditions that it provides, so when a change occurs it causes a big stress on the populations. Depending on the change that has occurred, it can cause changes in the populations, or it can even cause extinction to some populations.

Answer:

up quark

Explanation:

Answer:

up quark

Explanation:

D. Red and Violet are reflected, Green is absorbed

Leaves of plants are green because chlorophyll pigments absorb red and blue light and reflect green light. The correct answer is B - red and blue are absorbed, and green is reflected.

The color absorbed and reflected by the leaves of most plants can be understood by examining the pigments chlorophyll a and chlorophyll b, which absorb light for photosynthesis. Chlorophyll a absorbs light primarily in the blue-violet and red regions, and chlorophyll b absorbs red-blue light. Both pigments reflect green light, which is why leaves appear green to us. Addition to this, there are carotenoids that absorb light in the blue-green and violet region and reflect longer yellow, red, and orange wavelengths.

The correct answer to the question is B. Red and blue are absorbed; green is reflected. This is because chlorophyll a and b absorb light at blue and red wavelengths, which are essential for photosynthesis, and reflect the green wavelengths that they do not absorb.

Answer & Explanation:

I'm not sure if this is the right one because there are 3 choices haha...

So it's either

1. Sound

2. Mechanical

3. Low frequency

The answer is:

The new volume will be 1 L.

[tex]V_{2}=1L[/tex]

To solve the problem, since we are given the volume and the first and the second pressure, to calculate the new volume, we need to assume that the temperature is constant.

To solve this problem, we need to use Boyle's Law. Boyle's Law establishes when the temperature is kept constant, the pressure and the volume will be proportional.

Boyle's Law equation is:

[tex]P_{1}V_{1}=P_{2}V_{2}[/tex]

So, we are given the information:

[tex]V_{1}=2L\\P_{1}=50kPa\\P_{2}=100kPa[/tex]

Then, isolating the new volume and substituting into the equation, we have:

[tex]P_{1}V_{1}=P_{2}V_{2}[/tex]

[tex]V_{2}=\frac{P_{1}V_{1}}{P_{2}}[/tex]

[tex]V_{2}=\frac{50kPa*2L}{100kPa}=1L[/tex]

Hence, the new volume will be 1 L.

[tex]V_{2}=1L[/tex]

Have a nice day!

Ethanol is the correct answer as it can dissolve both polar and nonpolar solutes due to its polar -OH group and a nonpolar ethyl group.

Among these, ethanol is the solvent that can dissolve both polar and nonpolar substances. Water is a polar solvent and typically dissolves polar or ionic solutes like methanol (CH3OH) and sodium sulfate (Na2SO4), but not nonpolar solutes like octane (C8H18). On the other hand, nonpolar solvents like toluene and hydrocarbon such as heptane (C7H16) would dissolve nonpolar substances like octane (C8H18), but not polar solutes. Ethanol's unique properties allow it to dissolve wide-ranging solutes because it contains a polar -OH group and a nonpolar ethyl group (C2H5-), making it suitable for both polar and nonpolar solutes.

Answer:

17,140 g = 17.14 kg.

Explanation:

Q = m.c.ΔT,

where, Q is the amount of heat absorbed by ice (Q = 3600 x 10³ J).

m is the mass of the ice (m = ??? g).

c is the specific heat of the ice (c of ice = 2.1 J/g.°C).

ΔT is the difference between the initial and final temperature (ΔT = final T - initial T = 100.0°C - 0.0°C = 100.0°C).

∵ Q = m.c.ΔT

∴ (3600 x 10³ J) = m.(2.1 J/g.°C).(100.0°C)

∴ m = (3600 x 10³ J)/(2.1 J/g.°C).(100.0°C) = 17,140 g = 17.14 kg.

Answer:

question 1:

The right choice is  → c. KNO₃

question 2:

The right choice is  → c. 784 mm Hg

Explanation:

===============================================================

question 1:

From the figure, the solubility of the different salts at 90 °C is:

NaCl:

It is 40 g per 100 g water.

KBr:

It is 100 g per 100 g water.

KNO₃:

It is about 240 g per 100 g water.

NaClO₃:

It is about 220 g per 100 g water.

∴ The most soluble salt in water at 90°C is KNO₃.

So, the right choice is

→ c. KNO₃

===============================================================

question 2:

We can use the general law of ideal gas: PV = nRT.

where, P is the pressure of the gas in atm.

V is the volume of the gas in L.

n is the no. of moles of the gas in mol.

R is the general gas constant,

T is the temperature of the gas in K.

If n and T are constant, and have two different values of P and V:

P₁ * V₁= P₂ * V₂

from the given data :

P₁ = 3060 mm Hg

V₁ = 0.520 L.

V₂ = 2.03 L.

∴ P₂ = [P₁ * V₁] / V₂ = [3060 mm Hg  * 0.520 L] / 2.03 L = 783.84 mm Hg

      ≅ 784 mm Hg

So, the right choice is

→ c. 784 mm Hg

===============================================================

Answer: covalent bond

Explanation: Tetracarbon Hexahyride is built using covalent bonds

Hope this helps please mark brainlist it would be greatly appreiciated :)

Answer:

The missing coefficient is 2

Neutralization

Explanation:

Mg(OH)₂ + H₂SO₄ ⟶ MgSO₄ + _____H₂O

Let us use alphabets a,b, c and d to represent the coefficients of the compounds in the given equation:

aMg(OH)₂ + bH₂SO₄ ⟶ cMgSO₄ + ___d__H₂O

In balancing chemical equations, we must bear in mind that they must obey the law of conservation of mass. We can use two approach in balancing a reaction.

We can inspect the individual atoms to check if they are balanced. We can also do this by using a simple mathematical method.

For the given reaction:

                        aMg(OH)₂ + bH₂SO₄ ⟶ cMgSO₄ + ___d__H₂O

For Mg:

          a = c                                (i)

For O:

        2a + 4b = 4c + d                (ii)

For H:

       2a + 2b =  2d                       (iii)

For S:

         b = c                                   (iv)

If a = 1, then c = 1, b = 1

we can then use either equation (ii) or (iii) to solve for the unknown "d":

         2a + 4b = 4c + d

Making the d the subject of the equation:

        d = 2a + 4b - 4c

        d = 2(1) + 4(1) - 4(1)

        d = 2 + 4 - 4

        d = 2

The missing coefficient is 2 and the complete equation is given as:

                       Mg(OH)₂ + H₂SO₄ ⟶ MgSO₄ + 2H₂O

The reaction is a neutralization process. In neutralization, an acid and a base react together to produce salt and water. As we can see, Mg(OH)₂ combines with H₂SO₄ to produce salt and water.

The balanced equation is Mg(OH)₂ + H₂SO₄ ⟶ MgSO₄ + 2H₂O. The reaction is a neutralization reaction. Therefore, the correct option is option B.

An equation per a chemical reaction is said to be balanced if both the reactants or the products have the same number of atoms and total charge for each component of the reaction. In other words, each side of the reaction have an equal balance of mass and charge. It is typical to balance chemical formulas for both mass plus charge in aqueous solutions. Equal numbers and types of atoms are produced on both halves of the equation when balancing for mass.

aMg(OH)₂ + bH₂SO₄ ⟶ cMgSO₄ + dH₂O

For Mg

a = c                              

For O

2a + 4b = 4c + d    

For H

2a + 2b =  2d    

For S

b = c        

If a = 1, then c = 1, b = 1

2a + 4b = 4c + d

d = 2a + 4b - 4c

d = 2(1) + 4(1) - 4(1)

d = 2 + 4 - 4

d = 2

the balanced equation is Mg(OH)₂ + H₂SO₄ ⟶ MgSO₄ + 2H₂O

The reaction is a neutralization reaction

Therefore, the correct option is option B.

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Answer:

The second choice, or flammability.

Explanation:

The flammability of something is how easy it is for it to burn or ignite.

Answer:

The Answer in flammability

Explanation:

Both fire and the fire starter are chemicals therefore its B.

Answer:

0.21 M. (2 sig. fig.)

Explanation:

The molarity of a solution is the number of moles of the solute in each liter of the solution. The unit for molarity is M. One M equals to one mole per liter.

How many moles of NaOH in the original solution?

[tex]n = c \cdot V[/tex],

where

[tex]n = c\cdot V = 0.25\;\text{mol}\cdot\textbf{L}^{-1} \times 0.135\;\textbf{L} = 0.03375\;\text{mol}[/tex].

What's the concentration of the diluted solution?

[tex]\displaystyle c = \frac{n}{V}[/tex].

Concentration of the diluted solution:

[tex]\displaystyle c = \frac{n}{V} = \frac{0.03375\;\text{mol}}{0.160\;\textbf{L}} = 0.021\;\text{mol}\cdot\textbf{L}^{-1} = 0.021\;\text{M}[/tex].

The least significant number in the question comes with 2 sig. fig. Keep more sig. fig. than that in calculations but round the final result to 2 sig. fig. Hence the result: 0.021 M.

Answeri think 0.21 M

Explanation:

Answer:

[tex]\boxed{ \text{A double displacement reaction} }[/tex]

Explanation:

In a double displacement reaction, the metal cations change partners with the anions.

3Na₂CO₃(aq)  + 2AlCl₃(aq) ⟶ 6NaCl(aq) + Al₂(CO₃)₃(s)

This is also a precipitation reaction, because the aluminium carbonate is insoluble and precipitates from solution.

Answer:

ummmm have no clue

Explanation:

Answer:

The reaction is exothermic.

Explanation:

When the temperature changes in a balanced system, it ceases to be in equilibrium because the value of the equilibrium constant is modified. Thus, at a temperature T1 the constant is K1, and at a temperature T2, the constant is K2. The relationship between these magnitudes is given in the so-called Van't Hoff equation.

The Wan't Hoff equation is:

[tex]\frac{lnK1}{lnK2}=-\frac{H}{R} (\frac{1}{T1}-\frac{1}{T2})[/tex]

Where:

ΔH: standard enthalpy of the reaction

R: constant of ideal gases

K1: equilibrium constant at temperature T1

K2: equilibrium constant at temperature T2

The Van't Hoff equation allows us to study how the chemical equilibrium shifts with temperature depending on whether we have an endothermic or exothermic reaction. So if the reaction is exothermic, ΔH <0, increasing the temperature decreases the equilibrium constant and the reaction moves to the left, while if the temperature decreases, the equilibrium constant increases and the equilibrium moves to the right.

Therefore, given the values ​​of the equilibrium constant at different temperatures and observing that it decreases when the temperature rises, the reaction is exothermic.

a process where the scientists performing the research influence the results, in order to show a certain result

Answer:

Explanation:

An experimental bias can be define as the type of variable which is selectively chosen so as to obtain a desired result. It can also be said that a bias can be any kind of manipulation which is done by the experimenter so as to obtain a desired outcome or findings of the experiment.  An experimenter can also take the advantage of choosing the desired samples  from the collection of samples.

To avoid bias, a blinded study can be used in which the random variables as well as no bias while collecting the samples for study takes place.

Answer:

7.97 x 10⁻² mol.

Explanation:

where, P is the pressure of the gas in atm (P = 98.8 kPa = 0.975 atm).

V is the volume of the gas in L (V = 2.0 L).

n is the no. of moles of the gas in mol (??? mol).

R is the general gas constant (R = 0.0821 L.atm/mol.K).

T is the temperature of the gas in K (T = 25°C + 273 = 298 K).

∴ n = PV/RT = (0.975 atm)(2.0 L)/(0.0821 L.atm/mol.K)(298 K) = 7.97 x 10⁻² mol.

Using hydrogen peroxide to bleach hair is affordable and can give great results but only if used well. The following steps will help you bleach your hair safely with hydrogen peroxide: ... Shampoo, rinse and dry your hair. Apply the conditioner; let it stay for a few minutes before you comb it through.

Answer:

1. It's affordable

2. You can control the color

3. You'll be popular (at least in my school you will)

4. It can ruin your hair

5. Spillage on your skin

6. I don't think it's toxic

Explanation:

This is all I can come up with. If I'm able to think of more, I'll edit this.

Answer:

First ionization of lithium:

[tex]\text{Li}\;(g)\to \text{Li}^{+} \; (g) + \text{e}^{-}[/tex].

Second ionization of lithium:

[tex]\text{Li}^{+}\;(g) \to\text{Li}^{2+} \;(g) + \text{e}^{-}[/tex].

Explanation:

The ionization energy of an element is the energy required to remove the outermost electron from an atom or ion of the element in gaseous state. (Refer to your textbook for a more precise definition.) Some features of the equation:

First Ionization Energy of Li:

Second Ionization Energy of Li:

The first ionization energy of lithium is represented by the equation: Li(g) -> Li+(g) + e-, with an energy of +54.4 eV. The second ionization energy is represented by the equation: Li+(g) -> Li2+(g) + e-, with an energy of 30.6 eV. These equations demonstrate the process of ionization.

The ionization energy of an element is the energy required to remove an electron from a gaseous atom or ion. The first ionization energy of lithium is represented by the equation: Li(g) -> Li+(g) + e-, the energy required for this process is +54.4 eV.

The second ionization energy refers to the energy required to remove the second electron. For lithium, the second ionization energy is represented by the equation: Li+(g) -> Li2+(g) + e-, the energy needed for ionizing the second electron is 30.6 eV.

The equations represent the processes which occur when the first ionization and the second ionization energies of lithium are measured.

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Answer:

12560 J.

Explanation:

The amount of heat absorbed by water = Q = m.c.ΔT.

where, m is the mass of water (m = 1.5 kg = 1500.0 g).

c is the specific heat capacity of water = 4.186 J/g°C.

ΔT is the temperature difference = (final T - initial T = 27°C - 25°C = 2°C).

∴ The amount of heat absorbed by water = Q = m.c.ΔT = (1500.0 g)(4.186 J/g°C)(2°C) = 12560 J.

Answer:

K = 9.4 *10^5

The reaction favor product formation

Explanation:

Equilibrium constant of a chemical reaction is the value of its reaction quotient at chemical equilibrium. Also it is defined as the ratio of the product of concentration of products to the product of concentration of reactants each term raised to power equal their stochiometric coefficients.  

so, for the reaction,

The equilibrium constant can be expressed as following:

[tex]K_{eq}=\frac{[H_2S]^2}{H_2]^2\times [S_2]}[/tex]

where  concentration of reactants and products is expressed in molarity Molarity=(no of moles/ Volume L)

So,

[H₂] = (0.50 mol / 1 L) = 0.50 M

[S₂] = (0.02 mol / 1 L) = 0.020 M

[H₂S] = (68.5 mol / 1 L) = 68.5 M

∴ K_{eq}=\frac{[68.5]^2}{0.50]^2\times [0.020]}=9.4*10^5

As the value of K is greater than 1, the reaction favor product formation.

Answer:

No, it is not balanced.

The balanced equation is: Zn(OH)₂ + 2NaOH → Na₂ZnO₂ + 2H₂O.

Explanation:

The no. of Na atoms in reactants side is 1 but in products side is 2.

The no. of H atoms in reactants side is 3 but in product side is 2.

So, the equation is not balanced.

Zn(OH)₂ + 2NaOH → Na₂ZnO₂ + 2H₂O.

Zn (1), O (4), H (4), and Na (2).

Answer:8.35

Explanation:first subtract 0.002 by 1.00 witch is 1.002 then divid by 12,00 witch is 8.35

Answer:

Explanation: so a combustion occurs when we react a substance with oxygen .you commonly call this "burning'' .therefore combustion will always include oxygen in the equation and the product will include carbon dioxide and give off water vapours

Therefore the general equation for a complete combustion reaction would be

Fuel + O2 ------ CO2 + H2O

Answer:

Lewis concept

Explanation:

edg

Lewis concept  could be used to define SO[tex]_2[/tex] as a base. Inorganic chemical sulfur dioxide (SO[tex]_2[/tex]) is a heavy, colorless gas.

Inorganic chemical sulfur dioxide (SO2) is a heavy, colorless gas that is very toxic. It is created in enormous amounts during the transitional stages of the production of sulfuric acid. The stench of sulfur dioxide is as strong and unpleasant as that of a freshly struck match.

Sulfur dioxide, which naturally occurs as volcanic gases and also in solution inside the waters of certain warm springs, is often made industrially by burning sulfur or other sulfur-containing compounds like iron pyrite and copper pyrite in air or oxygen. Lewis concept  could be used to define SO[tex]_2[/tex] as a base.

Therefore, lewis concept  could be used to define SO[tex]_2[/tex] as a base.

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Answer:

Glucose

Explanation:

There are two types of respiration:

1. Aerobic respiration  

2. Anaerobic respiration

Aerobic respiration

It is the breakdown of glucose molecule in the presence of oxygen to yield large amount of energy. Water and carbon dioxide are also produced as a byproduct.

Glucose + oxygen → carbon dioxide + water + 38ATP

Anaerobic Respiration

It is the breakdown of glucose molecule in the absence of oxygen and produce small amount of energy. Alcohol or lactic acid and carbon dioxide are also produced as byproducts.  

Glucose→ lactic acid/alcohol + 2ATP + carbon dioxide

This process use respiratory electron transport chain as electron acceptor instead of oxygen. It is mostly occur in prokaryotes. Its main advantage is that it produce energy (ATP) very quickly as compared to aerobic respiration.  

Steps involve in anaerobic respiration are:

Glycolysis

Glycolysis is the first step of both aerobic and anaerobic respiration. It involve the breakdown of one glucose molecule into pyruvate and 2ATP.

Fermentation

The second step of anaerobic respiration is fermentation. It involve the fermentation of pyruvate into lactic acid or alcohol depending upon the organism in which it is taking place. There is no ATP produced in this step, however carbon dioxide is released.

What he said^

Ninja in resting pose

   -_-

-  I   I-

<       >

-Mr. Anon

Answer:

Returning passengers back safely to Earth

Explanation:

Answer: Solid and liquid

Explanation:

An aerosol is a suspension of fine solid particles or liquid droplets, in air or another gas.[1] Aerosols can be natural or anthropogenic. Examples of natural aerosols are fog, dust, forest exudates and geyser steam. Examples of anthropogenic aerosols are haze, particulate air pollutants and smoke.[dubious – discuss][1] The liquid or solid particles have diameters typically <1 μm; larger particles with a significant settling speed make the mixture a suspension, but the distinction is not clear-cut. In general conversation, aerosol usually refers to an aerosol spray that delivers a consumer product from a can or similar container. Other technological applications of aerosols include dispersal of pesticides, medical treatment of respiratory illnesses, and convincing technology.[2] Diseases can also spread by means of small droplets in the breath, also called aerosols (or sometimes bioaerosols).[3]

Aerosol science covers generation and removal of aerosols, technological application of aerosols, effects of aerosols on the environment and people, and other topics.

Aerosols, the atmospheric particles, consist of: D. Solid and liquid

Suspension is a heterogeneous mixture where the solute particles get suspended throughout the bulk of the solvent, then left floating around freely in the medium.

An aerosol is a suspension of fine solid particles or liquid droplets and it is in air or another gas. An aerosol is a gas containing very small particles of a solid or liquid with particle diameters in the range of [tex]10^-9[/tex] to [tex]10^-4[/tex]m.

Aerosols are come from volcanoes, dust storms, fires, vegetation, sea spray, burning of fossil fuels and land use. Primary aerosols are those particles emitted directly into the atmosphere. It is because the different sources of aerosols mix on the earth's surface. Warming aerosols are include black carbon and dark soot. Cooling aerosols include dust, sulfate particles and sea spray.

Aerosols can influence the Earth's climate in two ways. When the sky is clear (devoid of clouds), aerosols can reflect incoming sunlight back to outer space

Therefore aerosols, the atmospheric particles, consist of: Solid and liquid.

Grade:  9

Subject:  chemistry

Chapter:  aerosols

Keywords:   Aerosols, Solid, liquid, Water, the atmospheric particles