What is the dependent variable? Be specific. *
If a teacher washes the tops of the student
desks with rubbing alcohol daily, the
spread of germs in the classroom may be
diminished.Be specific when you write your answer HELPPPPP I NEED IT ASAP!

Answer:

major ecological grouping of plants and animals

food chain

*biome*

bacteria and fungi that break down dead matter

*decomposers*

a state of change in which the end result is equal or

balanced

*dynamic equilibrium*

the basic relationships that show how a community of plants,

animals, and bacteria live and grow and how these living

*ecosystem*

things are dependent on each other as well as the Sun, soil,

and other nonliving parts of their environment; a cycle of

relationships

line of plants and animals that shows the order in which

*Food chain*

organisms are eaten

a condition or conditions of the nonliving surroundings, such

*environmental factor*

Explanation:

This question is incomplete, the complete question is;

Tonksite is a solid at 300.00K.  At 300.00 K its enthalpy of sublimation is 66.00 kJ/mol. The sublimation pressure at 300.00 K is 5.00 × 10⁻⁴ atm

Calculate the sublimation pressure of the solid at the melting point of 400.00 K assuming that the enthalpy of sublimation is not a function of temperature.

Answer: the sublimation pressure of the solid at the melting point is  0.3727 atm

Explanation:

Given that;

T1 = 300 K

T2 = 400 K

H_sub = 66 kJ/mol = 66000 J/mol

P1 = 5.00 × 10⁻⁴ atm

p2 = ?

now using the expression

log( p2 / 5.00 × 10⁻⁴ ) = (H_sub / R ×  2.303 ) (( T2 - T1) / T1T2)

now we substitute of given values into the expression

log(p2/p1) = (66000 / 8.314 ×  2.303 ) (( 400 - 300) / 300 × 400 )

p2 = 0.3727 atm

therefore the sublimation pressure of the solid at the melting point is  0.3727 atm

Answer:

atom

Explanation:

the atom is the smallest form.

Answer : The number of moles of precipitate, [tex]PbBr_2[/tex] formed will be 0.01 moles.

Explanation : Given,

Concentration of NaBr = 0.200 M

Volume of solution = 100.0 mL = 0.1 L      (1 L = 1000 mL)

First we have to calculate the moles of NaBr.

[tex]\text{Moles of NaBr}=\text{Concentration of NaBr}\times \text{Volume of solution in L}[/tex]

[tex]\text{Moles of NaBr}=0.200M\times 0.1L=0.02mol[/tex]

Now we have to calculate the moles of precipitate, [tex]PbBr_2[/tex] formed.

The balanced chemical reaction is:

[tex]2NaBr(aq)+Pb(NO_3)_2(aq)\rightarrow PbBr_2(s)+2NaNO_3(aq)[/tex]

From the balanced chemical reaction we conclude that:

As, 2 moles of NaBr react to give 1 mole of [tex]PbBr_2[/tex]

So, 0.02 moles of NaBr react to give [tex]\frac{0.02}{2}=0.01[/tex] mole of [tex]PbBr_2[/tex]

Therefore, the number of moles of precipitate, [tex]PbBr_2[/tex] formed will be 0.01 moles.

The number of mole of the precipitate (i.e PbBr₂) formed when 100 mL of 0.2 M NaBr react with excess Pb(NO₃)₂ is 0.01 mole

Volume = 100 mL = 100 / 1000 = 0.1 L

Molarity of NaBr = 0.2 M

Mole = Molarity x Volume

Mole of NaBr = 0.2 × 0.1

2NaBr(aq) + Pb(NO₃)₂(aq) → PbBr₂(s) + 2NaNO₃ (aq)

From the balanced equation above,

2 moles of NaBr reacted to produce 1 mole of PbBr₂.

Therefore,

0.02 mole of NaBr will react to produce = [tex]\frac{0.02}{2} \\\\[/tex] = 0.01 mole of PbBr₂.

Thus, the number of mole of the precipitate (i.e PbBr₂) produced from the reaction is 0.01 mole

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Answer:

[tex]T=2.78x10^3 \°C[/tex]

Explanation:

Hello,

In this case, considering that the safe temperature may be computed via the ideal gas law as we now the pressure, mass and volume via the dimensions:

[tex]V=\pi r^2 h=\pi *(41.0cm)^2*49.2cm=2.60x10^5cm^3*\frac{1L}{1000cm^3} =260L[/tex]

The pressure in atm is:

[tex]P=3.70MPa*\frac{1x10^6Pa}{1MPa} \frac{1atm}{101325Pa} =36.5atm[/tex]

And the moles considering the mass and molar mass (66 g/mol) of dinitrogen difluoride (N₂F₂):

[tex]n_{N_2F_2}=2.50kg*\frac{1000g}{1kg}*\frac{1mol}{66g} =37.9mol[/tex]

In sich a way, by applying the ideal gas equation, which is not the best assumption but could work as an approximation due to the high temperature, the temperature, with three significant figures, will be:

[tex]T=\frac{PV}{nR}=\frac{36.5Pa*260L}{37.9mol*0.082\frac{atm*L}{mol*K} }\\ \\T=3053.6K-273.15\\\\T=2.78x10^3 \°C[/tex]

Best regards.

Answer:

A

Explanation:

Slow cooling of magma beneath the surface of earth

To solve this we must be knowing each and every concept related to rock and its formation. Therefore, the correct option is option A among all the given options.

Rock is a naturally occurring mineral aggregate that is cohesive and composed of one or even more minerals. These aggregates often take the shape of recognisable and mappable volumes and are the fundamental building block of the solid Earth.

Mineral crystals as well as the sorts of rocks that serve as their hosts cycle through many forms as geologic materials. Temperature, weight, time, and variations in the climate in the Earth's crust and on its surface all play a role in the process. Slow cooling of magma beneath the surface of Earth is the  statement that best describes the formation of rock.

Therefore, the correct option is option A.

To learn more about rock, here:

https://brainly.com/question/29767269

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Answer:

true

Explanation:

hope it helps

Answer:

I'm pretty sure it's true

Explanation:

20 characters

Answer:

2.28 atm

Explanation:

V₁ = 2.33L,  V₂ = 1.08L

T₁ = 289K,  T₂ = 304K

P₁ = 1.05 atm, P₂ = ?

Where V₁ and V₂ are initial and final volume respectively

T₁ and T₂ are initial and final temperature respectively

P₁ and P₂ are initial and final pressure respectively

The formula to be used here is the general gas equation:

P₁V₁/T₁=P₂V₂/T₂

1.05 × 2.23/289 = P₂ × 1.08/304

P₂ × 1.08 × 289 = 1.05 × 2.23 × 304

P₂ = (1.05 × 2.23 ×304) ÷ (1.08 × 289)

P₂ = 711.82 ÷ 312.12

P₂ = 2.28 atm

Answer:

Salinity, along with temperature, determines the density of seawater, and hence its vertical flow patterns in thermohaline circulation. 2. Salinity records the physical processes affecting a water mass when it was last at the surface. Hope this helps!

Explanation:

Answer:

Percent error = 3.7%

Explanation:

Given data:

Density of Al cylinder = ?

Weight of cylinder = 18 g

Diameter = 1.3 cm

Height = 5.2 cm

Actual density of Al = 2.7 g/cm³

Percent error = ?

Solution:

First of all we will calculate the volume of cylinder through given formula.

V = πr²h

r = diameter /2

V = 22/7 × (0.65 cm)²× 5.2 cm

V = 22/7 × 0.4225cm²× 5.2 cm

V = 6.89 cm³

Now we will calculate the density.

d = m/v

d = 18 g/ 6.89 cm³

d = 2.6 g/cm³

Percent error:

Percent error = measured value - actual value /actual value × 100

Percent error = 2.6g/cm³ - 2.7g/cm³ /2.7g/cm³  × 100

Percent error = 3.7%

Negative sign shows that measured or experimental value is less than actual value.

Answer:

C. molten rock below Earth’s surface

Explanation:

Answer:

Explanation:

Silk and wool

Answer:

silk and wool fibers are obtained from animals ​

Explanation:

good luck :)

Answer:

A catalytic converter changes nitrogen dioxide to nitrogen gas and oxygen gas is a chemical change.

Explanation:

Hello.

In this case, since physical changes do not modify the molecular composition and structure of the material undergoing it whereas the chemical change does, for catalytic converters we should know they promote chemical reaction in which the composition is changed; for instance, for the given example, the following chemical reaction is the evidence:

[tex]2NO_2\rightarrow N_2+O_2[/tex]

As you can see, nitrogen and oxygen are no longer bonded but separated by themselves, therefore, this is a chemical change.

Best regards.

Answer:

Kps = 3.07 x 10⁻⁸

pKsp= 7.51

Explanation:

First, we calculate the molar solubility of  silver(I)phosphate (Ag₃PO₄) from the solubility in g/L by using its molar mass (418.6 g/mol):

2.43 g/L x 1 mol/418.6 g = 5.8 x 10⁻³ mol/L= s

Now, we have to write the ICE chart for the aqueous equilibrium of Ag₃PO₄ as follows:

     Ag₃PO₄(g) ⇄ 3 Ag⁺(aq) + PO₄³⁻

I                               0              0

C                            +3s           +s

E                            3s               s

Ksp = [Ag⁺]³[PO₄³⁻]= (3s)³s= 27s⁴

Since s=5.8 x 10⁻³ mol/L, we calculate Ksp:

Ksp= 27(5.8 x 10⁻³ mol/L)⁴= 3.07 x 10⁻⁸

The pKsp value is:

pKsp= - log Ksp = -log (3.07 x 10⁻⁸) = 7.51

Answer:

C6H1206

Explanation:

C6H12O6 is a monomer of carbohydrates also known as glucose, so it is not an electrolyte at all.

Explanation:

Preciptation and air pressure

Answer:

It is Temperature and humidity. C

Explanation:

I took the test and it said it was C

Answer:

Which one of the table is element X?

Explanation:

I have no idea and help!!!!!!!!!!!!!!!!!!!!!!!!!

Answer: a) A decrease in the solubility of an ionic compound as a result of the addition of a common ion : Common ion effect

b) The mass of a salt in grams that will dissolve in 100 mL of water: Solubility

c) A solution that has dissolved the maximum amount of a compound at a given temperature. Any further addition of salt will remain undissolved: Saturated solution

d) The product of the molarities of the dissolved ions, raised to a power equal to the ion's coefficient in the balanced chemical equation : Solubility product constant

e) The maximum number of moles of a salt that will dissolve in 1 L of solution : Molar solubility

Explanation:

Solubility is expressed usually as the mass of solute per 100 grams or 100 ml of solvent.

Molar solubility of a solid is expressed as the concentration of the dissolved solid in a saturated solution.

Solubility product constant is defined as the equilibrium constant in which a solid ionic compound is dissolved to produce its ions in solution. It is represented as [tex]K_{sp}[/tex]

The common-ion effect is the decrease in solubility of a sparingly soluble salt by the addition to the solution of a soluble compound with an ion in common with the precipitate.

Saturated solution is defined as the solution in which no more solute particles can be dissolved in the solvent.

Answer:

The equilibrium concentration of [CH₃NH₂] = 0.23965 M.

The equilibrium concentration of CH₃NH₃⁺ and  OH⁻ =  0.01035 M respectively.

Explanation:

The first step is to write out the dissociation reaction. Therefore, the equation showing the dissociation is given as below;

CH₃NH₂ + H₂0   <--------------------------------------------------------> CH₃NH₃⁺ + OH⁻.

Kindly note that ''<----------->'' arrow shows that the reaction is an equilibrium reaction.

Therefore, at the start of the reaction [that is time, t =0], we have that the concentration of CH₃NH₂ = 0.25M, thus, the concentration of CH₃NH₃⁺  and  OH⁻ is zero respectively at this time, t =0.

At equilibrium, the concentration of CH₃NH₂ = 0.25M - x, thus, the concentration of CH₃NH₃⁺  and  OH⁻ is x respectively.

Therefore, kb =  4.47 × 10-4 = [CH₃NH₃⁺ ][OH⁻]/[CH₃NH₂].  Hence, slotting in the values into this equilibrium equation showing the relationship between kb and concentration of the species involved, we have that;

kb = 4.47 × 10⁻⁴ = x² /0.25 - x.

x² +  4.47 × 10⁻⁴x - 1.1175  × 10⁻⁴ = 0.

Solving this quadratic equation gives us the value of x as 0.01035 M.

Thus, the concentration of [CH₃NH₂] = 0.25 M - 0.01035 M = 0.23965 M

The equilibrium concentration of [CH₃NH₂] = 0.23965 M.

The equilibrium concentration of CH₃NH₃⁺ and  OH⁻ =  0.01035 M respectively.

Answer:

swap

Explanation: because it is a low wet land

Answer:

4.   swamp

5.   Island

Plz mark brainliest:)

Answer:

1) No

2) The solvent contaminated the analyte

3) The solvent should be evaporated properly before washing and drying the analyte

Explanation:

During separation of organic compounds, solvents are used. These solvents are able to contaminate the analyte and lead to a large difference in melting point of solids obtained.

However, the error can be minimized by evaporating the solvent before washing, drying and melting point determination of the solid.

Answer:

1) Increases

2) decreases

3) increases

4) decreases

Explanation:

When the intermolecular forces in a liquid increases, the greater vapour pressure of the liquid decreases accordingly.

Since the vapour pressure is proportional to temperature, as temperature increases, the vapour pressure increases alongside.

As intermolecular forces increases, the boiling point increases accordingly since more energy is required to break intermolecular bonds.

Lastly, the greater the surface area, tell greater the vapour pressure since more liquid surface area is now available.

Answer:  Since, the given weight of methane is 16 g, hence the water produced by the combustion of 16 g of methane is 36 g.

Explanation: Have a blessed day!

Answer: do not know how to answer this

Explanation:

Answer:I think it would be the third one.

Explanation:

Answer:

6.25e-6 is the value of the equilibrium constant

Explanation:

we have this equation

[tex]PbBr(s) ----- Pb^{2+}(aq) + 2Br(aq)[/tex]

When at a state of equilibrium,

we have the concentration of Pb^2+ to be 0.01

we have the concentration of Br^- to be 0.025

the equilibrium constant concentration of both pure solids and liquid s are said to be equal to 1

[PbBR2] = 1

such tht

Keq = [Pb^2+] x [Br-]^2

we already know the values of these from the above.

0.01x0.025^2

= 0.01 x 0.000625

= 0.00000625

= 6.25 x 10^-6

= 6.25e^-6

Answer: The answer is D.

Explanation:

The form of energy associated with the motion, position, or shape of an object is called mechanical energy. An object's mechanical energy is a combination of its potential energy and its kinetic energy. The basketball has both potential energy and kinetic energy.

Hope this helps!