Why is copper a pure substance? a. because it is an element b. because it is a compund c. because it is a homogenous mixture

Answer:

black.

Explanation:

I like seeing myslef, so therefore with black eyes I would be seeing my reflection

Answer:

The stigma on the underside of the leaf allows Gas and Water Vapour to move in and out of the leaf

The unbalanced equations are the equations with different atomic numbers on the sides of the reaction. The unbalanced reaction is Na + Cl₂ → NaCl

Balanced equations are the chemical reaction representation that has an equal number of the atomic number of the same species on the left and the right side of the reaction.

An unbalanced equation between sodium metal and chloride can be shown as:

Na + Cl₂ → NaCl

The equation is unbalanced as the number of chloride ions is more on the reactant side than the product side.

The balanced reaction will be:

2 Na + Cl₂  2NaCl

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Answer:this air polluction here.

Explanation:

air and soil polluction

Answer:

The oceans obtained freshwater from glaciers melting. The freshwater was then trapped into small places below waves, which could be a reason why there is not much freshwater in the world.

Answer:

b

Explanation:

is the dictionary definition of a word.

is the feeling or idea associated with a word.

[tex]\qquad\qquad\huge\underline{{\sf Answer}}[/tex]

Cations are ions that has a positive charge on it, and since it's a positive charge, it means that the ion has more protons than the number of electrons.

On the same contray, Anions are negatively charged particles having more electrons than protons in it, and hence bearing a negative charge.

property : non - alike ions attract each other by electrostatic force.

Answer:

Cations are positively-charged ions.

Anions are negatively-charged ions.

The best explanation would be that the temperature of the gas has dropped before measuring the pressure.

According to pressure law, the pressure of a gas is directly proportional to its temperature, provided the volume of the gas remains constant.

Thus, since the initial pressure of the gas was calculated to be 7.5 atm, the temperature of the gas must have dropped in order for the measured pressure to be 7.1 atm.

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The maximum mass of NH₃ that can be formed when 36.52 g of N₂ reacts with 10.62 g of H₂ is 44.35 g

N₂ + 3H₂ —> 2NH₃

Molar mass of N₂ = 14 × 2 = 28 g/mol

Mass of N₂ from the balanced equation = 1 × 28 = 28 g

Molar mass of H₂ = 2 × 1 = 2 g/mol

Mass of H₂ from the balanced equation = 3 × 2 = 6 g

Molar mass of NH₃ = 14 + (3×1) = 17 g/mol

Mass of NH₃ from the balanced equation = 2 × 17 = 34 g

SUMMARY

From the balanced equation above,

28 g of N₂ reacted with 6 g of H₂ to produce 34 g of NH₃

From the balanced equation above,

28 g of N₂ reacted with 6 g of H₂

Therefore,

36.52 g of N₂ will react with = (36.52 × 6) / 28 = 7.83 g of H₂

From the above calculation, we can see that only 7.83 g out of 10.62 g of H₂ are required to react completely with 36.52 g of N₂.

Therefore, N₂ is the limiting reactant

From the balanced equation above,

28 g of N₂ reacted to produce 34 g of NH₃

Therefore,

36.52 g of N₂ will react to produce = (36.52 × 34) / 28 = 44.35 g of NH₃

Thus, the maximum mass of NH₃ obtained from the reaction is 44.35 g

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Answer:

Partial pressure of O2 = 4.93 atm

Explanation:

PV = n RT        R = .082057 L-atm/mol-K

n = 6.3 + 8.15 = 14.45 moles

348 C = 621.15 K

P (65.1) = 14.45 ( .082057)(621.15) = 11.31 atm

Now the fraction of pressure from Oxygen is

   6.3 / (6.3+8.15)  * 11.31 = 4.93 atm

Ideal gas law states

V is volume (L), P is pressure (atm), R is universal gas constant: 0.0821 L·atm/mol· K, n is number of moles, T is temperature in Kelvin

Here given:

[tex]\blacksquare[/tex] mass of O₂ : 100 gram

[tex]\blacksquare[/tex] moles: mass/molar mass = 100/32 = 3.125 moles

[tex]\blacksquare[/tex]  25.0 °C = (25+273.15) = 298.15 K

[tex]\blacksquare[/tex]  pressure: 1.25 atm

Volume:

[tex]\boxed{\sf V=\dfrac{nRT}{P}}[/tex]

[tex]\Rightarrow \sf V=\dfrac{(3.125 \ x \ 0.0821 \ x \ 298.15 )}{1.25}[/tex]

[tex]\Rightarrow \sf V=61.195 \ L[/tex]

[tex]\Rightarrow \sf V=61.2 \ L \ \ \ (rounded \ to \ nearest \ tenth)[/tex]

Additional Explanation:

In Liters: 61.2 Liters

In cubic meter: 0.061163 m³

In cubic centimeter: 61,163.5 cm³

Let's see

moles of CO_2

Mass of CO_2

ANSWER

B po yung ans:)

Considering Gay-Lussac's law, a gas exerts a pressure of 4.00 atm at 1,092 K.

Gay-Lussac's law states that the pressure of a gas is directly proportional to its temperature: when there is a constant volume, as the temperature increases, the pressure of the gas increases. And when the temperature is decreased, gas pressure decreases.

Gay-Lussac's law can be expressed mathematically as follows:

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

where P= pressure, T= temperature, k= Constant

This law states that the ratio of pressure to temperature is constant.

Studying an initial state 1 and a final state 2, it is fulfilled:

[tex]\frac{P1}{T1}=\frac{P2}{T2}[/tex]

In this case, you know:

Replacing in Gay-Lussac's law:

[tex]\frac{1 atm}{273 K}=\frac{4 atm}{T2}[/tex]

Solving:

[tex]T2\frac{1 atm}{273 K}=4 atm[/tex]

[tex]T2=\frac{4 atm}{\frac{1 atm}{273 K}}[/tex]

T2= 1,092 K

Finally, a gas exerts a pressure of 4.00 atm at 1,092 K.

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After acid was added to the solution and the hydronium ion concentration becomes 100 times greater, the pH of the new solution is 5.

The pH of a solution is defined as the logarithm of the reciprocal of the hydrogen ion concentration  [H+] of the given solution.

It is expressed as;

pH = -log[ H⁺]

Given that;

pH = -log[ H⁺]

H⁺ = 10^( -pH )

H⁺ = 10^( -7 )

H⁺ = 10⁻⁷

When acid is added to the solution, the hydronium ion concentration becomes 100 times greater.

H⁺ = 10⁻⁷ × 100

H⁺ = 10⁻⁵

pH of the new solution will be;

pH = -log[ H⁺ ]

pH = -log[ 10⁻⁵ ]

pH = 5

Therefore, after acid was added to the solution and the hydronium ion concentration becomes 100 times greater, the pH of the new solution is 5.

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Answer:

1. We get the symbol and formulas of the reactants and products.

2. The physical state of the reactants and products.

3. From this reaction, we can know the molecular formula of ammonia, water and nitrogen.

4. Here all the species are in a gaseous state.

5. The reaction takes place at a high temperature and pressure.

6. Zinc metal reacts with dilute sulphuric acid to form zinc sulphate and hydrogen gas. This equation is written as:

Zinc metal reacts with dilute sulphuric acid to form zinc sulphate and hydrogen gas. This equation is written as: Zn+H2SO 4→ZnSO 4 +H2.

The spectrum of the first compound will have only one signal, but the spectrum of the second compound will have two signals.

A compound is a substance formed by combining two or more different chemical elements in such a way that the atoms of the individual elements are linked together by chemical bonds that are difficult to break in chemistry.

Hence it is right to state that the spectrum of the first compound will have only one signal, but the spectrum of the second compound will have two signals.

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Answer:

1.Ecologists often estimate the size and density of. populations using quadrats and the mark-recapture method.

2. The two key components of ecosystem stability are resilience and resistance.

3.The availability of abiotic factors (such as water, oxygen, and space) and biotic factors (such as food) affect population

4. When the climate is changing in the colder direction it effects the planet in the opposite way than it does when it is changing in the warmer direction. Ad nauseam the contemporary, it’ll keep getting hotter and at a greater rate so the ecosystem is going to die.

The phase of water at 0.5 atm and 100°C is gaseous phase.

Water exists in three different phases such as liquid, gas, and solid.

The phase of the given water can be determined using phase diagram at standard temperature and pressure as shown in the image uploaded.

At 0.5 atm and 100 °C, the water is still in vapour or gaseous phase.

Thus, the phase of water at 0.5 atm and 100°C is gaseous phase.

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Considering the Hess's Law, the desired enthalpy is obtained through adding intermediate reactions together. (option D)

Hess's law, also called Law can also be called Law of additivity of the enthalpies of reaction, it is a useful method when it is not possible to calculate the enthalpies of reaction from the enthalpies of formation, or in reactions in which the reaction enthalpy cannot be determined experimentally because it is very slow or very explosive.

Hess's law states that when reactants are converted to products, the enthalpy change is the same whether the reaction takes place in one step or in a series of steps.

In this way, Hess's Law determines that when a chemical reaction can be expressed as an algebraic sum of other reactions, its reaction enthalpy is equal to the sum of the enthalpies of the partial reactions. In this way, it allows thermochemical equations to be treated as algebraic equations, and can be added, subtracted, or multiplied by a number to find the desired thermochemical equation.

Hess's Law states that the sum of the ∆H of each stage of the reaction will give us a value equal to the ∆H of the reaction when it occurs in a single stage.

That is, the desired enthalpy is obtained through adding intermediate reactions together. (option D)

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Glutamic amino acid is the non-essential amino acid and an excitatory neurotransmitter. When Glu is found in the core then the pKa of the side chain group increases.

pKa is the acid strength or the estimate that shows whether the solution is weak or strong acid. pKa less than zero is a strong acid and portrays the bonding of the proton by the acids.

In the Glu amino acid, the value of the pKa of the side chain functional groups increases as the amino acid is found in the interior of the water-soluble folded protein structure.

Therefore, the pKa of the side-chain increases.

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Answer:

on-skin silicone, liquid latex, and gelatine

Explanation:

hope this helps:)

The amount of [tex]Al_2O_3[/tex] that would be formed will be 44.59 grams

From the equation of the reaction:

[tex]4Al + 3O_2 --- > 2Al_2O_3[/tex]

The mole ratio of Al to  [tex]Al_2O_3[/tex] is 2:1

Mole of 23.6 g Al = 23.6/26.98 = 0.87 moles

Equivalent mole of  [tex]Al_2O_3[/tex] = 0.87/2 = 0.44 moles

Mass of 0.44 mole  [tex]Al_2O_3[/tex] = 0.44 x 101.96 = 44.59 grams

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Answer:

You will need a Kukushili pressure cooker for this experiment. This pressure cooker will allow you to compress the gases and observe its volume.

sink: w cube+w sand>Fb(buoyant force)

w cube = massless = 0

w sand>Fb

w sand > 1000 x 10 x (11/100)³

w sand > 13.31 N

ρgV sand > 13.31

3.5 x 10³ x 10 x V sand > 13.31

V sand = 13.31 : 3.5 x 10⁴ = 3.803 x 10⁻⁴ m³ = 380.3 cm³  

…Answer:

Explanation:

Answer:

299.60 g

Explanation:

Use the formula q = mCΔT (q= heat, m= mass, c = specific heat for that specific substance, ΔT is change in temperature Final Temp - Initial Temp)

Released heat means it has negative sign.

q = mCΔT

-2744 = (mass) (0.129) (19-90)

mass= 299.60 g