Why is a solution not a pure substance?

A) It is made up of two substances that are chemically combined.
B) It is made up of one substance.
C) It is a mixture between a solute and solvent.
D) The solute and solvent cannot be separated.

Answer:

Aluminum

Explanation:

Its the same as the top on but easier to understand

and the top one was approved so.................its right

Answer: [tex]29.37\times 10^{23}molecules [/tex]

Explanation: To calculate the moles, we use the equation:

[tex]\text{Number of moles}=\frac{\text{Given mass}}{\textMolar mass}}[/tex]    

Given mass of ammonia [tex]NH_3[/tex] given = 82.9 g

Molar mass of ammonia [tex]NH_3[/tex] = 17 g/mol

Putting values in above equation, we get:

[tex]\text{Moles of sodium}=\frac{82.9g}{17g/mol}=4.87mol[/tex]

According to Avogadro's law,

1 mole of any substance contains avogadro's number  [tex]6.023\times 10^{23}[/tex] of particles.

Thus 4.87 moles of ammonia contains=[tex]\frac{6.023\times 10^{23}}{1}\times 4.87=29.37\times 10^{23}molecules [/tex] of ammonia.

Explanation:

Ionization energy is defined as the energy necessary to remove an electron from a gaseous atom or ion.

Therefore, smaller is the size of an atom or ion more energy it needs to remove an electron because more is the charge on an ion smaller will be its size.

Hence, more will be the attraction between nucleus and valence electrons of the atom. So, more difficulty is faced by the atom to lose an electron. As a result, ionization energy will increase.

Across the period, there will be decrease in size of elements of the periodic table.

Thus, we can conclude that there will be increase in first ionization energy across the periodic table.

The ocean is much too deep for light to penetrate, thus it cannot reach the bottom of the water. Electromagnetic radiation that the human eye can detect as light.

Electromagnetic radiation that the human eye can detect as light. From radio waves with wavelengths measured in meters to gamma rays with wavelengths shorter than roughly 1 1011 meter, electromagnetic radiation occurs throughout a very broad range of wavelengths.

The wavelengths of light that are visible to humans fall into a relatively small range within that wide spectrum, ranging from about 700 nanometers for red light to roughly 400 nm for violet light. Infrared and ultraviolet are two spectral bands that are close to the visible band and are frequently referred to as light as well. The ocean is much too deep for light to penetrate, thus it cannot reach the bottom of the water.

Therefore, the ocean is much too deep for light to penetrate, thus it cannot reach the bottom of the water.

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Answer:

3.35 g Na2C2O4

Explanation:

They gave us the molarity and the liters of solution so using the relationship (M=mol/V) we can get the moles of solution.

0.250 L (0.100 mol/L) = 0.0250 mol Na2C2O4

Now that we have the moles of sodium oxalate, we can use its molar mass (134 g/mol) to convert to grams.

0.0250 mol (134.0 g/mol) -=3.35 grams (rounded to three sig figs

Approximately 3.35 grams of sodium oxalate (Na2C2O4) are needed to prepare 0.250 L of a 0.100 M solution.

The mass of sodium oxalate (Na2C2O4) needed to prepare a 0.100 M (mol/L) solution in a volume of 0.250 L, we can use the formula:

Mass = molar concentration × molar mass × volume

First, we need to calculate the number of moles of sodium oxalate required:

Number of moles = molar concentration × volume

Number of moles = 0.100 mol/L × 0.250 L

Number of moles = 0.025 mol

The molar mass of sodium oxalate (Na2C2O4) can be calculated as follows:

Molar mass = (2 × atomic mass of sodium) + (2 × atomic mass of carbon) + (4 × atomic mass of oxygen)

Molar mass = (2 × 22.99 g/mol) + (2 × 12.01 g/mol) + (4 × 16.00 g/mol)

Molar mass = 134.03 g/mol

Finally, we can calculate the mass of sodium oxalate needed:

Mass = number of moles × molar mass

Mass = 0.025 mol × 134.03 g/mol

Mass = 3.35 g

Therefore, approximately 3.35 grams of sodium oxalate (Na2C2O4) are needed to prepare 0.250 L of a 0.100 M solution.

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Answer: Rn

Explanation:

The elements in the noble gas family share the property of being extremely unreactive due to their full valence shells. This makes them stable and resistant to forming compounds.

The elements in the noble gas family, also known as Group 8A, share the property of being extremely unreactive. This is because they have a full valence shell of electrons, making them stable and unlikely to form compounds. The noble gases are helium, neon, argon, krypton, xenon, and radon. These gases are characterized by their full outer subshell and large ionization energies, which make them highly stable and resistant to forming chemical bonds.

Noble gases, found in Group 18 of the periodic table, are extremely unreactive due to having a full valence shell of electrons, leading to stable noble gas configurations and high ionization energies. They are gases at room temperature and are used in situations requiring minimal reactivity.

The elements of the noble gas family all share the property of being extremely unreactive, and this is due to each having a full valence shell of electrons. For helium, this means two valence electrons, and for the others, like neon, argon, krypton, xenon, and radon, it is eight valence electrons. The full valence shell makes noble gases very stable and not inclined to participate in chemical reactions that involve the transfer or sharing of electrons. This unique characteristic can be traced to their position in Group 18 (or 8A) of the periodic table, where all elements are gases at room temperature.

Because the noble gases have their outermost electron shell completely filled, they naturally have the most stable electron configuration possible, which is known as a noble gas configuration. Other elements strive to achieve a similar configuration by gaining, losing, or sharing electrons. The full valence shell also means that the noble gases have high ionization energies, which means they do not easily lose electrons, and would only accept an extra electron at a significantly higher and less stable energy level. These properties explain why the noble gases are found in their elemental form in nature and are used in applications where minimal reactivity is desired.

Answer:

Number of moles of hydrogen gas produced is 463.

Explanation:

Mass of hydrogen gas measured by chemist = 926 g

Molar mass of hydrogen gas = 2 g/mol

[tex]Moles=\frac{\text{Given mass of compound}}{\text{Molar mass of compound}}[/tex]

Moles of hydrogen gas:

[tex]\frac{926 g}{2 g/mol}=463 mol[/tex]

Number of moles of hydrogen gas produced is 463.

Iron(III) sulfide reacts with oxygen to produce iron(III) oxide and sulfur dioxide. The reaction can be represented by this balanced chemical equation: 4 Fe2S3(s) + 11 O2(g) -> 2 Fe2O3(s) + 12 SO2(g). This is an example of a combination reaction; a type of redox reaction.

The reaction of solid iron(III) sulfide (Fe2S3) with oxygen gas (O2) produces solid iron(III) oxide (Fe2O3) and sulfur dioxide gas (SO2). The chemical equation representing this reaction is:

4 Fe2S3(s) + 11 O2(g) -> 2 Fe2O3(s) + 12 SO2(g)

In this equation, (s) represents solid, (g) represents gas, and the numbers in front of the chemical formulas are coefficients indicating the number of moles of each substance involved in the reaction. This reaction is an example of a combination reaction, which is a type of oxidation-reduction (or redox) reaction where a substance reacts with oxygen to form oxides.

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To determine the number of oxygen atoms in the given compound, barium nitrate Ba(NO3)2, we can see that in each mole of barium nitrate, there are 6 moles of oxygen atoms in it. In this problem, the correct answer is D.

6 moles of oxygen.

Explanation:

Ba(NO3)2 ,is a composite called 'barium nitrate.' It's also described as 'barium dinitrate.' Ba(NO3)2 is created up of atoms of barium (Ba), nitrogen (N) and oxygen (O). Barium nitrate is the inorganic compound with the chemical equation Ba(NO3)2. It, like most barium salts, is transparent, toxic, and water-soluble. It fires with a green flame and is an oxidizer, it is practiced in pyrotechnics.

The reaction is likely exothermic as bond formation is usually accompanied by release of energy. However, without enthalpy values of the reactants and products, it is hard to definitively classify the reaction.

The reaction stated, mg²⁺(aq) + h₂o(l) → mgo(s) + 2h⁺(aq), does not directly tell us whether it's endothermic or exothermic. However, we can try to infer the nature of the reaction based on general principles. Endothermic reactions usually involve the breaking of bonds, which requires energy, whereas exothermic reactions involve the formation of new bonds, which usually releases energy. By looking at the equation, it can be inferred that a bond formation (MgO) is taking place and energy likely being released, which suggests that the reaction is exothermic. However, without specific enthalpy values of the reactants and products, it would be hard to definitively classify the reaction as endothermic or exothermic.

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Mole measure the number of elementary entities of a given substance that are present in a given sample. Therefore, 78 g of aluminum were oxidized.

The SI unit of amount of substance in chemistry is mole. The mole is used to measure the quantity or amount of substance. We know one mole of any element contains 6.022×10²³ atoms which is also called Avogadro number. Stoichiometry represents the number of moles.

4 Al + 3 O[tex]_2[/tex]→ Al[tex]_2[/tex]O[tex]_3[/tex]

moles of aluminium oxide = 77 g/101.96

moles of aluminium oxide=0.75moles

The mole ratio of aluminium oxide to aluminium is 1:3

moles of aluminium= 4×0.75moles

moles of aluminium= 3 moles

mass of aluminium = moles × molar mass

mass of aluminium= 3 ×26

mass of aluminium = 78 g

Therefore, 78 g of aluminum were oxidized.

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The molarity of the NaCl solution is calculated to be 0.0685 M.

To calculate the molarity of the solution, we need to determine the number of moles of NaCl dissolved in the solution. First, we convert 400 mg of NaCl to grams:

400 mg = 0.400 g

Using the molar mass of NaCl (58.44 g/mol), we find the number of moles:

Number of moles = 0.400 g / 58.44 g/mol ≈ 0.00685 moles

The volume of the solution is 100 mL, which we convert to liters:

Volume in liters = 100 mL / 1000 mL/L = 0.1 L

Finally, we calculate the molarity (M) of the solution:

Molarity (M) = Number of moles / Volume in liters = 0.00685 moles / 0.1 L = 0.0685 M

Therefore, the molarity of the NaCl solution is 0.0685 M.

Answer:

upper right of the periodic table

1. The formula for absorbance is given as:

A = log (Io / I)

where A is absorbance, Io is initial intensity, and I is final light intensity

log (Io / I) = A

log (Io / I) = 2

Io / I = 100

Taking the reverse which is I / Io:

I / Io = 1 / 100

I / Io = 0.01

Therefore this means that only 0.01 fraction of light or 1% passes through the sample.

2. What is meant by transmittance values is actually the value of I / Io. So calculating for A:

at 10% transmittance = 0.10

A = log (Io / I)

A = log (1 / 0.10)

A = 1

at 90% transmittance = 0.90

A = log (Io / I)

A = log (1 / 0.90)

A = 0.046

So the absorbance should be from 0.046 to 1

3. at 10% transmittance = 0.10

A = log (Io / I)

A = log (1 / 0.10)

A = 1

Final answer:

A neutral magnesium (Mg) atom, with atomic number 12, has 2 electrons in its outermost shell.

Explanation:

The atom with atomic number 12 is magnesium (Mg), and according to its electronic configuration, it has 12 electrons.

In a neutral magnesium atom, the first shell (1s) is filled with 2 electrons, the second shell (2s and 2p) contains a total of 8 electrons, and the third and outermost shell has 2 electrons, as expressed in the electronic configuration of Mg (1s²2s²2p¶3s²).

Therefore, the number of electrons in the outermost electron shell of an atom with atomic number 12 would be 2.

To change from a solid to a gas, particles must gain sufficient energy to overcome intermolecular forces, a process known as sublimation when it occurs directly, or through melting and evaporation in two steps. This significantly increases the substance's volume. Sublimation and deposition are energy-involving phase transitions affected by temperature and pressure changes.

To change from a solid to a gas, particles need to gain enough energy to overcome their intermolecular interactions and disperse throughout the available space. This increase in energy allows the particles to move from a closely packed structure to one where they move about randomly and independently. This process is known as sublimation when a solid turns directly into a gas without passing through the liquid phase. However, typically a solid will first melt into a liquid and then the liquid will evaporate into a gas. This is achieved through the addition of energy, which can come from heat, for example.

The characteristic increase in volume that accompanies this transition is considerable. During the transition from liquid to gas especially, the volume of a substance can increase by a factor of 1,000 or more. Sublimation and the reverse process, deposition (where a gas becomes a solid directly), are facilitated by changes in temperature and pressure, and these phase transitions are both isothermal and involve a measurable change in energy.

At the molecular level, each state of matter—solid, liquid, gas—has different properties. Solids have particles in a fixed arrangement, while in liquids particles are still in contact but can move past one another. The gas phase is a state in which particles are separated by large distances relative to their size and move independently in a container, expanding to fill its shape and volume.