Answer:
0.
Explanation:
All elements existing on their own in their free states has an oxidation number of 0.
The oxidation number of Se in Se8 is 0. The element Se in its elemental state has an oxidation number of 0.
Chemistry uses the idea of oxidation number, also known as oxidation state, to describe the charge that an atom seems to have when it forms a compound or ion. It is a notion that aids in our comprehension of how electrons are distributed within a molecule or ion. Oxidation numbers can be used to balance chemical equations and identify the many kinds of chemical reactions that may take place. For a better understanding of the reactivity and bonding of various elements in compounds, they offer insights into the transfer or sharing of electrons between atoms. Se in Se8 has an oxidation number of 0. Se has an oxidation number of 0 when it is in its purest form.
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Dinitrogen tetraoxide, a colorless gas, exists in equilibrium with nitrogen dioxide, a reddish brown gas.
One way to represent this equilibrium is:
N2O4(g)----------> 2NO2(g)
<----------
Indicate whether each of the following statements is true or false
At equilibrium at a fixed temperature, we can say that:
1. The concentration of NO2 is equal to the concentration of N2O4.
2. The rate of dissociation of N2O4 is equal to the rate of formation of N2O4.
3. The rate constant for the forward reaction is equal to the rate constant of the reverse reaction.
4. The concentration of NO2 divided by the concentration of N2O4 is equal to the same constant (regardless of initial concentrations)
Explanation:
N2O4(g) <----------> 2NO2(g)
Before proceeding,
A chemical equilibrium can be defined as a condition in the course of a reversible chemical reaction in which no net change in the amounts of reactants and products occurs.
Statement 1.
This statement is false. Equilibrium is not about equal concentrations but rather zero change in concentration of the reactants and products.
Statement 2.
This statement is True in chemical equilibrium; the forward and reverse reactions occur at equal rates.
Statement 3.
This statement is False. The rate constant for the forward reaction is not equal to the rate constant of the reverse reaction.
Statement 4.
The concentration of NO2 divided by the concentration of N2O4 is NOT equal to a constant. To obtain a constant value irregardless of the concentrations, the concentration of NO2 must be squared. This comes from the stoichiometry of the reaction
Kc= [NO2]2 / [N2O4]
This statement is false.
Why Graphite is Diamagnetic?
Answer: Through years of studying and research ;
Graphite has shown that in weak and quantizing magnetic fields it is material is a highly anisotropie diamagnetic substance whose non-oscillating part of the magnetic suscepti- bility weakly depends on magnetic field.
Explanation:
Diamagnetism is a (very) weak form of magnetism which is caused (induced) by a change in the orbital motion of electrons mostly due to an applied magnetic field.
Identify which of the following are carbohydrates.
Check oh that apply
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.
What are carbohydrates?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.
First given compound is not a carbohydrates as in that NH₃ group is present.Second given compound is also not a carbohydrate as in that carboxylic (-COOH) group is present.Third compound is a carbohydrate as in that compound same number of carbon and oxygen atoms are present and number of hydrogen atom is double to C & O atom.Fourth compound is also not a carbohydrate, as in that molecule number of carbon and oxygen atom is same but number of hydrogen is not double with respect to C & O.Hence compound C is carbohydrate.
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if 2.22 moles of ammonia (NH3) decomposes according to the reaction shown how many moles of hydrogen (H2) are formed?
Answer:
five(5) hydrogen are formed
Which element's neutral atoms will have the electron configuration
1s22s22p3s23p'?
a. boron
b. carbon
c. silicon
d. aluminum
Answer:
Alumunium
Explanation:
Alumunium = [Ne] 3s² 3p¹
Ne = [He]2s²2p⁶
He = 1s
Alumunium = 1s 2s²2p⁶3s² 3p¹
Answer:
D
Explanation:
which factor is most responsible for the fact that water is a liquid rather than a gas at room temperature
The answer is Hydrogyn bonding. It keeps the water molocules bonded together and in a liquid state, without it it'd be in a gashious state.
Answer:Hydrogen bonds keep them together in room temperature, hope this helps!
Explanation:
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what is the molarity of a solution that contains 49.8 grams of nai and is dissolved in enough water to make 1.50 liters
Answer: The molarity of solution is 0.221 M
Explanation:
Molarity of a solution is defined as the number of moles of solute dissolved per liter of the solution.
[tex]Molarity=\frac{n}{V_s}[/tex]
where,
n = moles of solute
[tex]V_s[/tex] = volume of solution in L
moles of [tex]NaI[/tex] = [tex]\frac{\text {given mass}}{\text {Molar mass}}=\frac{49.8g}{149.89g/mol}=0.332mol[/tex]
Now put all the given values in the formula of molality, we get
[tex]Molarity=\frac{0.332mol}{1.50L}[/tex]
[tex]Molarity=0.221mol/L[/tex]
Therefore, the molarity of solution is 0.221 M
Based on the type or types of intermolecular forces, predict the substance in each pair that has the higher boiling point Given the molecules propane (C3H8) and n-butane (C4H10)_________ has the higher boiling point mainly due to_______ Given the molecules diethyl ether (CH3 CH2OCH2 CH3) and 1-butanol (CH3 CH2CH2 CH2OH) higher boiling point mainly due to______________ .
Answer:
See explanation
Explanation:
-) Given the molecules propane (C3H8) and n-butane (C4H10) n-butane has the higher boiling point mainly due to a larger chain of carbons.
In this question, in propane, we have a chain of three carbons. In butane, we have fourth carbons. If we have more carbons we will have more interactions. If we have more interactions we have to give more energy to go from liquid to gas, therefore we will have a higher boiling point.
-) Given the molecules diethyl ether (CH3 CH2OCH2 CH3) and 1-butanol (CH3 CH2CH2 CH2OH) 1-butanol has a higher boiling point mainly due to hydrogen bonding.
In the case of butanol, we have the "OH" group. If we have a hydrogen bond to a heteroatom (O, S, P, or N) we will have the presence of this type of interaction between molecules. If we have more interactions we have to give more energy to go from liquid to gas, therefore we will have a higher boiling point.
I hope it helps!
when dissolved in water, an acid or a base breaks down into a. a proton and an electron b. two negative ions c. a positive and a negative ion d. a positive ion and a proton
Answer:
C. A positive and a negative ion
Explanation:
Acids and bases are made up of charged particles known as ions. The ions present in acids are oppositely charged and are held together by strong electrostatic forces. When acids or bases are dissolved in water, the electrostatic forces holding their individual molecules together are weakened and these ions are free to move apart in a process known as dissociation. Dissociation occurs because of the attraction between the positive and negative ions in the acid and bases and the negative and positive polarity of water.
For example, when an acid like hydrochloric acid is dissolved in water it dissociates into positive and negative ions as follows:
HCl(aq) -----> H+ + Cl-
When a base like sodium hydroxide is dissolved in water, it dissociates into positive and negative ions as follows:
NaOH(aq) ----> Na+ + OH-
Answer:
yeah C is correct
Explanation:
What is ductility in a solid?
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:
Describe the formation of an aqueous libr solution when solid libr dissolves in water
Fill in the blanks with words given below.
K and I atoms
K and IF ions
dissociation
atoms
KI molecules
polar dilution
hydration
molecules ions
nonpolar
At the_______ surface of the solid _____________are pulled into solution by___________ the water molecules, where the______________ process surrounds separate with water molecules.
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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1. Corrosion in metals is an example of what?
Answer:
In the most common use of the word, this means electrochemical oxidation of metal in reaction with an oxidant such as oxygen or sulfates. Rusting, the formation of iron oxides, is a well-known example of electrochemical corrosion.why is copper and iron are used for cooking utensils
Answer:
because according to the electron sea model they are good conductor of heat so,they can be used for cooking.
What element forms an ion with an electronic configuration of 1s22s22p6 (or [Ne] ) and a −2 charge? Give the symbol for the element. g
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⁺
How many moles of carbon atoms are there in 0.500 mol of C2H6?
The number of moles of carbon atoms in 0.500 mol of ethane (C₂H₆) is equal to one mole.
What is a 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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Which element has the largest atomic radius
Answer:
Francium
Explanation:
The atomic radius increases from top to bottom in a group, and decreases from left to right across a period.
so francium (Fr) is the largest atom or has highest radii.
Hope this helps & please mark as brainiest!
Answer:
Francium has the largest atomic radius.
The general trend for atomic radii is increasing from top to bottom and decreasing from left to right so the one with the largest atomic radius will be in the bottom left of the periodic table.
What is the mass of 3.45 moles
NO2?
(N = 14.01 g/mol, O = 16.00 g/mol)
Answer:
158.7 g
Its the right answer
The percent yield (isolation yield) of guaifenesin isolated from a 650 mg tablet containing 400 mg dose of drug, can be expressed as: Group of answer choices
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%
A naturally occurring oil co-distills with water to produce an oil/water distillate that is 20% oil by weight. If the molecular weight of the oil 100 g/mol, what was the partial pressure of the oil during distillation assuming atmospheric pressure is 760 mm Hg
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 .
What are the three types of combustion reactions
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! :)
Consider the following four solutions: a. NaCl in water b. Acetic acid in water c. Acetic acid in benzene d. Naphthalene in benzene Which of these solutions has the strongest solute-solvent interactions and the interaction is of which type?1. Acetic acid in water; hydrogen bonding2. Acetic acid in benzene; dipole-induced dipole interaction3. NaCl in water; ion-dipole interaction4. Naphthalene in benzene; London Dispersion Forces5. NaCl in water; hydrogen bonding
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
What is Sodium chloride?
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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Use your trendline equation to determine the gas pressure at 200 K and 400 K. (notice the temperature units) How many times greater is the pressure at 400 K in comparison to 200 K? Is this what you’d expect? Why?
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.
Vitamin c is known chemically by the name ascorbic acid determine the empirical formula of ascorbic acid if it is composed of 40.92% carbon, 4.58% hydrogen, and 54.50% oxygen.
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]
(-)-Cholesterol has a specific rotation of -32o. A mixture of ( )- and (-)-cholesterol was analyzed by polarimetry, and the observed rotation was 14o. What is the percent composition of the ( ) isomer in this mixture
Answer:
(+)-cholesterol = 71.88%
(-)-cholesterol = 28.12%
Explanation:
Asuming 1 gram of sample is dissolved in 1mL of water and the sample cell was 1dm long.
Enantiomeric excess is defined as the amount of pure enantiomer in a sample. The formula is:
ee = [α]mixture / [α]pure enantiomer.
Replacing:
ee = 14° / 32°×100 = 43.75%
As the sample is 14°, There is an excess of (+)-cholesterol and 56.25% is a 1:1 mixture of enantiomers.
That means percent composition of enantiomers is:
(+)-cholesterol = 43.75% + 56.25%/2 = 71.88%(-)-cholesterol = 56.25%/2 = 28.12%A small amount of red paint is mixed with water. When a laser pointer shines through the mixture, the beam is clearly visible in the mixture. This mixture is a .
Answer: Heterogeneous (Colloid)
Explanation: This is because your solution is a colloid. A colloidal solution has particles between 40 and 900 nm and as the laser light shines through the paint and Water mixture, the paint particles scatter the light because of the Tyndall Effect (Named after the physicist John Tyndall). A Colloidal Solution is a heterogeneous solution that looks like its homogeneous but is a mixture of very small particles that don't really become a solution.
A small amount of red paint is mixed with water. When a laser pointer shines through the mixture, the beam is clearly visible in the mixture. This mixture is a Heterogeneous.
What is mixture?A mixture is a substance made by combining two or more dissimilar chemical compounds that are not chemically linked in chemistry. When two or more substances are physically combined, their identities are maintained, and the mixture takes the shape of solutions, suspensions, or colloids.
Chemical elements and compounds, among others, can be mechanically blended or mixed to create mixtures without causing any chemical bonding and other chemical change, preserving the chemical characteristics and makeup of each ingredient. A small amount of red paint is mixed with water. When a laser pointer shines through the mixture, the beam is clearly visible in the mixture. This mixture is a Heterogeneous.
Therefore, the mixture is Heterogeneous mixture.
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How many formula units make up 36.0 g of magnesium chloride (MgCl2)?
Express the number of formula units numerically.
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
How many oxygen molecules are needed to make 10 carbon dioxide molecules according to the following balanced chemical equation? 2 CO + O2 → 2 CO2
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
A cylindrical rod of length 1 m and radius 1 cm is submerged in water. The rod has a non-uniform mass distribution such that one half of the rod is much more massive than the other half. At which point in the rod can the buoyant force be considered to be acting?
A) at the rod's geometrical center
B) two of the given choices are correct
C) none of these
D) at the rod's center of mass
E) at the rod's center of gravity
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
Which pair of factors affects the force of gravity between objects
Answer:
The Answer is B. Mass and distance
Explanation:
Trust me lol
Answer:mass and distance
Explanation:
1-chloro-4-methyl-2-pentene undergoes hydrolysis in warm water to give a mixture of 4-methyl-2-penten-1-ol and 4-methyl-1-penten-3-ol. Draw the structure of the intermediate's resonance contributor leading to the formation of 4-methyl-1-penten-3-ol.
Answer:
Explanation:
attached here is the diagram representing the structure