For the reaction below, use the bond energies to calculate the net energy of reaction and state if reaction is exothermic or endothermic reaction with reason(s). 2N≡N + 2O=O 2N=O + 2N= O(N≡N is +946 Kj/mole; O=O is +498 Kj/mole; N=O is -631 Kj/mole).

Remember that electronegativity measures the type of bond formed. When the electronegativity is above 1.7 it represents an ionic bond when the electronegativity is between 0.4 and 1.7 consists of a polar covalent bond, and when the electronegativity is under by 0.4 the bond is a polar non-covalent, so the answer is A: if the electronegativity difference between two atoms is above 1.7, the bond is ionic.

Step 1

Molarity can be defined as follows:

---------------------------

Step 2

Information provided:

0.34 moles LiNO3

Volume = 6.42 L

---------------------------

Step 3

Procedure:

From step1,

Molarity = 0.34 moles/6.42 L

Molarity = 0.053 M

Answer: Molarity = 0.053 M

Answer: the pressure of the gas after the compression is 3.88 atm

Explanation:

The question requires us to calculate the new pressure of a gas, given its initial volume at STP, new volume after compression and temperature after compression.

The following information was provided by the question:

Initial volume = V1 = 0.700 L

Final volume = V2 = 0.200 L

Final temperature = T2 = 30 °C = 303.15 K

To solve this problem, we can apply the equation for ideal gases (shown below) considering the conditions after the compression:

where R is the constant of gases (R = 0.082057 L.atm/K.mol), n is the number of moles of gas, T2 is the temperature after compression and V2 is the volume after compression.

Note that the number of moles of gas remains the same even after compression. Thus, we can calculate this number of moles considering the inital volume at STP, knowing that 1 mol of a gas at Standard Temperature and Pressure corresponds to 22.4 L of this gas:

22.4 L ------------------------- 1 mol

0.700 L ----------------------- x

Solving for x, we'll have:

Therefore, the number of moles before and after compression is 0.0312 mol.

Now that we have the values for n, T2 and V2, we can calculate the pressure after compression (P2):

Therefore, the pressure of the gas after the compression is 3.88 atm.

ANSWER

The smallest particle is an atom

EXPLANATION

An atom is defined as the smallest indivisible particle of a substance that can take part in a chemical reaction and still retain it properties

An atom make up everything in the universe

Hence, the smallest particle is an atom

When we make a mixture, the molecules and bonds present in each of the substances can exert attraction or repulsion and can absorb or release energy. This energy is evidenced by an increase or decrease in temperature.

When the mixture releases energy, the temperature will increase and is called exothermic. When the mixture absorbs energy, the temperature will decrease and is called endothermic.

Therefore, if the beaker becomes cold it means that the mixture of these two compounds is endothermic.

Answer: D.) Dissolving this solute is an endothermic process.

Rather than presenting a marked difference between plastics and polymers, it should be emphasized that polymers are a group of compounds that encompass large molecules formed by the union of covalent bonds. Within the polymers there are some subgroups, these subgroups are classified according to the properties that the polymer has and its origin. They can come from natural or synthetic sources.

Plastics are a subgroup of synthetic polymers that possess temperature-sensitive properties, that is, they deform at a certain temperature, so their molding is done with heat.

Answer:

Nonpolar = A bond with equal sharing of electrons.

Diatomic = Composed of two atoms.

Polar = A bond with a negative end and a positive end.

Electronegativity = the ability of an atom to attract electrons.

Ionic = A bond formed between ions.

Explanation:

Let's review each concept:

Nonpolar: a nonpolar covalent bond is a covalent bond in which the bonding electrons are shared equally between the two atoms.

Diatomic: it is a molecule that contains two atoms of the same or different elements.

Polar: a polar covalent bond is a covalent bond in which the atoms have an unequal attraction for electrons, and so the sharing is unequal.

Electronegativity: it is the tendency of an atom to form covalent or ionic bonds.

Ionic: an ionic compound is a compound that contains positive and negative ions.

Based on the last concepts, we have the answers are:

Nonpolar = A bond with equal sharing of electrons.

Diatomic = Composed of two atoms.

Polar = A bond with a negative end and a positive end.

Electronegativity = the ability of an atom to attract electrons.

Ionic = A bond formed between ions.

An atom or group of atoms that carries a positive or negative electric charge as a result of having lost or gained one or more electrons.

In this case, we can see that Aluminum's atom is losing three electrons as it has a +3 charge, so:

The name of Al3+ is aluminum ion.

Answer:

Explanation:

Here, we want to get the molecular formula of the substance

We start by dividing the percentages by the atomic masses of the individual elements

The atomic mass of Selenium is 79 amu

The atomic mass of Carbon is 12 amu

The atomic mass of hydrogen is 1 amu

From the given percentages, to get the percentage for hydrogen, we subtract the percentages of carbon and selenium

We have that as 100- (12.9 + 84.9) = 2.2%

We have the calculation as follows:

From the above, we can see that the minimum value is 1.075

Now, we divide the values by the smallest

We have that as:

We can see that the empirical formula is thus:

Now, let us get the molecular formula

We have to find the mass of the empirical formula, then divide the molar mass by it

This will give us the required multiple needed to get the molecular formula from the empirical formula

Mathematically, we have that as:

This means that the molecular formula is:

Answer:

Atoms of one or more substances rearrange into a new substance. (second )

Explanation:

When a chemical change occurs, the original substance before the change is different from the substance after the change, in this case, that change is due to the fact that the atoms of one or more substances are rearranged into a new substance, since the other options include a physical change.

Answer

E

Explanation

The combustion of CH4 is when CH4 reacts with oxygen to produce carbon dioxide and water in the following balanced equation:

All the other e

ANSWER

Calcium atom has two electrons to contribute to the sea of delocalized electrons

EXPLANATION

Calcium belongs to group two metals with the atomic number of 20

The electronic configuration of calcium is written below as

In the above configuration, calcium has two electrons at its outermost shell. This means it valence electrons is 2

Therefore, calcium is readily to lose the two electrons two attain it octet configuration.

Hence, calcium atom has two electrons to contribute to the sea of delocalized electrons

A change in temperature will affect the equilibrium state of a reaction. For example,

The position of equilibrium will move to the right if we increase temperature. More A and B are converted into C and D at the lower temperature. Increasing the temperature of a system in dynamic equilibrium favours the endothermic reaction.

Therefore the statement is true.

ANSWER

EXPLANATION

Given that;

The atomic number of magnesium is 12.

In a neutal atom, the atomic number is equal to the number of proton

Therefore, the number of proton is 12

The magnesium ion lose one electron and it has 11 electrons

Hence, the Bohr model of Mg+ is drawn below as

ANSWER

The process of a solid changing to a gas is called SUBLIMATION

The process of solid turning to liquid is called MELTING

EXPLANATION:

Sublimation is the transition of a substance directly from the solid phase to the gas phase without passing through the liquid phase.

This occurs when the particle of the solid acquires enough energy to completely overcome the force of attraction holding the solid particles together.

Example: dry ice in water changing directly to carbon dioxide gas

Therefore, the process of a solid changing to a gas is called SUBLIMATION

The process of solid turning to liquid is called MELTING

A compound is just when 2 or more elements bond together and form sometimes a molecule or an ionic compound (NaCl and C6H12O6 for example), although the Gatorade drink has lots of compounds in it, is not a classification that fits it.

A homogenous solution is usually a liquid in which we don't see different phases, like water and oil for example, so in Gatorades case we see a homogenous solution because all of the salts and sugar are dissolved in water.

Mechanical mixture is more used in solids, and it doesn't have only one phase, but several, like chocolate chips, granola.

Element is what we find in the periodic table, and although Gatorade has lots of it, it is not the right classification, the same way as a compound classification.

Let's see that 3 moles of magnesium chloride (MgCl2) produce 2 moles of aluminum chloride (AlCl3), we can do a rule of three to find the number of moles required of AlCl3 by 2.1 moles of MgCl2, like this:

The calculation would be:

So, the answer is that 1.4 moles of aluminum chloride are produced by 2.1 moles of magnesium chloride.

Answer:

Explanation:

Here, we want to select the correct option for a water molecule

In a water molecule, the atoms present are 2 hydrogen atoms and 1 oxygen atom

While the hydrogen is positive, the oxygen is negative

Thus, from the list of options given, the oxygen atom is slightly negative in charge is the correct option

38.55L

Given the following parameters

Mass of propane = 25.3 grams

Determine the moles of propane

Moles of propane = Mass/molar mass

Moles of propane = 25.3/44.1

Moles of propane = 0.574moles

The combustion of propane is given according to the equation below:

According to stoichiometry, 1mole of propane produces 3 moles of CO2, the moles of CO2 required will be:

Since 1 mole = 22.4L, volume of CO2 gas that will be produced is:

Hence the volume of carbon dioxide produced is 38.55L

1) Proton. A proton is a positive particle found in the nucleus. The number of these particles defined the properties of an element.

We refer to the proton number as the atomic number. So, the proton number and the atomic number are the same.

We have here calcium fluoride CaF2.

This is a binary compound. It is formed by a nonmetal and a metal.

The metal is Ca and the nonmetal is F.

It is an inorganic compound.

If we write the reaction:

CaF2 ===> Ca+2 + 2 F-1

Oxidation state of Ca = +2

Oxidation state of F = - 1

If we balance this reaction, we will also have to balance the net charge here.

On the left, we have a charge = 0

On the right, we have +2 for Ca ion and -1 for F ion. But if you add these values, the result would be +1, and this would be wrong because we must have a 0 charge on the right too.

To solve this, we need to multiply by 2 the F- ion, then we will have +2 from Ca and 2 x (-1) = -2 from F ion. The net charge will be 0, as the charge on the left side of the reaction.

If you take a look you need to have the same number of atoms on both sides of the reaction.

Explanation:

The emission of a beta particle is the result of the rearrangement of the unstable nucleus of the radioactive atom in order to acquire stability. For that, a phenomenon occurs in the nucleus, in which a neutron decomposes giving rise to three new particles: a proton, an electron (β particle), and a neutrino. The antineutrino and electron are emitted. The proton, however, remains in the nucleus.

The symbol is used to represent beta particles.

Answer: b. Beta

An endothermic reaction is a type of reaction in which we need an input of energy in order for the reaction to properly occur, we will usually see this type of reaction represented by the positive sign, whereas exothermic reactions are the opposite, they release energy as product of the reaction. In this question, since the sign of the energy is positive, we have an Endothermic reaction

To achieve stability Na⁺ looses its electron to chlorine ion to complete its octet, and cl⁻ gain electron from sodium ion to complete its octet, so option A and B both are right.

What is electronic configuration ?

According to electronic configurations, each electron moves individually within an orbital while being surrounded by an average field produced by all other orbitals.

The octet rule can be better understood by considering the electron configurations of sodium and chloride ions, which are the main ingredients of table salt ( NaCl ).

The Na+ ion has an electron configuration of 1s₂, 2s₂ ,2p₆ after sodium     ( Na ), with an electron configuration of 1s₂, 2s₂, 2p₆, 3s₁, loses its outermost 3s electron.

So, chlorine atom gain one electron from sodium atom to complet octet and become stable.

Hence, option  A and B both are correct.

To learn more about electronic configuration follow the link below;

https://brainly.com/question/28045031

#SPJ2

In order to solve this question, we will need to use two very common formulas, the first it will be the Ideal gas Law, but with a few changes, and the second it will be the density formula:

PV = nRT, this is the Ideal gas formula, and we have:

P = 3.00 atm

T = 45°C, but we need it in Kelvin, 318 K

R = 0.082, this is the gas constant

d = m/V, this is the density formula, and we have:

d = 2.65 g/L

Now let's make a few changes on the ideal gas formula, first switching n (number of moles) for m/MM (mass/molar mass)

PV = m/MM * RT

P*MM/RT = m/V, now we have m/V, which is the same as density, now we can use the values

3 * MM/0.082 * 318 = 2.65

3 * MM/26.076 = 2.65

3MM = 69.10

MM = 23.03g/mol, this is the final molar mass

Answer

Oxygen.

Explanation

The trend of electronegativity in the periodic table is: electronegativity generally increases as you move from left to right across a period and decreases as you move down a group.

As a result, the most electronegative elements are found on the top right of the periodic table, while the least electronegative elements are found on the bottom left.

That is alkali metals have the lowest electronegativities, while halogens have the highest. Because most noble gases do not form compounds, they do not have electronegativities.

Therefore, from the given set of atoms, the atom that has the highest electronegativity is oxygen.

Explanation:

We have 135 g of ice and we place it inside a beaker with hot water. The final temperature of the mixture is 19.7 °C, so the ice will cool the hot water.

The ice will melt and its temperature will increase from 0°C to 19.7 °C (if we suppose that the initial temperature of ice is 0°C).

First we have to determine the amount of energy that the ice absorbed to melt.

ΔHf = Cf * m

Where ΔHf is the amount of energy that the ice will absorb, Cf is the heat of fusion and m is the mass of ice in this case.

Cf = 334 J/g m = 135 g

ΔHf = Cf * m

ΔHf = 334 J/g * 135 g

ΔHf = 45090 J

Once the ice is melted, that sample of water will increase its temperature from 0 °C to 19.7 °C. Let's find the amount of heat that it is necessary to do that.

Q = m * C * ΔT

Where Q is the amount of heat that the water will absorb, C is the specific heta of water and ΔT is the change in temperature.

Q₁ = m * C * ΔT

Q₁ = 135 g * 4.184 J/(g°C) * (19.7 °C - 0.0 °C)

Q₁ = 11127 J

The total amount of energy that the ice will absorb to go from solid ice at 0°C to liquid water at 19.7 °C is:

Qice = Q₁ + ΔHf

Qice = 11127 J + 45090 J

Qice = 56217 J

The ice is absorbing energy from the hot water that was in the beaker. So the heat that the ice gained is the same amount of heat that the hot water released with opposite sign.

Qice = - Qhw

Qhw = -56217 J

The heat that the hot water gave to the ice can be calculated using this formula.

Qhw = m * C * ΔT

We can replace the values that we already know and solve that equation for m to get the initial volume of water in the beaker.

Qhw = m * C * ΔT

- 56217 J = m * 4.184 J/(g *°C) * (19.7 °C - 67.0 °C)

m = -56217 J /(4.184 J/(g*°C) * (-47.3 °C)

m = 284 g

Since the density of water is 1 g/mL, we can convert the mass of water into volume.

Initial volume = 284 g / (1 g/mL)

Initial volume = 284 mL

Now we know the volume of water that was in the beaker before the ice is added, and we are given the mass of ice. We can find the final volume of water in the baker.

Final volume = initial volume + volume from ice

Final volume = 284 mL + 135 g /(1 g/mL)

Final volume = 419 mL

Answer:

a) The initial volume of water in the beaker was 284 mL.

b) The final volume of water in the beaker is 419 mL.

Answer

pH = 4.40

Explanation

Given:

[H⁺] = 3.95 x 10⁻⁵ M

What to find:

The pH of the solution.

Step-by-step solution:

Using the pH formula;

So,

Answer:

-The letter O is the symbol of the element while the dots represent the electrons

- Another element with the same arrangement of valence electrons would be Sulfur (they belong to the same group)

Explanation:

Here, we want to draw the electron dot diagram for the atom

The electron dot diagram will only recognize the valence electrons which are the electrons that help it in partaking in chemical reactions

From the image shown, the atom has 6 valence electrons (in the outermost shell)

Thus, we have the dot diagram as follows: Let us call the atom X:

The letter O is used to represent the symbol of the element which is Oxygen in the real sense.

The letters 16 p and 16 n represent 16 neutrons and 16 protons respectively. The very black circle represents the nucleus where the neutrons and protons reside

Since the valence electrons contain 6 electrons, another element with a similar arrangement of valence electrons would be an element in the same group which in this case is sulfur

Answer:

Explanation:

Here, we want to convert from mg to kg

Mathematically:

To convert the given value to kg, we have to divide it by 10 raised to the power of -6

Thus, we have it that: