2 FONS
How does the electric force between two charged particles change if the
distance between them is increased by a factor of 22
A. It increases by a factor of 4.
B. It increases by a factor of 2.
C. It decreases by a factor of 4
O
D. It decreases by a factor of 2.
SUB

Answer:

ΔH of the reaction is -802.3kJ.

Explanation:

Using Hess's law, you can know ΔH of reaction by the sum of ΔH's of half-reactions.

Using the reactions:

(1) Cgraphite(s)+ 2H₂(g) → CH₄(g) ΔH₁ = −74.80kJ

(2) Cgraphite(s)+ O₂(g) → CO₂(g) ΔH₂ = −393.5k J

(3) H₂(g) + 1/2 O₂(g) → H₂O(g) ΔH₃ = −241.80kJ

The sum of (2) - (1) produce:

CH₄(g) + O₂(g) → CO₂(g) + 2H₂(g) ΔH' = -393.5kJ - (-74.80kJ) = -318.7kJ

And the sum of this reaction with 2×(3) produce:

CH₄(g) + 2 O₂(g) → CO₂(g) + 2H₂O(g) And ΔH = -318.7kJ + 2×(-241.80kJ) =

-802.3kJ

Answer:

I. Lewis acid-base reaction

II. Arrhenius, Brønsted-Lowry, and Lewis' acid-base reaction

III. Brønsted-Lowry and Lewis'acid-base reaction

IV. Lewis acid-base reaction

Explanation:

According to Arrhenius, an acid is a substance that dissolves in water to produce H+ ions, and a base is a substance that dissolves in water to produce hydroxide (OH−) ions.

In the reaction below, AH is an avid, BOH is a base reacting together to form a salt(A-B+) and water only.

AH + BOH ---> A-B+ + H2O

According to Brønsted-Lowry definition, an acid is any substance that can donate a proton, and a base is any substance that can accept a proton.

In the reaction below, AH is an acid while B is a base, reacting together to form an acid-base conjugate pair.

AH + B <-----> BH+ + A-

According to Lewis' definition, an acid is a species that accepts an electron pair while a base donates an electron pair resulting in a coordinate covalently bonded compound, also known as an adduct. In the reaction below, A+ is an acid, B- is a base, reacting together to form product A-B.

A+ + B- ------> A-B

Considering the above definitions;

I. Cu²+ + 4 Cl− ---> CuCl4²− is a Lewis acid-base reaction because it involves electron sharing only.

II. Al(OH)3 + 3HNO3 ---> Al3+ + 3H2O + 3 NO3− is an Arrhenius, Brønsted-Lowry, and a Lewis acid-base reaction because it involves protons, electrons and hydroxide ions.

III. N2 + 3 H2 ---> 2NH3 is a Lewis acid-base reaction because it involves sharing of electrons only.

IV. CN− + H2O ---> HCN + OH is both a Lewis and Brønsted-Lowry acid-base reaction because both protons and electrons sharing is involved.

In a Bronsted-Lowry acid-base reaction reaction, an acid donates protons which is accepted by the base.

The following are useful definitions of acids and bases;

Based on these, we can now classify the reactions accordingly;

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Answer:

The concentration of the sample is 3.564x10⁻³M.

Explanation:

Using Lambert-Beer law, absorbance of a sample is directely proportional to its concentration.

The general graph of the absorbance of the standards with different concentrations is:

Y = 75.9X + 0.0045

R² = 0.9946

Where Y is the absorbance of the sample and X its concentration in mole/L.

If a solution has an absorbance of 0.275:

0.275 = 75.9X + 0.0045

0.2705 = 75.9X

3.564x10⁻³M = X → The concentration of the sample.

Answer:

D

Explanation:

gr. 2.3 at 25°C; valence +3. Boron is a nonmetallic element existing as a dark brown to black amorphous powder or as an extremely hard, usually jet-black to silver-gray, brittle, lustrous, metallike crystalline solid

it is a network solid, a lattice of many covalent bonds (like diamond, except that it is black rather than transparent).

Network solid kind of solid is crystalline boron (B). Hence, option D is correct.

A network solid is a solid where all the atoms are covalently bonded in a continuous network.

Boron is a nonmetallic element existing as a dark brown to black amorphous powder or as an extremely hard, usually jet-black to silver-grey, brittle, lustrous, metallike crystalline solid

It is a network solid, a lattice of many covalent bonds (like a diamond, except that it is black rather than transparent).

Hence, option D is correct.

Learn more about Network solid here:

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Answer:

they must be heated

Explanation:

Answer:

The half-life of the material is 2 years

Explanation:

Given;

initial count rate = 2000 decays/minute

final count rate =  500 counts/min

decay time = Four hours

To determine the half life of the material; we create a simple decay table that matches the decay time and count rates.

time (years)                     count rate

0                                    2000 decays/minute

2                                     1000 decays/minute

4                                     500 decays/minute

Half life is the time intervals = 2 years

Also using a formula;

[tex]N = \frac{N_o}{(t/2)^2} \\\\N_o-is \ the \ initial \ count\ rate\\\\N-is \ the \ final \ count\ rate\\\\t/_2 - is \ the\ half\ life \\\\N = \frac{N_o}{(t/2)^2} \\\\500 = \frac{2000}{(t/2)^2}\\\\(t/_2)^2 = \frac{2000}{500} \\\\(t/_2)^2 = 4\\\\t/_2 = \sqrt{4} \\\\t/_2 = 2 \ years[/tex]

Therefore, the half-life of the material is 2 years

Answer:

219.15 grams

Explanation:

What is the mass of 3.75 moles of NaCI? ( Na= 22.99g/mol, CI= 35.45 g/mol)

Mole of Na = 22.99g

Mole of Cl = 35.45g

For NaCl we have ratio of 1:1, so we have 1 Na for every Cl

So we just add the two together to get the molar mass of NaCl which is

22.99 + 35.45 = 58.44g/mol

And we know we have 3.75 moles of NaCl so we multiply that by the molar mass of NaCl to get our answer

3.75 x 58.44 = 219.15grams

Answer:

Ice (frozen water) is part of the hydrosphere, but it's given its own name, the cryosphere.

The cryosphere is part of the hydrosphere of the Earth system. The correct option is D.

The cryosphere contains all the frozen parts of the earth. The term is made up of the Greek word “krios” which means cold. All the frozen water of the oceans and snow comes under the cryosphere.

The atmosphere contains all spheres, it is an envelope of gases. The geosphere is the land part of the earth, and the biosphere is the part where the living part is present.

The cryosphere is h habitat of many living creatures, and the climate of the earth is highly dependent on this sphere. The warmth of the earth is increasing and the cryosphere part is decreasing day by day, which is having problems for many animals.

Thus, the correct option is D, hydrosphere.

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Answer: The molecules in the thermometer's liquid spread apart.

Explanation:

Mercury is the only metal that remains liquid at room temperature. It has a high coefficient of expansion therefore the its level rises when exposed to a temperature range. It can detect a slight change in temperature. It has a high  boiling point.

When the thermometer is placed in the water to measure the temperature, the molecules of thermometer liquid that is mercury only will spread due to high coefficient of expansion. This can be seen as rise in temperature.

Answer:

B

Explanation:

Just did the test

Answer:

43.45g of water would be produced from the reaction.

Explanation:

Liquid became reacts with oxygen to produce carbon dioxide and water.

This type of reaction is known as combustion reaction between alkanes.

Equation of reaction.

Assuming the reaction occurs in an unlimited supply of oxygen,

2C₆H₁₄ + 19O₂ → 12CO₂ + 14H₂O

From the above equation of reaction,

2 moles of C₆H₁₄ reacts with 19 moles of O₂ to produce 14 moles of H₂O.

To find the theoretical mass,

Number of moles = mass / molar mass

Molar mass of C₆H₁₄ = 86g/mol

Molar mass of O₂ = 16g/mol × 2 = 32g/mol

Molar mass of H₂O = 18g/mol

Mass of H₂O = number of moles × molar mass

Mass of H₂O = 14 × 18 = 252g

Mass of C₆H₁₄ = number of moles × molar mass

Mass of C₆H₁₄ = 2 × 86 = 172g

Mass of O₂ = number of moles × molar mass

Mass of O₂ = 19 × 32 = 608g

From the equation of reaction,

172g of C₆H₁₄ reacts with 608g of O₂ to produce 252g of H₂O

(172 + 608)g of reactants produce 252g of H₂O

780g of reactants produce 252g of H₂O

(60 + 75.5)g of reactants will produce a x g of H₂O

780g of reactants = 252g of H₂O

134.5g of reactants = x g of H₂O

X = (134.5 × 252) / 780

X = 43.45g of H₂O

Therefore, 43.45g of H₂O would be produced from 60g of hexane and 74.5g of oxygen

Answer:

[tex]m_{H_2O}=30.9gH_2O[/tex]

Explanation:

Hello,

In this case, the combustion of hexane is given by:

[tex]C_6H_{14}+\frac{19}{2} O_2\rightarrow 6CO_2+7H_2O[/tex]

The next step is to compute the reacting moles of hexane:

[tex]n_{C_6H_{14}}=60gC_6H_{14}*\frac{1molC_6H_{14}}{86gC_6H_{14}} =0.698molC_6H_{14}[/tex]

Then, the moles of hexane consumed by 74.5 g of oxygen using the molar ratio in the chemical reaction (1:19/2):

[tex]n_{C_6H_{14}}=74.5gO_2*\frac{1molO_2}{32gO_2} *\frac{1molC_6H_{14}}{19/2molO_2} =0.245molC_6H_{14}[/tex]

Therefore, as less moles of hexane are consumed by oxygen, it is in excess, so we compute the mass of water produced by the consumed 0.245 moles of hexane:

[tex]m_{H_2O}=0.245molC_6H_{14}*\frac{7molH_2O}{1molC_6H_{14}}*\frac{18gH_2O}{1molH_2O} \\\\m_{H_2O}=30.9gH_2O[/tex]

Best regards.

Answer:

301.8 g

Explanation:

We prepare a solution with 200.4 g of water (solvent) and 101.42 g of salt (solute). The mass of the solution is equal to the sum of the mass of the solvent and the mass of the solute.

m(solution) = m(solute) + m(solvent)

m(solution) = 200.4 g + 101.42 g

m(solution) = 301.8 g (we round-off to one decimal according to the significant figures rules)

Answer: Transpiration---A

Explanation: Transpiration is the process in the water cycle whereby plant loose(excess) water by evaporation through the stomata of their leaves since not all water absorbed by the root is actually used for growth in plants.In order to allow the intake of carbon-dioxide, water must exit the leaves through transpiration which then  provides the plant with cooling, rigidity and maintaining the overall water balance of the plant.

Answer:

[Z] = 0.00248M

Explanation:

Based in the reaction:

2A(aq) + B(aq) ⇄ 2Z (aq)

K of the reaction is defined as:

K = [Z]² / [A]²[B] = 0.43

If you add, in the first, just 0.033M of  Z, concentrations in equilibrium are:

[Z] = 0.033M - 2X

[A] = 2X

[B] = X

Replacing in K equation:

0.43 = [0.033M - 2X]² / [2X]² [X]

0.43 = [0.033M - 2X]² / [2X]² [X]

0.43 = 4X² -0.132X + 0.001089 / 4X³

1.72X³ - 4X² + 0.132X - 0.001089 = 0

Solving for X:

X = 0.01526M

Replacing, concentration in equilibrium of Z is:

[Z] = 0.033M - 2*0.01526M = 0.00248M

Answer:

Less than 0.033 M

Explanation:

Hello,

In this case, given the equilibrium:

[tex]2A(aq) + B(aq) \rightleftharpoons 2Z (aq)[/tex]

Thus, the law of mass action is:

[tex]K=\frac{[Z]^2}{[A]^2[B]}[/tex]

Nevertheless, given the initial concentration of Z that is 0.033 M, we should invert the equilibrium since the reaction will move leftwards:

[tex]\frac{1}{K} =\frac{[A]^2[B]}{[Z]^2}=2.33[/tex]

Know, by introducing the change  due to the reaction extent, we can write:

[tex]2.33=\frac{(2x)^2*x}{(0.033M-2x)^2}[/tex]

Which has the following solution:

[tex]x_1=2.29M\\x_2=0.0181M\\x_3= 0.0153M[/tex]

But the correct solution is [tex]x=0.0153M[/tex]  since the other solutions make the equilibrium concentration of Z negative which is not possible. In such a way, its concentration at equilibrium is:

[tex][Z]_{eq}=0.033M-2*0.0153M=0.0024M[/tex]

Which is of course less than 0.033 M since the addition of a product shift the reaction leftwards in order to reestablish equilibrium (Le Chatelier's principle).

Regards.

Answer:

balanced because the total number of oxygen atoms is 3.

Answer:

C₅H₅N being the weakest base

Explanation:

A weak base (B) is defined as a chemical compound that, in reaction with water, produce a small quantity of BH⁺

The general reaction is:

B + H₂O ⇄ BH⁺ + OH⁻ Where Kb is defined as:

Kb = [BH⁺] [OH⁻] / [B]

That means the smallest Kb is the weakest base because is producing the smallest quantity of BH⁺.

In the problem, the smallest Kb is C₅H₅N being the weakest base.

Answer:

E. Gain of electrons

Explanation:

A reduction reaction is one part of the two concurrent reactions that take place in a redox (reduction-oxidation) reaction.

During reduction, an atom gains electrons from a donor atom, and it's oxidation number becomes smaller.

Option A is wrong because reduction does not increase oxidation state nor are neutrons involved

Option B is wrong because reduction is not a nuclear reaction (does not involve the nucleons)

Option C is wrong because reduction leads to reduction in oxidation state

Option D is wrong leads to a reduction in oxidation state when electrons are gained

Option E is correct because reduction involves gain of electrons

Answer:

N≡N

Explanation:

The image attached shows the nitrogen compounds that are being referred to in the question.

There are certain things we ought to know in order to answer the question accurately.

The bond order of a compound is equal to the number of bonds between two atoms. The greater the bond order, the shorter the bond length between the two atoms.

N≡N has a bond order of three, this is the highest bond order among all the species listed in the question. Hence it has the shortest bond length among the trio. Hence the answer.

The correct answer is C. Bohr's model

Explanation:

Bohr's model of the atom developed in 1913 proposed each atom contained a nucleus with protons and neutrons. Also, there were electrons that orbited the nucleus. About this, Niels Bohr proposed the orbits of electrons were similar to those of planets around the sun; however, these did not occur due to gravity but to attraction forces. This model integrated new accurate ideas about the atom. However, this model was still inaccurate because particles in an atom are electrically charged and electrons do not orbit in fixed stable orbits and cannot be compared to the movement of planets around a star.  

Answer:

Bohr's model

Explanation:

Answer:

- Four for iron, three for oxygen and 2 for iron (III) oxide:

[tex]4Fe+3O_2\rightarrow 2Fe_2O_3[/tex]

Explanation:

Hello,

In this case, the oxidation of iron is a widely acknowledged reaction occurring in ships and other machines exposed to the air or highly oxidizing medias. Thus, by the effect of oxygen, iron undergoes oxidation typically to iron (III) oxide:

[tex]Fe+O_2\rightarrow Fe_2O_3[/tex]

Nonetheless, the law of conservation of mass must be respected, therefore the coefficients balancing the reaction are four for iron, three for oxygen and 2 for iron (III) oxide:

[tex]4Fe+3O_2\rightarrow 2Fe_2O_3[/tex]

Best regards.

Answer:

Your question is complex, because I think you wrote it wrong.

Although in front of this what I can help you is that the carbons are associated between a single, double or triple union.

This depends on whether they are attached to more or less carbons or hydrogens, the carbons have the possibility of joining 4 radicals, both other carbons and hydrogens.

Simple junctions talks about compound organisms called ALKANS.

The double unions, in organic these compounds are called as ALQUENOS.

And as for the tertiary unions, the organic chemistry names them as ALQUINOS.

These compounds that we write, a simple union, the less energy, the less this union, that is why the triple bond is the one that contains the most energy when breaking or destroying it in a reaction.

Explanation:

In a chemical compound the change of these unions if we modified them we would generate changes even in the classifications naming them as well as different compounds and not only that until they change their properties

Answer:

Answer:

The first should be left asis because carbon already has 4 bonds/8 electrons

The second needs to have a double bond to give carbon 4 bonds/8 electrons

The third must have a triple bong between the carbons to give them both 4 bonds/8 electrons

Explanation:

Make sure Hydrogen only has 1 bond/2 electrons at all times. Carbon needs a total of 4 bonds/8 electrons

Answer: [tex]2(NH_4)_3PO_4(aq)+3CaS(aq)\rightarrow Ca_3(PO_4)_2(aq)+3(NH_4)_2S(s)[/tex] is a double displacement reaction (dr).

Explanation:

A double displacement reaction (dr) is one in which exchange of ions take place. The salts which are soluble in water are designated by symbol (aq) and those which are insoluble in water and remain in solid form are represented by (s) after their chemical formulas.

[tex]2(NH_4)_3PO_4(aq)+3CaS(aq)\rightarrow Ca_3(PO_4)_2(aq)+3(NH_4)_2S(s)[/tex]

Combination reaction (C) is defined as the reaction where substances combine in their elemental state to form a single compound.

Single displacement reaction (sr) is defined as the reaction where more reactive element displaces a less reactive element from its chemical reaction.

Decomposition reaction (d) is defined as the reaction where a single substance breaks down into two or more simpler substances.

Combustion (Co) is a type of chemical reaction in which hydrocarbons burn in the presence of oxygen to form carbon dioxide and water along with heat.

Answer:c

Explanation: rusting, burning and fuzzing are all examples of chemical reactions/changes.

Answer: Thus the mass, in grams, of 27 moles of smooth muscle myosin is 12960000 grams

Explanation:

According to avogadro's law, 1 mole of every substance weighs equal to the molecular mass, occupies 22.4 L at STP  contains avogadro's number [tex](6.023\times 10^{23})[/tex] of particles.

Molecular mass of protein = 480,000 g/mol

Thus 1 mole of protein weighs = 480,000 g

So 27 moles of protein weighs = [tex]\frac{480,000}{1}\times 27=12960000g[/tex]

Thus the mass, in grams, of 27 moles of smooth muscle myosin is 12960000 grams

Answer:

85.34g of NH3

Explanation:

Step 1:

The balanced equation for the reaction. This is given below:

N2 + 3H2 —> 2NH3

Step 2:

Determination of the number of moles of NH3 produced by the reaction of 2.51 moles of N2. This is illustrated below:

From the balanced equation above,

1 mole of N2 reacted to produce 2 moles of NH3.

Therefore, 2.51 moles of N2 will react to produce = (2.51 x 2)/1 = 5.02 moles of NH3.

Therefore, 5.02 moles of NH3 is produced from the reaction.

Step 3:

Conversion of 5.02 moles of NH3 to grams. This is illustrated below:

Molar mass of NH3 = 14 + (3x1) = 17g/mol

Number of mole of NH3 = 5.02 moles

Mass of NH3 =..?

Mass = mole x molar Mass

Mass of NH3 = 5.02 x 17

Mass of NH3 = 85.34g

Therefore, 85.34g of NH3 is produced.

Answer:

they would repel

Explanation:

unlike charges attract while like ones repel.

Answer:

the volume of the gas at conditions of STP = 151.04998 ml

Explanation:

Data given:

V1 = 180 ml

T1 = 35°C or 273.15 + 35 = 308.15 K

P1 = 95.9 KPa

V2  =?

We know that at STP

P2 = 1 atm or 101.3 KPa

T2 = 273.15 K

At STP the pressure is 1 atm and the temperature is 273.15 K

applying Gas Law:

[tex]\frac{P_1V_1}{T_1} =\frac{P_2V_2}{T_2}[/tex]

putting the values in the equation of Gas Law:

[tex]V_2=\frac{P_1V_1T_2}{T_1P_2}[/tex]

V_2 =[tex]\frac{95.9\times180\times273.15}{308.15\times101.3}[/tex]

V2 = 151.04998

therefore, V2 = 151.04998 ml

Answer:

151 mL is the correct answer to the given question .

Explanation:

We know that

[tex]PV =n RT[/tex]

Where P =pressure ,V=volume and T=Temperature

Given

P=95.9 kPa.

V=[tex]180 * 10 ^{-3}[/tex]

R=25/3

T=273 + 35 =308k

Putting these value into the equation we get

[tex]95.9\ * 180\ *\ 10^{-3} \ =\ n * \frac{25}{3} * 308[/tex]

n=[tex]6.72 * 10^{-3}[/tex]

Now using the equation

[tex]n= \ \frac{V}{22.4}[/tex]

[tex]6.72 * 10^{-3} =\frac{V}{22.4}\\ V\ =\ 150.6mL[/tex]

This can be written as  151mL

Answer:

140 T or thymine base

Explanation:

Adenine pairs with Thymine in DNA thus the number of adenine will always equal number of thymine (unless some sort of mutation), therefore in this problem you have 140 A so you have 140 T as well. Remember: Adenine (A) and Thymine(T) is equal, & Cytosine (C) and Guanine (G) is equal

Answer:

218.3 g/mol

Explanation:

Boiling point elevation occurs when a solute is added to a solvent increasing the boiling point of the solution with regard to the pure solvent.

The law is:

ΔT = Kb×m×i

Where ΔT is change in temperature (3.67°C), Kb is the boiling point constant of the solvent (4.95°C/m), m is molality of the solution and i is Van't Hoff factor (1 for a non-electrolyte).

3.67°C = 4.95°C/m×m×i

0.7414m = molality of the solution (Moles solute / kg solvent).

As the mass of the solvent is 50.0g = 0.0500kg:

0.7414m = Moles solute / 0.0500kg

0.0371 = moles of solute

As the mass of the solute is 8.1g, molar mass of the solute (Ratio between mass in g and moles) is:

8.1g / 0.0371mol =