PLEASE HELP ME Calculate the change in boiling point when 0.402 moles of sodium chloride are added to 0.200 kilograms of water. Kf = -1.86°C/m; Kb = 0.512°C/m -2.1°C 2.1°C -7.5°C 7.5°C

Answer:

Explanation:

RX + AgNO₃ = R⁺ ( carbocation ) + AgX + NO₃⁻

C₂H₅OH ( a nucleophile ) + R⁺ = ROC₂H₅

C₅H₁₁X + AgNO₃ = C₅H₁₁⁺ + AgX + NO₃⁻

In the first case carbocation produced is CH₃CH₂CH₂CH₂CH₂⁺

CH₃CH₂CH₂CH₂CH₂⁺ ⇒  CH₃CH₂CH₂C⁺HCH₃ ( secondary carbocation more stable )

CH₃CH₂CH₂C⁺HCH₃ + C₂H₅OH ⇒ CH₃CH₂CH₂CH(OC₂H₅)CH₃

Hence option D is correct .

b )

In the second case carbocation produced is

CH₃CH₂CH₂CH⁺CH₃

CH₃CH₂CH₂C⁺HCH₃ + C₂H₅OH ⇒ CH₃CH₂CH₂CH(OC₂H₅)CH₃

The product formed is same as in case of first

Option B is correct

Answer:

Kf

Explanation:

The stability constant Kf of a given complex specie is an equilibrium constant that represents the formation of that particular complex specie in solution. It measures the strength of the interaction between the ligands and metal that form the particular complex specie. The magnitude of Kf shows how easily a complex specie is formed in solution.

Hence if I want to dissolve the bromides or chlorides of silver which are ordinarily insoluble in water by means of complex formation, the magnitude of the stability constant for each particular complex specie is important as it gives information regarding the thermodynamic feasibility of the process.

Answer:

A. it gives up electrons

Explanation:

In a redox reaction, the reducing agent is the element or compound that undergoes oxidation and gives up electrons. The oxidizing agent is the element or compound that undergoes reduction and gains electrons.

Hope that helps.

Answer:

time taken for one-half of the BrO⁻ ion to react is t= 27.45 secs

Explanation:

equation of reaction

3BrO⁻(aq) → BrO₃⁻(aq) + 2Br⁻(aq) (second order reaction)

given

the slope of the graph is 0.056M⁻¹s⁻¹ = k(constant)

initial concentration [A]₀ = 0.65M

for second order reaction,we can calculate the time taken for one-half of the BrO- ion to react using:

[tex]\frac{1}{[A]}[/tex] =[tex]\frac{1}{[A]}[/tex]₀ ⁺ k × t

where initial concentration [A]₀ = 0.65M

[A] = [A]₀÷2 = 0.325M

[tex]\frac{1}{0.325M}[/tex] = [tex]\frac{1}{0.65M}[/tex] + 0.056M⁻¹s⁻¹ × t

3.077= 1.54 + 0.056t

3.077-1.54=0.056t

1.537=0.056t

t= 27.45 secs

Answer:18.4 ML

Explanation:

easy add

Answer:

D) 1 iron(II), 2 chloride

Explanation:

Iron II chloride is the compound; FeCl2. It is formed as follows, ionically;

Fe^2+(aq) + 2Cl^-(aq) -----> FeCl2

The formation of one mole of FeCl2 involves the reaction one mole of iron and two moles of chloride ions. This means that in FeCl2, the ratio of iron to chlorine is 1:2 as seen above.

Therefore there is one iron II ion and two chloride ions in each mole of iron II chloride, hence the answer.

Answer:

See figure 1

Explanation:

For this question, we have to remember that a hydrogen bond is an interaction in which we have a partial attraction between a positive dipole and a negative dipole, and in this attraction, we have in the middle a hydrogen atom.

In this interaction, we can have a donor (positive dipole) or a receptor (negative dipole). The receptor is a heteroatom (an atom different to carbon or hydrogen) with high electronegativity. The donor is usually hydrogen atom bonded to the heteroatom.  

I hope it helps!

Answer:

gaining two electrons

Explanation:

electron configuration

2:6

so add two to 6 to get stable 2:8

Answer:

How the chemical reacts

Explanation:

Answer:

The correct answer is 2.75 grams of HCl.

Explanation:

The given balanced equation is:  

CaCO₃ (s) + 2HCl (aq) ⇒ CaCl₂ (aq) + H₂O (l) + CO₂ (g)

Based on the given information, one mole of calcium carbonate is reacting with two moles of HCl. The molecular mass of HCl is 36.5 grams, thus, the mass of 2 moles of HCl will be, 36.5 × 2 = 73 grams

The molecular mass of CaCO₃ is 100 gram per mole, that is, the mass of 1 mole of CaCO₃ is 100 grams, therefore, the mass of HCl required for reacting with 3.75 grams of CaCO₃ will be,  

= 3.75 × 2 × 36.5 / 100 = 2.74 grams of HCl.  

Answer:

concentration is the abundance of a constituent divided by the total volume of a mixture.

In a liquid, the expansion is a little more than in

solids. The bonds in a liquid are weaker than in a

solid, so as you heat up a liquid, the particles can

move around each other faster and in so doing,

move further apart. Solids and liquids occupy a

'set' volume at a certain temperature.

Answer:

1. 0.90 are the initial moles of X and Y

2. 0.60 moles are the moles of Y and Z after the reaction

3. 0.90 moles of X and 0.30 moles of Y

4. 3X + 1Y → 2Z

Explanation:

1. For the reaction, initial moles of X and Y are:

500mL = 0.500L × (1.8 moles / L) = 0.90 are the initial moles of X and Y

2. After the reaction. The total volume is 500mL + 500mL = 1L

Moles Y and Z = 1L × (0.60 moles / 1L) = 0.60 moles are the moles of Y and Z after the reaction

3. As there is no moles of X after the reaction, all X reacts, that is 0.90 moles of X. And moles of Y that reacts are 0.90 mol - 0.60mol = 0.30 moles of Y

4. That means 3 moles of X reacts per mole of Y 0.90/0.30 = 3. Also, 2 moles of Z are produced per mole of Y 0.60/0.30 = 2.

That means balanced equation is:

aX + bY → cZ

Answer:

Question 1

A. Empirical formula is C8H8O3

B. Molecular formula is C8H8O3

Question 2.

A. Empirical formula is CH2

B. Molecular formula is C4H8

Explanation:

Question 1:

A. Determination of the empirical formula:

Carbon (C) = 63.2%

Hydrogen (H) = 5.26%

Oxygen (O) = 31.6%

Divide by their molar mass

C = 63.2/12 = 5.27

H = 5.26/1 = 5.26

O = 31.6/16 = 1.975

Divide by the smallest

C = 5.27/1.975 = 2.7

H = 5.26/1.975 = 2.7

O = 1.975/1.975 = 1

Multiply through by 3 to express in whole number

C = 2.7 x 3 = 8

H = 2.7 x 3 = 8

O = 1 x 3 = 3

Therefore, the empirical formula for the compound is C8H8O3

B. Determination of the molecular formula of the compound.

From Avogadro's hypothesis, 1 mole of any substance contains 6.02×10²³ molecules.

Now from the question given, we were told that 1 molecule of the compound has a mass of 2.53×10¯²² g.

Therefore, 6.02×10²³ molecules will have a mass of = 6.02×10²³ x 2.53×10¯²² = 152.306 g

Therefore, 1 mole of the compound = 152.306 g

The molecular formula of the compound can be obtained as follow:

[C8H8O3]n = 152.306

[(12x8) + (1x8) + (16x3)]n = 152.306

[(96 + 8 + 48 ]n = 152.306

152n = 152.306

Divide both side by 152

n = 152.306/152

n = 1

The molecular formula => [C8H8O3]n

=> [C8H8O3]1

=> C8H8O3

Question 2:

A. Determination of the empirical formula of the compound.

Mass sample of compound = 0.648 g

Carbon (C) = 0.556 g

Mass of Hydrogen (H) = mass sample of compound – mass of carbon

Mass of Hydrogen (H) = 0.648 – 0.556

Mass of Hydrogen (H) = 0.092 g

Thus, the empirical formula can be obtained as follow:

C = 0.556 g

H = 0.092 g

Divide by their molar mass

C = 0.556/12 = 0.046

H = 0.092/1 = 0.092

Divide by the smallest

C = 0.046/0.046 = 1

H = 0.092/0.046 = 2

Therefore, the empirical formula of the compound is CH2.

B. Determination of the molecular formula of the compound.

Mole of compound = 0.5 mole

Mass of compound = 28.5 g

Molar mass of compound =.?

Mole = mass /Molar mass

0.5 = 28.5/ Molar mass

Cross multiply

0.5 x molar mass = 28.5

Divide both side by 0.5

Molar mass = 28.5/0.5 = 57 g/mol

Thus, the molecular formula of compound can be obtained as follow:

[CH2]n = 57

[12 + (1x2)]n = 57

14n = 57

Divide both side by 14

n = 57/14

n = 4

Molecular formula => [CH2]n

=> [CH2]4

=> C4H8.

Answer:

[tex]\boxed{\text{Q1. 3.6 g; Q2. 0.2 A}}[/tex]

Explanation:

Q1. Mass of Cu

(a) Write the equation for the half-reaction.

Cu²⁺ + 2e⁻ ⟶ Cu

The number of electrons transferred (z) is 2 mol per mole of Cu.

(b) Calculate the number of coulombs

q  = It  

[tex]\text{t} = \text{1.0 h} \times \dfrac{\text{3600 s}}{\text{1 h}} = \text{3600 s}\\\\q = \text{3 C/s} \times \text{ 3600 s} = \textbf{10 800 C}[/tex]

(c) Mass of Cu

We can summarize Faraday's laws of electrolysis as

[tex]\begin{array}{rcl}m &=& \dfrac{qM}{zF}\\\\& = &\dfrac{10 800 \times 63.55}{2 \times 96 485}\\\\& = & \textbf{3.6 g}\\\end{array}\\\text{The mass of Cu produced is $\boxed{\textbf{3.6 g}}$}[/tex]

Note: The answer can have only two significant figures because that is all you gave for the time.

Q2. Current used

(a) Write the equation for the half-reaction.

Ag⁺ + e⁻ ⟶ Ag

The number of electrons transferred (z) is 1 mol per mole of Ag.  

(a) Calculate q

[tex]\begin{array}{rcl}m &=& \dfrac{qM}{zF}\\\\2.00& = &\dfrac{q \times 107.87}{1 \times 96 485}\\\\q &=& \dfrac{2.00 \times 96485}{107.87}\\\\& = & \textbf{1789 C}\\\end{array}[/tex]

(b) Calculate the current

t = 3 h = 3 × 3600 s = 10 800 s

[tex]\begin{array}{rcl}q&=& It\\1789 & = & I \times 10800\\I & = & \dfrac{1789}{10800}\\\\& = & \textbf{0.2 A}\\\end{array}\\\text{The current used was $\large \boxed{\textbf{0.2 A}}$}[/tex]

Note: The answer can have only one significant figure because that is all you gave for the time.

Answer:

Its C I hopefully help you

Answer:

A tetraquark in physics is an exotic meson composed of four valence quarks.

Explanation:

It has been suspected to be allowed by quantum chromodynamics, the modern story of strong interactions.

Hope it helps.

Answer:

Group 12

Explanation:

Group 12 transition metals are diamagnetic. They behave properties that distinguish them. They naturally have twelve electrons hence their outermost shell is fully filled.

Transition metals have high densities which increases down the group. However, the increase in density of transition elements of group 12 varies with temperature at a rate that is quite different from other transition elements. Hence the differences in the value of melting points and density changes by only a very small amount as you come down group 12 compared to other groups of transition elements.

Answer:

[tex]m=0.395mol/kg[/tex]

Explanation:

Hello,

This is a problem about boiling point elevation which is modeled via:

[tex]\Delta T=i*m*Kb[/tex]

Whereas for this solvent (nonpolar, nonionizing), the van't Hoff factor is one. In such a way, the molality of the solute is simply computed as shown below:

[tex]m=\frac{\Delta T}{Kb}=\frac{(81.10-80.10)\°C}{2.53\°C/m} \\\\m=0.395mol/kg[/tex]

In this manner, we can also compute the molar mass of the solute by noticing 20.0 g (0.020 kg) of benzene were used:

[tex]n=0.395mol/kg*0.020kg=7.9x10^{-3} mol[/tex]

And considering the 2.15 g of the solute:

[tex]Molar\ mass=\frac{2.15g}{7.9x10^{-3}mol}\\ \\Molar\ mass=271.975g/mol[/tex]

Best regards.

Answer:

Other substances that give a positive test with AgNO3 are other chlorides present, iodides and bromide. However iodides and bromides have different colours hence they will not give a false positive test for KCl. Other chlorides present may lead to a false positive test for KCl.

Explanation:

In the qualitative determination of halogen ions, silver nitrate solution is used. Various halide ions give various colours of precipitate with silver nitrate. Chlorides yield a white precipitate, bromides yield a cream precipitate while iodides yield a yellow precipitate. All these ions or some of them may be present in the system.

However, if other chlorides are present, they will also yield a white precipitate just as KCl leading to a false positive test for KCl. Since other halogen ions yield precipitates of different colours, they don't lead to a false test for KCl. We can exclude other halides from the tendency to lead us to a false positive test for KCl but not other chlorides.

In the qualitative analysis test of chloride upon addition of AgNO₃, presence of diffrerent chloride salts other than KCl will gives false test.

On adding halogens on the silver nitrate solution we will get the precipitate of diffrent colors of diffrent halides.

So, presence of diffrent chloride salt in the silver nitrate solution in addition with KCl will gives a false positive result for the test.

To know more about qualitative analysis, visit the below link:

https://brainly.com/question/1779681

Answer:

The products have a higher heat content than the reactants.

Explanation:

The statement above is not true for an exothermic reaction because in an exothermic reaction heat is released to the surroundings. This simply means that the total energy of the products is less than that of the reactants.

Answer:

See explanation

Explanation:

We have to start, remembering the mechanism behind the McLafferty rearrangement. The hydrogen in the gamma carbon (in this case, carbon 5) would be removed by a heterolytic rupture due to the cation-radical placed in the oxygen of the carbonyl group. Then we will have several heterolytic ruptures. Between carbons alpha and beta (in this case, 4 and 3) and a rupture in the carbonyl group. Due to these ruptures, two double bonds would be formed. One double bond in the alcohol cation-radical and the other one in the alkene.

See figure 1

I hope it helps!

Answer:

Hexane

Explanation:

You have a carbon structure with only single bonds.  This means that the name will end in -ane.

There are 6 carbon atoms.  This means that the name will begin with hex-.

The structure is hexane.

Answer:

$306 = Cost of 1 square inch of the patching material in question.

$306 = 1 in²

Explanation:

The conversion factor is am expression that is used to prove the equivalence of some quantities with different units.

The conversion factor basically converts from one quantity to another.

For this question, the conversion factor given for the patching material is $306/in².

This means that the patching material costs $306 for every square inch, the equation for the conversion is thus

$306 = 1 in² of the patching material.

Hope this Helps!!!

double displacement

bcoz each of the reactants combines with other reactants to obtain the product

Answer:

244.7 g of acetylene

Explanation:

The balanced reaction equation is shown below;

2H20 (l) + CaC2 (s) → Ca(OH)2 (s) + C2H2 (g)

Number of moles of were reacted = reacting mass/molar mass = 358g/18gmol-1 = 19.89 moles of water

From the balanced reaction equation;

2 moles water yields 1 mole of acetylene

19.89 moles of water will yield 19.89 × 1/2 = 9.945 moles of acetylene

Theoretical yield of acetylene = 9.945 moles of acetylene × molar mass of acetylene

Molar mass of acetylene = 26.04 g/mol

Theoretical yield of acetylene = 9.945 moles of acetylene × 26.04 g/mol

Theoretical yield of acetylene = 258.9678 g of acetylene

% yield = actual yield/ theoretical yield × 100

94.5 = actual yield/258.9678 g × 100

Actual yield= 94.5 × 258.9678 g/100

Actual yield = 244.7 g of acetylene

Answer:

negative charge electrode

Explanation:

In cathode positive ions are picked up to perform reduction.At the same time negative ions are picked up at anode to get oxidized from electrolyte.

Answer:

The electrode that removes ions from the solution :) a p e x

Answer:

pH of the buffer is 7.48

Explanation:

The H₂PO₄⁻/HPO₄²⁻ buffer has a pKa of 7.21. You can find pH of this buffer following H-H equation:

pH = pKa + log [A⁻] / [HA]

pH = 7.21 + log [HPO₄²⁻] / [ H₂PO₄⁻]

Where [] represents molarity of each specie of the buffer and, as volume is 1.00L, also represents its moles.

Thus, to find pH of the buffer we need to calculate moles of each specie, thus

Moles of 18.0g of KH₂PO₄(Molar mass: 136.086g/mol) = moles of H₂PO₄⁻ are:

18.0g KH₂PO₄ ₓ (1mol / 136.086g) = 0.132 moles of KH₂PO₄= H₂PO₄⁻

Moles of 35.0g of Na₂HPO₄(Molar mass: 141.96g/mol) = moles of HPO₄²⁻ are:

35.0g Na₂HPO₄ ₓ (1mol / 141.96g) = 0.2465 moles of Na₂HPO₄= HPO₄²⁻

Replacing in H-H equation:

pH = 7.21 + log [HPO₄²⁻] / [ H₂PO₄⁻]

pH = 7.21 + log [0.2465] / [0.132]

pH = 7.48

Answer:

0.1736 L or 173.6 ml

Explanation:

Number of moles of lead II nitrate is obtained by;

Number of moles = concentration × volume of solution

Concentration= 0.112 M

Volume of solution= 310 ml

n= 0.112 × 310/1000

n= 0.03472 moles

From the reaction equation;

2 moles of potassium iodide reacted with 1 mole of lead II nitrate

x moles of potassium iodide will react with 0.03472 moles of lead II nitrate

x= 2 × 0.03472 moles= 0.06944 moles of potassium iodide

Volume of potassium iodide solution = number of moles/ concentration = 0.06944/ 0.4

Volume of potassium iodide solution= 0.1736 L or 173.6 ml

Answer:

[N2O4] = 0.0573M

[NO2] = 0.0163M

Explanation:

The equilibrium of N2O4 is:

N2O4(g)⇌2NO2(g)

Where Kc is defined as:

Kc = 4.64x10⁻³ = [NO2]² / [N2O4]

When you add just N2O4, the reaction will occurs until  [NO2]² / [N2O4] = 4.64x10⁻³. Here, the system reaches equilibrium.

That means if 0.0655M N2O4 begin reaction, in equilibrium we will have:

[N2O4] = 0.0655M - X

[NO2] = 2X

Where X is defined as reaction coordinate

Replacing in Kc:

4.64x10⁻³ = [NO2]² / [N2O4]

4.64x10⁻³ = [2X]² / [0.0655-X]

3.0392x10⁻⁴ - 4.64x10⁻³X = 4X²

3.0392x10⁻⁴ - 4.64x10⁻³X - 4X² = 0

Solving for X:

X = -0.0093 → False solution. there is no negative concentrations

X = 0.008156M → Right solution.

Replacing X, equilibrium concentrations are:

[N2O4] = 0.0655M - X

[NO2] = 2X