A 25.0 mL sample of a saturated C a ( O H ) 2 solution is titrated with 0.029 M H C l , and the equivalence point is reached after 37.3 mL of titrant are dispensed. Based on this data, what is the concentration (M) of the hydroxide ion?

Answer:  The correct answer is B.

Explanation:  Segregate most organic acids from oxidizing mineral acids. Keep oxidizers away from other chemicals, especially flammables.

Answer:

Segregate most organic acids from oxidizing mineral acids. Keep oxidizers away from other chemicals, especially flammables, combustibles, and toxic materials. Keep corrosives away from substances that they may react with and release corrosive, toxic, or flammable vapors.

Answer:

3.88 atm

Explanation:

We'll begin by calculating the number of mole of CO₂ in each case. This can be obtained as follow:

For 2.50 g of CO₂:

Mass of CO₂ = 2.5 g

Molar mass of CO₂ = 12 + (2×16) = 44 g/mol

Mole of CO₂ =?

Mole = mass / molar mass

Mole of CO₂ = 2.5 / 44

Mole of CO₂ = 0.06 mole

For 0.42 g of CO₂:

Mass of CO₂ = 2.5 g

Molar mass of CO₂ = 44 g/mol

Mole of CO₂ =?

Mole = mass / molar mass

Mole of CO₂ = 0.42 / 44

Mole of CO₂ = 0.010 mole

Finally, we shall determine the new pressure. This can be obtained as follow:

Initial mole (n₁) = 0.06 mole

Initial pressure (P₁) = 4.65 atm

Final mole (n₂) = 0.06 – 0.010 = 0.05 mole

Final pressure (P₂) =?

NOTE: Temperature and volume is constant.

P₁ / n₁ = P₂ / n₂

4.65 / 0.06 = P₂ / 0.05

Cross multiply

0.06 × P₂ = 4.65 × 0.05

0.06 × P₂ = 0.2325

Divide both side by 0.06

P₂ = 0.2325 / 0.06

P₂ = 3.88 atm

Thus, the new pressure is 3.88 atm.

Answer:

SN1 mechanism

Explanation:

The mechanism of this reaction is shown in the image attached.

The Di- n- pentyl ether is first protonated. The CH3(CH2)4OH is now a good leaving group as shown.

The attack of the bromide ion on the cation formed completes the mechanism to yield 1- bromopentane as shown in the mechanism.

Answer:

The correct answer is Option c (0.163 g).

Explanation:

Given:

Heat energy,

Q = 0.21 J

Specific heat,

c = 4.184 J/g°c

Change in temperature,

ΔT = 0.308°C

As we know,

⇒ [tex]Q=mc \Delta T[/tex]

By substituting the values, we get

 [tex]0.21=m\times 4.184\times 0.308[/tex]

     [tex]m=\frac{0.21}{0.308\times 4.184}[/tex]

         [tex]=\frac{0.21}{1.28867}[/tex]

         [tex]=0.163 \ g[/tex]

Answer: it will be basic

pH that ranges from 0-6 are acid

pH of EXACTLY 7 is neutral

pH greater than 7 are strongly basic or base

Answer:

Explanation:

From the given reaction:

[tex]6Cl_{2(g)}+2Fe_2O_{3(s)} \to 4FeCl_{3(s)}+3O_2[/tex]

From the Gibbs Free Energy table at standard conditions, the value of each compound is as follows:

[tex]G_f^0 \ of \ Cl_2 = 0 \ KJ/mol[/tex]                       [tex]G_f^0 \ of \ Fe_2O_3 = -742.24 \ KJ/mol[/tex]

[tex]G_f^0 \ of \ Fe_2Cl_3 = -334.05 \ KJ/mol[/tex]      [tex]G_f^0 \ of \ O_2 = 0 \ KJ/mol[/tex]

Now, the standard Gibb's Free energy for the given reaction can be estimated as follows:

[tex]\mathtt{\Delta G^0 = (4 *G_f^0(FeCl_3) +3*G_f^0(O_2)) - (6*G_f^0 (Cl_2) +2*G_f^0(Fe_2O_3))}[/tex]

[tex]\mathtt{\Delta G^0 = (4 *(-334.05) +3*(0)) - (6(0) +2(-742.24))}[/tex]

[tex]\mathtt{\Delta G^0 = 148.28 \ kJ/mol}[/tex]

using the following formula:

[tex]\mathtt{\Delta G^0 =-RTIn K_{eq}}[/tex]

the equilibrium constant can  be determined as:

[tex]\mathtt{ In K_{eq} =\dfrac{\Delta G^0 }{-RT}}[/tex]

[tex]\mathtt{ In K_{eq} =\dfrac{148.28*10^3 J/mol }{-(8.314 \ J/k mol )*298 \ K}}[/tex]

[tex]\mathtt{ In K_{eq} =-59.85}[/tex]

[tex]\mathtt{ K_{eq} =e^{-59.85}}[/tex]

[tex]\mathtt{ K_{eq} =1.0*10^{-26}}[/tex] to 2 significant figures.

Answer:

indicates the number of subshells

Answer:

0.0900 mol/L

Explanation:

A chemist makes 330. mL of nickel(II) chloride working solution by adding distilled water to 220. mL of a 0.135 mol/L stock solution of nickel(II) chloride in water. Calculate the concentration of the chemist's working solution. Round your answer to significant digits.

Step 1: Given data

Step 2: Calculate the concentration of the final solution

We prepare a dilute solution from a concentrated one. We can calculate the concentration of the working solution using the dilution rule.

C₁ × V₁ = C₂ × V₂

C₂ = C₁ × V₁/V₂

C₂ = 0.135 mol/L × 220. mL/330. mL = 0.0900 mol/L

Answer:

See detailed explanation.

Explanation:

Hello there!

In this case, according to the given description, it turns out possible for us to infer that the second fractionating column on top of the first one will favor the light product, in this case hexane as it has the lowest boiling point and molar mass; in such a way, we can tell the following:

a) The separation between hexane and heptane will be increased as a purer hexane-rich product will be obtained on the top of the second column.

b) Will be increased as well, because the second column will remove more heptane.

c) Also, more pure heptane will be obtained on the bottom of the two columns, yet the most favored yield will be that of hexane.

All of the aforementioned is possible due to the fact that the second column will remove the amount of heptane that could not be removed on the top of the first column by taking the vapor-liquid equilibrium further from the first column's maximum separation, which is known as distillation sequences.

Regards!

Answer:

Percent yield = 17.3%

Explanation:

The percent yield is defined as 100 times the ratio between actual yield in grams and theoretical yield in grams (123g).

Percent Yield = Actual Yield / Theoretical yield (123g) * 100

To find actual yield we need to convert the 0.209moles to grams:

Actual yield -Molar mass Al2O3: 101.96g/mol-

0.209mol * (101.96g/mol) = 21.3g

Percent yield = 21.3g / 123g * 100

Percent yield = 17.3%

Answer:

Einstein realized that the energy in electrons was caused by the frequency of light and not the intensity of light. This made him realize that he needed to explain the photoelectric effect.

Explanation:

Einstein realized that the photoelectric effect was a system that should be studied and explained in more depth, when he saw how the energy of electrons behaved in the presence of light. He saw that this energy depends entirely on the frequency of light and not on the intensity of light. From this observation, he realized that the photoelectric effect was essential for the production of an electric energy system, through light energy, such as solar energy.

It is important to note that the photoelectric effect refers to the ejection of electrons on a light surface that comes into contact with a light source.

Answer:

C₂H₃O

Explanation:

From the question given above, the following data were obtained:

Carbon (C) = 48.8383%

Hydrogen (H) = 8.1636%

Oxygen (O) = 43.1981%

Empirical formula =?

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

C = 48.8383%

H = 8.1636%

O = 43.1981%

Divide by their molar mass

C = 48.8383 / 12 = 4.07

H = 8.1636 / 1 = 8.1636

O = 43.1981 / 16 = 2.7

Divide by the smallest

C = 4.07 / 2.7 = 2

H = 8.1636 / 2.7 = 3

O = 2.7 /2.7 = 1

Thus, the empirical formula of the compound is C₂H₃O

Answer:

a. 8.3= pKa of the aminoacid

b. Cysteine

Explanation:

The pH of an acid can be obtained using the H-H equation:

pH = pKa + log [A-] / [HA]

Where pH is the pH of the buffer = 7.0

pKa is the pka of the conjugate acid = ?

[A-] / [HA] is the ratio between conjugate base and conjugate acid. As the ratio of conjugate acid to conjugate base = 20:1, the [A-] / [HA] = 1/20

Replacing:

7 = pKa + log 1/20

7 = pKa - 1.30

7+1.30 = 8.3 = pKa of the aminoacid

The only aminoacid with a side chain with pKa = 8.3 is:

Cysteine. Allowing its identification.

Answer:

a)calculated molarity of NaOH would be lower

b) calculated molarity of NaOH would be lower

c) calculated molarity of NaOH would be lower

d) calculated molarity of NaOH would be unaffected

Explanation:

Let us recall that the reaction of NaOH and HCl is as follows;

NaOH(aq) + HCl(aq) ----> NaCl(aq) + H2O(l)

Since the reaction is 1:1, when the number of moles of HCl reacting with NaOH is low due to dilution, the calculated molarity of NaOH also becomes less than it's accurate value.

When 40mL of water is added to the titration flask rather than 25ml of water, the acid is more dilute hence less number of moles of acid than necessary reacts with the base thereby yielding a less than accurate value of the molarity of NaOH.

If the burette wet with water is not rinsed with NaOH solution, the concentration of the NaOH in the burette decreases due to dilution with water and a less than accuracy value is calculated for the molarity of NaOH.

If five drops of phenolphthalein is used instead of one or two drops, there is no qualms since enough phenolphthalein may be added to ensure that a sharp end point is obtained.

Answer:

Ni

Explanation:

An active metal is a highly reactive metal. Active metals are found high up in the activity series.

Active metals react with other metals that are lower than them in the activity thereby displacing the lower metals from a solution of their salts. This is what may have happened in the other two reactions.

Ni is the most active metal listed in the question since it can react a compounds with Pb(NO3)2(aq) to liberate Pb metal.

Answer:

to the right (products side)

Explanation:

The equilibrium constant K describes the ratio between the concentration of products and reactants at equilibrium. For a general reaction:

a A + b B → c C + d D

The equilibrium constant expression is:

[tex]K = \frac{[C]^{c} [D]^{d} }{[A]^{a} [B]^{b} }[/tex]

A low value of K indicates that the concentration of products (C and D) is low in relation with the concentration of reactants (A and B).

Conversely, a high value of K indicated that the concentration of products is high compared with the concentration of reactants.

Since K = 6.4 × 10⁹ is a high value, the concentration of products is higher than the concentration of reactants at equilibrium. Thus, the position of the equilibrium is favored to the right.

Answer:

2040 kJ

Explanation:

Step 1: Calculate the energy provided by 21 g of protein

17 kJ are provided per gram of protein.

21 g × 17 kJ/g = 357 kJ

Step 2: Calculate the energy provided by 59 g of carbohydrate

17 kJ are provided per gram of carbohydrate.

59 g × 17 kJ/g = 1003 kJ

Step 3: Calculate the energy provided by 18 g of fat

38 kJ are provided per gram of fat.

18 g × 38 kJ/g = 684 kJ

Step 4: Calculate the total energy provided by the dinner

357 kJ + 1003 kJ + 684 kJ = 2044 kJ ≈ 2040 kJ

Answer:

Explanation:

·  44 g NaCl Explanation: The problem provides you with the molarity and volume of the target

The answer is rounded to two sig figs, the number of sig figs you have for the molarity of the solution.

The mass of a solute needed to prepare a solution with given volume is find by molarity. The mass of NaCl need to make a 138.1 mL solution of 0.190 M is 1.53 grams.

Molarity of a solution is a term to express its concentration. Mathematically, it is the ratio of no.of moles of solute to the volume of solution in litres.

Given that, the volume of solution is 138.1 mL. One litre solution is 1000 mL. Hence, 138.1 mL is 0.1381 L. The molarity of the solution is 0.190 M. From these data we can calculate the no.of moles of NaCl as below:

no.of moles = molarity × volume of solution in L

                    =  0.190 M × 0.1381 L

                    = 0.0262 moles.

This is the no.of moles required to make the solution.

Molecular mass of NaCl = 58.4 g/mol.

Thus mass of 0.0262 moles of NaCl = 0.0262  mol × 58.4 g/mol

                                                             = 1.53 g.

Therefore, the mass of NaCl required is 1.53 g.

To learn more about molarity, refer the link below:

https://brainly.com/question/16727614

#SPJ2

Answer:

72.96 of water produce by 45.4 L of oxygen at STP.

Explanation:

[tex]H_2+\frac{1}{2}O_2\rightarrow H_2O[/tex]

1 mole of oxygen=22.4 L at STP

[tex]\frac{1}{2}[/tex]\mole of oxygen=22.4/2=11.2 L

11.2 L of oxygen required to produce water=1 mole

1 L of oxygen required to produce water=1/11.2 mole

45.4 L of oxygen required to produce water=[tex]\frac{1}{11.2}\times 45.4[/tex]

45.4 L of oxygen required to produce water=[tex]\frac{45.4}{11.2}[/tex]moles

1 mole of water=18 g

[tex]\frac{45.4}{11.2}[/tex]moles of water=[tex]18\times \frac{45.4}{11.2}[/tex]

[tex]\frac{45.4}{11.2}[/tex]moles of water=72.96 g

Hence, 72.96 of water produce by 45.4 L of oxygen at STP.

Answer:

somebody small boy is not w e a r d

z0 0m = 257 473 5835 p c:- 12 34

Acids have sour taste, low pH and dissolves metals.

The list that describes the characteristics of an acid is that it has sour taste, low pH, and dissolves metals.

An acid is a chemical substance that has the ability to donate hydrogen ions when involved in a chemical reaction.

The following are the characteristics or features of an acid:

Therefore, the list that describes the characteristics of an acid is that it has sour taste, low pH, and dissolves metals.

Learn more about acids here:

https://brainly.com/question/1302816

Answer:

According to the four quantum numbers; magnetic quantum number is the same as angular momentum quantum number. so the answer is 5

Explanation:

for d subshell angular momentum "d" is assigned a value of : m= 2(range from negative to positive i.e, -2 to 2) so we have [ -2, -1 ,0, 1 , 2] which concludes to 5.

Answer:

C2H3O3

Explanation:

Empirical formula is the simplest whole number ratio of moles of atoms that you can find in a molecule.

In combustion analysis all Carbon reacts producing CO2 and all hydrogen reacts producing H2O. With the differences in masses we can find the mass of oxygen and their moles:

Moles CO2 = Moles C:

14.08g * (1mol/44.01g) = 0.3199 moles C * (12.01g/mol) = 3.8423g C

Moles H2O:

4.32g H2O * (1mol/18.01g) = 0.2399 moles H2O * (2mol H / 1molH2O) = 0.4797moles H = 0.4797g H

Mass O:

12.01g = Mass O + 3.8423g C + 0.4797g H

Mass O = 7.688g O

Moles O:

7.688g O * (1mol/16g) = 0.48 moles O

The ratio of atoms (Dividing in the moles of C that are the lower number of moles):

O: 0.48moles O / 0.3199 moles C = 1.50

C: 0.3199 moles C / 0.3199 moles C = 1

H: 0.4797 moles H / 0.3199 moles C = 1.50

As empirical formula requires whole numbers:

O: 1.50* 2 = 3

C: 1*2 = 2

H: 1.50*2 = 3

The empirical formula is:

Answer:

The unbalanced chemical equation is

K

2

Cr

2

O

7

+HCl→KCl+CrCl

3

+H

2

O+Cl

2

Balance all atoms except H and O.

K

2

Cr

2

O

7

+10HCl→2KCl+2CrCl

3

+H

2

O+Cl

2

Assign oxidation numbers.

K

2

+6

Cr

2

O

7

+10H

−1

Cl

→2KCl+2

+3

Cr

Cl

3

+H

2

O+

0

Cl

2

The oxidation number of Cr decreases from +6 to +3. Total decrease in the oxidation number of two Cr atoms is 6. The oxidation number of Cl increases from -1 to 0. Total increase in the oxidation number of 2 Cl atoms is 2.

Balance increase in oxidation number with decrease in oxidation number by using appropriate coefficients.

K

2

Cr

2

O

7

+14HCl→2KCl+2CrCl

3

+H

2

O+3Cl

2

Balance O atoms by adding six water molecules on products side.

K

2

Cr

2

O

7

+14HCl→2KCl+2CrCl

3

+7H

2

O+3Cl

2

H atoms are balanced.

K

2

Cr

2

O

7

+14HCl→2KCl+2CrCl

3

+7H

2

O+3Cl

2

This is balanced chemical equation.

The sum of the coefficients of the products is 2+2+7+3=14

Answer:

The ratio of carbon and hydrogen atoms = 3.5 : 8

= 7 : 16

Then,the empirical formula is C7H16

Answer:

Water has strong hydrogen bond dipole-dipole intermolecular forces that give water a high surface tension and a high heat of vaporization and that make it a strong solvent

The Urms refers to the root mean square speed of the gas. The order of increasing Urms for the gases shown in the question; NF3 < H2S < H2O < He.

The Urms refers to the root mean square speed of the gas. This is ultimately dependent on the relative molecular mass of the gases when they are maintained at the same temperature.

Now, let us look at the order of increasing Urms for the gases shown in the question; NF3 < H2S < H2O < He.

Learnmore about Urms: https://brainly.com/question/365923

Answer:

a. [tex]Ag^0[/tex]

b. [tex]Ag^{+}[/tex]

c. [tex]Ca^{2+}F_2^-[/tex]

d. [tex]H_2^+S^{2-}[/tex]

e. [tex](C^{4+}O_3^{2-})^{-}[/tex]

f. [tex](Cr^{6+}O_4^{2-})^{2-}[/tex]

g. [tex]Cl_2^0[/tex]

h. [tex]Fe^0[/tex]

i. [tex]Cu^{2+}Cl_2^-[/tex]

j. [tex]C^{4-}H_4^+[/tex]

Explanation:

Hello there!

In this case, according to the concept of charge balance, which tell us that the overall charge is zero for any compound, except ions, it turns out possible to proceed as follows:

a. [tex]Ag^0[/tex]

b. [tex]Ag^{+}[/tex]

c. [tex]Ca^{2+}F_2^-[/tex]

d. [tex]H_2^+S^{2-}[/tex]

e. [tex](C^{4+}O_3^{2-})^{-}[/tex]

f. [tex](Cr^{6+}O_4^{2-})^{2-}[/tex]

g. [tex]Cl_2^0[/tex]

h. [tex]Fe^0[/tex]

i. [tex]Cu^{2+}Cl_2^-[/tex]

j. [tex]C^{4-}H_4^+[/tex]

Keep in mind lonely elements have 0 as their oxidation state.

Regards!

Answer:

290 g Al₂O₃

General Formulas and Concepts:

Atomic Structure

Stoichiometry

Explanation:

Step 1: Define

[Given] 2.8 mol Al₂O₃

[Solve] g Al₂O₃

Step 2: Identify Conversions

[PT] Molar Mass of Al: 26.98 g/mol

[PT] Molar Mass of O: 16.00 g/mol

Molar Mass of Al₂O₃: 2(26.98) + 3(16.00) = 101.96 g/mol

Step 3: Convert

Step 4: Check

Follow sig fig rules and round. We are given 2 sig figs.

285.488 g Al₂O₃ ≈ 290 g Al₂O₃

Topic: AP Chemistry

Unit: Atomic Structure