Answer:
6.023*10^23........ .......
15. You are interested in separating 4-methylbenzoic acid from 1,4-dimethoxybenzene using a procedure similar to the extraction procedure we used in lab. You plan to use sodium bicarbonate instead of sodium hydroxide. a) Show the reaction between salicylic acid and sodium bicarbonate. Label the acid, base, conjugate acid, conjugate base. b) Give the pKa values of the acid and conjugate acid. c) Which base will work better, sodium hydroxide or sodium bicarbonate
Solution :
a). The separation of 4-methylbenzoic acid from 1,4-dimethoxybenzene will work but it will result in lower recovery.
In the reaction of acid-base to form a sodium 4 - methoxy benzoate, that is soluble in the water, 4-methoxy benzoic acid reacts with the sodium bicarbonate to give sodium 4-methoxybenzoate as well as carbonic acid.
b). The pKa for the 4-methoxybenzoic acid is [tex]4.46[/tex], and that of carbonic acid is [tex]6.37[/tex]
c). The Keq for the reaction is [tex]10(6.37 - 4.46) = 101.91[/tex]
Therefore, the equilibrium lies to the right and also the reaction favors the products and the separation works.
But the recovery will be low when compared to the extraction with Sodium hydroxide as the strong base will drive the equilibrium further to the right position, thus neutralizing all the acids virtually. And the weak base will partially neutralize the acid.
What mass of steam initially at 120oC is needed to warm 200g of water in a glass container from 20.0 oC to 50.0 oC
Complete question:
What mass of steam initially at 120 ⁰C is needed to warm 200g of water in a 100 g glass container from 20.0 oC to 50.0 ⁰C
Answer:
the initial mass of the steam is 10.82 g
Explanation:
Given;
mass of water, m₁ = 200 g
mass of the glass, m₂ = 100 g
temperature of the steam = 120 ⁰C
initial temperature of the water, 20⁰ C
final temperature of the water, = 50⁰ C
let the mass of the steam = m
specific heat capacity of water c = 1 cal/g ⁰ C
specific heat capacity of glass c₂ = 0.2 cal/g ⁰ C
laten heat of vaporization of steam L = 540 cal/g
Apply principle of conservation energy;
Heat given off by the steam = Heat absorbed by water + heat absorbed by glass
[tex]mc\Delta T_1 + mL + mc\Delta T_2 = m_1c\Delta T_3 + m_2c_2\Delta T_3\\\\mc\Delta T_1 + mL + mc\Delta T_2 = [m_1c + m_2c_2]\Delta T_3[/tex]
m(1) (120 - 100) + m(540) + m(1) (100 - 50) = [200(1) + 100(0.2)] (50 - 20)
20m + 540m + 50m = 6600
610 m = 6600
m = 6600 / 610
m = 10.82 g
Therefore, the initial mass of the steam is 10.82 g
what mass of phenol must be dissolved in 25.0 g of naphthalene to produce a solution that is 0.22 m in phenol
Answer: A mass of 0.518 g of phenol must be dissolved in 25.0 g of naphthalene to produce a solution that is 0.22 m in phenol.
Explanation:
Given: Mass of naphthalene = 25.0 g
Molality = 0.22 m
This means that 0.22 moles of solute is present per kg of solvent.
As 25.0 g of naphthalene is there that will be 25.0 g per 1000 g (1 kg) is equal to 0.025 kg.
Hence, moles of phenol are calculated as follows.
[tex]Molality = \frac{moles}{mass (in kg)}\\0.22 m = \frac{moles}{0.025 kg}\\moles = 0.0055 mol[/tex]
Also, molar mass of phenol is 94.11 g/mol. This means that 1 mole of phenol contains 94.11 g.
Therefore, mass contained by 0.0055 moles of phenol is as follows.
[tex]0.0055 mol \times 94.11 g/mol \\= 0.518 g[/tex]
Thus, we can conclude that a mass of 0.518 g of phenol must be dissolved in 25.0 g of naphthalene to produce a solution that is 0.22 m in phenol.
The table shows the nature of reactants and products formed in a certain type of chemical reaction.
Nature of Reactants and Products
Reactants
Metal + lonic compound
Products
Metal + lonic compound
Which of the following is true about the type of chemical reaction?
it is a single replacement reaction, and the anions in the two inic compounds are different.
It is a single replacement reaction, and the cations in the two ionic compounds are different.
It is a double replacement reaction, and the anions in the two ionic compounds are different.
It is a double replacement reaction, and the cations in the two ionic compounds are different.
Answer: It is true about the type of reaction that it is a single replacement reaction, and the cations in the two ionic compounds are different.
Explanation:
When one element in a compound is replaced by another element in a chemical reaction then it is called a single replacement reaction.
For example, [tex]K + NaCl \rightarrow KCl + Na[/tex]
Here, potassium metal is replacing the sodium metal in the sodium chloride compound.
As metals become cation by losing an electron in a chemical reaction.
Thus, we can conclude that it is true about the type of reaction that it is a single replacement reaction, and the cations in the two ionic compounds are different.
Answer: Its A
Explanation:
a single replacement reactions, and the ANIONS in the two ionic compounds are different
which selection is an example of an electrolyte
a. potassium iodide in water
b. sucrose in water
c. pentane in octane
d. methanol in water
Answer:
i believe its A, potassium iodide in water
Explanation:
Calculate the moles of H3PO4 that reacted (8). Consult the coefficients in the balance chemical reaction to obtain the mole ratio. Show your calculation here.
Answer:
The number of moles of H₃PO₄ that reacted is 0.000343 moles
Note: Some data is missing. Data from the attachment is used for the calculationsinnthe explanation below.
Explanation:
The reaction is a neutralization reaction between NaOH and H₃PO₄. The equation of the reaction is given as follows:
3 NaOH + H₃PO₄ ---> Na₃PO₄ + 3 H₂O
The molarity of the NaOH solution is 0.238 mol/L.
Average volume of NaOH used during the titration to arrive to endpoint = (4.6 + 3.9 + 4.5) mL / 3 = 4.33 mL
Molarity is defined ratio of the number of moles of solute to the volume of solution. Mathematically, molarity = number of moles/volume in Litres
Number of moles of NaOH reacted = 0.238 mol/L × (4.33mL × 1 L/1000 mL)
Number of moles of NaOH = 0.00103 moles
From the equation of the reaction, 3 moles of NaOH reacts with 1 mole of H₃PO₄
0.00103 moles of NaOH will react with 0.00103 x 1/3 moles of H₃PO₄ = 0.000343 moles of H₃PO₄.
Therefore, number of moles of H₃PO₄ that reacted is 0.000343 moles
Name two natural sources of esters.
Answer:
"Esters are widespread in nature and are widely used in industry. In nature, fats are in general triesters derived from glycerol and fatty acids. Esters are responsible for the aroma of many fruits, including apples, durians, pears, bananas, pineapples, and strawberries."
Explanation:
17. The density of a population would influence which limiting factor?
O niche
O growth rate
O weather
O space
Answer:
The answer is growth rate
Explanation:
it will help you
The following statements either define or are closely related to the terms periodic law, period, or group. Match the terms to the appropriate statements.1. This is a vertical arrangement of elements in the periodic table. 2. This is a horizontal arrangement of elements in the periodic table. 3. The properties of the elements repeat in a regular way as the atomic numbers increase. 4. Element 19 begins this arrangement in the periodic table 5. The chemical properties of elements 12, 20, and 38 demonstrate this principle.
Answer:
Please find the complete solution in attached file.
Explanation:
Periodic law is the the properties of the elements that repeat in a regular way as the atomic numbers increase.
What is periodic table?Periodic chart organized collection of all chemical elements arranged roughly according to increasing atomic weight. The periodic recurrence of several features in the elements was originally identified by Dmitry I. Mendeleyev in 1869.
1. This is a vertical arrangement of elements in the periodic table group
2. This is a horizontal arrangement of elements in the periodic table period
3. The properties of the elements repeat in a regular way as the atomic numbers increase periodic law
4. Element 19 begins this arrangement in the periodic table period
5. The chemical properties of elements 12, 20, and 38 demonstrate this principle. periodic law
Therefore, periodic law is the the properties of the elements that repeat in a regular way as the atomic numbers increase.
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What is the phase of water at 0.25 atm and 0°C?
Water
(liquid)
Pressure (atm)
0.5-
0.25
Ice
(solid)
Water vapor
(gas)
0
000
Temperature (°C)
O A. Gas
O B. Solid and gas
O C. Solid and liquid
D. Solid
Water is in the solid phase at 0.25 atm and 0°C.
In what phase is water at 25?A pressure of 50 kPa and a temperature of 50 °C correspond to the “water” region—here, water exists only as a liquid. At 25 kPa and 200 °C, water exists only in the gaseous state.
What phase is water in at 0 C?Under standard atmospheric conditions, water exists as a liquid. But if we lower the temperature below 0 degrees Celsius, or 32 degrees Fahrenheit, water changes its phase into a solid called ice.
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Question 1
1 pts
How many mols of bromine are present in 35.7g of
Tin(IV) bromate?
Answer:
n = 0.0814 mol
Explanation:
Given mass, m = 35.7g
The molar mass of Tin(IV) bromate, M = 438.33 g/mol
We need to find the number of moles of bromine. We know that,
No. of moles = given mass/molar mass
So,
[tex]n=\dfrac{35.7}{438.33}\\\\n=0.0814\ mol[/tex]
So, there are 0.0814 moles of bromine in 35.7g of Tin(IV) bromate.
The volume of a single tantalum atom is 1.20×10-23 cm3. What is the volume of a tantalum atom in microliters?
Answer:
1.20x10⁻²⁰μL
Explanation:
1cm³ is equal to 1milliliter. As we must know, 1milliliter = 1000 microliters, 1000μL. To convert the 1.20x10⁻²³mL we need to use the conversion factor: 1mL = 1000μL.
The volume of tantalum in μL is:
1.20x10⁻²³mL * (1000μL /1L) = 1.20x10⁻²⁰μL
The position of the equilibrium for a system where K = 6.4 × 10 9 can be described as being favoring ________________
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.
Calculate the mass of water produced when 1.57g of butane reacts with excess oxygen
Explanation:
So, first you will want to write the balanced chemical equation for this reaction.
Butane = [tex]C_4H_{10}[/tex]
[tex]2C_4H_{10}+13O_2=>10H_2O+8CO_2[/tex]
^ This ends up being your balanced chemical equation. Now, you can do the math!
[tex]1.57gC_4H_{10}*\frac{1molC_4H_{10}}{58.12gC_4H_{10}}*\frac{10molH_2O}{2molC_4H_{10}}*\frac{18gH_2O}{1molH_2O}[/tex]
After plugging this into a calculator, your final mass of water should be:
2.43gH2O
Complete and balance the equations for the given single displacement reactions. Write the reaction in molecular form. Phases are optional. If you need to clear your work and reset the equation, click the CLR button.Li(s) + H2O---------- Ca(s) + H2O ---------------
Answer:
Li(s) + H2O(l) -----> LiOH(aq) + H2(g)
Ca(s) + 2H2O(l) ---------------> Ca(OH)2(aq) + H2(g)
Explanation:
Metals react with water to yield the metal hydroxide and hydrogen gas as shown in the answer above.
The reaction equations were balanced, the number of atoms of each element on both side of the reaction equation is exactly the same.
This is the way to write a balanced reaction equation for the species shown in the question.
How much carbon dioxide is released when it is fully combusted with 4Kg of ethanol with more than enough oxygen? How do you work it out?
Answer:
7.640 kg
Explanation:
Step 1: Write the balanced complete combustion equation for ethanol
C₂H₆O + 3 O₂ ⇒ 2 CO₂ + 3 H₂O
Step 2: Calculate the moles corresponding to 4 kg (4000 g) of C₂H₆O
The molar mass of C₂H₆O is 46.07 g/mol.
4000 g × 1 mol/46.07 g = 86.82 mol
Step 3: Calculate the moles of CO₂ released
86.82 mol C₂H₆O × 2 mol CO₂/1 mol C₂H₆O = 173.6 mol CO₂
Step 4: Calculate the mass corresponding to 173.6 moles of CO₂
The molar mass of CO₂ is 44.01 g/mol.
173.6 mol × 44.01 g/mol = 7640 g = 7.640 kg
Ammonium phosphate is an important ingredient in many solid fertilizers. It can be made by reacting aqueous phosphoric acid with liquid ammonia. Calculate the moles of phosphoric acid needed to produce 1.80 mol of ammonium phosphate. Be sure your answer has a unit symbol, if necessary, and round it to the correct number of significant digits.
Answer:
Explanation:
The reaction is
H3Po4+3NH3\to→ (NH4)3PO4
Given,7.10g NH3=7.10g/molar mass of NH3
=7.10g/(17.031g/mol)
=0.416mol
From the reaction
3 mol ammonia reacted and produced 1 mole of ammoniam phosphate
So,One mole ammonia reacted and produced 1/ 3 mole ammonium phosphate.
And Also,0.416 mole ammonium reacted and produced (1/3)0.416=0.138 mole ammonium phosphate.
Hence 0.138mole=0.138mole*149.08 g/mole
=20.573gm ammonium phosphate produced.
Hence 20.573g of ammonium phosphate is produced by the reaction of 7.10 g of ammonia.
Which 2 resonance forms destablize the carbocation intermediate if bezonitrile undergoes chlronation at the ortho or para positions
The question is incomplete, the complete question is shown in the image attached
Answer:
A and B
Explanation:
The electrophilic substitution of arenes yields a cation intermediate. The positive charge of the cation is delocalized over the entire ring.
The -CN group directs incoming electrophiles to the ortho/para position. The resonance structures for the chlorination of benzonitrile are shown in the question.
Recall that -CN is an electron withdrawing group. The resonance forms that destablize the carbocation intermediate are those in which the -CN group is directly attached to the carbon atom bearing the positive charge as in structures A and B.
How many hydrogen atoms are in 3.90 mol of ammonium sulfide?
Answer:
First, the number of ammonium sulfide molecules should be calculated:
N = NA × n,
where NA - the Avogadro number, n - number of moles.
N (ammonium sulfide) = 6.022 × 1023 × 8.5 mol = 51.187 × 1023.
The moelcular formula of ammonium sulfide is (NH4)2S. It means that each molecule contains 8 hydrogen atoms.
As a result, 8.5 mol of (NH4)2S contain:
51.187 × 1023 × 8 = 41 × 1024 hydrogen atoms.
Answer: 41 × 1024 hydrogen atoms
liquid junction potential arise due to?
Answer:
liquid junction potentials
when a cell contains a boundary between two electrolytic solutions of different composition or concentration, a liquid junction potential is developed due to the "diffusion of the various components at characteristic rates in the boundary zone."
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Certain ketones such as fructose can be oxidized by Benedict's reagent under basic conditions to form what type of compound
Answer:
Certain ketones such as fructose can be oxidized by Benedict's reagent under basic conditions to form what type of compound
Explanation:
Benedict's solution is a mixture of copper sulfate, anhydrous sodium carbonate, and sodium citrate.
In presence of mild reducing agents, Cu(II) ion in Benedict's solution becomes the Cu(I) ion.
Fructose has an alpha-hydroxy ketone group.
It undergoes tautomerism and forms alpha-hydroxy aldehyde which gives a positive test with Benedict's reagent.
During this test, aldehydes will be converted into carboxylic acids.
The reaction of fructose with Benedict's reagent is shown below:
Wine goes bad soon after opening because the ethanol dissolved in it reacts with oxygen gas to form water and aqueous acetic acid , the main ingredient in vinegar. Calculate the moles of acetic acid produced by the reaction of of ethanol. Be sure your answer has a unit symbol, if necessary, and round it to significant digits.
Answer:
The answer is "It takes 1,70 mol of ethanol".
Explanation:
To make acetic acid, we must first write the balanced reaction that occurs of ethanol with oxygen
The response is balanced:
[tex]CH_3CH_2OH+O_2\to CH_3COOH+H_2O[/tex]
1 mol of ethanol creates 1 mol of According the equilibrium Ethanol moles, therefore, required 1.70 mol of water = 1.70 mol
Which is the primary type of radiation from the sun that is absorbed by the ozone layer?
A. infrared radiatin
B. UV-B
C. X-rays
D. UV-C
E. UV-A
the answer to the question is B.UV-B
Name the following aldehyde PLEASE PLEASE HELP
Answer:
Explanation:
Answer is D 2,5-dimethylheptanal
You should accern the lowest possible number close to the parent name
I don’t want to fail help
I need correct answer if u don’t know I will report
When the researcher compiled information which research method did they most likely utilize?
a) documentary
b) survey
c) participant observation
d) case study
Answer:
a
Explanation:
documentary is best researcher!.
compound of aspartame is a dipeptide that is often used as a sugar substitute which functional groups are present
Answer:
Carboxyl, primary amine, amide, ester, and phenyl.
Explanation:
The functional groups present in the compound of aspartame are carboxyl, primary amine, amide, ester, and phenyl. Aspartame is an artificial non-saccharide sweetener which is 200 times sweeter than sucrose. This aspartame is commonly used as a sugar substitute in many foods and beverages. It has the trade names such as NutraSweet, Equal, and Canderel.
g 0.500 L of a solution with a concentration of 0.25 M is needed. To prepare this solution, a stock solution with a concentration of 1.25 M is prepared. What volume of the stock solution is needed to create the desired solution
Answer:
0.1 L
Explanation:
From the question given above, the following data were obtained:
Concentration of stock solution (C₁) = 1.25 M
Volume of diluted solution (V₂) = 0.5 L
Concentration of diluted solution (C₂) = 0.25 M
Volume of stock solution needed solution (V₁) =?
The volume of the stock solution needed can be obtained as follow:
C₁V₁ = C₂V₂
1.25 × V₁ = 0.25 × 0.5
1.25 × V₁ = 0.125
Divide both side by 1.25
V₁ = 0.125 / 1.25
V₁ = 0.1 L
Therefore, the volume of the stock solution needed is 0.1 L
How many molecules of C 2H 5Br will be present if you had 4.52 g of this compound?
Zn-64 = 48.63%
Zn-66 = 27.90%
Zn-67 = 4.10%
Zn-68 = 18.75%
Zn-70 = .62%
Calculate the average atomic mass/given their percent abundance
Answer:
A = 65.46 u
Explanation:
Given that,
The composition of zinc is as follows :
Zn-64 = 48.63%
Zn-66 = 27.90%
Zn-67 = 4.10%
Zn-68 = 18.75%
Zn-70 = .62%
We need to find the average atomic mass of the given element. It can be solved as follows :
[tex]A=\dfrac{48.63\times 64+27.90\times 66+4.1\times 67+18.75\times 68+0.62\times 70}{100}\\A=65.46\ u[/tex]
So, the average atomic mass of zinc is 65.46 u.
Determine the molarity of the sodium ions when 78.0 g Na2S is dissolved in water for a final volume of 1.0 L.
Answer:
[Na⁺] = 1.99 M
Explanation:
Na₂S is a ionic salt that can be dissociated.
Dissociation equation is:
Na₂S → 2Na⁺ + S⁻²
1 mol of sodium sulfide can give 2 moles of sodium cation.
We convert moles of salt: 78 g . 1mol / 78.06 g = 0.999 moles
As ratio is 1:2, after dissociation we have (0.999 . 2) = 1.998 moles of Na⁺
Molarity is a type of concentration.
It indicates moles of solute in 1 L of solution and in this case, we have 1 L as final voulme.
Moles of Na⁺ are 1.998 moles. Then molarity (mol/L) is:
M =1.99 mol/L
