This question is incomplete, the complete question is;
In recrystallization from boiling water of benzoic acid contaminated with acetanilide, you begin with an impure sample of 5 grams. If the % composition of the acetanilide impurity in the sample is 6.3 %, what is the minimum amount in mL of solvent (water) required for the recrystallization
Compound Solubility in water at 25°C Solubility in water at 100°C
Benzoic Acid 0.34 g/100mL 5.6 g/100mL
Acetanilide 0.53 g/100mL 5.5 g/100mL
Answer:
The minimum amount in mL of solvent (water) required for the recrystallization is 91 mL
Explanation:
Given the data in the question;
mass of sample = 5 g
percentage composition of the acetanilide impurity = 6.3%
mass of the acetanilide in impure sample will be;
⇒ 6.3% × 5 g = 0.315 g
Mass of benzoic acid in impure sample;
⇒ 5 g - 0.315 g = 4.685 g
now, solubility in water at 100°C for benzoic acid = 5.6 g/100mL
hence 4.685 g of benzoic acid is soluble in x mL
x = [ 100 mL × 4.685 g ] / 5.6 g
x = 83.66 ≈ 84 mL
Also, solubility in water at 100°C for acetanilide = 5.5 g/100mL
hence 0.315 g of benzoic acid is soluble in x mL
x = [ 100 mL × 0.315 g ] / 5.5 g
x = 5.727 ≈ 6 mL
So, the minimum amount in mL of solvent (water) required for the recrystallization will be;
⇒ 85 mL + 6 mL = 91 mL
The minimum amount in mL of solvent (water) required for the recrystallization is 91 mL
what characterizes a homogeneous mixture?
Answer:
a mixture that doesn't really show the ingredients or things put into the material or food.
For which of the following reactions is the enthalpy change equal to the second ionization energy of nitrogen?
Answer:
"[tex]N^+(g) \rightarrow N^{2+}(g) + e^-[/tex]" is the appropriate answer.
Explanation:
Whenever one electron or particle must be removed from some kind of gas atom or molecule, it requires that the very first amount of energy necessary.Two electrons must be removed from such a mono-positive exhaust gases structure or position of ion before they may become a dipositive gaseous ion.Thus the above is the correct answer.
Hãy cho biết giá trị và ý nghĩa của số lượng tử n, l, m, ms khi mô tả trạng thái của electron trong nguyên tử?
The specific heat capacity of lead is 0.13 J/g-K. How much heat (in J) is required to raise the temperature of 15 g of lead from 22 °C to 37 °C? a. 5.8 × 10-4 J b. 0.13 J c. 29 J d. 2.0 J e. -0.13 J
Answer:
c. 29 J
Explanation:
Step 1: Given data
Specific heat capacity of Pb (c): 0.13 J/g.K (= 0.13 J/g.°C)Mass of Pb (m): 15 gInitial temperature: 22 °CFinal temperature: 37 °CStep 2: Calculate the temperature change
ΔT = 37 °C - 22 °C = 15 °C
Step 3: Calculate the heat (Q) required to raise the temperature of the lead piece
We will use the following expression.
Q = c × m × ΔT
Q = 0.13 J/g.°C × 15 g × 15 °C = 29 J
What is Bose Einstein state of matter and their examples
Answer:
A BEC ( Bose - Einstein condensate ) is a state of matter of a dilute gas of bosons cooled to temperatures very close to absolute zero is called BEC.
Examples - Superconductors and superfluids are the two examples of BEC.
Explanation:
Tapeworm is grouped in the phylum Platyhelminthes
Answer:
Tapeworm, also called cestode, any member of the invertebrate class Cestoda (phylum Platyhelminthes), a group of parasitic flatworms containing about 5,000 species. ... Tapeworms also lack a circulatory system and an organ specialized for gas exchange.
Nucleophilic aromatic substitution involves the formation of a resonance-stabilized carbanion intermediate called a Meisenheimer complex as the nucleophile attacks the ring carbon carrying the eventual leaving group.
a. True
b. False
Answer:
True
Explanation:
Aromatic rings undergo nucleophillic substitution reactions in the presence of a electron withdrawing group which stabilizes the Meisenheimer complex.
When the nucleophile attacks the ring carbon atom carrying the eventual leaving group. A resonance-stabilized carbanion intermediate called a Meisenheimer complex is formed.
Subsequent loss of the leaving group from the intermediate complex yields the product of the reaction.
Which of the following are examples of single replacement reactions? Select all that apply.
Answer:
Na2S(aq)+Cd(No3)2(aq)=CdS(s)+2NaNo3(aq)
Answer: it’s checkbox 2&3
A chemist determines by measurements that moles of bromine liquid participate in a chemical reaction. Calculate the mass of bromine liquid that participates. Round your answer to significant digits.
Answer:
5.20 grams of Br₂
Explanation:
From our previous knowledge;
We understand that:
The number of moles of a given element = mass of the element divided by its molar mass.
Mathematically:
[tex]\mathbf{no \ of \ moles =\dfrac{ mass}{ molar \ mass}}[/tex]
From the given information, let's assume that the 0.065 moles of liquid -bromine partake in the reaction.
From the periodic table, the molar mass of Bromine is = 79.9 g/mol
As such, the mass of liquid that partakes is calculated as:
0.065 mol = mass/ 79.9 g/mol
mass = 0.065 mol × 79.9 g/mol
mass of liquid that partakes in the reaction = 5.20 grams of Br₂
Sodium acetate is produced by the reaction of baking soda and vinegar. The resultant solution is then heated until it becomes saturated and allowed to cool. As a result, the solution has become supercooled. Upon addition of a small seed crystal, the solution temperature increases as sodium acetate trihydrate crystallizes. Its molar enthalpy of fusion is 35.9 kJ/mol. How much thermal energy would be released by 276.0 g of sodium acetate trihydrate (molar mass
Answer: The thermal energy that would be released by 276.0g of sodium acetate trihydrate is 71.8kJ.
Explanation:
Supercooling is the process of lowering the temperature a liquid below its freezing point, without it becoming solid. A liquid below its freezing point will crystallize in the presence of a seed crystal because it serves as a structure for formation of crystals. From the question,
The given mass of sodium acetate trihydrate
(CH3COONa.3H2O)= 276.0g
Molar mass of sodium acetate
trihydrate= 136.08g/mol
Thermal heat of fusion of sodium acetate
trihydrate = 35.9 kJ/mol
From the given mass the number of moles present= 276.0/ 136.08
= 2.0moles
Therefore the heat (thermal) energy of the given mass of sodium acetate
trihydrate = 2.0 × 35.9
= 71.8kJ
Therefore, upon addition of a small seed crystal, the solution temperature increases as sodium acetate trihydrate crystallizes.
What is the correct ratio of carbon to hydrogen to oxygen in glucose (CH1206)?
•12:12:6
•2:1:1
•1:2:1
•6:6:12
Answer:
1:2:1 is the correct ratio of carbon hydrogen to oxygen in glucose.
Isotopes are: A. are only theoretical. B. only formed in laboratories. C. found in nature. D. found in the nuclear reactions in stars but not on Earth.
Answer:
B. only formed in laboratories
Explanation:
i know
Isotopes are only formed in Laboratories. hence, Option (B) is correct.
What are Isotopes ?
Each of two or more forms of the same element that contain equal numbers of protons but different numbers of neutrons in their nuclei, and hence differ in relative atomic mass but not in chemical properties; in particular, a radioactive form of an element is known as Isotope.
Isotopes are two or more types of atoms that have the same atomic number and position in the periodic table, and that differ in nucleon numbers due to different numbers of neutrons in their nuclei.
Therefore, Isotopes are only formed in Laboratories. hence, Option (B) is correct.
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Consider the reaction between CaCO3 and HCl. Which of the following could speed up the reaction?
I. Increasing concentration of the HCl
II. Increasing size of the CaCO3 pieces
III. Increasing temperature
a) I and III only
b) I, II, and III
c) I only
d) II and III only
What does quantization refer to?
Answer:
Quantization is the process of constraining an input from a continuous or otherwise large set of values (such as the real numbers) to a discrete set (such as the integers).
Explanation:
Quantization refers to the situation where an electromagnetic field consists of discrete energy parcels, photons.
What is Quantatization in Chemistry ?In Chemistry , the concept that a system cannot have any possible energy value but instead is limited to certain specific energy values (states). This states depend on the specific system in question.
Under this system, Energy could be gained or lost only in integral multiples of some smallest unit of energy, a quantum (the smallest possible unit of energy).
Hence, Quantization refers to the situation where an electromagnetic field consists of discrete energy parcels, photons.
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1. Explain the test for unsaturation.
2. Write down the balanced chemical equations for the complete and incomplete
combustion of octene
3. Explain how propanol, an alcohol, is formed from propene..
4. How is margarine formed?
Answer:
1)In organic chemistry, the bromine test is a qualitative test for the presence of unsaturation (carbon-to-carbon double or triple bonds), phenols and anilines. ... The more unsaturated an unknown is, the more bromine it reacts with, and the less coloured the solution will appear.
2)The equation for incomplete combustion of propane is: 2 C3H8 + 9 O2 → 4 CO2 + 2 CO + 8 H2O + Heat. If not enough oxygen is present for complete combustion, incomplete combustion occurs. The result of incomplete combustion is, once again, water vapour, carbon dioxide and heat. But it also produces carbon monoxide.
Explanation:
3)Propene, also known as propylene, is an unsaturated organic compound with the chemical formula {\displaystyle {\ce {CH3CH=CH2}}}. It has one double bond, and is the second simplest member of the alkene class of hydrocarbons. It is a colorless gas with a faint petroleum-like odor.
Formula: C3H6
IUPAC ID: Propene
4)Margarines are chemically created during hydrogenation which, until January 1, 2006, relied upon trans fats to solidify their vegetable oils. Food companies have been exploring options for replacing trans fat in partially hydrogenated margarine.
HELP!!!!! Substance A and substance B are mixed together. To separate the mixture, water is added, and substance A is filtered out. Then, the remaining liquid is heated to remove the water, leaving a residue of substance B. Which statement about substance A and substance B could be correct?
A. Substance A is rice, and substance B is sugar.
B. Substance A is alcohol, and substance B is salt.
C. Substance A is sand, and substance B is alcohol.
D. Substance A is sugar, and substance B is instant coffee.
The statement that "substance A is rice, and substance B is sugar" is correct.
WHAT IS A MIXTURE?
A mixture in chemistry is a substance that contains two or more different substances. One notable characteristics of a mixture is that it can easily be separated using physical means.According to this question, a mixture contains two substances A and B. Water is added to this mixture for easy separation.
Substance A is filtered out. This means that substance A is a solid that is insoluble in water. This substance is RICE. The remaining liquid is heated to remove the water content leaving a residue of substance B. This shows that substance B is also a solid but soluble in water. SUGAR best fits this description.Therefore, in the mixture of two substances A and B, substance A is rice, and substance B is sugar.
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In a quantitative analysis, a methanol (CH3OH) contaminated water sample was titrated with 0.0021 mol L- potassium permanganate (KMnO4). 50.00 mL samples of the water to be tested were acidified by sulfuric acid, then titrated with the permanganate solution. The results are shown below. Burette reading, ml 1st titration 2nd titration 3rd titration 4th titration Final volume 12.40 19.60 26.60 17.25 Initial volume 4.45 12.50 19.60 10.15 Titre 7.95 7.10 7.00 7.10 The complete equation for the redox titration reaction is: 4MnO4- + 12H+ + 5CH3OH → 4Mn2+ + 11H2O + 5HCOOH a. [5] Calculate the concentration of the methanol in mol L-1.
In a REDOX titration, one specie is oxidized while the other is reduced. The concentration of methanol is 0.012 mol L-1. Methanol is the oxidizing agent while permanganate is the reducing agent.
The average titre value is; [tex]\frac{7.95 + 7.10 + 7.00 + 7.10}{4}[/tex] = 7.29 mL
Equation of the reaction is:
[tex]4MnO4- + 12H+ + 5CH3OH ----> 4Mn2+ + 11H2O + 5HCOOH[/tex]
Concentration of oxidizing agent = CA = ?
Concentration of reducing agent = CB = 0.0021 mol L-1
Volume of oxidizing agent = VA= 7.29 mL
Volume of reducing agent = VB = 50.00 mL
Number of moles of oxidizing agent NA = 4
Number of moles of reducing agent NB = 5
Note that NA and NB are obtained from the balanced reaction equation
CAVA/CBVB = NA/NB
CAVANB = CBVBNA
CA = CBVBNA/VANB
CA = 0.0021 mol L-1 * 50.00 mL * 4/7.29 mL * 5
CA= 0.012 mol L-1
For a comprehensive definition of redox titration see
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For each reaction, write the chemical formulae of the oxidized reactants.
a. ZnCl2 (aq) + 2Na(s) → Zn(s) + 2NaCl(aq)
b. Al(s) + FeBrz (aq) → AlBrz (aq) + Fe(s)
c. FeSO4 (aq) + Zn (s) → Fe(s) + ZnSO4(aq)
Answer:
a. Na(s); b. Al(s); c. Zn(s)
Explanation:
Let's consider the following redox reactions.
a. ZnCl₂ (aq) + 2 Na(s) → Zn(s) + 2 NaCl(aq)
Na is oxidized because its oxidation number increases from 0 to +1 (in NaCl) whereas Zn is reduced because its oxidation number decreases from 2+ (in ZnCl₂) to 0.
b. Al(s) + FeBr₃ (aq) → AlBr₃ (aq) + Fe(s)
Al is oxidized because its oxidation number increases from 0 to +3 (in AlBr₃) whereas Fe is reduced because its oxidation number decreases from 3+ (in FeBr₃) to 0.
c. FeSO₄ (aq) + Zn(s) → Fe(s) + ZnSO₄(aq)
Zn is oxidized because its oxidation number increases from 0 to +2 (in ZnSO₄) whereas Fe is reduced because its oxidation number decreases from 2+ (in FeSO₄) to 0.
what are the five main points of kinetic theory of gas?
The kinetic-molecular theory of gases assumes that ideal gas molecules
(1) are constantly moving;
(2) have negligible volume;
(3) have negligible intermolecular forces;
(4) undergo perfectly elastic collisions; and
(5) have an average kinetic energy proportional to the ideal gas's absolute temperature.
The five main postulates of the KMT are as follows:
(1) the particles in a gas are in constant, random motion,
(2) the combined volume of the particles is negligible
(3) the particles exert no forces on one another,
(4) any collisions between the particles are completely elastic.
(5) the average kinetic energy of the particles is proportional to the temperature in kelvins.
Urea, CH4N2O (s), is manufactured from NH3 (g) and CO2 (g). H2O (l) is another product of this reaction. An experiment is started with 2.6 grams of NH3 (g) added into a reaction vessel with CO2 (g).
Write the balanced equation for this reaction, being sure to include physical states. Based on the balanced equation above, calculate the following:
a. the theoretical yield of urea in grams that can be made from the NH3
b. the actual amount of urea made if the percent yield for this reaction is 34%.
Answer:
a. 4.41 g of Urea
b. 1.5 g of Urea
Explanation:
To start the problem, we define the reaction:
2NH₃ (g) + CO₂ (g) → CH₄N₂O (s) + H₂O(l)
We only have mass of ammonia, so we assume the carbon dioxide is in excess and ammonia is the limiting reactant:
2.6 g . 1mol / 17g = 0.153 moles of ammonia
Ratio is 2:1. 2 moles of ammonia can produce 1 mol of urea
0.153 moles ammonia may produce, the half of moles
0153 /2 = 0.076 moles of urea
To state the theoretical yield we convert moles to mass:
0.076 mol . 58 g/mol = 4.41 g
That's the 100 % yield reaction
If the percent yield, was 34%:
4.41 g . 0.34 = 1.50 g of urea were produced.
Formula is (Yield produced / Theoretical yield) . 100 → Percent yield
FILL IN THE BLANK:
The rate of a reaction is measured by how fast a (Product Or Reactant)
is used up or how fast a
(Reactant Or Product) is formed?
Answer:
the rate of a reaction is measured by how fast a REACTANT is used up or how fast a PRODUCT is formed
H2SO4 ????????????????
Explanation:
Sulfuric Acid (H2SO4) is a strong mineral acid that has is colorless when pure. This chemical is used as a chemical intermediate to manufacture other chemicals and cleaning metal surfaces. The formula for sulfuric acid is H2SO4. The molar mass of sulfuric acid is 98.07848 g mol.
what is the charge on the Mn ions in Mn2o3? 1+, 2+, 3+,3-,4+?
Based on periodic properties, choose the more metallic element from each of the following pairs.
Match the words in the left column to the appropriate blanks in the sentences on the right.
Between Sr and Sb, the more metallic element is ______
Between \rm Sr and \rm Sb, the more metallic element is _______
Between As and Bi, the more metallic element is ______
Between \rm As and \rm Bi, the more metallic element is _______
Between Cl and O, the more metallic element is ______
Between \rm Cl and \rm O, the more metallic element is ______
Between S and As, the more metallic element is ______
Between \rm S and \rm As, the more metallic element is _______
Answer:
Sr is the more metallic element
Bi is the more metallic element
O is the more metallic element
As is the more metallic element
Explanation:
One thing should be clear; metallic character increases down the group but decreases across the period.
Hence, as we move across the period, elements become less metallic. As we move down the group elements become more metallic.
This is the basis upon which decisions were made about the metallic character of each of the elements listed above.
What is the minimum pressure in kPa that must be applied at 25 °C to obtain pure water by reverse osmosis from water that is 0.690 M in sodium chloride and 0.08 M in zinc sulfate? Assume complete dissociation for electrolytes.
Answer:
1. Water purification method by reverse osmosis – membrane filtration
2. Method of purifying pure water by filter
3. Demineralization by ion exchange method
3. Demineralization by ion exchange method
Explanation:
calculate the total consumer surplus in the amusement park market if they a 12
Answer:
The total consumer surplus is 240.
Explanation:
If p=12 then q=20
0.5×(36−12)×20=240
here's the graph to help you see the change.
Name the following cycloalkane:
H3C-
CH2CH3
A. 1-ethyl-4-methylcyclohexane
B. 4-ethyl-1-methylcyclohexane
C. 1-methyl-4-ethylcyclohexane
Answer:
A
Explanation:
1-ethyl-4-methylcyclohexane
i believe it is A
hope that helped :)
What can be found on the periodic table?
A. the name of molecules formed by the element
B. the number of isotopes an element has
C. the date an element was discovered
D. the number of protons an element has
Answer:
I think the answer is..
The name of molecules formed by the element.
I hope it will help you !
The solubility of lithium fluoride, LiF, is 1.6 g/L, or 6.2 x 10â2 M.
a. Write the balanced solubility equilibrium equation for LiF.
b. Determine the molar concentration of the lithium ion and the fluoride ion.
c. Write the Ksp expression for the reaction.
d. Calculate Ksp for lithium fluoride.
Answer:
a. LiF(s) ⇄ Li⁺(aq) + F⁻(aq)
b. [Li⁺] = [F⁻] = 6.2 x 10⁻² M
c. Ksp = [Li⁺] [F⁻]
d. Ksp = 3.8 × 10⁻³
Explanation:
The solubility (S) of lithium fluoride, LiF, is 1.6 g/L, or 6.2 x 10⁻² M.
a. The balanced solubility equilibrium equation for LiF is:
LiF(s) ⇄ Li⁺(aq) + F⁻(aq)
b. We will make an ICE chart.
LiF(s) ⇄ Li⁺(aq) + F⁻(aq)
I 0 0
C +S +S
E S S
Then, [Li⁺] = [F⁻] = S = 6.2 x 10⁻² M
c. The solubility product constant, Ksp, is the equilibrium constant for a solid substance dissolving in an aqueous solution.
Ksp = [Li⁺] [F⁻]
d.
Ksp = [Li⁺] [F⁻] = (6.2 x 10⁻²)² = 3.8 × 10⁻³
A sample of gas is held at constant volume. If the number of moles of this sample of gas is doubled and the pressure of this sample of gas is halved, what happens to the absolute temperature of the gas?
Select one
a. The absolute temperature is doubled.
b. The absolute temperature is halved.
c. The absolute temperature is quadrupled.
d. The absolute temperature is quartered.
e. The absolute temperature stays the same.
Answer:
number of moles of gas increases the volume also increases.
