Explanation:
for immiscible liquids it is quite easy to separate and the separating funnel can be used but for miscible liquid they form a single entity and separating them is quite impossible if the differences in temperature is not considered,so in distillation the one with lower boiling point evaporates out living behind the one with high boiling point
Explain the concept of significant figures and why it is important in scientific experiments.
Answer:
Significant figures (also called significant digits) are an important part of scientific and mathematical calculations, and deals with the accuracy and precision of numbers. It is important to estimate uncertainty in the final result, and this is where significant figures become very important.
Explanation:
For isotopic analysis, an ice core sample was heated to produce gaseous H2O. If 3.00 μg of gaseous H2O was injected into a mass spectrometer:
How many moles of water were injected? Answer: 1.67×10−7
If the sample contains 0.0156% deuterium, how many deuterium atoms were injected?
Answer:
1.67 × 10⁻⁷ mol H₂O
3.14 × 10¹³ atoms deuterium
Explanation:
How many moles of water were injected?
We have 3.00 μg of gaseous H₂O. To calculate the number of moles of water we will use the following relationships:
1 g = 10⁶ μgThe molar mass of water is 18.02 g/mol.[tex]3.00 \mu g \times \frac{1g}{10^{6}\mu g } \times \frac{1mol}{18.02g} = 1.67 \times 10^{-7} mol[/tex]
If the sample contains 0.0156% deuterium, how many deuterium atoms were injected?
We will use the following relationships:
1 mole of water contains 6.02 × 10²³ molecules of water.
There are 2 hydrogen atoms per water molecule.
0.0156% of hydrogen atoms are deuterium atoms.
[tex]1.67 \times 10^{-7} molH_2O \times \frac{6.02 \times 10^{23}moleculesH_2O }{1molH_2O} \times \frac{2atomsH}{1moleculeH_2O} \times 0.0156 \% = 3.14 \times 10^{13} atomsD[/tex]
Iridium-192 is used in medicine to treat prostate cancer. Iridium-192 has two modes of radioactive decay: 96% of the time it decays by beta emission and 4% of the time it decays by electron capture. What are the daughter nuclides of these two decay processes?
Answer:
The daughter nuclides of these two decay processes are [tex]^{192}_{78}Pt [/tex] and [tex]^{192}_{76}Os[/tex].
Explanation:
The beta emission is represented by:
A = (Z + 1) + (n - 1) = is invariant
n: neutron
p: proton
[tex]^{A}_{Z}X \rightarrow ^{A}_{Z+1}Y[/tex]
Hence, the daughter nuclide of the beta emission of Ir-192 is:
[tex]^{192}_{77}Ir \rightarrow ^{192}_{78}Pt[/tex]
Now, electron capture is represented by:
A = (Z - 1) + (n + 1) = is invariant
[tex]^{A}_{Z}X \rightarrow ^{A}_{Z-1}Y[/tex]
Then, the daughter nuclide of the electron capture of Ir-192 is:
[tex]^{192}_{77}Ir \rightarrow ^{192}_{76}Os[/tex]
Therefore, the daughter nuclides of these two decay processes are [tex]^{192}_{78}Pt [/tex] and [tex]^{192}_{76}Os[/tex].
I hope it helps you!
Consider the following redox reaction: Ag⁺(aq) + Fe²⁺(aq) ⇌ Ag(s) + Fe³⁺(aq). How many moles of electrons are exchanged?
Answer:
1 mol of electron is exchanged. The mol of electrons that is released by the iron, is gained by the silver.
Explanation:
We need to determine the half reactions:
Ag⁺ → Ag
These is the reduction reaction, where Silver decreases the oxidation state. It gained 1 mol of e⁻
Fe²⁺ → Fe³⁺
In this case, iron increases the oxidation state, from +2 to +3. It has released 1 mol of electrons. This is the oxidation reaction.
The complete redox is:
Ag⁺ + 1e⁻ → Ag
Fe²⁺ → Fe³⁺ + 1e⁻
Ag⁺(aq) + 1e⁻ + Fe²⁺(aq) ⇌ Ag(s) + Fe³⁺(aq) + 1e⁻
The electrons will be cancelled.
In the redox reaction Ag⁺(aq) + Fe²⁺(aq) ⇌ Ag(s) + Fe³⁺(aq),
1 mole of electrons is exchanged.
Let's consider the following balanced redox reaction.
Ag⁺(aq) + Fe²⁺(aq) ⇌ Ag(s) + Fe³⁺(aq).
We can identify both half-reactions.
Reduction: Ag⁺(aq) + 1 e⁻ ⇌ Ag(s)Oxidation: Fe²⁺(aq) ⇌ Fe³⁺(aq) + 1 e⁻We can conclude that:
In the reduction, 1 mole of Ag⁺ gains 1 mole of electrons to form 1 mole of Ag.In the oxidation, 1 mole of Fe²⁺ loses 1 mole of electrons to form 1 mole of Fe³⁺All in all, 1 mole of electrons is exchanged.In the redox reaction Ag⁺(aq) + Fe²⁺(aq) ⇌ Ag(s) + Fe³⁺(aq),
1 mole of electrons is exchanged.
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What amount of heat is required to vaporize 143.45 g of ethanol (C₂H₅OH)? (∆Hvap = 43.3 kJ/mol)
Answer:
135 KJ.
Explanation:
The following data were obtained from the question:
Mass of ethanol, C₂H₅OH = 143.45 g
Heat of vaporisation, ∆Hvap = 43.3 kJ/mol
Heat required (Q) =.?
Next, we shall determine the number of mole in 143.45 g of ethanol (C₂H₅OH). This is can be obtained as follow:
Mass of ethanol, C₂H₅OH = 143.45 g
Molar mass of ethanol, C₂H₅OH = (12×2) + (1×5) + 16 + 1
= 24 + 5 + 16 + 1
= 46 g/mol
Mole of ethanol, C₂H₅OH =?
Mole = mass /Molar mass
Mole of ethanol, C₂H₅OH = 143.45/46
Mole of ethanol, C₂H₅OH = 3.118 moles
Finally, we shall determine the heat required to vaporize the ethanol, C₂H₅OH as follow:
Heat of vaporisation, ∆Hvap = 43.3 kJ/mol
Mole of ethanol, C₂H₅OH (n) = 3.118 moles
Heat required (Q) =.?
Q = n•∆Hvap
Q = 3.118 × 43.3
Q = 135 KJ
Therefore, the heat required is 135 KJ
Using the molecular weight (258 g/mol) determine the amount of mmol of (3S)-2,2,- dibromo-3,4-dimethylpentane required.
The question is incomplete, the complete question is;
With all of this data in hand, we can now set up our reaction. To begin we are going to use 0.7 g of (35)-2.2-dibromo-3,4-dimethylpentane. Question #7: Using the molecular weight (258 g/mol) determine the amount of mmol of (3S)-2,2,- dibromo-3,4-dimethylpentane required. Round to the tenths place
Answer:
2.70 mmols
Explanation:
Given that;
Mass of (3S)-2,2,- dibromo-3,4-dimethylpentane = 0.7 g
Molar mass of (3S)-2,2,- dibromo-3,4-dimethylpentane = 258 g/mol
From,
Number of moles = mass/molar mass
Number of moles of (3S)-2,2,- dibromo-3,4-dimethylpentane = 0.7g/258 g/mol = 2.7 ×10^-3 moles
Therefore;
Number of moles of (3S)-2,2,- dibromo-3,4-dimethylpentane = 2.70 mmols
The pKb of the base cyclohexamine, C6H11NH2, is 3.36. What is the pKa of the conjugate acid, C6H11NH3
Answer:
10.64
Explanation:
Let's consider the basic reaction of cyclohexamine, C₆H₁₁NH₂.
C₆H₁₁NH₂(aq) + H₂O(l) ⇄ C₆H₁₁NH₃⁺(aq) + OH⁻ pKb = 3.36
C₆H₁₁NH₃⁺ is its conjugate acid, since it donates H⁺ to form C₆H₁₁NH₂. C₆H₁₁NH₃⁺ acid reaction is as follows:
C₆H₁₁NH₃⁺(aq) + H₂O(l) ⇄ C₆H₁₁NH₂(aq) + H₃O⁺(aq) pKa
We can find the pKa of C₆H₁₁NH₃⁺ using the following expression.
pKa + pKb = 14.00
pKa = 14.00 - pKb = 14.00 - 3.36 = 10.64
The pKa of conjugate acid of cyclohexamine has been 10.64.
The pKa has been acid dissociation constant, and has been describing the hydrogen ion concentration in the sample.
The pKb has been the base dissociation constant and has been describing the hydroxide ion concentration in the sample.
The sum of pKa and pKb has been found to be 14.
[tex]\rm pKa \;+\;pKb=14[/tex]
The pKb of cyclohexamine has been 3.36. The pKa of conjugate acid in the sample has been given by substituting the values as:
[tex]\rm pKa\;+\;3.36=14\\pKa=14\;-\;3.36\\pKa=10.64[/tex]
The pKa of conjugate acid of cyclohexamine has been 10.64.
For more information about pKa and pKb, refer to the link:
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a) What volume of a 1.0 M KI solution must be added to 470.0 mL of a solution that is 0.11 M in Pb2 ion to precipitate all the lead ion
Answer:
0.168mL of the 1.0M KI solution must be added
Explanation:
The PbI₂ is in equilibrium with water as follows:
PbI₂ ⇄ Pb²⁺ + 2I⁻
Where Ksp is:
Ksp = 1.4x10⁻⁸ = [Pb²⁺] / [I⁻]²
As molarity of Pb²⁺ is 0.11M:
1.4x10⁻⁸ = [0.11M] / [I⁻]²
1.27x10⁻⁷ = [I⁻]²
3.57x10⁻⁴M = [I⁻]
Thus, to precipitate all Pb²⁺ you need to add 3,57x10⁻⁴M of I⁻. As volume of the solution is 470.0mL = 0.47L, you need to add:
0.47L * (3,57x10⁻⁴moles / L) = 1.68x10⁻⁴ moles of I⁻ = Moles of KI.
That comes from the 1.0M KI. You need to add:
1.68x10⁻⁴ moles of KI * (L / 1.0 mol) = 1.68x10⁻⁴L =
0.168mL of the 1.0M KI solution must be addedThe C_7 compound which gives 3 signals in the broadband proton-decoupled ^13C spectrum could be:______
a) Heptane
b) 2-Methylhexane
c) 3, 3-Dimethylpentane
d) 2, 4-Dimethylpentane
e) 2, 2, 3-Trimethylbutane
Answer:
d) 2, 4-Dimethylpentane
Explanation:
2, 4-Dimethylpentane is the c_7 compound that gives 3 signals in the broadband proton decoupled ¹³C spectrum.
This compound is classified as an alkane and it's chemical formula is [(CH3C)2CH]2CH2. It is a hydrocarbon that has no odor. When it is combined with other gas compounds it gives high octane fuel.
What is the molarity (M) of an 85.0-mL solution (total volume) containing 1.77 g of ethanol (C2H5OH)
Answer: The molarity of solution is 0.453 M
Explanation:
Molarity of a solution is defined as the number of moles of solute dissolved per liter of the solution.
[tex]Molarity=\frac{n\times 1000}{V_s}[/tex]
where,
n = moles of solute
[tex]V_s[/tex] = volume of solution in ml
moles of [tex]C_2H_5OH[/tex] = [tex]\frac{\text {given mass}}{\text {Molar mass}}=\frac{1.77g}{46g/mol}=0.0385mol[/tex]
Now put all the given values in the formula of molality, we get
[tex]Molarity=\frac{0.0385\times 1000}{85.0}[/tex]
[tex]Molarity=0.453[/tex]
Therefore, the molarity of solution is 0.453 M
What must be true of the free energy change, trangle G, for a reaction to be spontaneous?
A) It must be negative
B) it must be greater than the change in entropy
C) It is dominated by the enthalpy change, (triangle H)
D) It must be driven by a large change in both entropy and enthalpy
E) It must be positive
Answer:
A) It must be negative
Explanation:
A spontaneous reaction in Chemistry is that which is proceeding in a particular direction without the intervention of any external effect. As a spontaneous reaction proceeds (which can be relatively slow), free energy ΔG, which is the available energy for work, is released.
Gibbs free energy, ΔG, is released during a spontaneous process and hence the ΔG is negative because the reactants have more free energy than the products, hence, no energy input is needed for the reaction to proceed forward but rather an energy output. This is what makes a negative ΔG depict a spontaneous reaction.
which skill involves creating representation of complex objects or processes
Answer:
Making models
Explanation:
Classifying is the grouping together of items that are alike in some way. Answer: Making models involves creating rep- resentations of complex objects or processes.
The principle applied to the design of an airplane wing was developed by
Answer:
Bernoulli’s PrincipleThis states principle helps explain that an aircraft can achieve lift due to the shape of its wings.
They wings are shaped that way so that that air flows faster over the top of the wing and slower underneath the wing .
In simple terms ;
Fast moving air equals low air pressure while slow moving air equals high air pressure
Explanation:
49.The 1H NMR spectrum of a compound with formula C7H14O gives a doublet at 9.2 ppm. Which of these structures is a possible one for this compound?
Answer: The possible structure for this compound is 2,4-dimethyl-3-pentanone
Explanation:
It should be noted that, If the 1H NMR spectrum of a compound with formula C7H14O gives a doublet at 9.2 ppm. The possible structure for this compound is 2,4-dimethyl-3-pentanone
A. What is the Name of Hydrogen Isotope
with one proton?
B. What is the Name of Hydrogen Isotope
with two protons?
C. What is the Name of Hydrogen Isotope
with three protons?
Answer:
A. Protium
B. Deutrium
C. Tritium
Explanation:
A hydrogen isotope with one proton:
Protium
A hydrogen isotope with two protons:
Deutrium
A hydrogen isotope with protons:
Tritium
Hope this helped ;) ❤❤❤
The number of moles of HCl in an aqueous hydrochloric acid solution can be determined as follows
moles=(concentration in M units) (Volume in liters)
for example - in 10.00 ml of 10 M HCI, the number of moles is: moles = (10 moles/L) (0.0100 L) = 0.10 moles
Using this method, which of the follow is correct for the Zn+HCl reaction? we were asked to mix 2 g of Zn with 10ml of HCL
1) HCl reagent was added in excess
2) HCl was the limiting reagent
3) Zn and HCl were added in the stoichiometric amounts
4) The reaction stoichiometry of Zn and HCl cannot be determined
Answer:
1) HCl reagent was added in excess
Explanation:
The equation of the reaction is given as;
Zn + HCl --> ZnCl2 + H2
From the stoichiometry;
1 mol of Zn reacts with 1 mol of HCl
In 2g of Zn;
mass = 2
Molar mass = 65.38g/mol
Number of moles = Mass/ Molar mass = 2 / 65.38 = 0.03059 mol
In 10ml of HCl;
the number of moles is: moles = Concentration * Volume = (10 moles/L) (0.0100 L) = 0.10 moles
Comparing 0.03059 mol of Zn : 0.10 mol of HC with the stochiometry, we can deduce that HCl is by far greater. Hence the correct option is option 1.
What are the parts of the water system? Label the water wheel to show the matter and forms energy that flow through the system.
Answer:
Source, processing and distribution are the components of water system.
Explanation:
There are three parts of water system i. e. the source, the processing and distribution. Water is extracted from a source such as underground water, lake or river etc. After extraction this water is transported to the processing unit where it can be purified and after purification it is distributed to all places where it is needed. Potential energy is a form of energy that flows through this water system because the water is extracted from a depth and we know that depth and height refers to potential energy.
How many free neutrons are produced in each of the following uranium-235 fission reactions. (Please explain)
Answer:
A. 2
B. 3
C. 4
Explanation:
Please see attached photo for explanation.
What is the bond character of this molecule?
A.) strongly covalent
B.) Positively charged
C.) Strongly ionic
D.) Negatively charged
Read “The Ozone Hole” and answer the question below. Write a short evaluation of the article’s reliability and scientific worth. Support your evaluation with specific examples from the article.
Answer:
The article presented evidence of ozone damage from NASA, which is a reliable source. The article discussed scientific studies published in a reputable journal. The article presented scientific facts and historical facts and did not present any opinions.
The ozone layer is a shield district of Earth's stratosphere that ingests a large portion of the Sun's bright radiation. It contains a high grouping of ozone (). It contains atoms of oxygen that keep the environment from hurtful beams that are available in space and boundless by the sun, for instance, bright beams.
Is there still a hole in the ozone layer in 2020?Scientists from the Copernicus Atmosphere Monitoring Service confirm that the 2021 Antarctic ozone hole has almost reached its end, following a season with a considerably large and prolonged ozone hole. Its closure will occur only a few days earlier than in 2020, which was the longest-lived since 1979.
Has the ozone hole closed?It closed on 23 December, the third latest date after 1999 and 2020. The extent and longevity of the 2021 ozone hole can be explained by very cold temperatures in the stratosphere and a very stable polar vortex. This video shows the evolution of the 2021 Antarctic ozone hole.
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1) Describe enthalpy and the role specific heat plays in the formula. 2) Explain the significance of the sign of the enthalpy value (+ or -) . Provide a specific example. 3) Explain Collision theory and describe the two factors required for a chemical reaction to occur. 4) Connect each of these circumstances to the rate of a reaction. Explain how the change in circumstances could be implemented in a lab and describe the predicted outcome: - Increased temperature - Decreased solution concentration - Increased surface area - Speeding up the reaction without being involved in the reaction. 5) Analyze Le Chatelier’s principle. 6) Based on this theory, what is the overriding guide to predicting outcomes when changes are imposed upon a reaction. What is the impact on equilibrium?
Explanation:
5) Le Chatelier's principle says, when in a reversible reaction any of the concentration or temperature or pressure are changed, then the equilibrium shifts such a way to nullify the changes occurred. (hope you get it)
6) 1.change in concentrationR ======= P
if concentration of reactant R is increased then eqm shifts towards the one with lower concentration ,that is product P.
forward direction is favoured.
2.Change in temperatureif the above's reaction is endothermic, that is temp of product is low. So increasing temperature in such case reaction goes towards product.
forward direction is favoured.
If reaction is exothermic ,temp of reactant is more. So increasing temperature in such case, reaction goes towards reactants.
forward direction is favoured
........ plz brainliest my answer I definitely write you the complete explanation asap!
A rectangular solid has a length of 3 cm, a height of 4 cm and a
width of 5 cm. What is the solid's volume?
cm3
Answer:
[tex]60 cm^{3}[/tex]
Explanation:
volume=lwh
v=3*5*4
v=[tex]60 cm^{3}[/tex]
Who might benefit from this claim?
The correct answer is D. Grocery stores that sell legumes
Explanation:
One of the main points this claim proposes is that metabolism can be improved by consuming legumes, this is expressed in "incorporating legumes such as lentils and chickpeas... boosts metabolism." In this context, if this is proven as true through an argumentative text or speech, it is likely many people want to increase their intake of legumes because a better metabolism has multiple benefits for health. Moreover, increased intake of legumes means an increase in the sale of legumes and higher profits for stores selling legumes. This means the claim might benefit grocery stores that sell legumens (option D.)
A sample of pure gold has a mass of 10.2 g. Calculate the number of moles in the sample and gold atoms in the sample.
Answer:
Explanation:
molecular weight of gold = 197
converting 10.2 g into moles
no of moles = 10.2 / 197
= .0518 moles
one mole of any element contains 6.02 x 10²³ number of atoms
.0518 moles will contain 6.02 x .0518 x 10²³ atoms of gold
= .311 x 10²³ no of atoms of gold .
= 3.11 x 10²² no of atoms of gold
What is the theoretical yield (in grams) of soap if 500.0 grams of the triglyceride of stearic acid are used?
Answer:
The theoretical yield (in grams) of soap is 514.9 grams
Explanation:
Please see the attachments below
When an apple is cut, it often turns brown. What does the color change indicate?
A. physical change only
B. chemical change only
C. physical and chemical changes
Answer:
C
Explanation:
When an apple is cut (or bruised), oxygen is introduced into the injured plant tissue. When oxygen is present in cells, polyphenol oxidase (PPO) enzymes in the chloroplasts rapidly oxidize phenolic compounds naturally present in the apple tissues to o-quinones, colorless precursors to brown-colored secondary products
Calculate the concentration and pH of a M aqueous solution of sodium cyanide, . Finally, calculate the concentration. ()
Answer:
[OH⁻] = 0.000324619M
pH = 10.51
[CN⁻] = 5.175x10⁻³M
Explanation:
Full question says:
Calculate the OH- concentration and pH of a 5.5×10-3M aqueous solution of sodium cyanide, NaCN. Finally, calculate the CN- concentration.
Ka (HCN) = 4.9×10-10
Sodium cyanide, is in equilibrium with water as follows:
NaCN(aq) + H₂O(l) ⇄ HCN(aq) + OH⁻(aq)
Where Kb (Kb = Kw / Ka = 1x10⁻¹⁴ / 4.9x10⁻¹⁰ = 2.04x10⁻⁵) is:
2.04x10⁻⁵ = [HCN] [OH⁻] / [NaCN]
In equilibrium, ann amount of HCN and OH⁻ is produced = X and the molarity of NaCN is: 5.5x10⁻³M - X
Replacing in Kb expression:
2.04x10⁻⁵ = [X] [X] / [5.5x10⁻³M - X]
1.12x10⁻⁷- 2.04x10⁻⁵X = X²
1.12x10⁻⁷- 2.04x10⁻⁵X - X² = 0
Solving for X:
X = -0.0003 → False solution. There is no negative concentrations
X = 0.000324619
As [OH⁻] = X.
[OH⁻] = 0.000324619MpOH = -log [OH⁻]
pOH = 3.489
pH = 14 -pOH
pH = 10.51And as molarity of NaCN = [CN⁻] = 5.5x10⁻³M - X
[CN⁻] = 5.175x10⁻³MWhat is the free energy change in kJ/mol for the process below at 43.9 °C when the concentration of A =0.88 M, B = 0.49 M and C = 0.69 M? g
Answer:
-15.5 kJ/mol
Explanation:
2A ⇄ 2B + C
[tex]$ K = \frac{[C][B]^2}{[A]^2} $[/tex]
= [tex]$ \frac{(0.69)(0.49)^2}{0.88^2} $[/tex]
= 0.21
T = [tex]$ 43.9^{\circ} $[/tex]C
= (273 + 43.9) K = 316.9 K
[tex]$ \Delta G^{\circ} = -19.4 $[/tex] kJ/mol
R = 8.314 J/k-mol = 0.008314 kJ/k-mol
[tex]$ \Delta G = \Delta G^{\circ} - RT \ln K $[/tex]
[tex]$ =-19.4 - 0.008314 \times 316.9 \ln (0.21) $[/tex]
= -15.5 kJ/ mol
Convert 7.61x10-5 L to picoliters.
Answer:
38,050,000,000,000 picoliters.
Explanation:
10-5=5, 7.61 x 5=38.05 (38.05L)
every liter is equal to 1000000000000 picoliters, so you go from there and just multiply 1000000000000 by 38.05.
Can you tell from the periodic table exactly how many neutrons are in an atom?
Answer: Yes
Explanation:
On the periodic table, you can find the element symbol, name, atomic number, and atomic mass. Just knowing the atomic mass and atomic number can give you the amount of neutrons. The atomic number states the amount of protons. The atomic mass is proton+neutron. Knowing this, you can subtract the atomic mass by the atomic number to get neutron.
Example: Carbon
Atomic number: 6
Atomic mass: 12.011 or 12
12-6=6 [Atomic mass - Atomic number]
There are 6 neutrons in Carbon.