Answer: C
Explanation:
What is the specific rotation of a sample of carvone that is an equal mixture of the R and S enantiomers
Answer:
Zero
Explanation:
An an equal mixture of the R and S enantiomers of carvone is called a racemic mixture.
In a racemic mixture, the R enantiomer rotates plane polarized light in one direction while the S enantiomer rotates plane polarized light in another direction.
This cancels out the rotation due to each enantiomer since they are equal in magnitude but opposite in direction leading to a specific rotation of zero for the racemic mixture.
An excess of oxygen reacts with 451.4 g of lead, forming 374.7 g of lead(II) oxide. Calculate the percent yield of the reaction.
Answer: The percent yield of the reaction is 77.0 %
Explanation:
[tex]2Pb+O_2\rightarrow 2PbO[/tex]
[tex]\text{Number of moles}=\frac{\text{Given mass}}{\text{Molar mass}}[/tex]
[tex]\text{Number of moles of lead}=\frac{451.4g}{207.2g/mol}=2.18moles[/tex]
[tex]\text{Number of moles of lead oxide}=\frac{374.7g}{223.2g/mol}=1.68moles[/tex]
According to stoichiometry:
2 moles of [tex]Pb[/tex] produces = 2 moles of [tex]PbO_2[/tex]
2.18 moles of [tex]Pb[/tex] is produced by=[tex]\frac{2}{2}\times 2.18=2.18moles[/tex] of [tex]PbO_2[/tex]
Mass of [tex]PbO_2[/tex] =[tex]moles\times {\text {Molar mass}}=2.18\times 223.2g/mol=486.6[/tex]
percent yield =[tex]\frac{374.7g}{486.6g}\times 100=77.0\%[/tex]
When a material gains thermal energy and melts, it is undergoing a physical change.
Answer:
True, it undergoes a physical change.
Explanation:
A physical change is a change that does not change the chemical makeup of a material. This includes altering its shape.
What evidence should Mitchell collect to BEST support the second law of thermodynamics?
Answer:
The Second Law of Thermodynamics poses an insurmountable problem for ... More time will make things worse for the Darwinist, not better. ... error fail-safe and proof-reading devices utilized for quality control, assembly ... No one really supports the idea that the sun + non life = life
Explanation:
According to the second law of thermodynamics, the energy of the universe is conserved but the entropy of the universe is continuously increasing.
What is the second law of thermodynamics?The second law of thermodynamics put some restrictions on the direction of heat transfer and attainable efficiencies of heat engines. This law stated that any spontaneously happening process will lead to an escalation in the entropy (S) of the universe.
This law explains that the entropy of an isolated system will never decrease with time. Mathematically, the 2nd law of thermodynamics:
ΔS (universe) > 0
where ΔS of the universe is the change in the entropy of the universe.
The second law of thermodynamics provides the criterion for the feasibility of any physical or chemical process. A physical or chemical process cannot take place unless it must follow both the 1st and 2nd laws of thermodynamics.
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What is the relationship between temperature and pressure
Question 1 of 7
Which sentence correctly explains the change that occurs when ice melts?
Ice melting is a physical change, and the state of the substance remains the same.
Ice melting is a physical change, and the mass of the substance remains the same.
оо оо
Ice melting is a chemical change, and the state of the substance remains the same.
Ice melting is a chemical change, and the mass of the substance remains the same.
Answer:
Explanation:B ice melting is a phiyscal change and the mass of the substance remains the same
Answer:
b
Explanation:
Please help I will give brainiest
Answer:
1. Least
2. Most
Answer:
1st one is less 2nd is greater
Explanation:
Select the compound that is most likely to increase the solubility of AgCl when added to water.
a. MgBr2
b. KClO4
c. NH3
d. NaCl
Answer:
c
Explanation:
The compound which increase the solubility of AgCl in water is determined on the basis of the process called common ion effect. The solubility of AgCl will be maximum in NH₃. The correct option is C.
What is common ion effect?The process common ion effect can be defined as the suppression of the dissociation of a weak electrolyte (weak acid or weak base) by the addition of some strong electrolyte containing common ion.
The solubility is defined as the maximum amount of solute that can be dissolved in a given solvent. Here AgCl dissociates into Ag⁺ and Cl⁻ ions. Both KClO₄ and NaCl contain Cl⁻ ions and thus common ion effect takes place. So the solubility decreases.
When AgCl is dissolved in NH₃ it forms a complex [ Ag (NH₃)₂]⁺. So it is highly soluble in NH₃. It is also soluble in water but not more than NH₃.
Thus the correct option C.
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in the following chemical reaction between H_2 and Cl_2 to produce HCl, what is the sum of the mass of HCl produced plus the mass of left over reactants when 0.40 g of H_2 completely reacts with 12.35 g of Cl_2?
H_2(g) + Cl_2(g) → 2HCl(g)
Answer:
Left over mass of hydrogen = 0.06 g
Mass of HCl produced = 12.41 g
Explanation:
Given data:
Mass of H₂ = 0.40 g
Mass of Cl₂ = 12.35 g
Mass of left over reactant = ?
Mass of HCl produced = ?
Solution:
Chemical equation:
H₂ + Cl₂ → 2HCl
Number of moles of H₂:
Number of moles = mass / molar mass
Number of moles = 0.40 g/ 2 g/mol
Number of moles = 0.2 mol
Number of moles of Cl₂:
Number of moles = mass / molar mass
Number of moles = 12.35 g/ 71 g/mol
Number of moles = 0.17 mol
Now we will compare the moles of HCl with H₂ and Cl₂.
H₂ : HCl
1 : 2
0.2 : 2×0.2 = 0.4
Cl₂ : HCl
1 : 2
0.17 : 2 × 0.17 = 0.34
Chlorine is limiting reactant.
Mass of HCl produced:
Mass = number of moles × molar mass
Mass = 0.34 mol × 36.5 g/mol
Mass = 12.41 g
Leftover mass of hydrogen:
Cl₂ : H₂
1 : 1
0.17 : 0.17
Number of moles of H₂ react with Cl₂ are 0.17.
Moles remain unreacted = 0.2 - 0.17 = 0.03 mol
Mass left over:
Mass = number of moles × molar mass
Mass = 0.03 mol × 2 g/mol
Mass = 0.06 g
The sum of the mass of HCl produced plus the mass of left over reactants is:
Mass of hydrogen = 0.06 g
Mass of HCl = 12.41 g
Chemical ReactionGiven:
Mass of H₂ = 0.40 g
Mass of Cl₂ = 12.35 g
Mass of left over reactant = ?
Mass of HCl produced = ?
Chemical equation: H₂ + Cl₂ → 2HClNumber of moles of H₂:
Number of moles = mass / molar mass
Number of moles = 0.40 g/ 2 g/mol
Number of moles = 0.2 mol
Number of moles of Cl₂:
Number of moles = mass / molar mass
Number of moles = 12.35 g/ 71 g/mol
Number of moles = 0.17 mol
The moles of HCl with H₂ and Cl₂.
H₂ : HCl
1 : 2
0.2 : 2×0.2 = 0.4
Cl₂ : HCl
1 : 2
0.17 : 2 × 0.17 = 0.34
The chlorine is limiting reactant.
Mass of HCl produced:
Mass = number of moles × molar mass
Mass = 0.34 mol × 36.5 g/mol
Mass = 12.41 g
Leftover mass of hydrogen:
Cl₂ : H₂
1 : 1
0.17 : 0.17
Number of moles of H₂ react with Cl₂ are 0.17.
Moles remain unreacted = 0.2 - 0.17 = 0.03 mol
Mass left over:
Mass = number of moles × molar massMass = 0.03 mol × 2 g/molMass = 0.06 gLearn more about "Moles":
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formal charge of hcooh
Answer:
What is the question?
On average what is the time between collisions of a xenon atom at 300 K and (a) one torr pressure; (b) one bar pressure.
Answer:
(a). 132 × 10^-9 s = 132 nanoseconds.
(b)..176.5 pico-seconds.
Explanation:
(a). At one torr, the first thing to do is to find the speed and that can be done by using the formula below;
Speed = [ (8 × R × T)/ Mm × π]^1/2.
Where Mm = molar mass, T = temperature and R = gas constant.
Speed= [ ( 8 × 8.314 × 300)/ 131.293 × π × 10^-3)^1/2. = 220m/s.
The next thing to do now is to calculate for the degree of collision which can be calculated by using the formula below;
Degree of collision = √2 × π × speed × d^2 × pressure/ K × T.
Note that pressure = 1 torr = 133.32 N/m^2 and d = collision diameter.
Degree of collision = √2 × π × 220 × (4.9 × 10^-10)^2 × 133.32/ 1.38 × 10^-23 × 300.
Degree of collision = 7.55 × 10^6 s^-1.
Thus, 1/ 7.55 × 10^6. = 132 × 10^-9 s = 132 nanoseconds.
(b). At one bar;
1/10^5 × 10^3 × 56.65 = 1.765 × 10^-10 = 176.5 pico-seconds.
Predict and write the charges and symbols of the monatomic ions formed by the following atoms: bromine rubidium
Answer: The monoatomic ions formed by bromine and rubidium are [tex]Br^-[/tex] and [tex]Rb^+[/tex] respectively.
Explanation:
When an atom accepts an electron negative charge is created on atom and is called as anion. When atom loses an electron positive charge is created on atom and is called as cation.
The atomic number of bromine and rubidium is 35 and 37 respectively. So, the number of electrons is equal to 35 and 37 respectively. Bromine will gain one electron and rubidium will lose one electron to attain stable electronic configuration to form [tex]Br^-[/tex] and [tex]Rb^+[/tex] respectively.
[tex]Br:35:1s^22s^22p^63s^23p^64s^23d^{10}4p^5[/tex]
[tex]Br^-:36:1s^22s^22p^63s^23p^64s^23d^{10}4p^6[/tex]
[tex]Rb:37:1s^22s^22p^63s^23p^64s^23d^{10}4p^63s^1[/tex]
[tex]Rb^+:36:1s^22s^22p^63s^23p^64s^23d^{10}4p^6[/tex]
4. Question: What effect does the amount of light have on plant growth?
Solid nickel reacts with aqueous lead (II) nitrate to form solid lead. What is the net ionic equation for this reaction? • Hint: In this reaction, nickel exhibits its most common oxidation state of +2. • Be sure to include the charge for each ion in the net ionic equation. Provide your answer below: (s) + (aq) → *(n)
Answer:
Pb²⁺(aq) --> Ni²⁺(aq)
Explanation:
The equation of the reaction is given as;
Ni(s) + Pb(NO₃)₂(aq) --> Pb(s) + Ni(NO₃)₂(aq)
In writing the ionic equation, we break the aqueous compound into ions. The solid and liquid compounds are ignored.
We have;
Pb²⁺(aq) + NO₃²⁻(aq) --> Ni²⁺(aq) + NO₃²⁻(aq)
Canceling the spectator ions;
Pb²⁺(aq) --> Ni²⁺(aq)
Answer:
Ni(s)+Pb2+(aq)→Ni2+(aq)+Pb(s)
Explanation:
The complete ionic equation of this reaction is
Ni(s)+Pb2+(aq)+2 NO−3(aq)→Ni2+(aq)+2 NO−3(aq)+Pb(s)
The nitrate ions are spectator ions and can be removed from the equation, giving us
Ni(s)+Pb2+(aq)→Ni2+(aq)+Pb(s)
A neutral atom becomes a positive ion when it
Answer:
Neutral atoms can be turned into positively charged ions by removing one or more electrons.
Explanation:
If there is an atom that has 9 protons and 9 electrons, removing an electron from the atom will gain a postive charge.
A scientist is considering formaldehyde (HCHO) for use in an experiment. She is studying the strength of triple bonds in molecules. Is
ormaldehyde a good choice for her to use? Why?
A. Yes, HCHO has three triple bonds.
B. Yes, HCHO has one triple bond.
C. No, HCHO has a double bond but no triple bonds.
D. No, HCHO has only single bonds.
7) If the mass of an object is 20 g and its volume is 25 L. What is the density of this object? 1 8) What is the difference between accuracy and precision? Copy and paste a picture of something that accurate but not precise and also something that is precise, but not accurate. 9) What is the formula for percent error?
this is due under 30 mins, please help
Answer:
Accuracy is the closeness of a measured value to the accepted or exact value. The precision of a tool is the smallest unit of measure the tool provides. The smaller the units a tool can measure, the more precise the tool. A measurement can be precise and not be accurate.
Explanation:
Ram has power of 550 watt.What does it mean?
Answer:
for electricity, watts as in back to the future "1.21 jigga watts"!
Explanation:
which of these is a cost of using paper grocery bags
Answer:
15 cents where im from
Explanation:
what elements make up duralumin( an alloy)?
Answer:
In addition to aluminium, the main materials in duralumin are copper, manganese and magnesium.
Answer:
The original composition has been varied for particular applications; it may contain about 4 percent copper, 0.5–1 percent manganese, 0.5–1.5 percent magnesium, and, in some formulations, some silicon.
how many grams of diazine (N2H2) are there in 2.55 mol of the compound
Answer:
76.5g is present in 2.55mol of diazine
Explanation:
no. of mole equals mass over molar mass
molar mass of diazine equals 30g/mol.. then substitute to get the mass in grams which is 76.5g
A 7.28 g sample of chromium metal was heated to produce chromium oxide. The weight of the compound was 10.63 g. What is the percent chromium in this compound?
Answer:
68.48%
Explanation:
The percent mass of an element in a compound tells us about the amount of such element contributed to the total compound.
In this case, 7.28 g sample of chromium metal was heated to produce chromium oxide with weight of 10.63 g. The percent mass of chromium in chromium oxide can be calculated by using the formula:
%mass of Cr = mass of Cr/mass of Chromium oxide × 100%
%mass of Cr = 7.28/10.63 × 100
%mass of Cr = 0.6848 × 100
%mass of Cr = 68.48%
Question 2 of 25
Rain exists in which phase?
O A Liquid
O B. Solid
C. Plasma
D. Gas
Answer:
liquid
Explanation:
correct answer hope it helps
Describe how simple distillation is used to separate water from an aqueous solution of sodium
sulfate.
Answer:
hbyiy
Explanation:
Hello I was wondering if anyone knew how to draw the molecular geometry of fentanyl. I already did the Lewis structure.
Answer:
i dont
Explanation:
As a sample's temperature increases, which two factors also increase?
A. Particle speed
O.B. Particle boiling point
C. Particle kinetic energy
D. Particle size
Help please
Answer:
speed
energy
Answer:
particle speed and particle energy
Explanation:
i just took the quiz on a p e x
The three lines in this Lewis dot structure represent the.
A)
three valence electrons of dinitrous oxide.
B)
six electrons in the triple bond of diatomic nitrogen.
C)
three electrons joining two nitrogen atoms in a diatomic molecule.
D)
three double bonds between the valence electrons of diatomic nitrogen.
Answer:
B) . six electrons in the triple bond of diatomic nitrogen
Explanation:
The three line in this Lewis dot structure represents the six electrons in the triple bond of diatomic nitrogen.
Nitrogen is made up of 7 electrons with 5 valence ones.
A lewis structure is made up of the symbol of the element surrounded by dot to represent the valence electrons.
In this nitrogen molecule, both species share 6 electrons. This makes each nitrogen atom isoelectronic with neon.
The atomic masses of 20Ne (90.48 percent), 21Ne (0.27 percent), and 22Ne (9.25 percent) are 19.9924356, 20.9938428, and 21.9913831 amu, respectively. Calculate the average atomic mass of neon. The percentages in parentheses denote the relative abundance
Answer:
20.180042 amu
Explanation:
From the question given above, the following data were obtained:
Isotope A (20Ne)
Mass of A = 19.9924356 amu
Abundance (A%) = 90.48%
Isotope B (21Ne):
Mass of B = 20.9938428 amu
Abundance (B%) = 0.27%
Isotope C (22Ne):
Mass of C = 21.9913831 amu
Abundance (C%) = 9.25%
Average atomic mass of Neon =.?
The average atomic mass of Neon can be obtained as follow:
Average atomic mass = [(mass of A × A%)/100] + [(mass of B × B%)/100] + [(mass of C × C%)/100]
= [(19.9924356 × 90.48)/100] + [(20.9938428 × 0.27) /100] + [(21.9913831 × 9.25) /100]
= 18.0891557 + 0.05668338 + 2.03420294
= 20.180042 amu
Therefore, the average atomic mass of Neon is 20.180042 amu
Answer the question below
Answer:
C
Explanation: I think
List 5 foods that contain bacteria?