Answer:
Titration is used to determine the concentration of unknown solutions.
A dipole moments is a measurement of the separation of two opposite electrical charges
Which of the following isotopes are NMR inactive?
a. 1H
b. 12C
c. 15N
d. 16o
e. 19F
f. 31P
Answer:
12C and 16O
Explanation:
Here, we want to select which of the options are NMR inactive. For an isotope to be NMR inactive, then the net nuclear spin is zero.
What this means is that the number of proton present coupled with the number of neutrons are an even number pair.
What we are saying here is that the number of protons is an even number while the number of neutrons too is an even number. So the net nuclear spin in this case is zero.
in the case of oxygen, we have 8 protons and 8 neutrons. This makes the nuclear spin zero and consequently makes the isotope NMR inactive.
Same is in the case of carbon. There are 6 protons and 6 neutrons and this also makes nuclear spin zero .
In all the other isotopes in the question, we have odd number even number or even number odd number pairs of protons and neutrons.
Which solution has the lower freezing point in each of the following pairs? (a) 11.0 g of CH3OH in 100. g of H2O or 22.0 g of CH3CH2OH in 200. g of H2O? CH3OH/H2O CH3CH2OH/H2O Both solutions have the same freezing point. (b) 20.0 g of H2O in 1.00 kg of CH3OH or 20.0 g of CH3CH2OH in 1.00 kg of CH3OH? H2O/CH3OH CH3CH2OH/CH3OH Both solutions have the same freezing point.
Answer:
See explanation
Explanation:
(a)
From the data provided;
Mass of methanol =11.0 g
Mass of solvent (H2O) =100 g = 0.1 kg
Molar mass of CH3OH =32.04 g/mol
Number of moles of solute = 0.343 mol
molality(m) of methanol = 3.43 m
Also,
Mass of ethanol =22.0 g
Mass of solvent (H2O) =200 g = 0.2 kg
Molar mass of C2H5OH =46.068 g/mol
Number of moles of solute = 0.477 mol
molality(m) of ethanol= 2.38 m
The greater the concentration of a solution, the higher the freezing point of solvent will be depressed. Therefore, higher molality, leader to a greater decrease of the freezing point.
Therefore, the freezing point of methanol CH3OH/H2O is lower than the freezing point of ethanol.
b)
Mass of solvent = 1 kg
Mass of water = 20g or 0.02 Kg
Molar mass of water = 18 gmol-1
Number of moles of solute = 20g/18 gmol-1 = 1.11 moles
Molality= 1.11 moles/1 kg = 1.11 m
Also;
Mass of ethanol = 20 g = 0.02 kg
Mass of solvent = 1.00 Kg
Molar mass of solute = 46 gmol-1
Number of moles of solute = 20g/ 46 gmol-1 = 0.43 moles
Molality= 0.43 moles/ 1 kg = 0.43 m
The greater the concentration of a solution, the higher the freezing point of solvent will be depressed. Therefore, higher molality, leader to a greater decrease of the freezing point.
Therefore, the freezing point of water H2O/CH3OH is lower than the freezing point of ethanol.
Consider the following balanced equation:3Ca(NO3)2(aq) + 2Na3PO4(aq) → Ca3(PO4)2(s) + 6NaNO3(aq)If 24.2 moles of Na3PO4(aq) reacts with an excess of Ca(NO3)2(aq) to produce 50.6 moles of NaNO3(aq), what is the percent yield of the reaction?
Answer:
69.7% is percent yield
Explanation:
Based on the reaction:
3Ca(NO3)2(aq) + 2Na3PO4(aq) → Ca3(PO4)2(s) + 6NaNO3(aq)
2 moles of Na3PO4 react producing 6 moles of NaNO3.
As 24.2 moles of Na3PO4 react, theoretical moles of NaNO3 produced are:
24.2 moles Na3PO4 * (6 moles NaNO3 / 2 moles Na3PO4) =
72.6 moles of NaNO3
As there are produced 50.6 moles of NaNO3, percent yield is:
50.6 moles NaNO3 / 72.6 moles NaNO3 =
69.7% is percent yieldWhich of the following would be a good solvent choice when preparing your sample for 1H NMR?
a. CD2C12
b. СНЗОН
c. More than one of the answer choices
d. CH2C12
e. None of the answer choices
f. CD3OD
Answer:
e. None of the answer choices
Explanation:
The solvents used for 1HNMR analysis are chloroform D (CDCl3), and acetone D6 (CD3COCD3) and deuterium oxide (D2O). And here any of these three nans are listed in the given option so that we can say that none of the answers are correct. so correct answer is e. None of the answer choices
Which of the following statements is true about the arrangement of particles in matter?
B. The particles in aliquid are spread farther apart than the particles in a gas.
A. The particles in a gas are closer together than the particles in a liquid
D. The particles in a solid are spread farther apart than the particles in a liquid
C. The particles in a gas are spread farther apart than the partides in a solid
Answer:
C. The particles in a gas are spread farther apart than the particles in a solid
Explanation:
Solids are made up of tightly-packed particles that form a rigid shape. Liquids are comprised of loosely connected particles that can slightly move. Gases are made up of fast-moving disconnected particles that are spread far apart.
Not divisible
O atom
O compound
O mixture
O solution
Answer:
mixture or atom
Explanation:
I HOPE IT WILL HELP YOU
Explanation:
and ,answer is mixture.
In the following atomic model, where does the strong nuclear force happen?
Answer:
the strong nuclear force happens in the neuclus
How many m^3 are in 56cm^3?
Answer:
5.6 × 10-5 m^3
Explanation:
Hope this helps
how do you tell if an chemical eqaution is unbalanced
How do you scientist learn about the moon in other planets
Answer:NASA's Lunar Atmosphere and Dust Environment probe, for instance, orbits the moon and collects information about its atmosphere and surface. This important data can help scientists learn more about moons, asteroids and other objects in the solar system.
Explanation:
how do isotope of the same element differ?
Answer:
isotope of the same element differ
Explanation:
isotope is one of two or more forms of the same chemical element. Different isotopes of an element have the same number of protons in the nucleus, giving them the same atomic number.
Determine the number of protons (p) and electrons (e) in Mg2.
A) 10 p, 12 e
B) 12 p, 12 e
C) 12 p. 10 e
D) 12 p. 14 e
E) 10 p, 10 e
If your front lawn is 25.0 feet wide and 20.0 feet long, and each square foot of lawn accumulates 1350 new snowflakes every minute, how much snow, in kilograms, accumulates on your lawn per hour? Assume an average snowflake has a mass of 1.90 mg.
Answer:
19.17 kgExplanation:
calculate area of lawn
25 * 20 = 500 sq ft
calculate how many flakes fall per minute
500 * 1150 = 575 , 000 flakes/minute
convert per minute rate to per hour rate
575 , 000 * 60 = 34 ,500 , 000 flakes/hour
now you know how many flakes feel in that one hour so we can now weigh them
34 , 500 , 000 / 1.8 = 19 , 166 , 667 mg (rounded)
convert to kilograms
19 , 166 , 667 / 100 , 000 = 19.17 kg (rounded)
You heat 51 grams of magnesium over a Bunsen burner for several minutes until it reacts with oxygen in the air. Then you weigh the resulting product and see that it is now 53 grams. How does this happen without breaking the Law of Conservation of Mass?
Answer:
The mass was there all along, it was just in the air. The weight of the oxygen from the air is not weighed in the beginning, only at the end as part of the product, making it seem like there is a total mass change.
Explain why some people use the term decimal system as a synonym for the metric system?
Answer:
The term Decimal is coined from the word Decimus. Decimus is a Latin word which means ‘tenth’.
The Decimal system is a system of numbering that is based on multiples of tens. It is flexible and easy to convert from one metric to another.
The preference of the term over the Metric System is because the word Metric is related more to the measurement of lengths if we looked at the origin of the word which is French.
Cheers!
3 H2S + 2AuCl --> Au2S3 + 6 HCL is what type
of reaction
Answer:
Double Displacement (Metathesis)
Explanation:
Hover over answer image to enlarge
8)
Which part of the atom cannot have its location accurately determined and is modeled by a cloud around the center of
the atom?
-0)
A)
electron
B)
neutron
nucleus
D)
proton
An atomic nucleus is composed of
)
Which of the following would have the largest pKa?
a. CH3CH2NH+3
b. C6H5NH+3
c. C6H5NH2
d. CH3CH2NH2
Answer:
CH3CH2NH3+/CH3CH2NH2 would have the largest pKa
Explanation:
To answer this question we must know Kb of CH3CH2NH2 is 5.6x10⁻⁴, and for C6H5NH2 is 4.0x10⁻¹⁰. And the CH3CH2NH3+ and C6H5NH3+ are related with these substances because are their conjugate base. That means:
pKa of CH3CH2NH3+ = CH3CH2NH2; C6H5NH3+ = C6H5NH2
Also, Kw / Kb = Ka
Thus:
pKa of CH3CH2NH3+/CH3CH2NH2 is:
Kw / kb = Ka = 1.79x10⁻¹¹
-log Ka = pKa
pKa = 10.75
pKa of C6H5NH3+/ C6H5NH2 is:
Kw / kb = Ka = 2.5x10⁻⁵
-log Ka = pKa
pKa = 4.6
That means CH3CH2NH3+/CH3CH2NH2 would have the largest pKa
Brian's aunt has cats. When Brian recently visited her, he started sneezing badly and believes that it was because
he is allergic to cats.
What would be the next step for Brian to form a hypothesis?
O by avoiding going to his aunt's house
by wearing a nose mask near cats
by visiting other households with cats
O by visiting his aunt's house again with the cats outside
Answer:
By visiting other households with cats.
Explanation:
This will give Brian a variety of other houses and determine if it is truly cats or just alleries from other items. This is the most direct way to get Brian the answer he is looking for.
Answer:
c
Explanation:
i just did it
why do NH3 and SO3 have different bond angles, even though they have the same number of atoms?
Answer:
Due to different atoms and different values of electronegativities.
Explanation:
NH3 and SO3 have different bond angles because both molecules have different type of atoms combine together. In NH3, nitrogen react with hydrogen while in SO3, sulfur react with oxygen atom. The bond angle of NH3 is 107 while the bond angle of SO3 is 120. This difference in bond angle is also due to different electronegativities of the bonded atoms. The electronegativity of oxygen is higher than hydrogen so repulsion of hydrogen is less and that's why its bond angle is also lower than oxygen.
You left a glass full of water by a window in your house in the morning. Three hours later you walk by the glass, and the water level is significantly lower than it was in the morning. You have made the observation that the water level in the cup is lower. Then, you ask the following question: “Why is the water level in the cup lower?” What is a possible hypothesis you could make?
A jet airplane flies from St. Louis, Missouri, to Phoenix, Arizona, in 3 hrs. The distance is
1,500 miles. What is the plane's speed ?
Answer:
Distance = 1500miles
time taken = 3 hours
speed of plane = distance/time taken = 1500/3= 500milesperhour
Explanation:
According to the distance formula , the speed of the plane is 500 miles per hour.
What is speed?The speed of an object is the magnitude of the change of its position over time or the magnitude of the change of its position per unit interval of time indicating that it is thus a scalar quantity.The average speed of an object in an interval of time is the distance traveled by the object divided by the duration of the interval; the instantaneous speed is the limit of the average speed as the duration of the time interval approaches zero. Speed is not the same as velocity.
Speed has the dimensions of distance divided by time. The SI unit of speed is the metre per second (m/s), but the most common unit of speed in everyday usage is the kilometre per hour (km/h) or in the US and the UK, miles per hour (mph).
Here, speed is calculated as distance /time= 1500/3= 500 miles per hour.
Thus, the speed of plane is 500 miles per hour.
Learn more about speed,here:
https://brainly.com/question/7359669
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3 points
What is the energy (Joules) of violet light with a frequency = 3.43 x 10^14
1/s? *
4.54x10^-19 J
1.99x10^-25 J
1.93 x 10^-48 J
O 2.27 x 10^-19 J
Pls help me
Answer:
4.54x10^-19 J
1.99x10^-25 J
1.93 x 10^-48 J
(01.04 LC)
What phase of matter has particles that are held together but can flow past each
other and takes the shape of a container, filling it from the bottom up? (3 points)
1) Gas
2) Liquid
3) Plasma
4) Solid
PLEASE HELP ME, I HAVE NO IDEA HOW TO DO THIS :(
Lol . same here. If u get any ideas please let me know
Answer:
See the picture you have to write like this
Which pair of elements have chemical properties that are most similar
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Answer:
[tex]\large\boxed{(B)}[/tex]
Elements on the periodic table that are the closest in characteristics are in the same group, or column.
Looking at the answer choices, the only two pairs of elements that are in the same group are (B) Al and Ga, as well as (D) F and I.
On the periodic table, Al (Aluminum) and Ga (Gallium) are only one period (row) away from each other, while F (Flourine) and I (Iodine) are 3 periods away.
***Periods determine the number of energy levels and other properties, so elements that are closer to each other would have more similar properties.
Therefore, Aluminum and Gallium contain the most similar chemical properties.
When Z-4,5-dimethyloct-4-ene is treated with hydrogen chloride, HCl, the result is:________.
A. 4 stereoisomers
B. None of these
c. a pair of diastereomers
D. a racemic mixture OS a meso compound
Answer:
The correct option is c
Explanation:
The chemical equation for the reaction of Z-4,5-dimethyloct-4-ene and HCl is shown on the first uploaded image
Now looking at the product we see that there are two who has four different groups attached to them this carbon are known as chiral carbons hence the product formed is a pair of diastereomers
You estimate that you sent 135 texts last week but when you get the bill, it was actually 175. Calculate the percent error
Answer: -40
Explanation: Percent error is calculated by subtracting the value you actually recieved from the literature value (175 in your case) SO your answer should be 135-175=-40.
Miss White wants to make a (decidedly not poisoned) apple pie. The recipe she is
using asks for a specific mass of apples, but Miss White doesn't have a balance, so
finding mass directly will be difficult. What she DOES have is a graduated cylinder,
which she uses to find that her apples have a volume of 786,3 ml. She also knows
that her apples have a density of around 0.98 g/ml. What is the mass of Miss
White's apples? Please round your answer to 0.01 grams.
Which statement describes a property that is unique to metalloids?
Metalloids are shiny.
Metalloids are semiconductive.
Metalloids are solid.
Metalloids are brittle.
Answer:
Metalloids are semiconductive.
Explanation:
Answer: Metalloids are semiconductive.