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.
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.
Use the clues you highlighted to choose the best
meaning of beat in this sentence.
Highlight the context clues that help you choose
the best meaning of the word beat.
Our family beat a retreat back to the sofa as if chased by
enemy soldiers
- "The All-American Slurp."
Lensey Namioka
O defeated
O mixed
hurried
musical rhythm
Answer:
hurried
Explanation:
because they retreated back to the couch so hurried.
Answer:
c
Explanation:
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 yieldIf 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)
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.
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?
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
Determine the number of mm in 14.3cm
Answer:
143 mm . covert it an determine an individual percentage .
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.
how do you tell if an chemical eqaution is unbalanced
If a horse is at a stop and then starts running is the horse accelerating or decelerating?
Answer:
accelerating
Explanation:
technically, there is no such thing as deceleration, just negative acceleration.
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 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
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:
Which common item is made from copper?
soap
coins
baby powder
colored pencils
Answer:
coins
Explanation:
(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
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!
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.
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.
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.
How does the arrangement of atoms differ in crystals and glass?
How does the arrangement of atoms differ in a crystalline and a noncrystalline substance? Crystals have well organized arrangement of atoms. Non crystals have irregular unorganized arrangement of atoms. You just studied 13 terms!
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
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
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
In the following atomic model, where does the strong nuclear force happen?
Answer:
the strong nuclear force happens in the neuclus
A running track measures 1056 ft per lap. To run 15.0 km, how many laps should you run?
Answer:
46.6 laps
Explanation:
Step 1: Given data
Length of the lap (l): 1056 ftTotal distance to be run (d): 15.0 kmStep 2: Convert "l" to km
We will use the conversion factor 1 km = 3280.84 ft.
1056 ft × (1 km / 3280.84 ft) = 0.3219 km
Step 3: Calculate the number of laps that you should run
We will use the following expression.
laps = d/l
laps = 15.0 km/(0.3219 km/lap)
laps = 46.6 laps
Element T exists as three isotopes: T-12 (98.90%), T-13 (1.00%) and T-14 (0.10%). Calculate the
average atomic mass of the element T.
Answer choices:
- 12.01 amu
- 11.72 amu
- 1200 amu
- 13 amu
Answer:
-10.00amu
ok.......... !!!!!
The average atomic mass of the element T is 12.012 amu.
What is average atomic mass?The average atomic mass is defined as the atoms' weighted average mass in a naturally occurring sample of the element.
It is also defined as the average atomic mass of all naturally occurring isotopes of all elements.
The average atomic mass can be expressed as
Average atomic mass = f1m1 + f2m2 + f3m3
= 0.989 x 12 + 0.01 x 13 + 0.001 x 14
= 11.868 + 0.13 + 0.014
= 12.012 amu
Thus, the average atomic mass of the element T is 12.012 amu.
To learn more about average atomic mass, refer to the link below:
https://brainly.com/question/13753702
#SPJ5
How many m^3 are in 56cm^3?
Answer:
5.6 × 10-5 m^3
Explanation:
Hope this helps
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.