Answer: The value of [tex]K_{b}[/tex] for chloroform is [tex]3.62^{o}C/m[/tex] when 0.793 moles of solute in 0.758 kg changes the boiling point by 3.80 °C.
Explanation:
Given: Moles of solute = 0.793 mol
Mass of solvent = 0.758
[tex]\Delta T_{b} = 3.80^{o}C[/tex]
As molality is the number of moles of solute present in kg of solvent. Hence, molality of given solution is calculated as follows.
[tex]Molality = \frac{no. of moles}{mass of solvent (in kg)}\\= \frac{0.793 mol}{0.758 kg}\\= 1.05 m[/tex]
Now, the values of [tex]K_b[/tex] is calculated as follows.
[tex]\Delta T_{b} = i\times K_{b} \times m[/tex]
where,
i = Van't Hoff factor = 1 (for chloroform)
m = molality
[tex]K_{b}[/tex] = molal boiling point elevation constant
Substitute the values into above formula as follows.
[tex]\Delta T_{b} = i\times K_{b} \times m\\3.80^{o}C = 1 \times K_{b} \times 1.05 m\\K_{b} = 3.62^{o}C/m[/tex]
Thus, we can conclude that the value of [tex]K_{b}[/tex] for chloroform is [tex]3.62^{o}C/m[/tex] when 0.793 moles of solute in 0.758 kg changes the boiling point by 3.80 °C.
If a substance has a half life of 58 years and starts with 500 g radioactive, how much remains radioactive after 30 years?
Answer:
A = 349 g.
Explanation:
Hello there!
In this case, since the radioactive decay kinetic model is based on the first-order kinetics whose integrated rate law is:
[tex]A=Ao*exp(-kt)[/tex]
We can firstly calculate the rate constant given the half-life as shown below:
[tex]k=\frac{ln(2)}{t_{1/2}} =\frac{ln(2)}{58year}=0.012year^{-1}[/tex]
Therefore, we can next plug in the rate constant, elapsed time and initial mass of the radioactive to obtain:
[tex]A=500g*exp(-0.012year^{-1} *30year)\\\\A=349g[/tex]
Regards!
How much heat is gained by 1.25 grams of ice?
Answer:
Heat gained by 1.25 grams of ice is 250 joules
Explanation:
As we know
[tex]Q = mc\Delta[/tex]T
Where
[tex]\Delta[/tex]T is the change in temperature
Water freezes at 273.15 K/0 degree Celsius, and it boils at 373.15 K/00 degree Celsius,
[tex]\Delta[/tex]T
m is the mass in grams
c is the specific heat of water (ice) = 2.05 joules/gram
Substituting the given values, we get -
[tex]Q = 1.25 * 2.0 * 100\\Q = 250[/tex]Joules.
(4x972)+(76.4x29.3)-(12x7)
solve using significant figures please ASAP
You mix two amino acids together: glu and ser. If they reacted, how many different dipeptides would you expect to get? List them.
I'm really struggling with amino acids, so any help is appreciated! I won't be clicking any links, though.
Answer:
Answers 1. An amide linkage between the carboxyl group of one amino acid and the amine group of the other amino acid. 2. An ester is a compound formed from the reaction of a carboxylic acid and an alcohol. ( I apologise, I cant figure out number 3.. )
If I held a heavy rock up 6 feet from the ground and kept it completely still, what kind of energy does it have?
Answer:
kenetic
Explanation:
<3
while many microorganisms are harmful there are some that perform an important function. what is one example of suck a microorganisms
Answer:
Yeast
that helps in fermentation
It take 38.70cm³ of 1.90m NaoH to neutralize 10.30cm³ of H2so4 in a battery, calculate the molar concentration of H2so4
Answer:
[tex]M_{acid}=3.57M[/tex]
Explanation:
Hello there!
In this case, since this acid-base neutralization is performed in a 1:2 mole ratio of acid to base as the former is a diprotic acid (two hydrogen ions in the molecule), we can write the following equation:
[tex]2M_{acid}V_{acid}=M_{base}V_{base}[/tex]
In such a way, we can solve for the molarity of the acid, given the molarity and concentration of the NaOH base and the volume of the acid:
[tex]M_{acid}=\frac{M_{base}V_{base}}{2V_{acid}}[/tex]
Thus, we plug in the given data to obtain:
[tex]M_{acid}=\frac{38.70cm^3*1.90M}{2(10.30cm^3)} \\\\M_{acid}=3.57M[/tex]
Best regards!
Speed is the rate of change of position expressed as _____ traveled per unit of time. A. direction B. meter C. displacement D. distance... Help!!!
Answer:
Distance
Explanation:
what is the name of the chemical used for bleach in sugar industries?
Answer:
Sulfur Dioxide
Explanation:
Sulfur dioxide is the chemical that, when released by factories using fossil fuels, combines with the atmosphere and can produce acid raid.
What did Rutherford contribute to the model of the atom?
the neutron
the proton
the nucleus
the electron
Answer:
the nucleus
Explanation:
He proposed that the mass of an atom is concentrated in the nucleus which occupies a small volume in the center .He added that the nucleus comprises the protons and neutrons.where the neutron had no charge while the protons had charge of +1
Answer:
the nucleus
Explanation:
Which object will experience the strongest gravitational attraction to Earth?
A. a car
B. a notebook
C. a desk
D. a bowling ball
Answer:
A
Explanation:
The strength of the gravitational force between two objects depends on mass and distance. The object with the greatest mass would be the car.
calculate the molar mass for BaSO4
Answer:
233.38 g/mol
Explanation:
you find the molar mass of each element and then add them up.
How do you write the formula for the combination of 2 chemicals?
example: al3+, br1-, and o2- combined would be what?
Explanation:
[tex]Al(Br)O _{3} \\ name \: = > \: aluminiummonobromo(iii)oxide[/tex]
How do rock transformations on Venus and Earth indicate the planetary similarities between the two planets?
Answer:
Both the Earth and Venus show the appearance of igneous rocks due to the cooling of the magma.
Explanation:
As we know, ignea rock is the first step in the transformation of rocks. This rock is formed by the overflow of terrestrial magma which, upon cooling, turns into ignea rock, which will undergo metamorphism and transform into metamorphic rock, which will continue to undergo metamorphosis until it becomes the other rocks that complete the rock cycle. This is a terrestrial process that can be found on Venus, which also presents the cooling of magma in the formation of ignea rock, which will undergo metamorphism, transforming into other rocks, the way it occurs on Earth.
The balanced equation for the combustion of ethene is given below. If 97.7 g of oxygen is used, how much
heat energy will be produced?
C2H4+ 3O2 → 2CO2 + 2H2O + 1390 kJ
Answer:
c
Explanation:
A sample of gas is inside of a rigid container with fixed volume of 350mL. The initial pressure of the system is 366kPa, and the initial temperature is 88 degrees Celsius. How would the pressure of the system change if the temperature was increased to 110 degrees Celsius?
Answer:
457.5kPa
Explanation:
Given data
V1=V2=350mL (fixed volume )
P1=366kPa
T1= 88 degrees Celsius
P2=??
T2= 110 degrees Celsius
For the general gas equation
P1V1/T1= P2V2/T2
V1=V2
P1/T1= P2/T2
Substitute
366/88= P2/110
Cross multiply we have
P2*88=366*110
P2*88= 40260
P2= 40260/88
P2= 457.5 kPa
Hence the pressure will change to 457.5kPa
WILL GIVE BRAINLYEST.
Part C is what I need help with I was just showing the other answers I got for you if it would help.
Question: Which time shows the highest composition of all green house gasses? Comment on any quantitative comparisons with the ice age data.
Answer:
Today has the highest composition of greenhouse gases
Explanation:
Greenhouse gases have been linked to the rise in the temperature of the earth. they are believed to trap infrared ray close to the earth surface thereby causing a steady rise in the temperature of the earth, a phenomenon that has been widely called global warming.
The concentration of greenhouse gases in the atmosphere today ranks highest among other ages due to anthropogenic activities.
During the ice ages, the concentration of greenhouse gases was slightly higher (especially C02) due to natural feedback mechanisms and not due to anthropogenic activities.
How many kJ are needed to heat 300.0 g of ice at -5.00°C into steam at 100.°C?
Answer:
Q = 63.9 kJ
Explanation:
Given that,
Mass of ice, m = 300 g
We need to find the heat needed to heat the given amount of ice at -5.00°C into steam at 100.°C
The specific heat of ice, c = 2.03 J/g °C
The formula for heat needed is given by :
[tex]Q=mc\Delta T\\\\Q=300\times 2.03\times (100-(-5))\\\\Q=63945\ J\\\\Q=63.9\ kJ[/tex]
So, 63.9 kJ of heat is needed.
Wing practice problems:
1. How many grams of water could freeze at 0°C when 525 KJ of energy is released?
Answer:
g x 334 J/g = 3340J or 3.34kJ.
Explanation:
The energy required for one gram of a solid to melt without experiencing any temperature change is known as the heat of fusion. 3.34 KJ of energy is released.
What is heat of fusion ?The most typical illustration is when solid transforms into liquid water. The molecules within the substance become less structured as a result of this process, which is also known as melting or heat of fusion.
The change in enthalpy ( H ) that occurs when a substance transforms from a solid to a liquid state.
The amount of energy required for one gram of a liquid to evaporate (boil) without a change in pressure is known as the heat of vaporization.
Q = gram × 334 J / g
= 3.34 KJ
Thus, at 0°C when 525 KJ of energy released is 3.34 KJ.
To learn more about heat of fusion follow the link below;
https://brainly.com/question/14053504
#SPJ2
Mr. Romeo wants to make a solution of NaOH. He measures out 97.68 grams and puts it into 3 liters
What is the molarity of the solution he created? Round to 2 Decimal points
Answer: Molarity of the solution is 0.813 M.
Explanation:
Given : Mass of NaOH = 97.68 g
Volume of solution = 3 L
The molar mass of NaOH is 39.99 g/mol. Hence, moles of NaOH are calculated as follows.
[tex]No. of moles = \frac{mass}{molar mass}\\= \frac{97.68 g}{39.99 g/mol}\\= 2.44 mol[/tex]
Molarity is the number of moles of solute present in a liter of solution. Therefore, molarity of given solution is calculated as follows.
[tex]Molarity = \frac{no. of moles of solute}{Volume (in L)}\\= \frac{2.44 mol}{3 L}\\= 0.813 M[/tex]
Thus, we can conclude that molarity of the solution is 0.813 M.
answer asap pls i give brainliest
Answer:
B. Revolution is a planet's movement around the sun causing four seasons the occur. Rotation is the spinning of the planet on its axis causing day and night.
A.6.10
B.90
C.6.00
6.20
Answer:
6.1
Explanation:
Because if you get to the large mark it would be 5 but since its not at 5, it would be 6.1 as you can see in my drawing. It aligns perfectly with 6.1.
Examine your observations above and summarize the effects of each kind of radiation on the molecules in the simulation. Microwave Infrared Visible Light Ultraviolet Effect(s) on Molecules
Answer:
The effects of each kind of radiation is different on the molecules.
Explanation:
Microwave causes molecules that have two opposing poles to spin rapidly due to absorption of the electromagnetic radiation waves. When molecules absorb Infrared radiation, changes occur from a ground vibrational state to an excited vibrational state. When the visible light is absorbed by molecule, the electron is excited and goes to an orbital of higher energy than the lower energy. Ultraviolet radiation turns the stable molecule into a reactive species.
If the density of mercury is 13.6 g/mL, what is the mass of 25.4 cm3 of
mercury?
Answer:
345.44 g or 0.34544 kg
Explanation:
Applying
D = m/V...................... Equation 1
Where D = Density of mercury, m = mass of mercury, V = Volume of mercury.
make m the subject of the equation
m = D×V................. Equation 2
From the question,
Given: D = 13.6 g/mL = 13.6 g/cm³, V = 25.4 cm³
Substitute these values into equation 2
m = 13.6×25.4
m = 345.44 g
m = 0.34544 kg
Hence the mass of mercury is 345.44 g or 0.34544 kg
• Create a stoichiometry problem. It can be a problem using moles, grams, enthalpy, solutions, or acids and bases. Make
sure there is an equation to balance
Answer:
All I can give you is The steps for it.
Explanation:
Almost all stoichiometric problems can be solved in just four simple steps:
: Balance the equation. Convert units of a given substance to moles.
Using the mole ratio, calculate the moles of substance yielded by the reaction.
Convert moles of wanted substance to desired units.
Please help due tonight!!! NO LINKS PLEASE they will be flagged.
When 57,816 J of heat are transferred to a 240-g of an unknown metal, its temperature increases from 32⁰C to 164⁰ C. Identify the metal.
If there is a link and you can't answer please put it in the comments I really need help!!!
Answer:
Carbon fiber if I'm correct
____ occurs when the vapor pressure of a liquid is equal to the external atmospheric pressure.
A. Sublimation
B. Compression
C. Boiling
D. Freezing
Answer:
Boiling
Explanation:
c.boiling
choice number 3
A compound has an empirical formula of CH20. What is its molecular formula, if its molar mass is 360 g/mol?
a. C6H12O6
b. C12H24O12
Answer:
a
Explanation:
A actual molecule of glucose contains six carbon atoms, twelve hydrogen atoms, and six oxygen atoms.
Answer:
B.
Explanation:
State of matter
A gas made up of homonuclear diatomic molecules escapes through a pinhole 3.98 times as fast as oxygen gas. Write the Chemical formula of the gas.
Answer:
H₂
Explanation:
To solve this question we must find, as first, find the molar mass of the homonuclear diatomic gas using Graham's law. With the molar mass we can identify this gas
Graham's law:
[tex]\frac{V_a}{V_b} =\sqrt{\frac{m_B}{m_A} }[/tex]
Where V is the speed of the gases and m the molar mass of those:
As Va is 3.98 times Vb (And mB is molar mass of oxygen gas = 32g/mol)
[tex]3.98 =\sqrt{\frac{32g/mol}{m_A} }[/tex]
15.84 = 32g/mol / mA
mA = 2.02g/mol
As is a homonuclear diatomic gas, the molar mass of the atom is 1.01g/mol. Thus, the gas is:
H₂Describe the motion of particles in a
solid compared with a liquid or gas.