Answer:
vent vapor concentration in the air to nearly zero. The effective diffusion coefficient of the solvent molecules in the polymer is 2 x 10^-6 cm^2/s
Explanation:
How many grams of californium-254 will remain after 363 days if we
start with 64.0 grams of this substance? The half-life of californium-254
is 60.5 days.
Answer:
1.02 g OF CALIFORNIUM-254 WILL REMAIN AFTER 363 DAYS IF 64 g REACTS WITH HALF LIFE OF 60.5 DAYS.
Explanation:
Half life of a chemical reaction is the time required for a radioactive element to decay to half its original mass.
We will use the formula:
Nt = No (1/2)^t/t1/2 where;
Nt = quantity of substance remaining = unknown
No = original mass of the substance = 64 g
t = time elapsed = 363 days
t1/2 = half life of the substance = 60.5 days
Putting the values into the equation, we have:
Nt = 64 * (1/2)^(363/60.5)
Nt = 64 * (1/2) ^6
Nt = 64 * 0.015625
Nt = 1.0156
The amount of californium-254 remaining after 363 days is approximately 1.02 g
3Fe + 2O2 → Fe3O4 In this reaction, 200 grams of Fe react with 64 grams of O2. How many grams of Fe3O4 will be produced? A 230 grams B 264 grams C 280 grams D 460 grams
Answer:
just did it the answers b
Explanation:
If a 1.45 M solution has 2.43 g HCl dissolved, what is the volume of solution? (Change g HCl into mol using molar mass)
Answer: The volume of solution is 0.0459 L
Explanation:
Molarity of a solution is defined as the number of moles of solute dissolved per liter of the solution
[tex]Molarity=\frac{n}{V_s}[/tex]
where,
n = moles of solute
[tex]V_s[/tex] = volume of solution in L
moles of HCl (solute) = [tex]\frac{\text {given mass}}{\text {Molar mass}}=\frac{2.43g}{36.5g/mol}=0.0666[/tex]
Now put all the given values in the formula of molality, we get
[tex]1.45M=\frac{0.0666}{V_s}[/tex]
[tex]V_s=\frac{0.0666}{1.45}=0.0459[/tex]
Therefore, the volume of solution is 0.0459 L
The radioactivity due to carbon-14 measured in a piece of a wooden casket from an ancient burial site was found to produce 20 counts per minute from a given sample, whereas the same amount of carbon from a piece of living wood produced 160 counts per minute. The half-life of carbon-14, a beta emitter, is 5730 years. Thus we would estimate the age of the artifact to be about?
Answer:
17202.6 years
Explanation:
Activity of the living sample (Ao) = 160 counts per minute
Activity of the wood sample (A) = 20 counts per minute
Half life of carbon-14 = 5730 years
t= age of the artifact
From;
0.693/t1/2= 2.303/t log Ao/A
Then;
0.693/ 5730= 2.303/t log Ao/A
Substituting values;
0.693/5730= 2.303/t log (160/20)
Then we obtain;
1.209×10^-4 = 2.0798/t
t= 2.0798/1.209×10^-4
Thus;
t= 17202.6 years
Therefore the artifact is 17202.6 years old.
If a solution has a pOH=12, what is its pH?
Answer:
2
Explanation:
pH+pOH=14
- Hope that helps! Please let me know if you need further explanation.
Answer:
2
Explanation:
Ph+PoH=14
What is the molarity of a solution in
which 3.8 moles of sodium chloride
(NaCl) is dissolved in water to a final
volume of 2.5 L?
Answer:
1.52M in NaCl
Explanation:
Molarity = moles solute / volume solution in Liters
=> molarity (M) = 3.8 moles / 2.5 Liters solution = 1.52 molar solution in NaCl
Answer: 1.52
Explanation:
which would dissolve faster individual salt crystals a big block of salt
Answer:
Table salt (the iodine isn't important) consists of much smaller particles than rock salt and therefore has a much higher ratio of surface area to mass. Since chemical reactions occur at surfaces,the smaller table salt particles will dissolve far more quickly than the larger rock salt.
Explanation:
Answer:
Individual salt crystals
Explanation:
A given quantity of solute dissolves faster when it is ground into small particles than if it is in the form of a large chunk because more surface area is exposed.
Give me a good review if right please.
Which characteristic of a substance is considered a chemical property
Answer:
c
Explanation:
[HCN]=0.09974 M
Kp=7.52
Calculate the partial pressure of HCN ?
Answer:
i don't understand
Explanation:
A sample of helium gas at room temperature is compressed from 100 cm3 to 20 cm3. Its new pressure is now 30 cm Hg. What was the original pressure of the gas?
Answer:
6 cm Hg
Explanation:
Boyles Law: P1V1=P2V2
(100 mL)(x)=(20 mL)(30 cm Hg)
x = 6 cm Hg
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What is the boiling point of water
Answer:
100 °CExplanation:
The boiling point of water is 100 °C or 212 °F at 1 atmosphere of pressure (sea level).
I'll give you the brainiest please help.
Answer:
c
Explanation:
At what temperature will a gas be, if you allow it to expand from its original volume of 756 mL at 65.0 °C to 1.40 L? (hint volume needs to be the same)
Answer:
120.4 gradius Celcius
Explanation:
Please see the step-by-step solution in the picture attached below.
Hope this answer can help you. Have a nice day!
H2O(g) + Cl2O(g) ↔ 2 HOCl(g) (a) Initially, 0.0555 mol H2O and 0.0230 mol Cl2O are mixed in a 1.00 L flask. At equilibrium, there is found to be 0.0200 mol of HOCl(g). Calculate the concentrations of H2O(g) and Cl2O(g) at equilibrium. (b) Using your results from part (a), calculate the equilibrium constant, Kc. (c) 1.0 mol pure HOCl is placed in a 2.0 L flask. Use your Kc from part (b) to calculate the equilibrium concentrations of H2O(g) and Cl2O(g).
Answer:
a)
[H₂O] = 0.0455M
[Cl₂O] = 0.0130M
[HOCl] = 0.0200M
b) Kc = 0.676
c) [H₂O] = [Cl₂O] = 0.177M
Explanation:
Based on the reaction:
H₂O(g) + Cl₂O(g) ⇄ 2HOCl(g)
Kc is defined as:
Kc = [HOCl]² / [H₂O][Cl₂O] For molar concentrations in equilibrium
As volume of the flask is 1.00L, the initial molar concentrations of H₂O and Cl₂O is 0.0555M and 0.0230M, respectively.
In equilibrium, the concentrations are:
[H₂O] = 0.0555M - X
[Cl₂O] = 0.0230M - X
[HOCl] = 2x = 0.0200M → X = 0.0100M
Where X is reaction coordinate
a) Concentrations in equilibrium are:
[H₂O] = 0.0455M
[Cl₂O] = 0.0130M
[HOCl] = 0.0200M
b) Replacing in Kc:
Kc = [0.0200]² / [0.0455][0.0130] = 0.676
c) Initial concentration of HOCl is 1.0mol / 2.0L = 0.50M. In equilibrium concentrations are:
[H₂O] = X
[Cl₂O] = X
[HOCl] = 0.50M - 2X
Replacing in Kc formula:
0.676 = [0.50-2X]² / [X][X]
0.676X² = 4X² - 2X + 0.25
0 = 3.324X² - 2X + 0.25
Solving for X:
X = 0.177M
X = 0.425M → False answer, produce negative concentrations.
As X = [H₂O] = [Cl₂O]; equilibrium concentrations of both compounds is 0.177M
What is the hydrogen ion concentration [H+] of a HCl solution if the pH is measured to be 2.0?
Answer:
.01
Explanation:
H+=10^-pH
- Hope that helps! Please let me know if you need further explanation.
What did the periodic table help scientists discover?
A. Elements that are radioactive
O B. Elements that are harmful
C. Elements not yet known to exist
D. Elements that no longer exist
There are various kind of elements that are present in periodic table. Some elements are harmful, some are radioactive, some are noble gases. Option C is correct option.
What is periodic table?
Periodic table is a table in which we find elements with properties like metals, non metals, metalloids and radioactive element arranges in increasing atomic number.
Periodic table help a scientist to know what are the different types of elements are present in periodic table so that they can discover the new elements that are not being discovered yet.
Periodic table is the best platform to have a look to all elements at once that are arranged in columns and groups mentioning their valencies, electronegativity and Ionisation energy symbols. Thus the option c is correct option.
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What is the molar mass of ethanol (C2H60)?
Answer:
46.07 g/mol is the molar mass of ethonal
An empty weighing dish has a mass of 1.0041 ± 0.0002 g. After you add dried sodium chloride to the dish, the mass is 3.2933 ± 0.0002 g. You quantitatively transfer the sodium chloride into a 500.00 ± 0.05 mL volumetric flask and dilute to the mark with deionized water. The molar mass of sodium chloride is 58.440 g/mol. What is the absolute error in the concentration of the resulting solution? Report your answer normally to the correct number of significant figures with the correct unit.
Answer:
The correct answer to the following question will be "0.0013%".
Explanation:
The given values are:
Weight of an empty dish = 1.0041 ± 0.0002 g
Weight of dish + sodium chloride (NaCl) = 3.2933 ± 0.0002 g
Weight of NaCl = 2.2892 ± 0.0002 g
Now,
Volume of the solution = 500.00 ± 0.05 ± 0.0002
= 500.00 ± 0.0502 ml
So,
Molarity = [tex]\frac{W \ NaCl}{M \ NaCl} \times \frac{1000}{Volumes \ of \ solution}[/tex]
On putting the values in the above formula, we get
= [tex]\frac{(2.2892\addeq +0.0002)}{58.440}\times \frac{1050}{(500.00+0.0502)}[/tex]
= ([tex]3.917[/tex] ± [tex]0.0002[/tex]) × ([tex]2[/tex] ± [tex]0.0502[/tex])
= ([tex]0.7834[/tex] ± [tex].00001004[/tex])
Now,
Absolute error = [tex]\frac{0.00001004}{0.7834}\times 100[/tex]
= [tex]0.0013[/tex]%
PLEASE help! BRAINLIEST to correct answer!
Answer:
C
Explanation:
Answer:
I think its q
Explanation:
h is the Planck constant, c the speed of light
Sometimes in lab we collect the gas formed by a chemical reaction over water (see sketch at right). This makes it easy to isolate and measure the amount of gas produced.
Suppose the CO gas evolved by a certain chemical reaction taking place at 55 degree C is collected over water, using an apparatus something like that in the sketch, and the final volume of gas in the collection tube is measured to be 117 ml.
Calculate the mass of CO that is in the collection tube. Round your answer to 2 significant digits. You can make any normal and reasonable assumption about the reaction conditions and the nature of the gases.
Answer:
The correct answer is 0.12 grams.
Explanation:
The mass of carbon monoxide or CO collected in the tube can be determined by using the ideal gas equation, that is, PV = nRT.
Based on the given question, P or the pressure of the gas is given as 1 atm, volume of the gas collected in the tube is 117 ml or 0.117 L.
The number of moles or n can be determined by using the equation, mass/molar mass.
R is the universal gas constant, whose value is 0.0821 L atmK^-1mol^-1, and temperature is 55 degree C or 328 K (55+273).
On putting the values we get:
n = PV/RT
= (1 atm*0.117 L) / (0.0821 L atmK^-1mol^-1 * 328 K)
= 0.0043447 mol
Therefore, mass of CO will be moles * molar mass of CO
= 0.0043447 mol * 28 g/mol
= 0.12 g
the rule of eight chemistry
Answer:
octet rule
Explanation:
It refers to the tendency of atoms to prefer to have eight electrons in the valence shell.
which sublevels contain valence electrons in an atom of nitrogen
Sublevel 2s and 2p contains the valence electrons for nitrogen.
Living large means we use a lot of energy. What are three ways people use energy in their daily lives?
Answer:
right now we are using energy by online learning on our laptops , air conditioning, and transportation
Explanation:
A solution of KOH has a [OH-] concentration of 0.045 M. What is the pOH of the solution? *
1 point
-1.3
1.3
1.1
0.90
what is the answer?
Answer:
[tex]pOH=1.3[/tex]
Explanation:
Hello,
In this case, since pH is computed by knowing the concentration of hydrogen ions, one could compute the pOH by knowing the concentration of the hydroxyl ions as in this case which is 0.045M as shown below:
[tex]pOH=-log([OH^-])=-log([0.045])\\\\pOH=1.3[/tex]
Best regards.
Answer:
The pOH of the 0.045 M solution is 1.3
The second option (1.3) is correct
Explanation:
Step 1: Data given
Concentration [OH-] of KOH is 0.045 M
Step 2: Calculate pOH
pOH = -log[OH-]
pOH = -log (0.045)
pOH = 1.3
The answer:
The pOH of the 0.045 M solution is 1.3
The second option (1.3) is correct
Argon-40 undergoes positron emission as shown:
48 Ar X+ IB
Enter the appropriate values for A and Z and the chemical
symbol for X
Answer:
[tex]\frac{40}{18}Ar => \frac{40}{17}Cl + \frac{0}{1}e\\[/tex]
Explanation:
The process of positron emission is better understood by the following reaction:
[tex]\frac{40}{18} Ar[/tex] → + [tex]\frac{40}{17} Cl + \frac{0}{1} e[/tex]. What is Positron emission?Positron emission may be defined as a subordinate type of radioactive decay called which is effectively known as beta decay. Due to this emission, a proton that is present inside a radionuclide nucleus significantly transformed into a neutron while liberating a positron and an electron neutrino.
According to the context of this question, Argon-40 undergoes the process of beta decay. Through which X element is formed which is known as chlorine. The atomic number (Z) of chlorine is 17, while the atomic mass (A) is 40 which is as identical to argon.
Therefore, the appropriate values for A and Z and the chemical symbol for X are 40 and 17 respectively.
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What parts of the body are tested for rigor Mortis
5 Which state of matter takes both the shape and volume of its container?
liquid
solid
gas
Answer:
gas
Explanation:
If you put gas in anything, it will occupy shape and volume.
Liquid only occupies shape of the container, whereas, solid doesn't occupy shape or volume because it maintains a fixed volume and shape.
HELP PLEASE ILL GIVE 25 pointsWhich of the following practices could help reduce erosion of water banks? a. buffer strips b. natural fertilizers and pesticides c. decrease in fossil fuel emissions d. all of the above Please select the best answer from the choices provided A B C D
Answer:
A. Buffer strips
Explanation:
The practice that could help reduce erosion of water banks is buffer strips.
What is erosion?Erosion is the action of surface processes that removes soil, rock or dissolved material from one location on the Earth's crust, and then transports it to another location where it is deposited.
One of the practices that could be used to reduce the effect of erosion is buffer strips.
What buffer strips do is slow and filter storm runoff while helping to hold soil in place.
Learn more on buffer strips here; https://brainly.com/question/26872640
A child shivers in a cold rain but does not feel cold, what is the biochemistry behind it
Answer:
Homeostasis is defined as the process by which the internal body system maintains a suitable environment for its proper functions and survival.
When a person temperature drops a signal is sent to the brain which results in a reflex action being observed. The shiver makes the individual warmer and helps in the regulation of the body heat.
The limiting reactants appeared to be _______
Because___________
Answer:
The limiting reagents seemed to be those that were consumed first .
Because when this reagent is consumed, the reaction stops. The quantity of this determines the total quantity of the product formed.
Explanation:
A limiting reagent is one that is consumed in its entirety. In this way, it delimits the amount of product that can be formed.
Take the case of two substances that interact and produce a chemical reaction. If one of the substances runs out as it is consumed during the process, the reaction will stop. The reagent consumed acts as a limiting reagent, that is, it limits the possibility of the reaction proceeding, and therefore it also limits the amount of the product generated by the reaction.
