Answer:
so i think physical change
What is the chemical formula for carbon tetrafluoride?
The Periodic Table
1
mono-
2
di-
3
4
tetra-
5
penta-
hexa-
6
7
hepta-
8
Oct-
9
nano-
10
deca-
If the magnet loses its superconducting properties, all of the liquid helium could suddenly turn to a gas. If an MRI machine contains 1950 L liquid He with a density of 0.125g/mL, how many liters of He gas would be formed at 25°C and 1 atm? Use the ideal gas law. Round your final answer to two significant figures. Show your work. (4 points)
Answer:
Determine the volume of helium gas
Answer:
About 1,495 Liters of Helium.
Explanation:
To calculate the volume of helium gas formed when the magnet loses its superconducting properties, we can use the ideal gas law:
PV = nRT
Where:
P = Pressure (in atm)
V = Volume (in liters)
n = Number of moles of helium gas
R = Ideal gas constant (0.0821 L.atm/(mol.K))
T = Temperature (in Kelvin)
First, we need to find the number of moles of helium gas:
Given volume of liquid helium (V_liquid) = 1950 L
Density of liquid helium (ρ) = 0.125 g/mL = 0.125 g/cm³
To convert density from g/cm³ to g/L, we multiply by 1000:
Density of liquid helium (ρ) = 0.125 g/cm³ * 1000 cm³/L = 125 g/L
Mass of liquid helium (m) = Volume * Density = 1950 L * 125 g/L = 243,750 g
Next, we need to convert the mass of liquid helium to moles using the molar mass of helium:
Molar mass of helium (M) = 4.0026 g/mol
Number of moles (n) = Mass / Molar mass = 243,750 g / 4.0026 g/mol ≈ 60,907 mol
Now, we have the number of moles of helium gas (n), and we can calculate the volume of helium gas (V_gas) at 25°C (298.15 K) and 1 atm:
P = 1 atm
T = 25°C = 298.15 K
V_gas = nRT / P
V_gas = (60,907 mol) * (0.0821 L.atm/(mol.K)) * (298.15 K) / (1 atm)
V_gas ≈ 1,495 L
Therefore, approximately 1,495 liters of helium gas would be formed at 25°C and 1 atm when the magnet loses its superconducting properties.
Which would increase the reaction rate?
O A. Decreasing the reactant concentrations
B. Removing heat from the system
O C. Adding a catalyst
O D. Lowering the value of k
Answer:
C
Explanation:
C. Adding a catalyst would increase the reaction rate.
What is a catalyst?A catalyst is a substance that increases the rate of a chemical reaction by lowering the activation energy required for the reaction to occur.
A catalyst enhances the probability of successful collisions between reactant molecules, which raises the pace of the reaction by offering an additional avenue for the reaction to occur.
As there would be fewer reactant molecules accessible to react with one another, decreasing reactant concentrations would result in a slower pace of reaction.
Due to the fact that chemical reactions often require energy to take place, eliminating heat from the system would also slow down the reaction rate. A lower value for k would result in a lower rate constant, which would lower the response rate.
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100cm³ of ethane gas diffuses through a porous plug in 100 seconds.What is the molecular mass of the gas Q if 100cm³ of the gas diffuses through the same plug in 121 secknds under the same condition?(C=12.0,H=1.0)
Answer:
The molar mass of gas Q is 43.923 g/mol
Explanation:
The given volume of ethane gas that diffuses through a porous plug in 100 seconds = 100 cm³
Therefore;
The rate of diffusion of ethane gas through the porous plug, [tex]v_{ethane}[/tex], is given as follows;
[tex]v_{ethane}[/tex] = (100 cm³/100 s) = 1 cm³/s
The molar mass of ethane, C₂H₆ = 2×12 g/mol + 6×1 g/mol = 30 g/mol
The given volume of gas, Q, that diffuses through a porous plug in 121 seconds = 100 cm³
∴ The rate of diffusion of the gas, Q, [tex]v_Q[/tex] = 100/121 cm³/s
Graham's Law of diffusion states that the rate of diffusion of a gas is inversely proportional to the square root of the molecular mass of the gas
Mathematically, we have;
[tex]\dfrac{v_A}{v_B} =\sqrt{\dfrac{m_B}{m_A} }[/tex]
Where;
[tex]v_A[/tex] = The rate of diffusion of gas A
[tex]v_B[/tex] = The rate of diffusion of gas B
[tex]m_A[/tex] = The molar mass of the gas A
[tex]m_B[/tex] = The molar mass of the gas B
Therefore, for ethane and gas Q, measured under the same condition, we have;
[tex]\dfrac{v_{ethane}}{v_Q} =\sqrt{\dfrac{m_Q}{m_{ethane}} }[/tex]
[tex]\dfrac{1 \ cm^3/s}{\dfrac{100}{121} \ cm^3/s} =\sqrt{\dfrac{m_Q}{30 \ g/mol} }[/tex]
[tex]m_Q = \left ({\dfrac{121}{100} } \right) ^2 \times 30 \ g/mol = 43.923 \ g/mol[/tex]
The molar mass of gas Q, [tex]m_Q[/tex] = 43.923 g/mol.
One the first chemistry test. 12 students got As, 18 students got Bs, and 20 students got Cs.
a. What is the percentage of students received Bs.
b. What is the percentage of students who received Cs?
Express your answer to the ones place.
Answer:
A. 36 percent recieved Bs
B. 40 percent of students received Cs
Explanation:
Amount of students: 12+18+20=50
Students with Bs: (18÷50) x 100 = 36%
Students with C's: (20÷50) x100 = 40%
On the first chemistry test 12 students got A, 18 students got B, and 20 student got C. Thus the percentage of students received B is 0.36 and percentage of students received c is 0.40
What is the percentage of students received B and C?In mathematics, a number or ratio expressed as a fraction of 100. It is often denoted using the percent sign %. A percentage is a dimension less unit and it has no unit.
In above question 12 student got A, 18 student got B, and 20 student got C.
So total number of student = 12 + 18 + 20 = 50.
Then the percentage of students received B is as follows:-
Percentage of students who got B = (student who got B/Total number of student) X 100.
=(18/50) X 100
= 36%
Now percentage of students who got C = (No of students who got C/Total students)X100
=(20/50) X 100
=40%.
Therefore,On the first chemistry test 12 students got A, 18 students got B, and 20 student got C. Thus the percentage of students received B is 0.36 and percentage of students received c is 0.40 percentage of students who got B is 36% and percentage of students who got C is 40%
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A pupil has drawn the electronic structure of fluorine and the diagram is shown below. However,
mistakes have been made. State three mistakes that have been made.
The first shell can only hold 2 electrons, but the pupil placed in 8 electrons.
The second shell can hold up to 8 electrons, but the pupil only placed in 2 electrons.
Flourine only has 9 total electrons, yet there are 10 electrons in the diagram.
Answer:
Explanation:
In the Fluorine atom there are 2 electrons in the innermost shell and 7 i the outer shell.
Sodium is dissolved under kerosene oil or paroffin to protect it from the air. 3) State. Huckle's rule for aromaticity with example. How does benzene react with Chlorine in presense of Sun light
Answer:
His rule states that if a cyclic, planar molecule has 4n+2 π electrons
PLS GUYS ITS FOR 10TH GRADE CHEM
Answer:
1. 2.63x10^6
2. 39.2
Both answers have been rounded
Isotopes are atoms that have the same mass number, but different numbers.
atomic. True or false
Answer: Im not sure but I think it is false.
Explanation:
Pesticides and fertilizers are a major cause of
O air pollution
O acid rain
o the greenhouse effect
O groundwater pollution
Answer:
it means air pollution Environment. The chemicals and nutrients found in fertilizers, while beneficial for agricultural crops, can be lethal in high doses for fish, birds and other wildlife. Pesticides, designed to kill pests chemically, are also dangerous when leached into soil or groundwater supplies.
hurry
A solution:
A. is a mixture that is made when a solid dissolves and combines with a liquid.
B. is the amount of a substance that will combine with another substance before they begin to chemically combine.
C. is the amount of a substance that will dissolve in 1 dm3 of water at 25 C .
D. is two or more substances that are combined together but not chemically joined.
Reset Selection
Answer:
b is the correct answer ok
A solution is made up of solute and solvent. It is an addition of two or more substances to each other that combines physically and chemically. Thus, option B is correct.
What is a solution?A solution is the mixture of solutes that can be more than one in a solvent that has the same composition all over (homogenous). A solution comprises two main elements called a solute and a solvent.
A solute is the part of the solution that has been added to the solvent for desolvation. On the other hand, the solvent is the substance that dissolves the solute in them to make a solution.
The homogenous mixture or the solution can be created by mixing salt and water, sugar and water, mercury in amalgamated zinc, coffee, vinegar, etc.
Therefore, option B. a solution is the addition of the substances that combine physically.
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What is the order, plz answer
Answer:
C A B
Explanation:
come on, you also know this from normal water waves.
which ones are stronger (= have more energy) ? the small ones or the big ones ?
and the same applies to all waves. the bigger the waves (higher amplitude), the more energy.
with balanced chemical equations, show the different stages of fermentation
Answer:
formula for fermentation is: C6H12O6 → 2 C2H5OH + 2 CO.
what's the atomic weight of salt ?
Answer:
58.44 g/mol
Explanation:
58.44 g/mol
what are the main tybes of mixture
Answer:
salt and oil
water and salt
water and sugar
Explanation:
What name is given to a metal when it forms an ion, and what type of charge does it have?
Answer:
Cation metal. Positive charge.
Answer:
DHS has been working hard for years and it is still unclear whether this would happen if it is to end the market with the engine is a little less than the next 5years to be 8years in the first quarter and the same year in a quarter or less than a quarter or more than that
Assertion (A): An orbital cannot have more than two electrons, moreover, if an orbital has two electrons they must have opposite spins.
Reason (R): No two electrons in an atom can have the same set of all the four quantum
numbers.
a) Both A and R are true and R is the correct explanation of A.
b) Both A and R are true but R is not the correct explanation of A.
c) A is true but R is false.
d) Both A and R are false.
pls answer
Answer:
the correct answer is option ( A )
Both A and R are true and R is the correct explanation of A.
Explanation:
hope it helps you
Mark my answer as brainlist
have a nice day
HELP PLEASE 15 POINTS
The rate law for a reaction is found to be rate = k[X]4. By what factor does the rate increase if [X] is doubled?
What is the aim of cleaning of the iron nails before doing the experiment?
What is occurring during the flat section of the graph below on the red arrow labeled boiling, between liquid and gas? gas (3.) OO liquid temperature solid time (minutes) O A. Heat is being absorbed, allowing particles of the liquid to overcome the atmospheric pressure. B. Heat is being absorbed, allowing particles of the liquid to overcome the vapor pressure. C. Heat is being released, allowing particles of liquid to overcome the pressure, and is why the temp does not increase. D. The temperature is no longer increasing even though heat is still being added because the heat is being absorbed to lower the melting point
from the equation 2PbO + C = 2Pb + CO2, detemine which one is reactant is oxidised and which is reduced.
Answer:
Explanation:
C is oxidised because C up to C+4
PbO is reduced because PbO from Pb2+ down to Pb0
Answer:
lead (Pb) is reduced carbon is oxidized
If you started with 2 moles of Nitrogen and 3 moles of Hydrogen, then you
would not have any leftover reactants. Explain which material would be
limiting since no hydrogen or nitrogen were left over?
N2 + 3H2 -> 2NH3
Answer: 0.3 moles NH3
Explanation:
PLS HELP!! WILL MARK BRAINLIEST! 99 POINTS!
You're going to first balance the chemical equation.
After that, convert the grams of Na into moles of Na, and then multiply that with the ratio of moles of NaCl to Na, and then convert the mol of NaCl into grams in order to obtain the theoretical yield, since we are given that Na is the limiting reactant.
After that, plug the values into the yield formula, doing some basic algebra, and you should get your result.
You're going to first balance the chemical equation.
After that, convert the grams of Na into moles of Na, and then multiply that with the ratio of moles of NaCl to Na, and then convert the mol of NaCl into grams in order to obtain the theoretical yield, since we are given that Na is the limiting reactant.
After that, plug the values into the yield formula, doing some basic algebra, and you should get your result.
Which statement best describes what happens as thermal energy from the
sun warms the pavement?
A. The thermal energy absorbed by the pavement is destroyed.
B. The thermal energy that is not absorbed by the pavement is
destroyed.
C. Some thermal energy is absorbed by the pavement, and some is
destroyed.
D. The thermal energy of the sun is transferred to the pavement.
Answer:
D
Explanation:
The correct answer would be that the thermal energy of the sun is transferred to the pavement.
Thermal energy refers to the internal energy possessed by a system by virtue of the movement of molecules within such a system. In other words, it is the heat energy possessed by a system.
When the thermal energy from the sun warms the pavement, it means that the thermal energy from the sun has been successfully transferred to the pavement. Thermal energy can be transferred by conduction, convection, or by radiation depending on whether the system is a solid, liquid, gas respectively.
The correct option is, therefore, D.
que chest pain
These may be signs of a serious condition. See your doctor
Ask a doctor before use if you have:
had heartburn over 3 months. This may be a sign of a more serious condition.
sfregent wheezina, particularly with heartbum
unexplained weight loss
Bea or vomiting
stomach pain
Ask a doctor or pharmacist before use if you are taking a prescription drug Acid reducers
may utteract with certain prescription drugs.
Stop use and ask a doctor it:
your heartburn continues or worsens
you need to take this product for more than 14 days
you need to take more than 1 course of treatment every 4 months
w you got diarrhea
you develop a rash or joint pain
I pregnant or breast-teeding, ask a health professional before uso.
Koop out of reach of children. In case of overdose, get medical help or contact a Poison
Control Center night away (1-800-222-1222).
Answer:
.........................okay?
In a synthesis experiment you obtain a sample of product on which you do a melting point determination and find a melting point range of 114 to 125 degrees Celsius. The sample is supposed to be acetylsalicyclic acid. What preliminary conclusion(s) can you reach from this one determination
Answer:
The melting point determination may need improvement- it may not have been done properly, and make sure it was repeated at least once.
Explanation:
Given that we know the actual melting point of pure acetylsalicyclic acid to be 135°, it follows that the process followed to obtain the melting point range of 114 to 125 degrees Celsius must be inaccurate.
Therefore, we can conclude that, the melting point determination may need improvement. It may not have been done properly, and we must make sure it is repeated at least once.
Scientific notation ? Please help
(5.55 x 10^15) x (8.88 x 10^18)
Explanation:
I first take back the numbers to their original forms that is to say (5.55×10^15) = 5550000000000000 and (8.88×10^18) = 8880000000000000000 therefore the difference of the two will be 887445 which is notated to (8.87445×10^5)
Answer: (8.87445×10^5)
What's a third reaction? (Chemistry)
Explanation:
a chemical reaction in which the rate of reaction is proportional to the concentration of each of three reacting molecules
WHICH STATEMENT BEST REPRESENTS A HYPOTHESIS
Answer:
D
Explanation:
Hypotheses are educated guesses, and the best answer is the one with an if, as it indicates that it's a guess.
Answer:
letter b should be the answer
(answered on edge)
Calculate the percent by mass of each element.
%N = 35 %
%H = 5.0 %
%O = 60 %
Answer:
N=35%. so 35/100*7 =2.45%
H=5.0 so 5/100*1=0.05%
o=60% so 60/100*8=4.8%
