Answer:
C
Explanation:
It is C because the change is inversible, that means that it is a chemical change.
How many atoms are there in 2 moles of helium?
Answer:
1 mole Of Helium = Weight of Helium/4Weight of Helium = 1*4 = 4 grams 1 mole of Helium contains 6.023*10²³ ( Avogadro number) atoms. Number of moles of in 4 grams of Hydrogen 4 grams is = given weight / molecular weight of Hydrogen (H₂) = 4/2 =2 Number of atoms/molecules in 2 moles of Hydrogen is (2*6.023*10²³) atoms. = 12.046*10²³ atoms.
(Hope this helps)
The number of atoms in 2 moles of helium is 1.204×10²⁴ atoms
From Avogadro's hypothesis,
1 mole of any substance = 6.02×10²³ atoms
Thus,
1 mole of helium = 6.02×10²³ atoms
With the above information in mind, we can obtain the number of atoms in 2 moles of helium as follow:
1 mole of helium = 6.02×10²³ atoms
Therefore,
2 moles of helium = 2 × 6.02×10²³ atoms
2 moles of helium = 1.204×10²⁴ atoms
Thus, we can conclude that 2 moles of helium contains 1.204×10²⁴ atoms
Learn more: https://brainly.com/question/24848191
Why are cells important?
Answer:
Cells are the basic building blocks of all living things. The human body is composed of trillions of cells. They provide structure for the body, take in nutrients from food, convert those nutrients into energy and carry out specialized functions.
Best of luck.
when the surface of a mirror curves inward, like the inside of a bowl, it is called a ____.
A) plane mirror
B) convex mirror
C) concave mirror
D) diffuse mirror
Answer:
C
Explanation:
The answer is always C
Answer:C. Concave mirror
Explanation:
When the surface of a mirror curves inward, like the inside of a bowl, it is called c. Concave mirror.
Create a Element #Brainliest Challenge
Rules- It must Have Atomic mass and Number and it's Fictional name you created
For Fun Add #GoGenius
Answer:
NeHe
Explanation:
Atomic Mass: 24.182302
Number: 18
I don't know, I just made it up.
What is the answer ?
Answer:
b
Explanation:
Electromagnetic waves are waves that have no medium to travel whereas mechanical waves need a medium for its transmission.
The specific heat of iron is 0.107 cal/g x oC. How much heat is transferred when a 24.7 kg iron ingot is cooled from 880 oC to 13 oC?
Answer:
heat = 229139.43 cal
Explanation:
given data
specific heat of iron is 0.107 cal/g-°C C = 0.4494 J/g°C;
Mass of iron = 24.7 kg = 24700 g
temperature T1 = 880°C
temperature T2 = 13°C
solution
we know that Heat lost that is express as
heat loss = mcΔT .........................1
here m is the mass and c is specific heat capacity of iron and ΔT is the change in temperature
so here change in the temperature is = 880°C - 13°C
change in the temperature = 867°C
so put here value and we get
heat = 24700 × 0.107 cal/g-°C × 867°C
heat = 229139.43 cal
Which is usually associated with a slower reaction rate?
A. using a whole solid in the reactants
B. adding heat energy to the reactants
C. adding food coloring to the reactants
D. using a strong solution of the reactants
The oxidation number of bromine in bromine gas is _____. A. 0 B. +1 C. –1 D. –2
Answer:
the answer is 0
The answer to the question is
A. 0
Use the information provided in the table to determine the Kb for acetate ion, the conjugate base of acetic acid. 1.8 × 10-19 5.6 × 10-10 2.8 × 10-9 1.8 × 1010
Answer:
B. 5.6 × 10^-10
Explanation:
The Kb for the acetate ion can be obtained from; Kb = [CH3COOH] [OH-]/[CH3COO-]
The Kb of acetate ionThe term Kb refers to the base dissociation constant of a substance. We know that the Kb for the acetate ion can be obtained from;
Kb = [CH3COOH] [OH-]/[CH3COO-]
The numerical value of the Kb can be obtaned if we have the concentrations of the various species in the equation above.
Learn more about Kb: https://brainly.com/question/19165803
#SPJ2
How is a lithium atom (Li) different from a lithium ion (Li+)?
Li has fewer electrons than Li+
Li has more electrons than Li+
Li has fewer protons than Li+
Li has more protons than Li+
Answer:
Li has fewer protons than Li+
What is heat of vaporization?
ОА.
It is the heat required to change a substance's temperature by 1°C.
OB.
It is the heat required to change a gram of substance from a solid to a liquid.
Ос.
It is the heat required to change a substance from a solid directly to a gas.
OD.
It is the heat required to change a gram of substance from a liquid to a gas.
O E. It is the heat required to separate one substance into two substances.
Answer:
Your answer is D. It is the heat required to change a gram of substance from a liquid to a gas.
ASAP NEED HELP PLSSS
A gas occupying a volume of 3.75L at a pressure of 0.980 arm is allowed to expand at constant temperature until its pressure reaches 0.641 atm. What is the final volume of the sample?
Answer:
Volume = 5.73L
Explanation:
Data;
V1 = 3.75L
P1 = 0.980atm
P2 = 0.641atm
V2 = ?
This question involves the use of Boyle's law, which states that, the volume of a fixed mass of gas is inversely proportional to its pressure provided that temperature remains constant.
Mathematically,
V = kP, k = PV
P1V1 = P2V2 =P3V3=........=PnVn
P1V1 = P2V2
V2 = (P1 * V1) / P2
V2 = (0.980 × 3.75) / 0.641
V2 = 5.73L
The final volume of the gas is 5.73L
Which best describes heating by convection?
Air molecules touch the warm ground, heating it up.
Warm air rises and takes heat with it; eventually it cools and sinks.
Sunlight travels through empty space without the aid of fluids or solids.
If you had to choose to live on the moon or mars, explain why you would choose
one over the other based of the science that you know (give at least 4 reasons
and use evidence to support them)( 10 points)
Answer:
I would choose to live on mars
Explanation:
I would choose to live on mars because not only is it the most habitable planet in our solar system other than Earth, there is enough gravity on Mars to be believed that our bodies can adapt. It is also not too hot or cold for us. There is soil that water can be extracted from, and we can also use solar panels to collect energy. Although we would have to use advanced technology when going there, but I think these are a few reasons why I would prefer living on Mars over the Moon.
When a chemical reaction occurs,
O a phase change takes place
o the physical and chemical properties of the products are different from the reactants
O the physical and chemical properties of the reactants are the same as the properties of the products
o the compounds can be separated by physical means
Answer:
D. the physical and chemical properties of the products are different from the reactants
Explanation:
PLEASE HELP :"( DUE NOW!!
What is the equation for the equilibrium constant for this equation?
CO+3H2⇌CH4+H2O
[H2O][H2]/[CH4][CO]
[CO][H2]3/[CH4][H2O]
[CH4][H2O]/[CO][H2]3
[CH]4[H2O]/[H2]3
Answer:
The correct answer is
[CH4][H2O]/[CO][H2]3
Option 3 is correct
Explanation:
Step 1: Data given
For the equation aA + bB ⇆ cC + dD
The equilibrium constant is [C]^c * [D]^d / [A]^a*[B]^b
Step 2: Calculate the equilibrium constant Kc
CO+3H2⇌CH4+H2O
Kc = [H2O][CH4] / [CO][H2]³
The correct answer is
[CH4][H2O]/[CO][H2]3
Option 3 is correct
can somebody help me name this organic compound!!
Answer:
diethyl pentane bro.............
Answer:
Nonane
Explanation:
C₉H₂₀
Nonane is the name for the straight-chained hydrocarbon with nine carbons and 20 hydrogens.
modern vacuum techniques make it possible to reach a pressure of 1.00 * 10 ^ -10 mm Hg in a laboratory system. what volume in milliliters would 1.00 * 10 ^ 6 molecules of gas occupy at this pressure and standard temp?
Answer:
around 0.283
Explanation:
A volume of 5.0 L of air at 20°C is expelled from a container where it is instantly warmed to 50°C. Calculate the new volume that the air occupies at this temperature.
Answer: The new volume that the air occupies at this temperature is 5.5 L
Explanation:
To calculate the final temperature of the system, we use the equation given by Charles' Law. This law states that volume of the gas is directly proportional to the temperature of the gas at constant pressure.
Mathematically,
[tex]\frac{V_1}{T_1}=\frac{V_2}{T_2}[/tex]
where,
[tex]V_1\text{ and }T_1[/tex] are the initial volume and temperature of the gas.
[tex]V_2\text{ and }T_2[/tex] are the final volume and temperature of the gas.
We are given:
[tex]V_1=5.0L\\T_1=20^oC=(20+273)K=293K\\V_2=?\\T_2=50^0C=(50+273)K=323K[/tex]
Putting values in above equation, we get:
[tex]\frac{5.0}{293}=\frac{V_2}{323}\\\\V_2=5.5L[/tex]
Thus the new volume that the air occupies at this temperature is 5.5 L
the distance from the top of one sound wave to the top of the next sound wave is called a (n)
Answer:
The answer is wavelength
Explanation:
How many total atoms from Carbon are present on the reactant side?
20 points
2CH2+202
O2+HC4
5
2
1
3
Answer:
2 carbon atoms/molecules are present on the reactant side.
hope it helps!
(b) Which peak, the one at 365 nm or the one at 435 nm, results from the absorption of
photons with the greater energy? Justify your answer.
(c) Based on the diagram above, is the forward reaction endothermic or exothermic? Justify
your answer in terms of Le Châtelier's principle.
Answer:
365nm and Exothermic reaction
Explanation:
b) The Einstein Planck's equation states that
E = hf where E is the energy of a photon
h is the Planck's constant
f is the frequency
But Frequency f = c/λ where c is the speed of light
λ is the wavelength
Therefore Energy E = hc/λ
From the above equation we see that the Energy of a photon is indirectly proportional to its wavelength
Hence as the wavelength increases from 365nm to 435nm, the energy of the photons decreases
Therefore, a photon will wavelength 365nm would have a higher energy than one will wavelength of 435nm.
c) From the diagram we observe the following:
At high temperatures, HPR⁺ occurs at a higher concentration than at low temperatures.
At low temperatures, more of PR⁻ is formed than at high temperatures
The equation of the reaction is
HPR⁺ (aq) ⁺ ⇆ H⁺ + PR⁻(aq)
Le Chartelier's principle states that when an external constraint such as a change in concentration, pressure or temperature is placed on a system in equilibrium, the system acts in such a way as to oppose the change.
Hence a decrease in temperature on the side of reactant, HPR would force the equilibrium to the side of the products, PR in other to accommodate the change
The forward reaction, which produces more of the product PR⁻ is exothermic because the at low temperatures, the the forward reaction is favoured and equilibrium shifts to the right.
what are the possible values for standard temperature and pressure
Answer:
0 °C and 1 Atm,
Explanation:
Standard Temperature and Pressure. Standard temperature is equal to 0 °C, which is 273.15 K.
Standard Pressure is 1 Atm, 101.3kPa or 760 mmHg or torr
What is the percent yield of C when 35 g CS₂ are reacted and produce 36.4 g C. * LABEL THE LIMITING REACTANT IN YOUR WORK.* Use the following balanced chemical equation to solve the problem: CS₂ + 4 CO --> 5 C + 2 SO₂ *
Answer:
Limiting reactant is CS2
% yield = 131.8 %
Explanation:
Using the alanced equation given, Mole ratio of C to CS2 is 1 : 5.
That is, for every 1 mole of CS2 used, 5 moles of Carbon is produced.
35g of CS2 --- [tex]\frac{35}{76.14}[/tex] moles
= 0.4597 moles
⇒ mass of C produced = 5 × 0.4597 × 12 g/mol
= 27.6 g of C.
Percentage yield (%) = [tex]\frac{actual- yield}{theoretical- yield}[/tex]
= [tex]\frac{36.4}{27.6} * 100[/tex] =131.9%
Which of the following is the energy of moving electrons?
a. kinetic energy
b. thermal energy
c. nuclear energy
d. electrical energy
Answer:
Electrical energy
Explanation:
Electrical energy is caused by the moving of electrons.
hope it helps!
A student wants to increase the magnetic force between two bar magnets. What should the student do?
A
Make the positive poles face each other.
B
Move the magnets farther apart.
C
Make the negative poles face each other.
D
Move the magnets closer together.
Answer:
Option "D" is the correct answer to the following question:
Explanation:
Magnets usually have their pulling properties, which we call magnetic power.
A major feature of magnetic power is that the closer the magnets are brought together, the higher the magnetic force increases.
On increasing distance, the magnetic force starts to decrease.
So, we can say that students should bring magnets closer to each other to increase the magnetic power.
Balance the following equation by adding the correct mole numbers.
P⁴+Cl²->PCl³
Hey there!
P₄ + Cl₂ → PCl₃
First, let's balance Cl.
There are 2 on the left, and 3 on the right.
To balance this, let's put a coefficient of 3 in front of Cl₂ and a coefficient of 2 in front of PCl₃.
P₄ + 3Cl₂ → 2PCl₃
Now we have 6 on the left and 6 on the right.
Next, let's balance P.
There are 4 on the left and 2 on the right.
Let's change the coefficient in front of PCl₃ from 2 to 4.
P₄ + 3Cl₂ → 4PCl₃
There are now 4 P on each side.
However, now Cl is unbalanced, with 6 on the left and 12 on the right.
We can change the coefficient in front of Cl₂ from 3 to 6.
P₄ + 6Cl₂ → 4PCl₃
So now, we have 4 P on each side and 12 C on each side.
This is our final balanced equation.
Hope this helps!
Answer:
1:1
Explanation:
Took test
5.6 M KCl has 600. mL of water. How many grams are in this solution?
Answer:
250.656
Explanation:
find no of moles in the 600ml=3.36,find molar mass of kcl(35.5+39,if 1mole=74.6g what about 3.36moles
I AM GIVING BRAINLIEST PLEASEEEEEEE HELPPPPPPP I NEEDDDDD HELPP PLZ
If 0.020 mol of LiOH are dissolved to make 4.5L of solution, what is the molarity?
PLEASE WRITE WITH STEPS
Answer:
0.0044 M or mol/L
Explanation:
We have to know that molarity is moles of a certain thing/litres of solution.
So the info we are given is we have 0.020 mol of LiOH and the litres of solution is 4.5L, hence we just plug it into the
Molarity forumla= moles of a certain thing/litres of solution.
Molarity (M)= 0.020/4.5 = 0.0044 M or mol/L
the combustion of 0.1240 kg of propane in the presence of excess oxygen produces 0.3110kg of carbon dioxide what is the limittinf reacrant?
Answer:
Propane
Explanation:
From the question given, we were told that 0.1240 kg of propane reacted with excess oxygen to produce 0.3110kg of carbon dioxide.
Since the reaction took place in the presence of excess oxygen, therefore, propane is the limiting reactant as all of it is used up in the presence of excess oxygen.
Answer:
The limiting reactant is propane, C₃H₈ and the percentage yield is 83.77%
Explanation:
Mass of propane = 0.1240 kg = 124 g
Mass of carbon dioxide = 0.3110 kg = 311 g
Molar mass of propane = 44.1 g/mol
Molar mass of carbon dioxide = 44.01 g/mol
Number of moles of propane = 124/44.1 = 2.812 moles
Number of moles of carbon dioxide = 311/44.01 = 7.067 moles
Equation for the reaction
C₃H₈ + 5O₂ → 3CO₂ + 4H₂O
Hence 1 mole of propane ideally yields 3 moles of CO₂
Hence, 2.812 moles of propane will yield 3×2.812 moles = 8.44 moles of CO₂
Since, oxygen is in excess, therefore, the limiting reactant = Propane, C₃H₈
The percentage yield = 7.067/8.44× 100 = 83.77%.
