The mass of He gas = 21.428 g
Further explanationGiven
120 liters of He gas
Required
the mass in grams
Solution
Conditions at T 0 ° C and P 1 atm are stated by STP (Standard Temperature and Pressure). At STP, Vm is 22.4 liters/mol.
Mol for 120 L :
[tex]\tt \dfrac{120}{22.4}=5.357~moles[/tex]
Mass of He gas(MW=4 g/mol) :
[tex]\tt mass=mol\times Ar\\\\mass=5.357\times 4=21.428~g[/tex]
Can you please help on 17 and 18 pleaseeee
Answer:
17. Yes, it represents a chemical reaction. This is because new substances were formed from the original substance.
18. (a) Formation of new substances
(b) Evolution or absorption of large quantity of heat
(c)Change in mass of substances
Explanation:
17. In the model above, molecules of a compound of carbon and hydrogen (molecular formula is C2H6) combines with molecular oxygen (O2) to produce two new substances; a compound composed of two oxygen atoms and one carbon atom (CO2) and another compound composed of two atoms of hydrogen and one atom of oxygen (H2O). Since the new substances formed are completely different from the original substances, it a chemical reaction. Also, a large volume of heat would have been given off.
18. To determine if a chemical reaction has occurred, the following observations can be looked out for.
a. Formation of new substances different entirely from the original substances
b. Evolution or absorption of large quantity of heat during the change. Check whether the vessel containing the substances gets hotter or colder.
c. Change in mass of substances. Since new substances are formed in a chemical reaction, there is usually a significant change in mass of the products and reactants.
can someone answer that for me
Answer:
4^4, or 256
Explanation:
When dividing numbers with exponents and the same base, you will subtract from the exponents and keep the base the same.
write 4 important of measurement?
Answer:
Measurement helps in buying and selling goods
Measurement helps in doing various science
experiment
Measurement is used in our daily life
Measurement is essential for making roads, bridge etc
A subrule of the Cahn-Ingold-Prelog system specifies that higher mass number takes precedence over lower when distinguishing between isotopes. Determine the absolute configurations of the reactant and product in the biological oxidation of isotopically labeled ethane.
Answer:
The correct answer is - S- configuration.
Explanation:
Placing the numbers in order of the priorities of each reactant in the reaction is essential to determining the configuration of the reactant and product in the biological oxidation of isotopically labeled ethane.
CH3 - T- D is the correct order of the increasing of the priorties. so this is moving from CH3 to D which is Anti-clockwise which means the configuartion is S as we know clockwise movement is R configuarion and anti-clockwise in S configuartion.
If I have 80 grams of H2 how many molecules of H2 do I have?
Answer:
2 molecules
Explanation:
I don't know how to explain it
The chemical formula of water is H₂O. Then 1 mole of water weighs 18 gram. Hence, 80 gram of water is equal to 4.4 mole.
What is chemical formula ?
Chemical element symbols, numbers, and occasionally other symbols like parentheses, dashes, brackets, commas, and plus and minus signs are used in a chemical formula to represent information about the chemical proportions of the atoms that make up a certain chemical compound or molecule.
It displays the constituent elements and how many atoms of each element are found in a single complex molecule. It also represents the compound's molecular weight.
Water has the chemical formula H₂O. Water weights 18 grams per mole. 80 grams of water are therefore equivalent to 4.4 moles.
Thus, The chemical formula of water is H₂O. 80 grams of H₂ contain 4.4 molecules of water.
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In Space, an astronaut releases a wrench from his hand. The wrench has a mass of 4 grams and is traveling with a velocity of -15m/s. The Astronaut’s mass is 70kg. What is his Velocity?
Answer:
860 cm/s
Explanation:
Let P = momentum of wrench-man system before throwing the wrench and P' = momentum of wrench-man system before throwing the wrench.
From the law of conservation of momentum,
P = P'
P = 0 (since both Astronaut and wrench were initially stationary) and P' = m₁v₁ + m₂v₂ where m₁ = mass of wrench = 4g = 0.004 kg v₁ = velocity of wrench after releasing the wrench = -15 m/s m₂ = mass of Astronaut = 70 kg and v₂ = velocity of Astronaut after releasing the wrench.
So, P = P'
0 = m₁v₁ + m₂v₂
-m₁v₁ = m₂v₂
dividing both sides by m₂, we have
v₂ = -m₁v₁/m₂
substituting in the values of the variables, we have
v₂ = -0.004 kg × (-15 m/s)/70 kg
= 0.06 kgm/s ÷ 70 kg
= 8.6 × 10⁻⁴ m/s
= 860 × 10⁻² m/s
= 860 cm/s
Humans absorb oxygen from the air they breathe in and exhale carbon dioxide gas, CO2.Carbon dioxide gas is
A
an element made of carbon and oxygen atoms.
B
a solution made of carbon and oxygen atoms.
C
a compound of carbon and oxygen atoms.
D
a mixture of carbon and oxygen atoms.
Answer:
A
an element made of carbon and oxygen atoms.
So I think the answer is going to be A An element made of carbon and oxygen atoms.
PLEASE HURRY IM BEING TIMED time: 1:55:40
Which number belongsin the space labeled X?
O5
O7
O8
O 10
Answer:
a.) x = 5
Explanation:
Ammonium phosphate is an important ingredient in many solid fertilizers. It can be made by reacting aqueous phosphoric acid with liquid ammonia. Calculate the moles of ammonia needed to produce of ammonium phosphate. Be sure your answer has a unit symbol, if necessary, and round it to significant digits.
Answer:
The balanced chemical equation:
3 NH₃ + H₃PO₄ → (NH₄)₃PO₄
From the equation we see:
3 moles of NH₃ gives 1 mole (NH₄)₃PO₄
0.085 mole NH₃ will gives ?? mole (NH₄)₃PO₄
By cross multiplication:
number of moles of (NH₄)₃PO₄ = 0.085 * 1/3 = 0.028 mole
Explanation:
Which of the following determines the identity of an element?
A pure substance composed of two or more different elements is aln)
a. ion
b. heterogeneous mixture
c. chemical compound
d. solid
e. solution
chemical compound
Answer:
c
Explanation:
that is my dads answer
A pure substance composed of two or more different elements is a chemical compound.
When two or more atoms are chemically combined, we refer to such a combination as a chemical compound.
Since a chemical compound contains only a given set of elements which are chemically combined together, a chemical compound is also a pure substance.
Hence, a pure substance composed of two or more different elements is a chemical compound.
Learn more; https://brainly.com/question/6284546
One role of enzymes in the human body
digestion
does that answer it?
molecular formula of alkyne containing 10 carbon atom
Answer:
Decyne: C10H18
Hope it helps! please mark me brainliest..
Merry Christmas good day
The general formula for alkynes is CnH2n-2
the number of carbon atoms is 10 so the number of hydrogen atoms will be 10*2-2=20-2=18hydrogen atoms
the molecular formula for this alkyne is :
C₁₀H₁₈ which is called decyne
What is the mass in grams of 12.9 moles of water, H2O?
Answer:
232 g.
Explanation:
12.9 mol x 18.106g = 232 g H₂O
Human reaction time is usually about 0.18 s. If your lab partner holds a ruler between your finger and thumb and releases it from rest without warning, how far can you expect the ruler to fall before you catch it? (a = -g = -9.81 m/s .) - 0.32 m ⊝ - 0.88 m ⊝ - 0.16 m ⊝ - 0.09 m ⊝ CLEAR ALL ❮ PREVIOUS
Answer:
–0.16 m
Explanation:
From the question given above, the following data were obtained:
Time (t) = 0.18 s
Acceleration due to gravity (g) = –9.81 m/s²
Height (h) =?
We can obtain how far the ruler will fall by using the following equation:
H = ½gt²
H = ½ × –9.81 × 0.18²
H = ½ × –9.81 × 0.0324
H = –0.16 m
Thus, the ruler will fall –0.16 m before you will catch it.
NEED HELP ON 31,32,33..ONLY IF YOU KNOW PLEASE
Answer:
31. C
32. D
33. B
Explanation:
31. A plant cell is an eukaryotic cell i.e. it contains a membrane-bound nucleus, located CENTRALLY. The nucleus is the largest organelle in the plant cell. The cell/plasma membrane bounds the cell while the chloroplast organelle (site of photosynthesis) is also located in the plant cell. Based on this description, the image in OPTION C is correct.
32. Pottasium (K) is a highly reactive group 1 element. As stated in this question, pottasium reacts vigorously with water (H2O). This reactive property of K element is due to its valence electrons. However, elements in the same group as pottasium i.e same column on the periodic table will have the same number of valence electrons, hence, will behave chemically similar. Therefore, elements in the same column as pottasium will react the same way with water.
33. A reactant is a an element/compound in a chemical reaction that gets used up to form new products. They are usually the starting materials located on the left side of any equation. In this equation shown as:
2CuO + C → 2Cu + CO2
CuO and C are the REACTANTS while Cu and CO2 are the products.
You have two options for this task.
Option 1: Create your own stage or film interpretation of one scene or chapter from Journey to the Center of the Earth, write it out in script or screenplay format, or you can actually film it and upload it to your instructor. You can conduct an Internet search for sample scripts or screenplays to help you with the basics of formatting.
Remember, you are only doing one section. Pick a chapter and go to town!
Option 2: Write an analysis of how the filmmakers of one of the adaptations chose to recreate the movie. Pick a scene — for example, the desperate search for water — and describe and explain how the filmmakers adapted the novel. What parts did they keep? What parts did they change? Why do you think they did that? Do you agree with those decisions? Do you think they made for a better movie? Why or why not?
Write these answers up in a 2 paragraph essay and submit it to your instructor.
Answer:
Option 1
Explanation:
Harry: *wakes up and finds himself at the bottom of a mountain slope and asks, "Where are we?"
Harry: "Are we in Iceland?"
Hans: "Nej."
The Professor: *Gets up and says, "what do you mean? No----What are your reasons?"
Harry: *Rises* "No, Hans is wrong."
After all the innumerable surprises of this journey, a yet more singular one was reserved to us. I expected to see a cone covered by snow, by extensive and widespread glaciers, in the midst of the arid deserts of the extreme northern regions, beneath the full rays of a polar sky, beyond the highest latitudes.
*Time passes while we try to figure out what is happening and where we are. Harry finds that he was saved from death because Hans had saved him.*
What is the standard reduction potential,E, for the half-reaction Zn2+(aq)+2e- -> Zn(s)?
Answer:
E = -0.76 V
Explanation:
The potential between the anode and the cathode is called standard reduction potential. It gives the tendency of the species to get reduced.
The given half reaction is :
[tex]Zn^{2+}(aq)+2e^{-}\rightarrow Zn(s)[/tex]
Zn²⁺ is the reduced form of Zn.
It is a stronger reducng agent.
Its standard reduction potential (E) has a sandard value.
E = -0.76 V
Hence, the correct option is (c).
Calculate the molarity of a solution of potassium hydroxide if 19.55 mL of KOH is required for the titration of a 20.20 mL sample of a 0.3467 M sulfuric acid solution.
Answer:
The correct answer is 0.3582 M.
Explanation:
Based on the given information, the volume of KOH given is 19.55 ml, the volume of sulfuric acid given is 20.20 ml, and the molarity of sulfuric acid is 0.3467 M. There is a need to find the molarity of KOH.
The formula to use in the given case is,
M1V1 = M2V2
Here M1 is the molarity of KOH, V1 is the volume of KOH, M2 is the molarity of sulfuric acid, and V2 is the volume of H2SO4.
Here V1 is 19.55 ml, M2 is 0.3467 M, and V2 is 2020 ml.
Now putting the values in the equation we get,
M1 * 19.55 = 0.3467 * 20.20
M1 * 19.55 = 7.00334
M1 = 7.00334/19.55
M1 = 0.3582 M
Hence, the molarity of the given KOH is 0.3582.
The molarity of a solution of potassium hydroxide is 0.3582M
To get the molarity of the solution of potassium hydroxide KOH, we will apply the formula;
[tex]C_1V_1=C_2V_2[/tex]
C₁ and C₂ are the concentration of the solutionV₁ and V₂ are volumes of the solutionGiven the following parameters;
C₂ = 0.3467M
V₂ = 20.20mL
V₁ = 19.55mL
C₁ = ?
Substitute the given parameters into the formula:
C₁ × 19.55 = 0.3467× 20.20
C₁ × 19.55 = 7.00334
C₁ = 7.00334/19.55
C₁ = 0.3582M
Hence the molarity of a solution of potassium hydroxide is 0.3582M
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How are Parkinson's disease and ALS similar?
Both diseases are preventable.
Dementia is a symptom of both diseases.
Both diseases affect control of voluntary muscles.
Scientists understand the causes for both diseases.
HELP PLZ
Answer:
Both diseases affect the control of voluntary muscles.
Explanation:
Parkinson's disease is a progressive brain disease that affects movement. It affects the nerve cells that produce dopamine in the part of the brain called substantia nigra. The symptoms include shaking, stiffness, and difficulty with walking, balance, and coordination. Symptoms get worse with time, often leaving people with difficulty walking and talking.
ALS (amyotrophic lateral sclerosis) is a progressive nervous system disease that affects nerve cells in the brain and spinal cord. The first symptoms usually involve muscle weakness, and as the disease progresses, it results in the loss of muscle control.
Scientists don't know the exact cause of these diseases. As the cause is not known, there is no exact way to prevent them. There is no cure for them, either. The treatment is focused on the management of symptoms.
This is why the third option is the correct one.
True or False: Radon is a solid at – 100 °C.
Which best illustrates the way in which radiation transfers thermal energy?
A red ball at left labeled warm does not touch a blue ball labeled cool at right. Curved arrows point from the blue ball to the red ball.
A red ball at left labeled warm does not touch a blue ball labeled cool at right. Curved arrows point from the red ball to the blue ball.
A red ball at left labeled warm touches a blue ball labeled cool at right. Straight arrows point from the blue ball to the red ball.
A red ball at left labeled warm touches a blue ball labeled cool at right. Straight arrows point from the red ball to the blue ball.
Answer:
B or the second answer.
Explanation:
It's heat transfer and the objects aren't directly touching. B is the only answer that fits.
Hope this helps!
Answer:
b
Explanation:
Under what conditions does a Lunar eclipse occur?
Answer:
when the Moon moves into the Earth's shadow
when the Sun, Earth, and Moon are exactly or very closely aligned with the Earth between the other two, and only on the night of a full moon
Explanation:
A red laser pointer emits light at a wavelength of 488 nm. If the laser emits 7.5 10–4 J of energy per second in the form of visible radiation, how many photons per second are emitted from the laser?
a)
4.1 10–19 photons/sec
b)
5.4 10–16 photons/sec
c)
8.9 1014 photons/sec
d)
1.8 1015 photons/sec
e)
2.5 1018 photons/sec
The answer to the question, how many photons per second are emitted from the laser is d. 1.84 × 10¹⁵ photons/sec
Since the red laser pointer emits light of wavelength 488 nm, we need to find the energy of each photon from
E = hc/λ where h = Planck's constant = 6.63 × 10⁻³⁴ Js, c = speed of light = 3 × 10⁸ m/s and λ = wavelength of light = 488 nm = 488 × 10⁻⁹ m
Substituting the values of the variables into the equation, we have
E = hc/λ
E = 6.63 × 10⁻³⁴ Js × 3 × 10⁸ m/s ÷ 488 × 10⁻⁹ m
E = 19.89 × 10⁻²⁶ Jm ÷ 488 × 10⁻⁹ m
E = 0.04076 × 10⁻¹⁷ J per photon
E = 4.076 × 10⁻¹⁹ J per photon
Since the laser emits 7.5 × 10⁻⁴ J per second, the number of photons emitted from the laser per second = energy per second/energy per photon
= 7.5 × 10⁻⁴ J per second ÷ 4.076 × 10⁻¹⁹ J per photon
= 1.84 × 10¹⁵ photons/sec
The answer to the question, how many photons per second are emitted from the laser is d. 1.84 × 10¹⁵ photons/sec
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What is the mass of 1 mol of Ca atoms to three significant Figures of CaSO4
Answer:
40g
Explanation:
Given parameters:
Number of moles = 1mol
unknown:
mass of Ca = ?
Solution:
The number of moles of a substance is related to mass using the expression below;
Mass = number of moles x molar mass
Molar mass of Ca = 40g/mol
So;
Mass of Ca = 1 mol x 40g/mol = 40g
What is the molarity of 2.0 moles of glucose
in 4.0 L of glucose solution?
Answer:
0.5 M
General Formulas and Concepts:
Chemistry - Aqueous Solutions
Molarity = moles of solute / liters of solutionExplanation:
Step 1: Define
2.0 mol glucose
4.0 L glucose solution
Step 2: Find Molarity
Substitute: M = 2.0 mol / 4.0 LDivide: M = 1/2Evaluate: M = 0.5What is the free energy change if the ratio of the concentrations of the products to the concentrations of the reactants is 22.3, and the temperature is 37.0 °C? ?G°\' for the reaction is –16.7 kJ/mol.
The free energy change(Gibbs free energy-ΔG)=-8.698 kJ/mol
Further explanationGiven
Ratio of the concentrations of the products to the concentrations of the reactants is 22.3
Temperature = 37 C = 310 K
ΔG°=-16.7 kJ/mol
Required
the free energy change
Solution
Ratio of the concentration : equilbrium constant = K = 22.3
We can use Gibbs free energy :
ΔG = ΔG°+ RT ln K
R=8.314 .10⁻³ kJ/mol K
[tex]\tt \Delta G=-16.7~kJ/mol+8.314.10^{-3}\times 310\times ln~22.3\\\\\Delta G=-8.698~kJ/mol[/tex]
What is the volume of a sample that has a mass of 20 grams and density of 4 g/mL?
Answer:
5 mLExplanation:
The volume of a substance when given the density and mass can be found by using the formula
[tex]volume = \frac{mass}{density} \\[/tex]
From the question we have
[tex]volume = \frac{20}{4} \\ [/tex]
We have the final answer as
5 mLHope this helps you
A. An atom loses one electron. What is the overall charge now?
Answer:
it losses one neutrons that is hydrogen
Please show work!
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