The Mesopotamians discovered copper (Cu) in 9000 BC.
Which plate does not appear in both hemispheres?
Indo-Australian
African
Pacific
Eurasian
Answer:
Indo-Australian
Explanation:
Indo-Australian does not appear in both hemispheres.
Answer:
I can clarify, its into Australian
determine how many grams of kno3 would dissolve in 100g of water at 50 degrees celcuis to make a saturated solution
The amount of KNO₃ would dissolve in 100g of water at 50 degrees celcuis to make a saturated solution is 44 g.
To create a saturated solution of KNO₃ in 100g of water at 50 degrees Celsius, the following steps should be taken:
Step 1: Find out the mass of the solvent in the saturated solution.
The solvent is water in this instance. So, using the formula for the mass of a solution, we can calculate the mass of the solvent in the saturated solution as follows:
Mass of solvent = Mass of solution - Mass of solute
= 100 g - Mass of KNO₃
Step 2: Determine the amount of solute that would be dissolved in the solution to make it saturated.
The mass of KNO₃ that would dissolve in 100 g of water at 50°C to create a saturated solution is 56g/100g of water.
Step 3: Calculate the mass of KNO₃ that would dissolve in 100g of water to make a saturated solution.
Mass of KNO₃ = Solubility of KNO₃ × Mass of solvent
Mass of KNO₃ = 56 g/100 g × (100 g - Mass of KNO₃)
Now, let's solve for Mass of KNO₃;
56 = 56g(100-Mass of KNO₃)/100100 - Mass of KNO₃ = 100
Multiply both sides of the equation by 100 to obtain;
5600 - 100 Mass of KNO₃ = 100
Mass of KNO₃ = 5600/10100 - 56
= 44 g
Therefore, 44 g of KNO₃ would dissolve in 100g of water to make a saturated solution.
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identify the type of change (physical or chemical) that occurs when an iron bar rusts and when a substance freezes. use complete sentences to justify the type of change that occurs.
For the rusting of an iron bar, a chemical change occurs; while for the freezing of a substance , a physical change occurs.
When an iron bar rusts, a chemical change occurs. Rusting is a chemical reaction that involves the oxidation of iron in the presence of oxygen and water. The iron undergoes a chemical transformation and forms a new compound, iron oxide, which gives the rusty appearance. This change is irreversible and involves a rearrangement of atoms at the molecular level.
On the other hand, when a substance freezes, a physical change takes place. Freezing is a phase transition from a liquid to a solid state. During freezing, the substance undergoes a change in its physical state without any alteration in its chemical composition. The arrangement of molecules or atoms becomes more ordered as they transition from a disordered liquid state to a more structured solid state. This change is reversible, and the substance can return to its liquid state by melting.
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What is the maximum pH an aqueous solution of 0.050 M Cu(NO3)2 can be adjusted to before a precipitate of Cu(OH)2 will form?
a. 4.2
b. 5.0
c. 7.0
d. 8.5
5.0 is the maximum pH an aqueοus sοlutiοn οf 0.050 M Cu(NO₍)₂ can be adjusted tο befοre a precipitate οf Cu(OH)₂ will fοrm
What is pH?pH, οften knοwn as acidity in chemistry, has histοrically stοοd fοr "pοtential οf hydrοgen" (οr "pοwer οf hydrοgen"). It is a scale used tο describe hοw basic οr hοw acidic an aqueοus sοlutiοn is. When cοmpared tο basic οr alkaline sοlutiοns, acidic sοlutiοns—thοse with higher hydrοgen (H+) iοn cοncentratiοns—are measured tο have lοwer pH values.
Using a cοncentratiοn cell with transference, the pοtential difference between a hydrοgen electrοde and a standard electrοde, such as the silver chlοride electrοde, is measured tο get the primary pH standard values. With the use οf a glass electrοde, a pH metre, οr a cοlοr-changing indicatοr, the pH οf aqueοus sοlutiοns can be determined.
Cu(OH)2⇔[tex]Cu^2 +2OH-[/tex]
s[tex]^2=1.0*10^{-19}[/tex]
[tex]s=3.16*10^{=9}[/tex]
[tex]{OH-}=2s=6.3*10^{10^{-19}[/tex]
[tex]{H+}=10^{-14}/OH[/tex]
[tex]{H+}=1.58*10^{-6}[/tex]
[tex]pH=-log(1.58*10^{-6}[/tex]
pH≈5
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explain+how+you+could+estimate+22%+of+78+to+check+if+your+answer+is+reasonable....
You can estimate the value of 22 % of 78 by finding 10 % of 78 and then adding another 10% to reach as close to 22 % as possible.
How to estimate the value ?Start by finding 10% of 78. Divide 78 by 10 to get 7.8. Since you want to estimate 22%, you can take the calculated value of 10% (7.8) and multiply it by 2 to get 15.6.
Next, compare the estimated value of 15.6 with the actual value of 22% of 78. Calculate the actual value by multiplying 78 by 0.22 (since 22% is equivalent to 0.22). The result is 17.16.
Compare the estimated value of 15.6 with the actual value of 17.16.
By comparing the estimated value of 15.6 with the actual value of 17.16, you can assess the reasonability of your estimate.
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o facilitate ease of dose calculations for cefazolin injection, your department policy
states that the resulting concentration after reconstitution should be 100 mg/mL. The
packaging insert for cefazolin 1-g vial instructs you to add 3.4 mL of sterile water without
bacteriostat, resulting in a reconstituted solution of 250 mg/mL
i. What is the final volume of the reconstituted cefazolin solution?
A 3 mL
B. 4 mL
C. 5 mL
D. 2.5 mL
ii. What is the volume of the cefazolin powder?
A 0.4 mL
B. mL
C. 0.7 mL
D. 0.6 mL
iii. What is the final volume of the 100mg/mL cefazolin solution?
A. 6 mL
B. 8 mL
C. 7 mL
D. 10 mL
The final volume of the reconstituted cefazolin solution is 4 mL. The volume of the cefazolin powder is 0.6 mL. The final volume of the 100 mg/mL cefazolin solution is 10 mL.
The packaging insert instructs to add 3.4 mL of sterile water without bacteriostat to the 1-g vial of cefazolin. This results in a reconstituted solution with a concentration of 250 mg/mL.
To find the final volume, we can set up the equation:
Concentration of reconstituted solution = Amount of drug / Final volume
Using the given concentration (250 mg/mL) and the amount of drug (1 g = 1000 mg), we can rearrange the equation to find the final volume:
250 mg/mL = 1000 mg / Final volume
Solving for the final volume:
Final volume = 1000 mg / 250 mg/mL = 4 mL
Therefore, the final volume of the reconstituted cefazolin solution is 4 mL.
To find the volume of the cefazolin powder, we need to subtract the volume of sterile water added from the final volume of the reconstituted solution.
Given that 3.4 mL of sterile water is added to the vial, and the final volume of the reconstituted solution is 4 mL, we can calculate the volume of the cefazolin powder as follows:
Volume of cefazolin powder = Final volume - Volume of sterile water added
Volume of cefazolin powder = 4 mL - 3.4 mL = 0.6 mL
Therefore, the volume of the cefazolin powder is 0.6 mL.
To determine the final volume of the 100 mg/mL cefazolin solution, we can use the concentration and the amount of drug.
We are given that the resulting concentration after reconstitution should be 100 mg/mL. Considering the amount of drug is 1 g (1000 mg), we can set up the following equation:
Concentration of reconstituted solution = Amount of drug / Final volume
Using the given concentration (100 mg/mL) and the amount of drug (1000 mg), we can rearrange the equation to find the final volume:
100 mg/mL = 1000 mg / Final volume
Solving for the final volume:
Final volume = 1000 mg / 100 mg/mL
Final volume = 10 mL
Therefore, the final volume of the 100 mg/mL cefazolin solution is 10 mL.
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answer 1-5 of lesson outline for brainiest
Answer:
see explanation
Explanation:
1. mid-ocean ridge
2.gravity
3.normal,reverse
4.cools
5.stripes
6.spreading
7.continents
What is the pOH of a solution whose pH is 12.41?
Answer:
1.59
Explanation:
14=pOH+pH
pOH=14-12.41
pOH=1.59
In the cytosol of rat hepatocytes, the temperature is 37°C and the mass-action ratio, Q, is [ATP]/[ADP][Pi] = 5.33 x 10M- Calculate the free energy required to synthesize ATP in a rat hepatocyte (AG'º for ATP hydrolysis is -30.5 kJ/mol.)
The free energy required to synthesize ATP in a rat hepatocyte is 24,365.6364 J/mol
To calculate the free energy required to synthesize ATP in a rat hepatocyte, we can use the formula:
ΔG'º = -RTln(Q)
where:
ΔG'º is the standard free energy change,
R is the gas constant (8.314 J/(mol·K)),
T is the temperature in Kelvin,
ln(Q) is the natural logarithm of the mass-action ratio.
Given:
ΔG'º = -30.5 kJ/mol
T = 37°C = 37 + 273.15 = 310.15 K
Q = 5.33 x [tex]10^{(-10)[/tex] M
First, we need to convert ΔG'º from kJ/mol to J/mol:
ΔG'º = -30.5 kJ/mol = -30.5 x [tex]10^3[/tex] J/mol
Next, we can calculate the free energy required to synthesize ATP using the formula:
ΔG = ΔG'º - RTln(Q)
ΔG = [tex](-30.5 * 10^3 J/mol) - (8.314 J/(molK) * 310.15 K) * ln(5.33 x 10^{(-10))[/tex]
≈ -30,500 J/mol - 2576.1911 J × (-21.3364)
≈ -30,500 J/mol + 54,865.6364 J
≈ 24,365.6364 J/mol
Calculating this expression will give us the value of ΔG, which represents the free energy required to synthesize ATP in a rat hepatocyte.
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A lake has been infected by some type of new algae that is unknown. Every single day the amount of surface area that the algae takes up doubles. Day 1 has a certain amount, day 2 it is 2x that amount. It takes 87 days for the entire lake to be overrun by this new algae. How many days does it take to cover half of the lake? Show your work and explain your thinking. In science we need to be able to justify our answers.
hint: It is not the "obvious" answer.
Answer:
It takes 86 days take to cover half of the lake
Explanation:
In the day #1, the amount of the algae is X,
In the day #2 is 2X
In the day #3 is 2*2*X = X*2²
...
In the day #n the amount of the algae is X*2^(n-1)
Assuming X = 1m³. In the day 87, the area infected was:
1m³*2^(87-1)
7.74x10²⁵m³ is the total area of the lake
the half of this amount is 3.87x10²⁵m³
The time transcurred is:
3.87x10²⁵m³ = 1m³*2^(n-1)
Multiplying for 5 in each side:
ln (3.87x10²⁵) = ln (2^(n-1))
58.9175 = n-1 * 0.6931
85 = n-1
86 = n
It takes 86 days take to cover half of the lakeWrite the balanced net ionic equation for the following reaction between aqueous Pb(NO3)2 and aqueous NaI and correctly label the states. Use the solubility table to determine if a precipitate forms before writing the net ionic equation. Must show the (1) balanced chemical equation with the right states (2) the cancellation of appropriate spectator ions and the final net ionic equation.
Balanced net ionic equation will be: Pb2+(aq) + 2I-(aq) → PbI2(s)
The balanced chemical equation for the given reaction is;Pb(NO3)2(aq) + 2NaI(aq) → PbI2(s) + 2NaNO3(aq)
This equation is balanced because the number of atoms of the elements present on both sides of the equation is equal.
The states of the substances in the above equation are:
aqueous Pb(NO3)2(aq) , aqueous NaI (aq) → soluble, based on the solubility table PbI2 (s) → precipitate, based on the solubility tableaqueous NaNO3 (aq)
Cancel out the spectator ions from the above equation and the net ionic equation will be:
Pb2+(aq) + 2I-(aq) → PbI2(s)
Hence, the balanced net ionic equation for the given reaction between aqueous Pb(NO3)2 and aqueous NaI and correctly label the states are Pb2+(aq) + 2I-(aq) → PbI2(s) and the states are as follows;
Pb2+(aq) → AqueousI-(aq) → AqueousPbI2(s) → Solid
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The ionic equation for the reaction is given as follows:Pb2+ (aq) + 2NO3- (aq) + 2Na+ (aq) + 2I- (aq) → PbI2 (s) + 2Na+ (aq) + 2NO3- (aq)The net ionic equation is the same as the ionic equation, with spectator ions removed.Pb2+ (aq) + 2I- (aq) → PbI2 (s)The final balanced net ionic equation is given as follows:Pb2+ (aq) + 2I- (aq) → PbI2 (s).
The balanced net ionic equation for the following reaction between aqueous Pb(NO3)2 and aqueous NaI and correctly label the states are given below:Explanation:Aqueous lead(II) nitrate (Pb(NO3)2) and aqueous sodium iodide (NaI) are mixed to form solid lead(II) iodide (PbI2) and aqueous sodium nitrate (NaNO3).Before writing the net ionic equation, it is important to determine whether a precipitate will form. By referencing the solubility table, it is discovered that lead(II) iodide is insoluble in water, indicating that a precipitate will form when the two solutions are mixed.The balanced molecular equation for the reaction is given as follows:Pb(NO3)2 (aq) + 2NaI (aq) → PbI2 (s) + 2NaNO3 (aq)To write the ionic equation, the insoluble solid lead(II) iodide must be separated into its component ions. PbI2 is a precipitate; it will not dissociate, while NaNO3 will dissociate into its component ions. The ionic equation for the reaction is given as follows:Pb2+ (aq) + 2NO3- (aq) + 2Na+ (aq) + 2I- (aq) → PbI2 (s) + 2Na+ (aq) + 2NO3- (aq)The net ionic equation is the same as the ionic equation, with spectator ions removed.Pb2+ (aq) + 2I- (aq) → PbI2 (s)The final balanced net ionic equation is given as follows:Pb2+ (aq) + 2I- (aq) → PbI2 (s).
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if 15.70g of ticl4 reacts in excess oxygen to form 10.40g cl2 what is the percent yield of the reaction
The percent yield of the reaction is approximately 88.71%.
To calculate the percent yield of the reaction, we need to compare the actual yield (the amount of Cl₂ formed) to the theoretical yield (the amount of Cl₂ that would be formed if the reaction proceeded with complete conversion of TiCl₄).
First, we need to determine the molar masses of TiCl₄ and Cl₂. The molar mass of TiCl₄ is calculated as follows:
Ti: 1 atom x 47.87 g/mol = 47.87 g/mol
Cl: 4 atoms x 35.45 g/mol = 141.80 g/mol
Total molar mass of TiCl₄ = 47.87 g/mol + 141.80 g/mol = 189.67 g/mol
Next, we can calculate the number of moles of TiCl₄ and Cl₂ based on the given masses:
Moles of TiCl₄ = 15.70 g / 189.67 g/mol ≈ 0.08274 mol
Moles of Cl₂ = 10.40 g / 70.90 g/mol ≈ 0.14676 mol
From the balanced chemical equation for the reaction:
TiCl₄ + 2O₂ → TiO₂ + 2Cl₂
We can see that the stoichiometric ratio between TiCl₄ and Cl₂ is 1:2. Therefore, according to the balanced equation, the theoretical yield of Cl₂ would be:
Theoretical yield of Cl₂
= 2 (moles of TiCl₄)
= 2 (0.08274 mol)
= 0.16548 mol
Percent yield = (actual yield / theoretical yield) 100
= (0.14676 mol / 0.16548 mol) 100 ≈ 88.71%
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Which is a function common to both the muscular and skeletal systems?
Answer:
please give me brainlist and follow
Explanation:
In the musculoskeletal system, the muscular and skeletal systems work together to support and move the body. The bones of the skeletal system serve to protect the body's organs, support the weight of the body, and give the body shape.
Answer:
B. bending of the arm
Explanation:
When an aqueous solution of silver nitrate is
mixed with an aqueous solution of potassium
chloride which are the spectator ions?
Answer:
[tex]K^{+}[/tex] and [tex]NO_{3}^{-}[/tex]
Explanation:
The equation for the reaction is AgNO3(aq) + KCl(aq) ==> AgCl(s) + KNO3(aq)
With all the ions, it is
[tex]Ag^{+}[/tex](aq) + [tex]NO_{3} ^{-}[/tex](aq) + [tex]K^{+}[/tex](aq) + [tex]Cl^{-}[/tex](aq) ==> AgCl(s) +
[tex]K^{+}[/tex] and [tex]NO_{3} ^{-}[/tex] do not change, so they are the spectator ions and are removed
The ionic equation is:
[tex]Ag^{+}[/tex](aq) + [tex]Cl^{-}[/tex](aq) ==> AgCl(s)
in the following voltaic cell, the addition of cucl2(aq) to the cathodic compartment would cause the emf to increase. sn(s) 2 cu2 ⇄ sn2 (aq) 2 cu (aq) choix de groupe de réponses. true or false
The statement on the effect of the addition of CuCl₂(aq) to the cathodic compartment is True.
What effect does the addition of CuCl₂(aq) to the cathodic compartment bring ?According to Le Chatelier's principle, if the concentration of a reactant in a reaction at equilibrium is increased, the reaction will shift in the direction that consumes that reactant.
The reaction at the cathode is :
Cu₂ + ( aq ) + 2e- ⇄ Cu(s)
By adding CuCl₂(aq), we increase the concentration of Cu₂+ ions in the cathodic compartment. This would cause the reaction to shift to the right, which means more Cu(s) would be produced and more electrons would be consumed.
Therefore, increasing the concentration of Cu₂+ ions in the cathodic compartment will increase the cell potential or emf.
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Can someone help with 10 a and b please
Answer:
for question a element A and B are isobars
for question b element C and D have the same atomic numbers.
Explanation:
element A and B are isobars because they have the same mass numbers but different atomic numbers. The different atomic numbers is as a result of the difference in proton number of each elements A and B. (A and B are two different elements). element C and D are isotopes of the same element because they have the same atomic numbers (same number of protons) but differ in number of neutrons resulting in the different number of mass numbers. (C and D are the same elements)what product(s) forms at the cathode in the electrolysis of an aqueous solution of k2so4?
1. Sulfur
2. H2 and OH-
3. K
4. O2 and H+
We can see here that the product(s) formed at the cathode in the electrolysis of an aqueous solution of [tex]K_{2}SO_{4}[/tex] are: 2. H2 and OH-
What is electrolysis?Electrolysis is a chemical process that involves the use of an electric current to drive a non-spontaneous chemical reaction. It is typically carried out in an electrolytic cell, which consists of two electrodes—an anode (positive electrode) and a cathode (negative electrode)—immersed in an electrolyte solution.
During electrolysis, when an electric current is passed through the electrolyte, chemical reactions occur at the electrodes.
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I NEED HELP THIS IS DUE TMR!
A 124.6-g sample of copper has a volume of 14 cm. what is the density of copper?
Answer:
The density of copper is 8.9 grams per cubic centimeter.
Explanation:
There is a writing mistake in statement, correct form is written below:
A 124.6 grams sample of copper has a volume of 14 cubic centimeters. What is the density of copper?
Let suppose that mass of the copper sample is distributed uniformly in its volume, then we shall use the following definition of density ([tex]\rho[/tex]), in grams per cubic centimeter:
[tex]\rho = \frac{m}{V}[/tex] (1)
Where:
[tex]m[/tex] - Mass, in grams.
[tex]V[/tex] - Volume, in cubic centimeters.
If we know that [tex]m = 124.6\,g[/tex] and [tex]V = 14\,cm^{3}[/tex], then the density of the sample of copper is:
[tex]\rho = \frac{m}{V}[/tex]
[tex]\rho = 8.9\,\frac{g}{cm^{3}}[/tex]
The density of copper is 8.9 grams per cubic centimeter.
Which of the molecules are used as second messengers in signal transduction pathways? insulin adenyl cyclase CAMP calcium ions P3
The molecules used as second messengers in signal transduction pathways are cAMP (cyclic adenosine monophosphate) and calcium ions. Options C and D are correct.
Cyclic adenosine monophosphate (cAMP) and calcium ions are both important second messengers involved in signal transduction pathways. When a signaling molecule, such as a hormone or neurotransmitter, binds to a receptor on the cell surface, it initiates a cascade of intracellular events.
One of these events is the activation of enzymes, such as adenylate cyclase, which synthesizes cAMP from ATP. cAMP then acts as a second messenger by binding to and activating protein kinase A (PKA), leading to the phosphorylation of target proteins and the amplification of the signal. Calcium ions also play a crucial role as second messengers by mediating various cellular processes.
They can be released from intracellular stores or enter the cell through calcium channels, and their binding to specific proteins triggers downstream signaling events. Together, cAMP and calcium ions function as key mediators in signal transduction, transmitting and amplifying signals from the cell surface to the intracellular environment. Options C and D are correct.
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Why does the offspring have identical inherited traits as the parent?
What does it mean to say that scientific models are open to change? (2 points)
a
Scientific models are usually not very accurate.
b
Scientific models can be adjusted when new information is found.
c
People can adjust scientific models to fit their personal beliefs.
d
Experimental results can be changed to fit the accepted model
Coke in a Coca Cola bottle has a volume of 500 ml and a mass of 756 grams. What is its density
Answer: 1.11 g/mL is the density
what is an magnetic pole
Answer:
Earth's magnetic field, also known as the geomagnetic field, is the magnetic field that extends from the Earth's interior out into space, where it interacts with the solar wind, a stream of charged particles emanating from the Sun.
Which of the following equilibria could be used to support the claim that the addition of a small amount of NaOH to the buffer will result in only a very small change in pH? (see image)
I think First statement that is Option A, because, it has total equilibrium on both side, which will never result in increase of any pH level higher or lower than the state, hence
Option A.) is correct
Which of the following statements is not true? a. Water is polar. b. Water stabilizes temperature. c. Water is essential for life. d. Water is the most abundant atom in Earth’s atmosphere.
Answer: d. Water is the most abundant atom in Earth’s atmosphere.
Explanation:
Water percentage in the atmosphere is 0.001 percent only as it not the major reservoir or source of water. The water is available in the atmosphere in the form of water vapors. These water vapors when aggregate and their concentration becomes high they fall down as rain on earth so the rain is collected in water reservoirs like oceans, rivers, lakes, ponds, aquifers, and other sources of water, which are the components of hydrosphere on earth. So, hydrosphere is most abundant in water. Moreover, water is not an atom instead it is the molecule formed by the combination of two molecules of hydrogen and one molecule of oxygen.
An object traveling around another object space is in blank
Answer: An orbit is a regular, repeating path that one object in space takes around another one. An object in an orbit is called a satellite. A satellite can be natural, like Earth or the moon. Many planets have moons that orbit them
HOPE THIS HELPS
T/F. throughout history, people have used chemicals to change their moods, behavior, and levels of consciousness.
The statement "throughout history, people have used chemicals to change their moods, behavior, and levels of consciousness. " is true.
For example, ancient civilizations used alcohol, opium, and other natural substances for medicinal and religious purposes.
In modern times, psychoactive substances such as caffeine, nicotine, and prescription medications are widely used to alter mood, perception, and behavior.
Some of these chemicals are legal, while others are illegal or controlled substances that can lead to addiction, overdose, and other negative consequences. It is important to understand the risks and benefits of using these substances and to seek help if substance abuse becomes a problem.
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What are some ways your local environment would be affected if there was suddenly less water available?
I'll mark brainliest!
plant life dies
Explanation:
if all water disappears then plants would dry up and die, wich would impact the food chain
One advantage to using nuclear power is —
it produces no air pollution
it is hard to store and dispose of the waste
the expense of constructing nuclear reactors
the threat of an accident
Answer:
it produces no air pollution
What is the number of moles in 15.0 g AsH3?
O 5.2 mol
O 1200 mol
O 0.44 mol
O 0.19 mol
Answer:
n = 0.19 mol
Explanation:
Given mass = 15 g
The molar mass of AsH₃ = 77.94 g/mol
We need to find the number of moles in 15 g of AsH₃. We know that,
No. of moles = given mass/molar mass
[tex]n=\dfrac{15}{77.94 }\\\\n=0.19\ mol[/tex]
So, there are 0.19 g/mol. Hence, the correct option is equal to 0.19 mol.