Answer: There are 0.000043 moles of melatonin.
Explanation:
According to avogadro's law, 1 mole of every substance occupies 22.4 L at STP and contains avogadro's number [tex]6.023\times 10^{23}[/tex] of particles.
To calculate the moles, we use the equation:
[tex]\text{Number of moles}=\frac{\text{Given mass}}{\text {Molar mass}}[/tex]
given mass = 10 mg = 0.01 g
molar mass of [tex]C_{13}H_{16}N_2O_2[/tex] = 232.28 g
[tex]{\text {moles of melatonin}}=\frac{0.01g}{232.28g/mol}=0.000043moles[/tex]
Thus there are 0.000043 moles of melatonin
What is the process of old crust sinking back into the mantle? *
a. earthquake
b. transform boundary
c. seafloor spreading
d. subduction
Answer:
dddddddddddddd
ddddddddddddddddd
can any one solve this quiz plz
Answer:
1. It is stoichiometric.
2. O2 is the limiting reactant.
3. 9.0 g of C2H6 remain unreacted.
4. 17.6 g of CO2.
5. 85.2%.
Explanation:
Hello there!
In this case, for the given chemical reaction:
[tex]2C_2H_6+7O_2\rightarrow 4CO_2+6H_2O[/tex]
We can see that:
1. It is stoichiometric and is balanced because the reactants yields the products according to the law of conservation of mass.
2. In this part, it is possible to calculate the moles of ethane by using its molar mass:
[tex]n_{C_2H_6}=15g*\frac{1molC_2H_6}{30.08g} =0.50molC_2H_6[/tex]
And the moles of oxygen by knowing that one mole is contained in 22.4 L at STP:
[tex]n_{O_2}=\frac{1mol}{22.4L} *15.68L=0.7molO_2[/tex]
Thus, by calculating the moles of carbon dioxide product by each reactant, we can identify the limiting one:
[tex]n_{CO_2}^{by\ C_2H_6}=0.50molC_2H_6*\frac{4molCO_2}{2molC_2H_6} =1.0molCO_2\\\\n_{CO_2}^{by\ O_2}=0.70molO_2*\frac{4molCO_2}{7molO_2} =0.4molCO_2\\[/tex]
Thus, since oxygen yields the fewest moles of CO2 product, we infer it is the limiting reactant.
3. In this part, we calculate the mass of C2H6 that actually react first:
[tex]m_{C_2H_6}^{reacted}=0.4molCO_2*\frac{2molC_2H_6}{4molCO_2}*\frac{30.08gC_2H_6}{1molC_2H_6} =6.0gC_2H_6[/tex]
Thus, the leftover of ethane (C2H6) as the excess reactant is:
[tex]m_{C_2H_6 }^{leftover}=15g-6.0g=9.0g6.0C_2H_6[/tex]
4. Since 0.4 moles of carbon dioxide were produced, we use its molar mass to calculate the mass as its theoretical yield:
[tex]m_{O_2}^{theoretical}=0.4molCO_2*\frac{44gCO_2}{1molCO_2}=17.6gCO_2[/tex]
5. Finally, the percent yield is gotten by dividing the actual yield by the theoretical one:
[tex]Y=\frac{15g}{17.6}*100\%\\\\Y=85.2\%[/tex]
Best regards!
calculate the molarity of 0.57 moles NaHCO3 in 61.2 mL of solution. Report your answer 4 places after the decimal don’t forget to round.
Answer:
The correct response is "9.313 M".
Explanation:
According to the question, the values are:
Moles of solute,
= 0.57 moles
Liters of solution,
= 61.2 mL
or,
= 0.0612 L
Now,
The molarity will be:
= [tex]\frac{Moles \ of \ solute}{Liters \ of \ solution}[/tex]
On putting the given the values in the above formula, we get
= [tex]\frac{0.57}{0.0612}[/tex]
= [tex]9.313 \ M[/tex]
which of the following statement is not a property of ionic compounds?
A. they are formed because of electrostatic forces.
B. they conduct electricity when dissolve in water
C. they form crystals
D. they have low melting and boiling points
Answer:
I think it would be c
Explanation:
A gas confined in a 515cm3 container exerts a pressure of 107.4kPa at 38.6⁰C. At what Celsius temperature will it exert a pressure of 635.7kPa if it is placed into a 644cm3 container?
Answer: The temperature at pressure of 635.7 kPa is [tex]2033^0C[/tex]
Explanation:
The combined gas equation is,
[tex]\frac{P_1V_1}{T_1}=\frac{P_2V_2}{T_2}[/tex]
where,
[tex]P_1[/tex] = initial pressure of gas = 107.4 kPa
[tex]P_2[/tex] = final pressure of gas = 635.7 kPa
[tex]V_1[/tex] = initial volume of gas = [tex]515cm^3[/tex]
[tex]V_2[/tex] = final volume of gas = [tex]644cm^3[/tex]
[tex]T_1[/tex] = initial temperature of gas = [tex]38.6^0C=(38.6+273)K=311.6K[/tex]
= final temperature of gas = ?
Now put all the given values in the above equation, we get:
[tex]\frac{107.4\times 515}{311.6}=\frac{635.7\times 644}{T_2}[/tex]
[tex]T_2=2306K=(2306-273)^0C=2033^0C[/tex]
The temperature at pressure of 635.7 kPa is [tex]2033^0C[/tex]
HELP PLS !!!!! NO LINKS
Answer:
Option aWeatheringExplanation:
Weathering is a term which describes the general process by which rocks are broken down at the Earth's surface into such things as sediments, clays, soils and substances that are dissolved in water.As weathered products are carried away, fresh rocks are exposed to further weathering.
Answer:
melting
Explanation:
I think think helpful it is or not
An electric car has a mass of 2,000 kg. the engine is producing a force of 3,500 N to move the vehicle forward,but it must overcome air friction equal to 500 N
What is the acceleration of the electric car m/s2?
record your answer and fill in below
Answer:
1.5 m/s²
Explanation:
From the diagram,
F-F' = ma............... Equation 1
Where F = Forward force of the vehicle, F' = Frictional force, m = mass of the electric car, a = acceleration of the car.
make a the subject of the equation
a = (F-F')/m........... Equation2
Given: F = 3500 N, F' = 500 N, m = 2000 kg
Substitute into equation 2
a = (3500-500)/2000
a = 3000/2000
a = 1.5 m/s²
what is the mass of an electron?
0 amu
1 amu
2 amu
dependent upon the type of element
PLEASE HELP
Answer:
the answer is 0 amu I hope it helps
Why does water float on corn syrup
Answer:
density.
Explanation:
A cubic centimeter of water weighs 1 gram. Since a cubic centimeter of vegetable oil weighs less than 1 gram, oil will float on water. Corn syrup is more dense than water so 1 cubic centimeter of corn syrup weighs more than 1 gram. Therefore, corn syrup sinks in water.
Answer:
Click on the photo to see the full attachment
How many moles of calcium nitrate would react with 4.55 moles of chromium (III) sulfate to produce calcium sulfate and chromium(III) nitrate?
Answer:
13.65 moles
Explanation:
The equation of the reaction is;
3Ca(NO3)2 + Cr2(SO4)3 = 3Ca(SO4) + 2 Cr(NO3)3
4.55 moles of chromium (iii) sulfate reacts with calcium nitrate
The mole ratio of Chromium (iii) sulfate to calcium nitrate is 1: 3
Therefore; the moles of calcium nitrate will be given by
= (4.55/ 1)×3
= 13.65 moles
Hence; 13.65 moles of calcium nitrate would react with 4.55 moles of Chromium (iii) sulfate.
25 points!! Will give Brainliest What is the molarity of the dilute solution if you dilute 35.0 mL of a 12.0 M solution to make 1000.0 mL of a solution?
Answer:
0.72 good luck with the answer
Plz help ASAP plz and thx if u help
Answer:
3. c
4. d
5. c
Explanation:
The Law of Conservation of Mass state
3) Rubidium reacts with rubidium nitrate to produce rubidium oxide and nitrogen gas
a- Write the chemical reaction
b- Balance the chemical reaction
Find the molecules of nitrogen gas when 6.4 g of rubidium react
d- Find the mass of rubidium oxide produced when 7.1 g of rubidium nitrate react
Answer:
3) Rubidium reacts with rubidium nitrate to produce rubidium oxide and nitrogen gas
a- Write the chemical reaction
10Rb + 2RbNO3 → 6Rb2O + N2
What is the molarity of a 100 mL solution that contains 2.00 g KCL
Answer:
The molarity will be "0.26 M".
Explanation:
The given values are:
Mass,
= 2.00 g
Volume of solution,
= 100 mL
or,
= [tex]\frac{100}{1000}[/tex]
= [tex]0.1 \ L[/tex]
Molar mass of KCl,
= 74.5 gm
Now,
Moles of KCl will be:
= [tex]\frac{Given \ mass}{Molar \ mass}[/tex]
= [tex]\frac{2}{74.5}[/tex]
= [tex]0.026[/tex]
hence,
The molarity will be:
= [tex]\frac{Moles \ of \ solute}{Volume \ of \ solution}[/tex]
On substituting the values, we get
= [tex]\frac{0.026}{0.1}[/tex]
= [tex]0.26 \ M[/tex]
HELPP asap I’ll mark you as brainlister
Answer:
The solution is nopolar
Explanation:
Answer:
The solution does NOT conduct electricity.
Explanation:
Nonelectrolytes are usually held together by covalent bonds rather than ionic ones.
Metamorphic rock usually forms
Answer:
Metamorphic rocks form sedimets
44 mL of H2CrO4 is needed to neutralize 176mL of a 10M solution of Pd(OH)4. What is the molarity of this solution?
Answer: The molarity of this solution is 2.5 M.
Explanation:
Given : [tex]V_1 = 44 mL[/tex], [tex]V_2 = 176 mL[/tex]
[tex]M_1 = 10 M[/tex]
Therefore, the value of molarity of the solution is calculated using following formula.
[tex]M_1 \times V_1 = M_2 \times V_2[/tex]
Substitute the values into above formula as follows.
[tex]M_1 \times V_1 = M_2 \times V_2\\10 M \times 44 mL = M_2 \times 176 mL\\M_2 = \frac{10 M \times 44 mL}{176 mL}\\= 2.5 M[/tex]
Hence, molarity of the solution is 2.5 M.
Xavier was conducting a long term study of two populations of butterflies. Both populations had the same number of individuals. Both populations lived in forests that were the same size. Population A lived in a forest that was full of milkweed, the favorite food of this butterfly species. Population B lived in a forest that had limited amounts of milkweed and other foods. Over many years, Xavier found that one of the populations was showing signs of evolutionary change. Their mouth parts were changing and they could get food from new kinds of plants. Which statement explains why one population would be more likely to evolve in response to natural selection? *
a. Population B would be more likely to change because it has a ready supply of food, and only certain butterflies would be able to survive
b. Population A would be more likely to change because it has a ready supply of food and only certain butterflies would be able to survive
c. Population A would be more likely to change because it has a limited amount of food and some butterflies might be better able to get enough food, survive, and reproduce
d. Population B would be more likely to change because those butterflies have a limited supply of food, and butterflies with certain traits might be better able to get enough food, survive, and reproduce.
If a sulfur atom gained 3 protons what atom would be formed?
Answer:
The stable ion the sulfur would form is the sulfide ion,
Explanation:
When any atom accept electrons it converts into negative ion/an anion. So it will change into Z 3− after gaining 3 electrons.
Sulfur is an elemental atom that has an atomic number of 16 and an atomic mass of 32.065 amu. If the sulfur atom gains three protons then potassium will be formed.
What is a proton?A proton has been a sub-atomic particle that has been known to carry a positive charge and are tend to remain inside the nucleus with the neutrons bonded together by the nuclear force.
The proton of the atom is the characteristic property of the element in the periodic table. They are the sole sub-atomic particle that gives the atomic number of the elemental atom.
The sulfur atom has the atomic number 16 which means it has 16 protons, so if three protons are added to it then the number f protons become 19 which is an atomic number of the potassium (K) element.
Therefore, a potassium element is formed.
Learn more about protons, here:
https://brainly.com/question/24508299
#SPJ2
6. A piece of solid gold was heated from 274K to 314K. 35.73 of energy was needed to raise the temperature.
What mass of gold was present?
From Q = mcΔT, we can rearrange the equation to solve for mass, m = Q/cΔT. The specific heat capacity, c, of solid gold is 0.129 J/g °C. I'm assuming that the energy is given in joules, as it's not specified in the question as written.
m = Q/cΔT = (35.73 J)/(0.129 J/g °C)(40.85 °C - 0.85°C)
m = 6.92 g of gold was present
The heat of the substance depends on the mass, specific heat, and temperature change of the system. The mass of gold that was present was, 6.92 g.
What is mass?Mass of the substance in the thermodynamic system is the ratio of the heat to the product of the specific heat and the temperature change. It is given as,
[tex]\rm m = \rm \dfrac{Q}{c \Delta T}[/tex]
Given,
Heat (Q) = 35.73 J
Specific heat (c) = 0.129 J/g °C
Temperature change = 40 degrees celsius
Mass of gold is calculated as:
35.73 ÷ (0.129) (40) = 6.92 gm
Therefore, 6.92 gms of gold is present.
Learn more about mass here:
https://brainly.com/question/15528502
#SPJ2
Zinc nitrate can be produced by reacting an acid and a metal oxide.
Name the acid and the metal oxide used to produce zinc nitrate.
Acid....
Metal oxide.....
Answer:
Acid - dilute nitric acid
Metal oxide - zinc oxide, zinc hydroxide or zinc carbonate
Explanation:
Zinc Nitrate is produced by carrying out a reaction between the following metal oxides and acid
Acid - dilute nitric acid as concentrated nitric acid produces ammonium nitrate
Metal oxide - zinc oxide, zinc hydroxide or zinc carbonate
Hence the correct answer is
Acid - dilute nitric acid
Metal oxide - zinc oxide, zinc hydroxide or zinc carbonate
When a mixture of iron powder and sulphur is heated it glows more brightly than that of iron filings and sulphur.Explain this observation
Answer:
I don't know
Explanation:
mixture of iron powder and sulphur heated it glows because sulphur and iron are more reactive metals that they shine and sulphur can react with water produce fire it's write
What test would be done to prove the color of specific compounds is due to metal ions apart from flame test
Answer:
Borax bead test
Explanation:
Another test that can be used to identify colored ions in a specific compound such as salt is called "Borax bead test".
This test involves use of a clear glassy bead of borax that is joined together in a wire loop which is going to be involved in chemical reaction with the salts of certain metals.
This reaction will produce colors that we can use to identify the exact metal ions that are present.
Assume that the variables x and y are directly related. If k = 8, what is the value for each of the following polnts? Be sure
and record your data to be used in the following problem.
Texas hill country is largely composed of soft limestone rock. When exposed to carbonic acid in rainwater, limestone can deteriorate and weaken. What affect does this process have on the landforms of Texas hill country?
Answer:
The answer is "It leads to the formation of underground caves"
Explanation:
Texas Hill Land is popular for its rolling hills, good wine, and authentic food. Its Texas Hill Property appeal is no mystery, recognized as being one of the top vacation destinations in the World. Texas Hill Structure is primarily mostly of weak calcareous stone. Calcium may worsen or degrade if exposed to carbon dioxide in rainwater. This practice affects the land of the Texas smoky Mountains leading to the formation of underwater groves.
please what is catalyst
Answer:
a substance that increases the rate of a chemical reaction without itself undergoing any permanent chemical change.
"chlorine acts as a catalyst promoting the breakdown of ozone"
Explanation:
your welcome!
37.2 moles of hydrogen gas would have what mass?
Your answer
Answer:
74.99g
Explanation:
Mass of a substance can be calculated by using the formula;
mole = mass ÷ molar mass
mass = molar mass × mole
According to this question, 37.2 moles of hydrogen gas is given.
Molar mass of hydrogen gas (H2) = 1.008(2) = 2.016g/mol
mass = 2.016 × 37.2
Mass of H2 = 74.995
Mass = 74.99g
Does somebody know the answer ?
what do elements and atoms have in common
Answer:
what they have in common is consist of electrons, protons, and neutrons.
Explanation: