Answer:
2,47 * [tex]10^{24}[/tex] (molecules)
Explanation:
Avogadro's number is a very important relationship: 1 mole = 6,02 * [tex]10^{23}[/tex] atoms, molecules, protons, etc.
To convert from moles to molecules, multiply the molar amount by Avogadro's number.
4,1 mol * 6,02 * [tex]10^{23}[/tex] ≈ 24,7 * [tex]10^{23}[/tex] = 2,47 * [tex]10^{24}[/tex] (molecules)
Therefore the third answer is correct
18. What is one of the three things that cause the surface currents of the oceans?
A.differences in salinity
B.temperature differences
C. density differences
D. Coriolis effect
Answer:
b. temperature difference
I need help with this!!!
Answer:
0.73g/cm^3
Explanation:
d=m/v
d=11/15
d=0.73
Which of the following substances contains MOSTLY ionic bonding? A) LIF B) CO2 C) AICI: D) BeCl2 E) Cu
Answer: [tex]LiF[/tex] , [tex]AlCl_3[/tex] and [tex]BeCl_2[/tex]
Explanation:
An ionic bond is formed when an element completely transfers its valence electron to another element. The element which donates the electron is known as electropositive element or the metal and the element which accepts the electrons is known as electronegative element or non metal.
A covalent bond is formed when an element shares its valence electron with another element. This bond is formed between two non metals.
[tex]LiF[/tex] , [tex]AlCl_3[/tex] and [tex]BeCl_2[/tex] contain ionic bonds as they aremade up of metals and non metals.
What is the energy of an electron in the third energy level of hydrogen?
Answer:
Electrons in a hydrogen atom must be in one of the allowed energy levels. If an electron is in the first energy level, it must have exactly -13.6 eV of energy.
...
Energy Levels of Electrons.
Energy Level Energy
1 -13.6 eV
2 -3.4 eV
3 -1.51 eV
4 -.85 eV
When an oxidant is present, vitamin C can be converted to a product described as (5R)-5-[(1S)-1,2-dihydroxyethyl]-3,4-dihydroxy-furan-2,3,4(5H)-trione, which retains the furan-based nomenclature of vitamin C and describes the hydrogen placement at atom 5 of the ring. Which of the following statements best describes this vitamin C derivative?A) Vitamin C is reduced to yield a furan ring with 4 carbonyl groups and no double bonds.B) Vitamin C is oxidized to yield a furan ring with 3 carbonyl groups and 1 double bond.C) Vitamin C is reduced to yield a furan ring with 1 carbonyl group and no double bonds.D) Vitamin C is oxidized to yield a furan ring with 3 carbonyl groups and no double bonds
Answer:
D) Vitamin C is oxidized to yield a furan ring with 3 carbonyl groups and no double bonds
Explanation:
We can tell that the compound " (5R)-5-[(1S)-1,2-dihydroxyethyl]-3,4-dihydroxy-furan-2,3,4(5H)-trione " has 3 carbonyl groups due to it having "trione" in the name (and it lacking other carbonyl group names, like amide or carboxylic acid).
As there is no "-ene" part of the name referencing a double bond, the only option left is option D).
What is the percent composition of Mg in the compound Mg3(PO4)2?
A 21.92%
B 23.57%
C 32.32%
D 27.74%
Answer:
D 27.74%
Explanation:
Percent composition of Magnesium (Mg) in Magnesium Phosphate compound ie Mg3(PO4)2 = 27.74%
Answer:
The answer is D
Explanation:
I took the test
Which of the following metals (M) will form an ionic compound with nitrogen with the general formula M3N2?
Answer:
There are no options provided dude,
But i guess the answer will be a metal with valency 2 for sure as the subscript given for N in 'M3N2' is 2 so the valency of the metal u need to select will be 2 for sure
It can be magnesium or some other if the provided options in real question has Mg then its the answer
From where do the placenta and umbilical cord develop?
Answer:
it develops from the womb
Answer:
outer cells of the blastocyst
Explanation:
on edg:)
Please explain to me!!!
Answer:
nice handwrtting
Explanation:
Glycerol (C3H8O3), also called glycerine, is widely used in the food and pharmaceutical industries. Glycerol is polar and dissolves readily in water and polar organic solvents like ethanol. Calculate the mole fraction of the solvent in a solution that contains 2.51 g glycerol dissolved in 21.10 mL ethanol (CH3CH2OH; density
Answer: The mole fraction of the solvent in a solution that contains 2.51 g glycerol dissolved in 21.10 mL ethanol is 0.93
Explanation:
Given : Volume of ethanol (solvent) = 21.10 ml
density of ethanol (solvent)= 0.789 g/ml
Mass of ethanol (solvent) = [tex]0.789g/ml\times 21.10ml=16.6g[/tex]
Mass of glycerol (solute) = 2.51 g
Mole fraction of a component is the ratio of moles of that component to the total moles present.
moles of ethanol =[tex]\frac{\text {given mass}}{\text {molar mass}}=\frac{16.6g}{46g/mol}=0.36mol[/tex]
moles of glycerol =[tex]\frac{\text {given mass}}{\text {molar mass}}=\frac{2.51g}{92g/mol}=0.027mol[/tex]
mole fraction of ethanol (solvent) = [tex]\frac{\text {moles of ethanol}}{\text {moles of ethanol + moles of glycerol}}=\frac{0.36}{0.36+0.027}=0.93[/tex]
The mole fraction of the solvent in a solution that contains 2.51 g glycerol dissolved in 21.10 mL ethanol is 0.93
Why is it important to know gas properties at STP?
Answer:
STP values are most often cited for gases because their characteristics change dramatically with temperature and pressure. One common definition of STP is a temperature of 273 K (0° Celsius or 32° Fahrenheit) and the standard pressure of 1 atm. Under these conditions, one mole of a gas occupies 22.4 L.
According to the Bohr model of the atom, which particles are allowed to exist in any one of a number of energy levels?
Answer: the line-emission spectrum of an atom is caused by the energies released when electrons. releases energy of only certain values.
A crane lifts a 5,800-N block from the ground to 20 m above the ground in 80 seconds. How much Power
did the crane use?
Answer:
1450 W
Explanation:
5800n x 20m =1450w
80s
In which state of matter are the particles at rest (not moving at all)?
none of these
solid
liquid
gas
Answer:
Solids for sure
particles of solid cant flow.
Answer:
B)Solids
Solids have tightly packed particles unlike liquids and gases whose particles can move freely but rate of movement is highest in gas while compared to water
If 3.53 g of CuNO, is dissolved in water to make a 0.330 M solution, what is the volume of the solution in milliliters?
Answer:
84.8 mL
Explanation:
From the question given above, the following data were obtained:
Mass of CuNO₃ = 3.53 g
Molarity of CuNO₃ = 0.330 M
Volume of solution =?
Next, we shall determine the number of mole in 3.53 g of CuNO₃. This can be obtained as follow:
Mass of CuNO₃ = 3.53 g
Molar mass of CuNO₃ = 63.5 + 14 + (16×3)
= 63.5 + 14 + 48
= 125.5 g/mol
Mole of CuNO₃ =?
Mole = mass / Molar mass
Mole of CuNO₃ = 3.53 / 125.5
Mole of CuNO₃ = 0.028 moles
Next, we shall determine the volume of the solution. This can be obtained as follow:
Molarity of CuNO₃ = 0.330 M
Mole of CuNO₃ = 0.028 moles
Volume of solution =?
Molarity = mole /Volume
0.330 = 0.028 / Volume
Cross multiply
0.330 × Volume = 0.028
Divide both side by 0.330
Volume = 0.028 / 0.330
Volume = 0.0848 L
Finally, we shall convert 0.0848 L to millilitres (mL). This can be obtained as follow:
1 L = 1000 mL
Therefore,
0.0848 L = 0.0848 L × 1000 mL / 1 L
0.0848 L = 84.8 mL
Therefore, the volume of the solution is 84.8 mL.
please help me with this problem
the amount of reactants = the amount of products
N2 + 3H2 --> 2NH3
la densidad de un aceite liviano para vehiculo es 0.87g/cm3 calcules su volumen especifico y peso especifico
Answer:
Pe = 8700 N/m³
Vesp = 1,15 cm³/g
Explanation:
Ya que conocemos el valor de la densidad de este aceite, es muy sencillo calcular tanto volumen como peso específico.
En el caso de volumen específico, esta se refiere al cociente del volumen de un líquido con su masa respectiva. En otras palabras, es el inverso de la densidad, por tanto usamos la siguiente expresión para el volumen específico:
Vesp = 1/d
Vesp = 1 / 0,87
Vesp = 1,15 cm³/gPara el caso del peso específico, se calcula como el cociente de la masa del líquido y su volumen que ocupa. Sin embargo no conocemos ninguno de esos dos datos, por lo que para calcular el peso específico solo basta multiplicar este valor por la aceleración de gravedad, que vamos a asumir para este problema que es 10 m/s². Y ademas cambiaremos las unidades de densidad de g/cm³ a kg/m³. Esto es porque las unidades de peso específico son N/m³ y los newton (N) son kg m/s².
d = 0,87 g/cm³ * (1 kg/1000g) * (100 cm/1m)³ = 870 kg/m³
Pe = 870 kg/m³ * 10 m/s²
Pe = 8700 N/m³ESpero te sirva.
Calculate the kinetic energy of an electron ejected from a piece of sodium (Φ = 4.41x10–19 J) that is illuminated with 265 nm light.
in Joules
Answer:
Explanation:
Energy of falling radiation having wavelength of 265 nm
= h c / λ where h is plank's constant , c is velocity of light and λ is wavelength of radiation . Putting the values
Energy of light photon = 6.6 x 10⁻³⁴ x 3 x 10⁸ / 265 x 10⁻⁹
= .0747 x 10⁻¹⁷
= 7.47 x 10⁻¹⁹ J .
Work function of sodium is 4.41 x 10⁻¹⁹
So kinetic energy of ejected electron = energy of falling photon - work function
= 7.47 x 10⁻¹⁹ - 4.41 x 10⁻¹⁹
= 3.06 x 10⁻¹⁹ eV .
f) How many neutrons are there in the nucleus of arsenic?
1. Neodymium
2. Selenium
3. Strontium
Explanation:
How many neutrons are there in the nucleus of arsenic?42 neutrons
The nucleus consists of 33 protons (red) and 42 neutrons (blue).
What is the ratio
amount (mol) Fatoms
amount (mol) Xe atoms
Enter your answer as an integer.
Pls help
Answer:
Empirical formula
Explanation:
The empirical formula of a compound is the simplest whole number ratio of atoms of each element in the compound. It is determined using data from experiments and therefore empirical.
Observation of balloon rub with cloth?
Answer:
When rubbing a balloon with a wool cloth, it puts negative charges on the balloon. Negative charges attract to positive charges. ... When both balloons are rubbed with the wool cloth, the both receive negative charges, so they will repel each other.
What is the definition of lava?
Answer:
Lava, magma (molten rock) emerging as a liquid onto Earth's surface. The term lava is also used for the solidified rock formed by the cooling of a molten lava flow.
Explanation:
Please answer, this is due in 30 minutes
Answer:
0.591 g of magnesium phosphate is the theoretical yield.
Magnesium nitrate is the limiting reactant.
Explanation:
Hello!
In this case, since the balanced reaction turns out:
[tex]3Mg(NO_3)_2+2Na_3PO_4\rightarrow Mg_3(PO_4)_2+6NaNO_3[/tex]
Next, we compute the grams of magnesium phosphate yielded by each reactant, considering the present mole ratios and molar masses:
[tex]m_{Mg_3(PO_4)_2}^{by\ Mg(NO_3)_2}=1.00gMg(NO_3)_2*\frac{1molMg(NO_3)_2}{148.31gMg(NO_3)_2}*\frac{1molMg_3(PO_4)_2}{3molMg(NO_3)_2} *\frac{262.86gMg_3(PO_4)_2}{1molMg_3(PO_4)_2} \\\\m_{Mg_3(PO_4)_2}^{by\ Mg(NO_3)_2}= 0.591gMg_3(PO_4)_2\\\\m_{Mg_3(PO_4)_2}^{by\ Na_3PO_4}=1.00gNa_3PO_4*\frac{1molNa_3PO_4}{163.94gNa_3PO_4}*\frac{1molMg_3(PO_4)_2}{2molNa_3PO_4} *\frac{262.86gMg_3(PO_4)_2}{1molMg_3(PO_4)_2} \\\\m_{Mg_3(PO_4)_2}^{by\ Na_3PO_4} = 0.802gMg_3(PO_4)_2[/tex]
Thus, we infer that the correct theoretical yielded mass is 0.591 g as magnesium nitrate is the limiting reactant for which it produces the fewest grams of product.
However, is not possible to compute the percent yield since no actual yield is given, and must be provided or indicated by the problem or an experiment and it not here, nevertheless, you may compute the percent yield by dividing the actual yield by the theoretical and then multiplying by 100:
[tex]Y=\frac{actual}{0.591g}*100\%[/tex]
Best regards!
After two half-lives, how much of the original material has decayed? 25 percent 50 percent 75 percent 100 percent
The original material has decayed 75%
Further explanationGiven
two half-life
Required
The decayed sample
Solution
General formulas used in decay:
[tex]\large{\boxed{\bold{N_t=N_0(\dfrac{1}{2})^{t/t\frac{1}{2} }}}[/tex]
t = duration of decay
t 1/2 = half-life
N₀ = the number of initial radioactive atoms
Nt = the number of radioactive atoms left after decaying during T time
t = 2 x t 1/2
Input the value :
[tex]\tt \dfrac{Nt}{No}=\dfrac{1}{2}^2=\dfrac{1}{4}=25\%[/tex]
The amount of Nt = 25% No
Two colorless chemicals combine inside a glow
stick. When the chemicals combine, they produce
brightly colored light. The glow stick's temperature
does not change.
emission of heat
emission of light
color change
formation of gas
Answer:
Option B & Option C
Explanation:
correct on edge! :D
When chemicals combine chemical change takes place which is accompanied by emission of heat and light.
What is a chemical change?Chemical changes are defined as changes which occur when a substance combines with another substance to form a new substance.Alternatively, when a substance breaks down or decomposes to give new substances it is also considered to be a chemical change.
There are several characteristics of chemical changes like change in color, change in state , change in odor and change in composition . During chemical change there is also formation of precipitate an insoluble mass of substance or even evolution of gases.
There are three types of chemical changes:
1) inorganic changes
2)organic changes
3) biochemical changes
During chemical changes atoms are rearranged and changes are accompanied by an energy change as new substances are formed.
Learn more about chemical change,here:
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if a gas at 300k occupies 3.60 liters at a pressure of 1.00 atm, what will be it’s new pressure if the volume is compressed to 2.0 liters at a temperature of 450K?
Answer: The new pressure if the volume is compressed to 2.0 liters at a temperature of 450K is 2.7 atm
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 = 1.00 atm
[tex]P_2[/tex] = final pressure of gas = ?
[tex]V_1[/tex] = initial volume of gas = 3.60 L
[tex]V_2[/tex] = final volume of gas = 2.0 L
[tex]T_1[/tex] = initial temperature of gas = [tex]300K[/tex]
[tex]T_2[/tex] = final temperature of gas = [tex]450K[/tex]
Now put all the given values in the above equation, we get:
[tex]\frac{1.00\times 3.60}{300}=\frac{P_2\times 2.0}{450}[/tex]
[tex]P_2=2.7atm[/tex]
The new pressure is 2.7 atm
please help. im freaking out rn. i have like 40 missing assignments please
Answer:
I'm pretty sure its the one that says very little at the beginning but if I get it wrong I'm sorry
Write the equilibrium expression of each chemical equation.
2H2S(g) 2H2(g) + S2(g)
Answer:
[H2]2[S2][H2S]2Kc=[H2]2[S2][H2S]2
Explanation:
2H2S(g)⇋2H2(g)+S2(g)2H2S(g)⇋2H2(g)+S2(g)
The equilibrium constant expression in terms of concentrations is:
Kc=[H2]2[S2][H2S]2Kc=[H2]2[S2][H2S]2.
The equilibrium expression for the given reaction can be written in terms of equilibrium constant which is the ratio of power of molar concentration of the product to the product of power of molar concentration of the reactants.
What is equilibrium?Equilibrium is a state for a reversible reaction where, the rate of forward reaction is equal to the rate of backward reaction. The rate of a reaction is the rate of decrease in the concentration of reactants or the rate of increase in the concentration of the products.
The given reaction at equilibrium state is written as:
[tex]\rm 2H_{2}S (g)\leftrightharpoons 2H_{2} (g)+ S_{2}(g)[/tex]
The equilibrium constant Kb is ratio of power of molar concentration of the product to the product of power of molar concentration of the reactants.
[tex]Kb = \rm \frac{[H_{2}S]^{2}}{[H_{2}]^{2} [S_{2}]}[/tex]
The rate of the reaction will be r = Kb [H₂]² [S₂].
To find more on equilibrium constant, refer here:
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Over an interval of 2.0 s the average rate of change of the concentration of C was measured to be 0.0540 M/s. What is the final concentration of A at the end of this same interval if its concentration was initially 2.000 M
Answer:
Explanation:
the average rate of change of the concentration =
( initial concentration - final concentration ) / time
Initial concentration = 2.000 M
the average rate of change of the concentration = .0540 M/s
time = 2 s
Putting the values
.0540 = (2.000 - X ) / 2
0.108 = 2.000 - X
X = 1.892 M .
Final concentration = 1.892 M .
Which has more calories: table sugar or aspartame?
Hello there!
Aspartame has 4 kilocalories of energy per gram and table sugar has 3.9 kilocalories. They are pretty much same but aspartame is 200 times sweeter than sucrose so probably would be aspartame that has more calories.