Answer:
D. 9.0x10²³ atoms
Explanation:
First we use Avogadro's number to calculate how many molecules of Si₂H₆ are there in 0.75 mol:
0.75 mol * 6.023x10²³ molecules/mol = 4.52x10²³ moleculesThere are 2 Si atoms in one Si₂H₆ molecule, that means that in 4.52x10²³ Si₂H₆ molecules there will be:
2 * 4.52x10²³ = 9.03x10²³ Si atomsThus the answer is option D.
What is the volume occupied by 40 grams of argon gas (Ar) at standard conditions?
Answer:volume occupied by 40 grams of argon gas (Ar) at standard conditions = 22.443L
Explanation:
Using the ideal gas law that
PV =nRT
Where p =pressure,
V = volume,
n = number of moles
R = gas constant, and
T= temperature in Kelvin.
Since Argon is at STP( Standard conditions), This means that temperature is 273.15 K and pressure is 1 atm
Also the gas constant= 0.08206 L atm/K mol . we are using this value because its units match the units of our values to aid easy calculation
So,
Number of moles = Mass/ Molar mass
=40g/39.948 g/mol
Number of moles of Argon=1.0013moles.
Now Bringing
pV= nRT
V= nRT/p
=(1.0013mol x 0.08206 L atm/K mol x 273.15 K ) /1atm
Volume =22.443L
Which of the following statements about the domestication of animals during the agricultural revolution is FALSE?
A. The domesticated the animals so that they could use them as draft animals to help them on the farm.
B. The domesticated the animals so that they could use them for food (e.g., meat, milk, eggs, etc.)
C. They domesticated the animals so that they wouldn't have to worry about being attacked by wild animals.
D. They domesticated the animals so that they could use their fur for making clothes.
Answer:
b is the answer my brudaa
Explanation:
what is the energy of a resting object called
Answer:
the called potential energy because the potential energy is the latentenergy in an object at rest
Please help. I’m stuck
Which is a definition of motion?
A. Change in position
B. Force
C. Acceleration
D. Change in acceleration
Answer:
D.
Explanation:
Because force and energy are used to move.
what special requirements would a helicopter rotor need to have in order to make a helicopter flight possible on the red planet.
Answer:
Explanation:
may u explain what u mean then i will be able to help u because i like knows this but what u mean will be better so i can tell u the right answer thanks have a good day
Explain what you know about acid rain and why it is bad.
Answer:
Explanation:
Acid rain that seeps into the ground can dissolve nutrients, such as magnesium and calcium, that trees need to be healthy. Acid rain also causes aluminum to be released into the soil, which makes it difficult for trees to take up water. ... The acidic clouds and fog strip important nutrients from their leaves and needles.
A chemical process used to produce ethanol as a fuel additive was expected to produce 5,000 kilograms of ethanol based on the amounts of starting materials used, but only 4,760 kilograms were produced. What was the percent yield for ethanol in this process? A)1.09 percent B)4.80 percent C)95.2 percent D)105 percent
Answer:
The percent yield for ethanol in this process is 95.2%
Explanation:
Yield is the ratio between the amount of product actually obtained in the reaction and the maximum amount of product that could have been obtained if the reagents had been completely consumed.
The theoretical yield is the yield is the maximum you can get in a reaction.
On the other hand, the actual performance shows what you really get in experimentation. It is generally less than the theoretical yield.
So, the percentage return is the actual return times the theoretical return multiplied by 100.
So, in this case the percentage yield will be calculated as:
[tex]percent yield=\frac{4,760 kg}{5,000 kg} *100[/tex]
percent yield= 95.2%
The percent yield for ethanol in this process is 95.2%
Why does my hand get cold when I pick up a snowball?
Answer:
Cause snow is cold.
Explanation:
THANK YOU
An ice cube, a glass of cold water, and a swimming pool are each exposed to the same amount of sunlight on a hot day. After five minutes, the ice cube is
melted and the cold drink is two degrees warmer, but the temperature of the swimming pool remains unchanged. What is the best explanation for these
observations?
A. The ice cube has a higher heat capacity than the glass of water and the pool.
B. The ice cube has a lower heat capacity than the glass of water and the pool.
C. The ice cube and the glass of water have higher heat capacities than the swimming pool.
D. The ice cube and the glass of water have lower heat capacities than the swimming pool.
Answer:
D
Explanation:
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Answer:
C. the ice cube and the glass of water have higher heat capacity than the swimming pool
Plants need _______________ from the air for photosynthesis.
A. carbon dioxide B. soil
C. oxygen D. carbon monoxid
Answer:
A. carbon dioxide
Explanation:
If a cell were compared to a school, which part of the school would represent the cell's nucleus?
ОА the classroom walls because they give the structure to the school
B
the cafeteria cooks because they make food for the entire school
С
the principal because he or she controls all the activity in the school
D
the fence because it controls what enters and exits the school
Answer:
C-The principal because he or she controls all the activity in the school
4.) The temperature of solid silver increases from 30C to 40C by the addition of 117.5
joules of heat. What is the mass of the silver?
Answer:
The mass of silver is 49 g (0.049 kg).
Explanation:
Initial temperature = [tex]30^{o}[/tex]C
Final temperature = [tex]40^{o}[/tex]C
Quantity of heat required = 117.5 J
Specific heat capacity of silver = 0.240 J/g[tex]^{o} C[/tex]
mass of the silver can be determined by;
Q = mcΔθ
Where: Q is the quantity of heat required, m is the mass of substance, c is the specific heat capacity of the substance and Δθ is the change in temperature.
So that,
117.5 = m x 0.240 x (40 - 30)
117.5 = m x 0.24 x 10
= 2.4m
m = [tex]\frac{117.5}{2.4}[/tex]
= 48.9583
m ≅
m = 49 g
The mass of silver is 49 g (0.049 kg).
While the Bohr model fails to show the true shape of the electron orbitals with in an atom, it is still used because it ?
Answer:
Is used to predict the spectra of hydrogen and hydrogen like species
Explanation:
The Bohr's model of the atom was propounded by Neis Bohr. In his theory, an atom is composed of quantized energy levels in which electrons may be found.
The transition of an electron between energy levels leads to the absorption or emission of energy in the form of a photon of visible light. The energy absorbed or emitted depends on the energy difference between the two energy levels.
The model is successful at predicting the electronic spectra of one electron species but totally fails when the specie has more than one electron. Also, the model fails to show the true shape of the electron orbitals within an atom.
what type of reaction is CuO + NH3 = N2 + Cu + H2O?
A basketball has a mass of 0.625 kg. Most basketball hoops are at a height of 3 m above the ground. What is the gravitational potential energy of a basketball just before it goes through the hoop?
The gravitational potential energy of a basketball : PE = 18.375 J
Further explanationGiven
height = h = 3 m
mass = 0.625 kg
Required
The potential energy
Solution
The energy produced from its position is called potential energy (PE)
which can be formulated as:
PE = m. g. h (g = 9.8 m/s²)
Input the value :
PE = 0.625 x 9.8 x 3
PE = 18.375 J
C-14 has a half life of 5730 years, an artifact gives 4 counts per minute on a detector, living matter gives a count of 32. What is the estimated age of the artifact?
Answer:
17188 years
Explanation:
Given that;
0.693/t1/2 = 2.303/t log (Ao/A)
Where;
t1/2 = half life of carbon -14
t = time taken
Ao = activity of a living sample
A activity of the artifact
0.693/5730 = 2.303/t log (32/4)
1.21 * 10^-4 = 2.303/t * 0.9031
1.21 * 10^-4 = 2.0798/t
t = 2.0798/1.21 * 10^-4
t = 17188 years
GIVING BRAINLY PLEASE HELP ME!!
Answer:
1. Renewable Resource
2. Carbonate
3. Fossil Fuel
4. Nonrenewable Resource
5. Carbon Cycle
Answer:
1. Renewable Resource
2. Carbonate
3. Fossil Fuels
4. Non-renewable Resource
5. Carbon Cycle
a train is traveling on a straight track. it travels 200 kilometers in 4 hours, what measure can you find with these values?
Answer:
200 km is a measure of distance 4 hours is a measure of time Hence you can measure rate of change, instaneous rate of change, linear change and distribution of timeUpdated: SpeedHow many grams of NaOH do you need to dissolve to make 1.55 Liters of a 1.55 Molar solution?
Answer:
Mass = 96g
Explanation:
Molarity = number of moles/volume of solvent
According to the provided information, volume = 1.55L, Molarity = 1.55M
number of moles (n) = molarity × volume
n = 1.55 × 1.55
n = 2.4025
n = 2.40mol
For NaOH, molar mass = 23 + 16 + 1 = 40g/mol
mole = mass/molar mass
Mass = molar mass × mole
Mass = 40 × 2.40
Mass = 96g
there's 4.1*10^25 particles of calcium phosphate, how many grams of calcium phosphate is that
Mass of Calcium phosphate : = 21127.7 g
Further explanationGiven
4.1 x 10²⁵ particles of Calcium phosphate
Required
mass
Solution
The mole is the number of particles(molecules, atoms, ions) contained in a substance
1 mol = 6.02.10²³ particles
Can be formulated
N=n x No
N = number of particles
n = mol
No = Avogadro's = 6.02.10²³
mol Calcium phosphate :
n = N : No
n = 4.1 x 10²⁵ : 6.02 x 10²³
n = 68.11
mass Calcium phosphate Ca3(PO4)2 :
= mol x MW
= 68.11 x 310.2 g/mol
= 21127.7 g
= 21.13 kg
What do you predict would happen to the cytoplasm of the onion cell as distilled water is added?
A solute that has been dissolved in a solvent ________.
Select one:
a. cannot be recovered by any means
b. can be recovered by a process involving its chemical properties
c. can be recovered by a process involving its physical properties
d. is chemically changed
b or c
i think c im not sure
i hope it's right!!
A solute that has been dissolved in a solvent b) can be recovered by a process involving its chemical properties.
What is a solute?A substance that is dissolved in a solution is referred to as a solute. In fluid solutions, the quantity of solvent present is extra than the quantity of solute. One best example of solute in our each day hobby is salt and water. Salt dissolves in water and therefore, salt is the solute.
What's a solvent?A usually liquid substance is able to dissolve or disperse one or more other substances. some thing that provides a solution. some thing that gets rid of or attenuates something especially undesirable.Learn more about the solution here: https://brainly.com/question/723406
#SPJ2
How do I Remember carbon tax ?
Explanation:
you can watch this video and understand
17) In a 0.450 M HONH2 solution, [OH] = 5.28 x 10-6 M.
HONH2(aq) + H20(1) HONH3(aq) + OH(aq)
a. Find [HONH3).
b. Find Kb.
c. Find pOH.
d. Find H.
e. Find the percent ionization of HONH, in a 0.450 MHONH2 solution.
f. What concentration of NaOH would be required to make a solution with
the same pH that was calculated in part d.?
g. Find the percent ionization of NaOH in the above solution.
Answer:
Given
[HONH2] = 0.45M
[OH-] = 5.26 x 10-6 M
HONH2 + H2O -------------> HONH3+ + OH-
Initial 0.45 55 0 0
at equilibrium 0.45-x 55-x x x
Given
[OH-] = x = 5.26 x 10-6 M
Therefore [HONH3+] = x = 5.26 x 10-6 M
pOH = -log[OH-] = -log(5.26 x 10-6) = 5.279
=> pH = 14- pOH = 8.72
From hendersen-hasselbach equaiton
8.72 = pKa + log(0.45/5.26 x 10-6)
=> pKa = 3.788
=> pKb = 14-3.788 = 10.21
percent of ionization = 5.26 x 10-6 * 100/0.45 = 1.17 x 10-3 %
concentration of NaOH required to make the same pH= [OH-] = 5.26 x 10-6 M
Percent of ionization of NaOH = [OH-]*100/NaOH = 5.26 x 10-6 *100/5.26 x 10-6 = 100%
What is the mass of a 12.31 cm3 piece of copper having a density of 8.96 g/cm3
Answer:
the mass of the copper piece is 110.2976 grams
Place each noble gas symbol in front of the appropriate partial electron configuration to create an accurate electron configuration.
The noble gas that precedes a given partial electron configuration must itself have an electron configuration that is complete up to the partial electron configuration. The noble gas's electron configuration should, when fully written out right before the partial electron configuration, give us a valid electron configuration for some element.
For the first series, the highest principal energy level has the number 4, so our noble gas should at least be one that is in the third period (numerically, the energy level is the same as the period number). That noble gas would be argon. The partial electron configuration given is not that of a noble gas (note: all noble gases have an electron configuration that contains Np⁶, where N = the highest principal energy level). So, the noble gas that appropriately precedes our first partial electron configuration is [Ar].
Argon's electron configuration is 1s²2s²2p⁶3s²3p⁶. Using the Aufbau Principle, 4s² would correctly follow 3p⁶. [Ar]4s²3d¹⁰4p² is equivalent to writing out 1s²2s²2p⁶3s²3p⁶4s²3d¹⁰4p²; either way, this would happen to be the electron configuration of germanium.
Now that we hopefully have our fundamentals down, we can apply them to figure out the noble gases that precede the remaining partial electron configurations.
[Kr]5s²4d¹⁰5p⁵: This is the electron configuration of iodine.
[He]2s²2p⁵: This is the electron configuration of fluorine.
[Xe]6s²4f¹⁴5d¹⁰6p²: This is the electron configuration of lead.
[Ne]3s²2: This is the electron configuration of magnesium.
How many moles of NaF are produced in the resction between sodium bromide and calcium fluoride when 550 grams of sodium bromide are used
Answer: 5 moles of NaF would be produced when 550 grams of Sodium bromide are used.
Explanation:
From the question, the balanced chemical formula is illustrated below:
2NaBr + CaF2 → 2NaF + CaBr2
From the equation above;
Molecular mass of NaBr = 23 + 80 = 103g/ mol
Molecular mass of CaF2= 40+ (19×2)= 78g/ mol
Molecular mass of NaF = 23+19 = 42g/ mol
From the balanced chemical equation;
2 moles of NaBr reacted with 1mole of CaF to give 2 moles of NaF.
That is, 2 moles of NaBr= 2× 103 = 206g
2moles of NaF = 2×42= 84g
If 206g of NaBr yielded 84g of NaF
Therefore 550g of NaBr will yield Xg of NaF
X= 550×84/206
X= 224.27g of NaF
But 42g = 1 mole of NaF
Therefore 224.27g = X mole of NaF
X= 224.27 ×1/42
X is approximately 5moles.
Write 3 complete sentences about ionic bonding.
Picture a neutral P atom. This neutral atom will have
valence electrons. To reach a more stable configuration, this atom will
(gain, lose) electrons. The charge of the ion that forms will be
ASAP PLEASE
Answer:
It will have 5 valence electrons as its in group 5.
The atom will gain as its closer to the full configuration 8.
The charge will be 3- as it will gain 3 electrons.