13.29 X [tex]10^{21}[/tex] moles of NaCl are in a pinch of salt and a pinch of salt has
approximately 3.29x[tex]10^{21}[/tex] formula units of NaCl.
What are moles?The mole is the amount of substance of a system which contains as many elementary entities as there are atoms in 0.012 kilogram of carbon 12; its symbol is “mol”.
We know that 1 formula unit of sodium chloride has a molar mass of 58.44g/mol
Hence;
Mass of 1 formula unit = 58.44g
Mass of 3.29 x [tex]10^{21}[/tex] formula units
13.29 x [tex]10^{21}[/tex] x 58.44g
776.6676 x [tex]10^{21}[/tex]
Moles =[tex]\frac{776.6676 X 10^{21} }{ 58.44g}[/tex]
Moles = 13.29 X [tex]10^{21}[/tex]
Therefore;
13.29 X [tex]10^{21}[/tex] moles of NaCl are in a pinch of salt.
Learn more about moles here:
https://brainly.com/question/15209553
#SPJ1
calculate the moles of 70g of Li
[tex]\text{No. of moles} = \dfrac{\text{Mass of substance(Li)}}{\text{Molar mass of of substance(Li)}}\\\\\\~~~~~~~~~~~~~~~~~=\dfrac{70}{6.94}\\\\\\~~~~~~~~~~~~~~~~~=10.08~ \text{mol.}[/tex]
A hydrogen atom initially in its ground state absorbs a photon with a wavelength of 97.25 nm. To which energy level is it excited
This question involves the concept of excitation energy.
The energy level to which the atom is excited is "4".
What is excitation energy?The excitation energy of an atom is defined as the energy required by the atom to get excited from one energy level to some upper energy level. Mathematically, it can be given by the following formula:
[tex]E=E_o(\frac{1}{n_i^2}-\frac{1}{n_f^2})[/tex]
where,
E = excitation energy = [tex]\frac{hc}{\lambda} = \frac{(6.63\ x\ 10^{-34}\ J.s)(3\ x\ 10^8\ m/s)}{9.725\ x\ 10^{-8}\ m}=2.04\ x\ 10^{-18}\ J[/tex]
E (in eV) = [tex](2.04\ x\ 10^{-18}\ J)(\frac{1\ eV}{1.6\ x\ 10^{-19}\ J})[/tex] = 12.78 eV
h = plank's constant = 6.63 x 10⁻³⁴ J>s
c = speed of light = 3 x 10⁸ m/s
λ = wavelength = 97.25 nm = 9.725 x 10⁻⁸ m
E₀ = energy of hydrogen atom in ground state = 13.6 eV
[tex]n_i[/tex] = initial orbit = 1
[tex]n_f[/tex] = final orbit = ?
Therefore,
[tex]12.78\ eV=13.6\ eV(\frac{1}{1^2}-\frac{1}{n_f^2})\\\\\frac{12.78\ eV}{13.6\ eV}=1-\frac{1}{n_f^2}\\\\\frac{1}{n_f^2}=1-0.94\\\\n_f^2=\frac{1}{0.06}\\\\n_f=\sqrt{16.67}\\n_f = 4[/tex]
Learn more about excitation energy here:
https://brainly.com/question/2289096
#SPJ1
Which type of isomers are o-xylene, m-xylene, and p-
Xylene?
A.optical isomers
B.structural isomers
C.geometric isomers
The o-xylene, m-xylene, and p-Xylene are constitutional isomers. The correct option is D.
What are isomers?Isomers are the elements or polyatomic elements that have similar molecular formula.
All options are attached here:
A.optical isomers
B.structural isomers
C.geometric isomers
D.constitutional isomers
Thus, the correct option is D.constitutional isomers.
Learn more about isomers
https://brainly.com/question/13422357
#SPJ1
Consider the balanced reaction
below:
2AI+ 3Cl₂ → 2AICI 3
->>
How many grams of aluminum are
required to produce 8.70 moles of aluminum chloride?
The weight of aluminum are required to produce 8.70 moles of aluminum chloride is 234.9 g
What is the use of aluminium chloride ?
Aluminum chloride is useful for the treatment of palmar, plantar, and axillary hyperhidrosis.
Aluminum chloride has also been reported to be useful in facial and scalp hyperhidrosis
The balanced chemical equation represents the mole ratio in which the chemicals combine.
In this case, illustrates that 2 mol Al produces 2 mol Al Cl₃, hence these 2 chemicals are in a 1:1 ratio.
Thus, to produce 8.70 mol aluminium chloride, it will require 8.70 mol aluminium.
But this quantity of Al has a mass in grams of
m = n × Mr
= 8.70 mol × 27g/mol
= 234.9 g
Hence, The weight of aluminum are required to produce 8.70 moles of aluminum chloride is 234.9 g
Learn more about mole concept here ;
https://brainly.in/question/12599804
#SPJ1
Wave particle duality is most apparent in analyzing the motion of.
Answer:
Wave particle duality is most apparent in analyzing the motion of. an electron. A photon of which electromagnetic radiation has the most energy.
Wave particle duality is most apparent in analyzing the motion of an electron.
What is wave-particle duality used for?Wave-Particle duality used to realize the particle and wave nature of light. Based on the idea that light and all other electromagnetic radiation may be considered a particle or a wave nature, in 1923 physicists Louis De Broglie suggested that the same kind of duality must hold to matter.
For example, an electron that produced part of an electric current in a circuit behaves like a particle moving in unison with other electrons inside the conductor. The same electron acts as a wave when it passes over through with a solid crystalline structure and forms a diffraction image.
A photon of which electromagnetic radiation has the most energy.
Thus, Wave particle duality is most apparent in analyzing the motion of. an electron.
To learn more about the wave-particle, follow the link;
https://brainly.com/question/15385740
#SPJ2
Which of the following chemical reactions represents an acid-base reaction?
HBr + KOH -> KBr + H2O
ZnCl2 + MgSO4 -> ZnSO4 + MgCl2
H2SO4 + CaCl2 -> CaSO4 + HCl
NH4OH + KCl -> KOH + NH4Cl
Answer:
HBr + KOH -> KBr + H₂O
Explanation:
Acid-base reactions always produce a salt [KBr] and water [H₂O].
Out of the given reactions, the reaction HBr + KOH -> KBr + H₂O is an acid base reaction.
An acid–base reaction is a chemical reaction that occurs between an acid and a base and results in the formation of salt and water.
Here in this reaction HBr + KOH -> KBr + H₂O, HBr is an acid and KOH is a base, together they undergo a neutralization reaction to form a salt KBr and water .
An acid-base reaction involves the transfer of protons (H⁺) between an acid and a base. Acids are the substances which can donate protons, while bases are substances that can accept protons.
In an acid-base reaction, the acid donates a proton (H⁺) to the base, forming water (H₂O) and a salt. The salt is typically formed by the cation of the base combining with the anion of the acid.
In this reaction, HBr donates a proton (H⁺) to KOH, which acts as a base and accepts the proton to form water (H₂O), while KBr is formed as a salt. This is a classic example of an acid-base reaction, where an acid and a base react to form a salt and water.
To know more about acid-base reaction here
brainly.com/question/15209937
#SPJ2
How to draw ethyl pentanoate?
Choose all that apply for raft spiders.
question 9 options:
raft spider's legs have a waxy surface that repels water
raft spiders sprint along submerged plants to catch underwater prey.
raft spider's light weight and large surface area allow it to walk on water.
raft spider's heavy weight and small surface area allow it to walk on water
Raft spider's light weight and large surface area allow it to walk on water.
What are raft spiders?Raft spiders are a specie of siders that can move on the surface of water. They are found around the north-western and central Europe.
The following apply to the raft spiders;
raft spider's legs have a waxy surface that repels waterraft spider's light weight and large surface area allow it to walk on water.Learn more about raft spiders:https://brainly.com/question/11416236?
#SPJ1
the condensed formula ch3ch(ch3)2 represents
The molecular formula CH₃CH(CH₃)₂ is the condensed formula for the hydrocarbon methylpropane.
What are organic compounds?Organic compounds are compounds that are obtained from organic materials.
The most common organic compound are the hydrocarbons,
The hydrocarbons includes the alkanes, alkenes, alkynes, etc.
The given compound CH₃CH(CH₃)₂ is the condensed formula for the hydrocarbon methylpropane.
Learn more about hydrocarbons at: https://brainly.com/question/1489747
#SPJ1
Which statement is true about A nickel-cadmium dry cell?
Answer:
The cathode reaction is NiO2+H2O+2e−→Ni(OH)2+2OH−.
For group 1a metals, which electron is the most difficult to remove?
The periodic table contains groups and periods that include the elements. For group 1 metal lithium is least likely to lose an electron.
What are group 1 metals?Group 1 metals are the alkali metals that include, Li, Na, K, Rb, and Cs. They show the property exhibited by the metals. The chemical trends of group 1 show that cesium loses an electron more easily than the other elements.
When going down the group the tendency to lose electrons increases as the atomic radius increases. The electron gets far away from the nucleus making it easy to get removed.
Therefore, lithium being the first element of the group has the smallest radii and is least likely to lose an electron.
Learn more about the group I metals here:
https://brainly.com/question/27187436
#SPJ4
A solution of potassium nitrate is made when potassium nitrate dissolves in water.
Describe a method you could use to obtain crystals of potassium nitrate from
potassium nitrate solution.
You should include an explanation of the process by which the crystals are produced
from the solution.
[6 marks]
Answer:
Boil the water and stir in potassium nitrate. If it doesn't all dissolve, you can cook it on the stove or microwave it until the water boils again. Remove the solution from heat, but let it cool slowly for the best crystal formation.
What is the energy of a photon of infrared radiation with a frequency of 2.53 × 1012 Hz? Planck’s constant is
6.63 × 10–34 J • s.
Answer: C, 1.68 x 10^-21
Explanation: Edge 2022
Random molecular motion of a substance is the greatest when the substance is
Answer: a gas
The gas phase is the phase where particles are packed the least tightly together.
How do hollow bones improve the survival of birds? (1 point )
Answer:
Hollow bones allow the birds to fly. They're quite dense, and that density allows for flight! Because we humans do not have hollow bones, our bodies are much too heavy to fly on our own. If we did, we'd probably be able to fly.
Explanation:
Ionization, radical and valency electron
Answer:
Ionization, in chemistry and physics, any process by which electrically neutral atoms or molecules are converted to electrically charged atoms or molecules (ions).radical, also called Free Radical, in chemistry, molecule that contains at least one unpaired electron. For neutral atoms, the number of valence electrons is equal to the atom's main group number.What happens when a solid is dissolved into a liquid?
Solid particles float toward the surface layer of liquid particles.
O Solid particles sink down toward the bottom layer of liquid particles.
Solid particles become evenly dispersed among liquid particles.
Solid particles become suspended in the middle of liquid particles.
Answer:
C
Explanation:
chem ed 2022
When a solid is dissolved into a liquid,
Solid particles become evenly dispersed among liquid particles.So, option C is correct is one.
What is solution?When solid dissolve in liquid and form intimate mixture called solution.A solid mix completely in liquid by breaking solid particles into smaller one and dissolves in liquid.The minor part generally solid present in solution is called solute.The major part generally liquid in the solution is called solvent .learn about solid,
https://brainly.com/question/20461295
#SPJ2
Predict the products.
nabr (aq) + mgcl2 (aq) ----> __ + __.
will the reaction occur?
Answer:
MgBr
NaCl
Explanation:
In an electroplating apparatus, where does the reduction reaction occur?
On the surface of the anode
On the surface of the battery
In the solution
On the surface of the cathode
Answer:
on the surface of the cathode
When trying to identify an unknown element a scientist determines
Elements are a substance that is the smallest unit and can't be divided further. The number of valence electrons determines the reactivity with other elements.
What are valence electrons?Valence electrons are the electrons that are found in the outermost shell of the atom. These electrons take part in chemical reactions to form chemical bonds.
The number of these electrons will help determine how the unknown element reacts with the other elements chemically as valence electrons are responsible for the chemical bond formation.
Therefore, the valence electrons of the unknown element are used to determine the property.
Learn more about valence electrons here:
https://brainly.com/question/14459291
#SPJ4
I-131 undergoes beta-minus decay. The chemical symbol for the new element is.
The chemical element that is formed when I-131 undergoes beta-minus decay is Xe.
What is a beta minus decay?A beta minus decay is one in which an electron is changed into a proton. The atomic number of the daughter nucleus will increase by one unit and is one place after the parent in the periodic table.
The chemical element that is formed when I-131 undergoes beta-minus decay is Xe.
Learn more about beta decay:https://brainly.com/question/25455333
#SPJ1
According to the law of definite proportions, if a sample of a compound contains 24.00 grams of carbon and 4.00 grams of hydrogen, then another sample of the same compound which contains 48.00 grams of carbon must contain ________. Group of answer choices
Answer: 8.00 grams
Explanation:
The ratio of carbon and hydrogen must be the same.
what is an example of taking action or doing service in the cement industry
Answer:
mining of clay limestone and then heated to a certain temperature of 1450⁰ in a cement kiln
Which is the correct label of the parallel lines? Parallel lines a and b are shown. Points A and B lie on line a while points C and D lie on line b. The letters a and b are separated by two vertical lines. There is a horizontal line with arrows on either end over the letters A A. There is another horizontal line with arrows on either end over the letters C B. A vertical line with a horizontal line intersecting it at the bottom separates the two pairs. There is a horizontal line over the letter A with one arrow on the right end. There is a horizontal line over the letter B with one arrow on the right end. The letters are separated by two vertical lines. There is a horizontal line with arrows on either end over the letters A A. There is another horizontal line with arrows on either end over the letters C B. A vertical line with a horizontal line intersecting it at the bottom separates the two pairs. Question 5(Multiple Choice Worth 1 points) (01.01 LC) Anna draws an angle in her notebook. In how many points do the rays intersect? 2 0 1 3 Question 6(Multiple Choice Worth 1 points) (01.01 MC) Is the image an example of perpendicular lines? line AB intersects with another line at 90 degrees Yes; the lines intersect. Yes; the lines intersect at a right angle. No; the lines never touch. No; the lines are one-dimensional. Question 7(Multiple Choice Worth 1 points) (01.01 LC) Which term best describes the geometric figure? A location is labeled A. Line Point Ray Segment Question 8(Multiple Choice Worth 1 points) (01.01 LC) Which undefined term is needed to define a circle? Point Radius Line Ray Question 9(Multiple Choice Worth 1 points) (01.01 LC) Which of the following is a flat surface that extends infinitely, has length and width, but does not have depth? Angle Circle Plane Segment Question 10(Multiple Choice Worth 1 points) (01.01 MC) James defines an angle as "a figure consisting of two rays." His statement is not precise enough because he should specify that the rays must be
Answer: B) the answer is CD with the line on top
Explanation:
What is the chemical formula of polypropylene (in text, no pictures)?
Answer:
(C3H6)n
it is made up of carbon and hydrogen atoms.
If a solution is made by using 0.45 moles of NaCl and dissolving it with water so that the total volume is 0.750 liters, what will the concentration of that solution be in molarity?
Answer:
.6 M
Explanation:
.45 moles / .750 liters = .6 M
What is the mass number of an isotope with an atomic number of 57 and that has 69 neutrons?
Answer:
mass number=126
Explanation:
57+69=126
How much mass would a sample of magnetite, a magnetic stone, with a volume of 8 cm^3 and a density of 5 g/cm^3 have?
Question 7 (5 points)
(08.02 mc)
what is the mass of naci required to make 140 grams of a 12% solution of nach in water? (5 points)
12 grams
14 grams
oc
12 grams
od
18 grams
Answer: 18 g
Explanation:
[tex]0.12=\frac{\text{mass of NaCl}}{140}\\\text{mass of NaCl}=(0.12)(140)=16.8 \text{ g}[/tex]
The option closest to this is 18 g
what is the different nobel gases that didnt have octet rule
The noble gas, Helium has only two electrons with the electronic configuration as 1s2. Hence, it does not have a complete octet. and thus, it doesn't follow the octet rule.
An octet is a set of eight. Atoms of each of the noble gases (except helium) have eight electrons in their highest occupied energy levels and the general electron configuration of ns2np6.