Answer:
8.51 x 10²¹ atoms
Explanation:
Given parameters:
Mass of K = 0.551g
Unknown:
Number of atoms = ?
Solution:
To find the number of atoms in this given substance, we need to solve for the number of moles first.
Number of moles = [tex]\frac{mass}{molar mass}[/tex]
Now;
Molar mass of K = 39g/mol
Number of moles = [tex]\frac{0.551}{39}[/tex] = 0.014mole
Therefore,
1 mole of a substance contains 6.02 x 10²³ atoms
0.014 mole of K will contain 0.014 x 6.02 x 10²³ = 8.51 x 10²¹ atoms
Please help I need this done
Answer:
they arent alcohols.
Explanation:
Genetically engineered crops (3 points)
A. are often unsuccessful
B. create optimum soil
C. increase crop yields
D. prevent weed growth
Answer:
C. increase crop yields
Explanation:
Genetically modified organisms are those organisms that have been improved using genetic engineering procedures. Genetic engineering/modification is the manipulation of an organism's genome in order to get an improved organism with desirable traits.
The organisms being genetically modified or engineered is called GMO or transgenic organisms. Hence, in this case, one feature of the crops being genetically modified is to have an INCREASED YIELD.
If an element has 3 valence electrons, what charge will likely form on its ion
The element will lose electrons to become stable if the valence shell contains 3 or fewer electrons. The production of cations is a sign of electron loss. The species having positive charge are called cations. As a result, the ion will get a positive charge.
What is ion ?An atom or molecule with a net electrical charge is known as an ion. Conventionally, the charge of an electron is thought to be negative; this charge is equal to and opposite to the charge of a proton, which is thought to be positive.
An atom will shed its valence electrons in order to become a charged ion and create an ionic bond with another atom if it lacks one to three of them.
A positive ion is created by taking electrons from a neutral atom, whereas a negative ion is created by adding electrons to a neutral atom. The quantity of protons remains constant during the formation of an ion.
Thus, the ion will get a positive charge.
To learn more an ion, follow the link;
https://brainly.com/question/14982375
#SPJ2
One method used commercially to peel potatoes is to soak them in a solution of NaOH for a short time and then remove them from the NaOH. The peel will have separated from the potato and so it can then easily be sprayed off to yield beautifully peeled potatoes! The NaOH solution however, must be analyzed periodically to make sure its concentration is adequate for the reaction In one such analysis, 45.7 mL of 0.500 M H2SO4 is required to react completely with a 20.0 mL sample of the NaOH solution. The products of the reaction are Na2SO4 and water. What is the concentration of the starting NaOH solution?a. 1.14 M b. 2.28 M c. 0.438 M d. 0.500 M e. 0.571M
Answer:
b. 2.28 M
Explanation:
The reaction of neutralization of NaOH with H2SO4 is:
2NaOH + H2SO4 → Na2SO4 + 2H2O
Where 2 moles of NaOH react per mole of H2SO4
To solve the concentration of NaOH we need to find the moles of H2SO4. Using the chemical equation we can find the moles of NaOH that react and with the volume the molar concentration as follows:
Moles H2SO4:
45.7mL = 0.0457L * (0.500mol/L) = 0.02285 moles H2SO4
Moles NaOH:
0.02285 moles H2SO4 * (2moles NaOH / 1 mol H2SO4) = 0.0457moles NaOH
Molarity NaOH:
0.0457moles NaOH / 0.020L =
2.28M
Right option:
b. 2.28 MThe concentration of the starting NaOH solution is:
b. 2.28 M
Neutralization reaction:
The reaction of neutralization of NaOH with H₂SO₄ is:
2NaOH + H₂SO₄ → Na₂SO₄ + 2H₂O
Calculation for concentration of NaOH:We need to find the moles of H₂SO₄. Using the chemical equation we can find the moles of NaOH.
Moles of H₂SO₄:
45.7mL = 0.0457L * (0.500mol/L) = 0.02285 moles of H₂SO₄
Moles of NaOH:
0.02285 moles H₂SO₄ * (2moles NaOH / 1 mol H₂SO₄) = 0.0457moles NaOH
Molarity of NaOH:
0.0457moles NaOH / 0.020L =2.28M
Thus, the concentration of the starting NaOH solution is: 2.28 M.
Find more information about Molarity here:
brainly.com/question/17138838
Consider the elements: Na, Mg, Al, Si, P.
a. Which element has the lowest second ionization energy?
b. Which element has the smallest atomic radius?
c. Which element is least metallic?
d. Which element is diamagnetic?
Answer:
The elements mentioned in the series are Na, Mg, Al, Si, and P. It can be seen that all these elements are located in the same period. The atomic number of the mentioned elements are Na-11, Mg-12, Al-13, Si-14, and P-15.
a) There will be an increase in the ionization energy with the increase in the element's atomic number across a period. More energy is needed to withdraw an electron from a completely occupied shell in comparison to an incompletely occupied shell.
The atomic number of Na is 11. When one electron is withdrawn from Na, it gets converted into the inert gas configuration of Ne. Thus, it will require more energy to withdraw the second electron from Na. Hence, Na exhibits the lowest second ionization energy.
b) Across the period, with an increase in the element's atomic number, the atomic radii reduces from left to right. Thus, P exhibits the smallest atomic radius.
c) The metallic nature of the elements reduces from left to right across a period in the periodic table. Thus, P is the least metallic element.
d) Diamagnetic signifies towards the element that exhibits pair electrons in its sub-shells. The electronic configuration of Mg is,
1s2 2s2 2p6 3s2
In Mg, no unpaired electrons are present, while all the remaining elements mentioned exhibit unpaired electrons in their valence shell. Thus, Mg is the diamagnetic element.
A4 g sugar cube (Sucrose : C 12 H 22 O 11 ) is dissolved in a 350 ml teacup of 80 C water. What is the percent composition by mass of the sugar solution ? Density of water at 80 degrees * C = 0.975g / m * l Select one :- 1.96\% . 1.63% 1.36 % d% e 1.16 \%
Answer:
%Sgr = 1% (1 sig.fig.)
Explanation:
mass water = 350ml x 0.975g/ml = 341.25g
mass sugar added = 4g
solution mass = 341.25g + 4g = 345.25g
%sugar = (4g/345.25g)·100% = 1.1586% ≅ 1% (1 sig.fig)
The percent composition by the mass of the sugar solution is:
e. 1.16 %
This can be calculated by using mass of sugar.
Calculation of percent composition:Mass of water = 350ml x 0.975g/ml = 341.25g
Mass of sugar added = 4g
Total solution's mass = 341.25g + 4g = 345.25g
%sugar = (4g/345.25g)·100%
%sugar= 1.1586% ≅ 1.16 %
Thus, the percent composition of sugar is 1.16%. Hence, option E is correct.
Find more information about percent composition here:
brainly.com/question/17021926
can someone please help me with this....?
Answer:
Explanation:
The answer is D
PLEASE HELP WILL GIVE BRAINLEIST ASAP Determine the fraction of an original sample of K-42 that remains unchanged after 24.72 hours.
Answer:
25% or 0.25 or 1/4
Explanation:
don't know which form you need so here you have all 3
good luck :)
How does electroplating happen?
A. A thin layer of metal is removed from a cathode.
B. Metal ions form a solid layer on a metal cathode.
C. Metal on a cathode forms ions in solution.
D. Metal ions in solution form a precipitate.
(Answer is B.)
Answer:
B
Explanation:
An electroplating happen when metal ions form a solid layer on a metal cathode. Therefore, option B is correct.
What is an electroplating ?The term electroplating is defined as the process of aligning another metal on the metal. Electroplating is usually used to change the physical properties of an object.
An electroplating is accomplished by an electroplating apparatus that contain a brine solution, a battery, wires, and alligator clips that kept carbon rods attached to the metal to be electroplated and the metal to be layered.
This process is used to give objects increased wear resistance, corrosion protection or aesthetic appeal and greater thickness. While electroplating is like advanced technology. It is primarily used to change the physical properties of an object.
Thus, option B is correct.
To learn more about an electroplating, follow the link;
https://brainly.com/question/20112817
#SPJ5
If you have 23.8g of CaCl2, how many formula units is it?
Answer:
1.3×10²³ formula unit
Explanation:
Given data:
Mass of CaCl₂ = 23.8 g
Number of formula unit = ?
Solution:
Number of moles = mass/molar mass
Number of moles = 23.8 g/110.98 g/mol
Number of moles = 0.21 mol
1 mole of any substance contain 6.022×10²³ formula unit
0.21 mol × 6.022×10²³ formula unit / 1mol
1.3×10²³ formula unit
A sample of Neon and Helium gases at 298 K have a total pressure of 29 atm. If the partial pressure of He is 6 atm, what is the mole fraction of neon?
The following half-reaction method is used to balance oxidation-reduction equations.
(1) Determine which atoms change oxidation state from reactant to product in the reaction.
(2) Identify and write half reactions (oxidation and reduction).
(3) Return to the original chemical equation to balance it.
(a) Insert the coefficients from the half reactions first.
(b) Inspect the number of each atom on each side for all elements.
Which important step is missing from this procedure?
Check other reactions similar to this one.
Name the elements that are involved in the reaction.
Make sure the reduction half reaction is identified first.
Balance the half reactions based on the number of electrons.
Answer:
its (D) Balance the half reactions based on the number of electrons.
Explanation:
Answer:
D ✔️
Explanation:
"Balance the half reactions based on the number of electrons."
Which of the following determines the identity of an element?
Please please please help please
What is the chemical name of C4H10
Answer:
Butane
Explanation:
Answer:
Butane
Explanation:
Butane is a colorless gas with a faint petroleum-like odor.
Melting point: -138 °C
A student predicted the reaction between hydrogen and oxygen gas would yield 125 of water. However, after measuring the water formed in the reaction, student determined that only 110 of water was actually formed. What is the percent yield of this reaction ?
Help
Describe how you would prepare 5.00 × 102 mL of a 1.75 M H2SO4 solution, starting with an 8.61 M stock solution of H2SO4
We prepare the volume of the 8.61 M stock solution of 0.102 L, then we dilute it by adding water to 0.5 L
Further explanationGiven
5.00 × 10² mL of a 1.75 M H₂SO₄ solution
8.61 M stock solution
Required
The volume of stock solution
Solution
Molarity from 8.61 M to 1.75 M ⇒Dilution
We can use dilution formula :
[tex]\tt \boxed{\bold{M_1.V_1=M_2.V_2}}[/tex]
M₁=8.61 M
V₂=500 ml = 0.5 L
M₂=1.75 M
[tex]\tt V_1=\dfrac{M_2.V_2}{M_1}\\\\V_1=\dfrac{1.75\times 0.5}{8.61}\\\\V_1=0.102~L[/tex]
write the general formula of a. alkane b. aikyl radicals radicals
Answer:
General formula of alkanes is: [tex]C_{n}H_{2n+2}[/tex]
General formula of alkyl: [tex]C_{n}H_{2n+1}[/tex]
A red laser pointer emits light at a wavelength of 488 nm. If the laser emits 7.5 10–4 J of energy per second in the form of visible radiation, how many photons per second are emitted from the laser?
a)
4.1 10–19 photons/sec
b)
5.4 10–16 photons/sec
c)
8.9 1014 photons/sec
d)
1.8 1015 photons/sec
e)
2.5 1018 photons/sec
The answer to the question, how many photons per second are emitted from the laser is d. 1.84 × 10¹⁵ photons/sec
Since the red laser pointer emits light of wavelength 488 nm, we need to find the energy of each photon from
E = hc/λ where h = Planck's constant = 6.63 × 10⁻³⁴ Js, c = speed of light = 3 × 10⁸ m/s and λ = wavelength of light = 488 nm = 488 × 10⁻⁹ m
Substituting the values of the variables into the equation, we have
E = hc/λ
E = 6.63 × 10⁻³⁴ Js × 3 × 10⁸ m/s ÷ 488 × 10⁻⁹ m
E = 19.89 × 10⁻²⁶ Jm ÷ 488 × 10⁻⁹ m
E = 0.04076 × 10⁻¹⁷ J per photon
E = 4.076 × 10⁻¹⁹ J per photon
Since the laser emits 7.5 × 10⁻⁴ J per second, the number of photons emitted from the laser per second = energy per second/energy per photon
= 7.5 × 10⁻⁴ J per second ÷ 4.076 × 10⁻¹⁹ J per photon
= 1.84 × 10¹⁵ photons/sec
The answer to the question, how many photons per second are emitted from the laser is d. 1.84 × 10¹⁵ photons/sec
Learn more about number of photons per second emitted here:
https://brainly.com/question/13092011
One sugar produced by photosynthesis is called
Fill in the coefficients that will balance the following reaction: (Note: Use 1 as coefficient where appropriate.) NaCl + CaS → Na2S + CaCl2
Answer:
the answer is
2,1,1,1
Explanation:
what is the meaning of the word hydrocarbons
Answer:
An organic compound (such as acetylene or butane) containing only carbon and hydrogen and often occurring in petroleum, natural gas, coal, and bitumens.
Explanation:
Iooked it up
What volume, in mL, of concentrated 16 M nitric acid would you need to use in order to prepare 500.0 mL of a 0.250 M HNO3(aq) solution?
Given :
Initial concentration of nitric acid, [tex]C_1 = 16\ M[/tex].
Final concentration of nitric acid, [tex]C_2 = 0.250 \ M[/tex].
Volume of [tex]HNO_3[/tex], [tex]V _2= 500\ mL = 0.5\ L .[/tex]
To Find :
Volume needed( [tex]V_1[/tex] ).
Solution :
We know,
[tex]C_1V_1 =C_2V_2\\\\16 \times V_1 = 0.250 \times 0.5 \\\\V_1 = \dfrac{0.250 \times 0.5}{16}\\\\V_1 = 0.0078125\ L = 7.8125 \ mL[/tex]
Hence, this is the required solution.
1. Which groups of the periodic table constitute p-block?
Which trait can a plant acquire during its lifetime?
O A. A damaged stem
OB. A blue flower color
O C. A long, narrow leaf shape
O D. A smooth seed texture
Answer:
OB
Explanation:
wat does aquire mean
Answer:
a
Explanation:
a damaged stem
Which sphere forms Earth's outermost layer?
Atmosphere
Biosphere
Cryosphere
Hydrosphere
Answer: I believe the answer is A.
Explanation: Well, the lithosphere is rocks and earth, the hydrosphere makes up all the water on Earth, the biosphere is us, (living things,) and the atmosphere is the air that surrounds us and our planet. So if you go in order, it's basically lithosphere, hydrosphere, biosphere, and then atmosphere.
Answer:
Atmosphere
Explanation:
I took test
Naming Ionic Compounds.
What is the neutral Ionic Compound name of Be^+2 & S^-2?
What is the neutral Ionic Compound name of Pb^+2 & CO3^-2?
Answer:For binary ionic compounds (ionic compounds that contain only two types of elements), the compounds are named by writing the name of the cation first followed by the name of the anion. For example, KCl, an ionic compound that contains K+ and Cl- ions, is named potassium chloride.
Explanation:
A group of organs working together to perfrom a certain function called
Answer:
group. hfdzybidddiklllnjjooolll
Answer:
An organ system
Explanation:
:>
molecular formula of alkyne containing 10 carbon atom
Answer:
Decyne: C10H18
Hope it helps! please mark me brainliest..
Merry Christmas good day
The general formula for alkynes is CnH2n-2
the number of carbon atoms is 10 so the number of hydrogen atoms will be 10*2-2=20-2=18hydrogen atoms
the molecular formula for this alkyne is :
C₁₀H₁₈ which is called decyne
3
Solve and derive the unit for Power
Answer:
Unit of power is watt
Explanation:
Power = rate of doing work
or
Power, P = W/t
Where
W is work done and t is time
The unit of work done is Joules and that of time is seconds.
Power, P = J/s
We know that, J/s = watts
Hence, the unit of power is watts.
