Answer:
0.0041 mol
Explanation:
Given data:
Number of formula units = 2.45 × 10²¹ formula units
Number of moles = ?
Solution:
The given problem will solve by using Avogadro number.
It is the number of atoms , ions ,formula units and molecules in one gram atom of element, one gram molecules of compound and one gram ions of a substance. The number 6.022 × 10²³ is called Avogadro number.
1 mole = 6.022 × 10²³ formula units
2.45 × 10²¹ formula units × 1 mol / 6.022 × 10²³ formula units
0.41 × 10⁻² mol
0.0041 mol
Using energy efficiently and managing it well do not reduce society's impact on Earth.
True or False?
Answer:
False
Explanation:
Using less electricity will result in less fuel being burnt which will result in less fuel needing to be extracted from the earth which will reduce society's impact on earth.
meaning of science in university
Answer:
Science is the pursuit and application of knowledge and understanding of the natural and social world following a systematic methodology based on evidence. Experiment and/or observation as benchmarks for testing hypotheses
Explanation:
If the equilibrium constant for the reaction A 2B C 5/2 D has a value of 4.0, what is the value of the equilibrium constant for the reaction 2C 5D 2A 4B at the same temperature
Answer:
[tex]K'=\frac{1}{16}[/tex]
Explanation:
Hello!
In this case, since the given reaction is:
[tex]A+ 2B \rightleftharpoons C+ \frac{5}{2} D[/tex]
Whereas the equilibrium constant is:
[tex]K=\frac{[C][D]^{5/2}}{[A][B]^2} =4.0[/tex]
However, the new target reaction reverses and doubles the initial reaction to obtain:
[tex]2C+5D \rightleftharpoons 2A+4B[/tex]
Whereas the equilibrium constant is:
[tex]K'=\frac{[A]^2[B]^4}{[C]^2[D]^5}[/tex]
Which suggest the following relationship between the equilibrium constants:
[tex]K'=\frac{1}{K^2}[/tex]
So we plug in to obtain:
[tex]K'=\frac{1}{4.0^2}\\\\K'=\frac{1}{16}[/tex]
Best regards!
The unit of electrical resistance is the: ohm-cm ohm volt ampere
Answer:
Ohm/ Current = Resistance
Explanation:
Answer:
Ohm
Explanation:
Pleas help!!! I’ll make brainlist
Answer: 4.6 billion years ago
Explanation:
Answer:
4.6 billion years ago
hope this helps have a good day or night:)
help asap pls getting timed !
Answer:
Calcium carbonate and citric acid.
Explanation:
Hello!
In this case, considering the text, we can notice that calcium carbonate combines with citric acid to produce the calcium citrate water and carbon dioxide as shown on the following equation:
[tex]3CaCO_3+2C_6H_8O_7\rightarrow Ca_3C_{12}H_{10}O_{14}+CO_2+H_2O[/tex]
Whereas the reactants, at the left side, are identified as calcium carbonate and citric acid.
Best regards!
HELP ME PLEASE!! IAM BEING TIMED.
I WILL GIVE YOU BRAINLIEST!
Answer:
Element
Explanation:
Other things on that list like alloy and compound can be broken down, but elements cannot
Answer:
If it is made from solid silver then it is an element. If it is made from a silver alloy then it is a mixture. If it is a silver plated plate (i.e. a plate made from say, copper but with a thin layer of silver on top) then it is an element on top of an element.
Explanation:
I'm assuming you're talking about solid silver, so, i believe an element.
How many sigma bonds and how many pi bonds are there in the tetracyanoethylene molecule
Answer:
Nine σ- and nine π
Explanation:
Nine σ- and nine π are there in the molecule of tetracyanoethylene.
Which one is convection??? A heater in a fish tank warming the water at the bottom of the tank, Batteries in a flashlight converting chemical energy into light, Touching a stove and burning your hand, or Warming up next to a fire on a cold night
This is the chemical formula for acetone: CH32CO. Calculate the mass percent of carbon in acetone.
Answer:
62.07 %
Explanation:
Chemical Formula = (CH3)2CO = C3H6O
Mass of C = 12 g/mol
Mass of H = 1 g/mol
Mass of O = 12 g/mol
Mass of C3H6O = 3(12) + 6(1) + 16 = 58 g/mol
Total mass of C in Acetone = 12 * 3 = 36 g
Mass Percent of C = Total mass of C / Mass of Acetone * 100
Mass percent = 36 / 58 * 100
Mass percent = 62.07 %
prove that PV = nRT.
Find your answer in the explanation below.
Explanation:
PV = nRT is called the ideal gas equation and its a combination of 3 laws; Charles' law, Boyle's law and Avogadro's law.
According to Boyle's law, at constant temperature, the volume of a gas is inversely proportional to the pressure. i.e V = 1/P
From, Charles' law, we have that volume is directly proportional to the absolute temperature of the gas at constant pressure. i.e V = T
Avogadro's law finally states that equal volume of all gases at the same temperature and pressure contain the same number of molecules. i.e V = n
Combining the 3 Laws together i.e equating volume in all 3 laws, we have
V = nT/P,
V = constant nT/P
(constant = general gas constant = R)
V = RnT/P
by bringing P to the LHS, we have,
PV = nRT.
Q.E.D
An electron jumps from energy level 1 to energy level 2 by absorbing a photon of energy 8 eV. What is the most likely energy of the photon that will be emitted by the electron when it moves back down to energy level 1?
A. 2 eV
B. 4 eV
C. 8 eV
D. 12 eV
Answer:
C. 8 eV
Explanation:
In atoms, the energy of each level is quantised. That is one of the reasons why an electron can not exist between energy levels. Thus, when the electron absorbs energy of 8 ev, it get excited and jumps to energy level 2 which has the current value of energy of the electron.
Thus for the electron to move back to its initial energy level, it must emit the exact energy absorbed for its excitation. Therefore, the likely energy of the photon that will be emitted is 8 ev. This would make the electron to have energy that would make it to exist on energy level 1.
The freezing and thawing action of water affects a rock by...
A. leaving behind sedimentary particles from evaporation
B. gradually breaking down the rock into smaller pieces
C. chemically weathering the rock
D. transforming the rock into igneous rock
Answer:
B
Explanation:
Calculate the grams of sugar present in a 355ml can of soda if the water in the can weighs 355g and the density of the soda is 1.06g/mL?
Mass of sugar in the can : 21.3 g
Further explanationGiven
a 355ml can of soda
mass water = 355 g
density of soda = 1.06 g/ml
Required
mass of sugar
Solution
Mass of soda in the can :
= density x volume of the can
= 1.06 g/ml x 355 ml
= 376.3 g
Mass of sugar :
=mass of soda - mass of water
= 376.3 g - 355 g
= 21.3 g
Percentage of C in CO
The percentage of C in CO = 42.9%
Further explanationGiven
CO compound
Required
Percentage of C
Solution
Proust :
Compounds are formed from elements with the same Mass Comparison so that compounds have a fixed composition of elements
Ar of C = 12 g/mol
MW of CO = 28 g/mol
%C :
[tex]\tt =\dfrac{Ar~C}{MW~CO}\times 100\%\\\\=\dfrac{12}{28}\times 100\%\\\\=42.9\%[/tex]
answer to this question is = 42.9 %
Explanation:
mark me as brainliest
the 2 written in this formula (2 CH4 is a)
Answer : 2 represent the coefficient.
Explanation :
As we know that:
The coefficients used in the chemical equations shows that the relative amounts of each substance present and this amount can represent either the relative number of molecules or number of moles.
If there is no coefficient then one (1) is assumed.
That means,
The coefficient tell us about that how many molecules or atoms present in the chemical equation.
By the stoichiometry we have to convert moles of a reactant to moles of a product.
The given formula is: [tex]2CH_4[/tex]
In this formula, 2 represent the coefficient and 4 represent the subscript and C and H represents the symbol of element.
Hence, 2 represent the coefficient.
9. If the limits of cow hearing are 23 Hz to 35,000 Hz, what are the sound wavelengths that are
associated with both of these two extremes, assuming the speed of sound is 345 m/s.
Frequency= 23 Hz: Wavelength =
Frequency = 35,000 Hz: Wavelength =
Answer:
wave length=speed/frequency
=365/23
wave length=speed/frequency
=365/35000
How many moles of Ca are in 1.25x1023 atoms?
We used two conversion factors in this unit, they are provided below. It is your responsibility to know which conversion factor to use!
Avogadro’s number: 6.02x1023 atoms = 1 mole
Molar mass of calcium: 40.078 g Ca = 1 mol Ca
A. 3.12x10^21 mol
B. 0.21 mol
C. 3.12 mol
D. 0.21x10^21 mol
B. 0.21 mol
General Formulas and Concepts:Math
Pre-Algebra
Order of Operations: BPEMDAS
Brackets Parenthesis Exponents Multiplication Division Addition Subtraction Left to RightChemistry
Atomic Structure
Using Dimensional AnalysisAvogadro's Number - 6.022 × 10²³ atoms, molecules, formula units, etc.Explanation:Step 1: Define
1.25 × 10²³ atoms Ca
Step 2: Identify Conversions
Avogadro's Number
Step 3: Convert
Set up: [tex]\displaystyle 1.25 \cdot 10^{23} \ atoms \ Ca(\frac{1 \ mol \ Ca}{6.022 \cdot 10^{23} \ atoms \ Ca})[/tex]Multiply: [tex]\displaystyle 0.207572 \ mol \ Ca[/tex]Step 4: Check
Follow sig fig rules and round. We are given 3 sig figs.
0.207572 mol Ca ≈ 0.208 mol Ca
compared to a solution with a ph of 7, a solution with a ph of 4 is
Answer:
pH of 7 is neutral
pH of 4 is weak acid
Explanation:
hope it helps you..
Biological half-life of medicine works in the same way as radiological half-life. Acetaminophen (Tylenol) has a biological half-life of about 2 hours (though it varies depending on individual metabolism). What percentage of your original dosage remains in your system after 6 hours when you are allowed to take another dose?
Answer:
12.5%
Explanation:
From the question given above, the following data were obtained:
Half-life (t½) = 2 h
Time (t) = 6 h
Percentage remaining =.?
Next we shall determine the number of half-lives that has elapse. This can be obtained as follow:
Half-life (t½) = 2 h
Time (t) = 6 h
Number of half-lives (n) =?
n = t / t½
n = 6/2
n = 3
Finally, we shall determine the percentage of original dosage remaining as follow:
Amount remaining (N) = Original amount (N₀) /2ⁿ
N = N₀ / 2ⁿ
Divide both side by N₀
N/N₀ = 1/2ⁿ
Input the value of n i.e 3
N/N₀ = 1/2³
N/N₀ = 1/8
N/N₀ = 0.125
Multiply by 100 to express in percent.
N/N₀ = 0.125 × 100
N/N₀ = 12.5%
Thus, percentage of original dosage remaining is 12.5%
How does latitude affect climate? A The closer to the poles, the warmer it gets. B The closer to the equator, the warmer it gets. C The higher you go up a mountain, the colder it gets. D The higher you go up a mountain, the warmer it gets.
Explanation:
1. Latitude or distance from the equator – Temperatures drop the further an area is from the equator due to the curvature of the earth. In areas closer to the poles, sunlight has a larger area of atmosphere to pass through and the sun is at a lower angle in the sky.
Each element has a different:
Number of protons and electrons
Atomic mass and weight
Properties and characteristics
Number of neutrons
Select all that apply
Answer:
Your two answers are numbers of protons and electron and the second one is the atomic mass and weight.
Explanation:
God bless you are you got this
Answer:Number's 1, 2, and 4 are correct
Explanation:
Which type of change, chemical or physical, is a change on the atomic level?
Explanation:
Examples of chemical changes include, rusting, fire, and overcooking. Nuclear changes occur when the nuclei of atoms are rearranged to form new atoms. Examples of nuclear changes include atomic fission, nuclear fusion, and the energy of sun and stars.
Which best describes the changes occurring to the earth's surface over time?
1.) Mountains are gradually being worn down, but no new ones are formed
2.) New mountains are being formed as old mountains are gradually worn down
3.) More mountains are gradually formed as the oceans recede.
4.) New mountains are only formed under the oceans.
Answer:
I would say the answer is 2
The formation of new mountains due to tectonic movements is reporting now whereas, some of the olden mountains are worn down. Thus option 2 is correct.
What is tectonic movement?Earth crests is made of tectonic plates of different sizes and shapes. These plates were not apart and was one in the earlier times of earth and no separate continents were there. When heat in the atmosphere made the magma hot and the hot fluid flow makes the plate moving.
The tectonic plate movement is different in different regions and its results be different. Some movements results in the formation of mountains mostly when the plates are moving each other and one plate rise the edge of others.
Some movement results in islands, folded mountains, volcanic mountains etc. These mountains may worn down over time and there is a possibility of formation of new mountains in regions where significant plate movement occurs.
To find more about plate movement, refer the link bellow:
https://brainly.com/question/3970445
#SPJ2
What is the SI unit of mass?
Select one:
a.
Ounce
b.
Newton
c.
Pound
d.
Gram
Answer: The answer is D.gram
Explanation:
ltennelmessifcb avatar
ltennelmessifcb
45 minutes ago
Chemistry
Senior High School
You are given 600 grams of sodium chloride (NaCl), but you are planning to purify the substance and extract just the sodium. How many moles of Na can you theoretically extract from 600 grams of NaCl? Explain your reasoning.
Moles of Na theoretically extract : 10.256
Further explanationGiven
600 g of NaCl
Required
moles of Na
Solution
Na can be electrolyzed from NaCl(molten)
Na⁺ + e⁻⇒ Na
Cl⁻⇒1/2 Cl₂ + e⁻
Overall reaction :
NaCl⇒Na + 1/2 Cl₂ x2
2NaCl⇒2Na + Cl₂
mol of NaCl(MW=58.5 g/mol) :
= 600 g : 58.5 g/mol
= 10.256
From the equation, mol ratio of NaCl : Na = 2 : 1, so :
mol Na = mol NaCl = 10.256
how do the properties of a mixture explain how they can be sepetated
Answer:
Mixtures are unlike chemical compounds, because: The substances in a mixture can be separated using physical methods such as filtration, freezing, and distillation.
calculate the number of molecules in 6.4g of Sulphur (iv) oxide
Answer:
N= mass/molar mass
complete the solve
WILL GIVE BRAINEST + 500 PTS ...
1.Scientists have evidence that the universe is [expanding/shrinking].
2.Objects moving away from Earth appear [blue/red], and objects moving toward Earth appear [blue/red].
3. Light from most other galaxies appears [blue/red], which makes sense if the universe is [collapsing inward/spreading out].
Answer:
1. expanding
2. red, blue
3. red, spreading out
Explanation:
Write the following elements in increasing order of atomic radius.
Ca, Mg, Be, Sr
Answer:
In increasing order:
Sr, Ca, Mg, Br