Answer:
4.5425806678891E+22mol
Explanation:
ou dissolve a 2.50 g penny in 50.0 mL of HNO3. After reacting overnight, you dilute the blue solution to a volume of 100 ml. You test a sample of this solution, and find that it has an absorbance of 0.12 abs at 635 nm. i Calculate the concentration of Cu
This question is describing an spectrophotometry experiment in which the concentration of copper(II) ions has to be determined when 2.50 g of a copper-rich penny is reacted with 50.0 mL of nitric acid. In addition, the absorbance of a sample of the solution turned out to be 0.12 at 635 nm, so that the concentration was estimated as 12.8 g/L.
First of all, we must recall the Beer's law that can be written as follows:
[tex]A=ebC[/tex]
Whereas A is the absorbance of the sample, e the molar absorptivity, b the cuvette's path and C the concentration. However, this problem is not providing sufficient information to calculate the required concentration, however, similar absorbance experiments have graphed (absorbance vs concentration) calibration curves exhibiting trendlines as the one shown below:
[tex]y=0.009647x-0.003655[/tex]
Thus, since y stands for the absorbance and x for the concentration but in g/L not M (mol/L) for those experiments, we can set y equal to 0.12 so we solve for x as the concentration of the copper(II) ions in the sample:
[tex]y=0.009647x-0.003655\\\\x=\frac{0.12+0.003655}{0.009647}\\\\x=12.8g/L[/tex]
Nevertheless, it would be great if you come up with your own trendline, having clear the units for the absorbance vs concentration graph and thus double check your results because the data was not enough for the time being.
Learn more:
(Beer's law and trendlines) https://brainly.com/question/5093710(Spectrophotometry) https://brainly.com/question/14467788please explain me answer a b c d
Answer:
I don't know the answers of chemistry if you have an entrance question of maths so I can
[tex]\rule{2000pt}{1000000pt}[/tex]
What is the role of starch in the titration reaction?
Answer:
Starch reacts with Iodine in the presence of Iodide ion to form an intensely colored blue complex, which is visible at very low concentrations of Iodine, making it a very good indicator in both direct and indirect lodometric titrations.
Explanation:
hope this helps
Help asap plzzzzz!!!!!!!!!!!!!
Answer:
Water will generally require more energy for a phase change compared to a similar substance without hydrogen bonds.
Explanation:
Need ASAP will give brainlist
Answer:
i think the answer will be C.
Explanation:
correct me if im wrong
loveya
In general, people of __ heritage will be the last to get
white hair.
Answer:
African?
Explanation:
why lysine is less basic than arginine
Answer:
Arginine is the most basic among them because it contains guanidine side group, −(CH2)4NHC(=NH)NH2, which is basic. Lysine has two amine groups, which makes it overall basic because of the second isolated amine group (−(CH2)4NH2). Histidine, on the other hand, contains imidazole group, which is also basic.
Explanation:
hope this helps
if its helps please please please please please please please reply
What are the five different types of leaves? Subject: science
Answer:
Needle and Scale Leaves. This kind of leaves are mostly found in 'evergreen' trees. ...
Lanceolate Leaf. ...
Oblong Leaf. ...
Linear Leaves. ...
Cordate Leaves.
Explanation:
Answer:
Broad
Flat Leaves.
Needle and Scale Leaves.
Oblong Leaf.
Cordate Leaves.
Explanation:
what percentage of oxygen is attributed fossil fuel combustion
A.43%
B.77%
C.4%
D.17%
Answer:
C. 4%
Explanation:
The answer is 4%
Chlorine is a halogen and has 7 valence electrons, which is represented by crosses on the left
and dots on the right. You'll notice that their orbitals are overlapping and it looks almost like a
Venn Diagram. How many electrons are in the overlapping region?
There are 2 electrons in the overlapping region.
Chlorine is the second member of the halogen group which are form of family of elements that resemble one another very closely.
The electronic configuration of chlorine shows the arrangement of chlorine electrons within it's atom.
At the outer most shell of the atom is seven electrons, therefore requires only one electron each to attain the octet arrangement.
The overlapping of the orbitals indicates the chemical bond formed by sharing of electrons between atoms called covalent bonding.
To complete it's outer most shell, it will need to share electron with another chlorine atom.
Therefore, there are 2 electrons in the overlapping region.
Learn more here:
https://brainly.com/question/16396974
What is chlorine iodine ?
Answer:
Chlorine Iodine is a compound made out of one Chlorine molecule and one Iodine molecule
Explanation:
How do you out pizza the hut?
The store paid 4.50 for a book and sold it for $7.65.what is the profit as a percent of the cost to the store? A. 3. 15% b. 58.8% c. 70% d. 315%
Answer: This would be C.) 70%
Explanation:
Select True or False: The entropy of a perfectly ordered crystalline substance at 0 K is 0 J/mol. Bloom's Level: Understand
True, the entropy of a perfectly ordered crystalline substance at 0 K is 0 J/mol.
The third law of thermodynamics states that, the entropy of a system approaches a constant value as the temperature of the system approaches absolute zero.
The entropy of any perfectly ordered, crystalline substance at absolute zero temperature is zero. That is, the entropy of a pure, perfect crystalline substance at 0 K is 0 J/K.
Thus, we can conclude that the given statement is true. The entropy of a perfectly ordered crystalline substance at 0 K is 0 J/mol.
Learn more about third law of thermodynamics here: https://brainly.com/question/1156831
. What is meant by periodic in Periodic Table?
a. the table has b. the elements
repeated cycles occur more than
once
c. the table is only d. the table can be
good for so long changed as
needed
Answer:
B
Explanation:
Periodic refers to properties that repeat at certain intervals. Click to see full answer. In respect to this, what does periodic mean in the term periodic table? In the context of chemistry and the periodic table, periodicity refers to trends or recurring variations in element properties with increasing atomic number.
How many carbon atoms are in 11.2 ML of C3H6O
1 mL = 0.815 g
11.2 mL = X
X = 11.2 × 0.815
= 9.128 g
mole = 9.128/58
= 0.157 mole
1 mole = 6.02 × 10^23 atoms
0.157 mol = x
X = 0.157/1 × 6.02 × 10^23
= 9.451 × 10^22 atoms of C
please to recheck answers to ensure they are correct
I really hope this helps
In the chemical stockroom, there is a 0.500 L bottle filled with 2.30 M CuSO4 solution. How many moles of CuSO4 are in the bottle?
A. 0.217 moles
B. 4.60 moles
C. 01.15 moles
D. 1.80 moles
The number of moles of the solute in the solution is the product of its volume and molarity. The number of moles of copper sulphate in 0.500 L of 2.30 M solution is 1.15 moles.
What is molarity?Molarity of a solution is the common term used to represent the concentration of a solution. It is the ratio of its number of moles of solute to the volume of solution in liters.
Molarity = no.of moles/volume in L.
Molarity is a temperature dependant quantity.
The given solution has a volume of 0.500 L.
molarity of copper sulphate solution = 2.30 M
Thus, number of moles of copper sulphate solute dissolved in 0.50 L of water is calculated by multiplying the volume with molarity.
No. of. moles of copper sulphate = molarity × volume
= 0.500 L × 2.30 M = 1.15 moles.
Therefore, there will be 1.15 moles of copper sulphate in the solution.
To find more on molarity, refer here;
https://brainly.in/question/9793108
#SPJ2
what is the result of collisions of particles with an object? *
A. pressure on the object
B. pressure away from the object
C. the object gets lighter
D. the object gets heavier
Answer:
Particle collisions cause pressure.
Explanation:
The fast motion of gas particles gives them a relatively large amount of kinetic energy. Recall that kinetic energy is the energy that an object possesses because of its motion. The particles of a gas move in straight-line motion until they collide with another particle or with one of the walls of its container.
If you add the same amount of heat to two different substances, will they both change phase?
Answer:
It depends on their melting and/or their boiling points, because the heat provides the particles with kinetic energy to break the electrosatic bonds in the substances, which can differ in strength
Explanation:
Sound travels from a phone speaker to the ear of the person listening to the call. Sound waves are modeled by the image below. 1) What do the dots in the image represent? 2) How do sound waves travel through air to a person’s ear?
Answer:
Remember the black and red dots represented in the below animation are not molecules. They are just markers enabling us to visualize the local displacement of air particles and so, the rise and fall of pressure within the wave medium.
The air is made up of many tiny particles. When sound is created, the air particles vibrate and collide with each other, causing the vibrations to pass between air particles. The vibrating particles pass the sound through to a person's ear and vibrate the ear drum. Light travels much faster than sound through air.
Explanation:
How many K are in 32 o C?
Answer:
273.15 Kelvins
Explanation:
Hope this helps !!!
PLEASE HELP ME!!
The molar mass of BF3 is 67.81 g/mol. How many molecules of BF3 are there in 2 g? (1 point)
A) 1.776 x 1022
B) 8.881 x 1021
C) 1.204 x 1024
D) 4.084 x 1025
Answer:
A
Explanation:
We are given that the molar mass of boron triflouride BF₃ is 67.81 g/mol. We want to determine the number of molecules of BF₃ in 2 g of BF₃.
Recall that there are 6.02 × 10²³ molecules in any mole of a substance. In other words, there are 6.02 × 10²³ BF₃ molecules in a mole of BF₃. Starting with the initial value, multiply:
[tex]\displaystyle \begin{aligned} 2\text{ g BF$_3$}&\cdot \frac{1\text{ mol BF$_3$}}{67.81 \text{ g BF$_3$}} \cdot \frac{6.02\times 10^{23} \text{ molecules BF$_3$}}{1 \text{ mol BF$_3$}} \\ \\ &= 1.776 \times 10^{22} \text{ molecules BF$_3$}\end{aligned}[/tex]
Hence, our answer is A.
*Perhaps it rendered the values incorrectly, but since we started with only 2 g of BF₃, our resulting calculation should only contain one significant digit. Hence, the correct answer should be 2 × 10²² molecules of BF₃.
The molecules of BF₃ that are there in 2 g is 1.776 × 10²² molecules and the correct option is option A.
The mole is an amount unit similar to familiar units like pair, dozen, gross, etc. It provides a specific measure of the number of atoms or molecules in a bulk sample of matter.
A mole is defined as the amount of substance containing the same number of atoms, molecules, ions, etc. as the number of atoms in a sample of pure 12C weighing exactly 12 g.
Given,
Molar mass of BF₃ = 67.81 g/mol
Mass = 2g
Moles = mass / molar mass
= 2 / 67.81
= 0.029 moles
1 mole = 6.023 × 10²³
0.029 moles = 6.023 × 10²³ × 0.029
= 1.776 × 10²² molecules
Thus, the ideal selection is option A.
Learn more about Moles, here:
https://brainly.com/question/15209553
#SPJ6
whats a covalent bond ?
Answer:
A covalent bond is a chemical bond that involves the sharing of electron pairs between atoms. These electron pairs are known as shared pairs or bonding pairs, and the stable balance of attractive and repulsive forces between atoms, when they share electrons, is known as covalent bonding.
Answer:
A covalent bond is the “interatomic linkage that results from the sharing of an electron pair between two atoms.”
Explanation:
Hope this helps have a nice day
Which line of evidence has been traditionally accepted as conclusive proof of evolution? the presumed age of the Earth the fossil record Darwin's treatise on the Origin of the Species absolute dating of rocks
The most generally accepted form of conclusive evidence for the theory of Evolution is the fossil record.
What is the theory of Evolution?The theory of evolution was proposed by Charles Darwin.It states that as time passes, organisms evolve to better adapt to their environments.This is closely related to natural selection, which is considered a driving force of evolution. How the fossil record supports this theoryThe fossil record provides essential data to support this claim.The data comes in the form of the comparison between fossils of two closely related organisms, separated by a matter of generations, that present changes in the genetic code that made them more apt for survival.Therefore, we can confirm that the most generally accepted form of conclusive evidence for evolution is the presence of fossils that show the genetic correlation between two organisms and the progression of evolution between them.
To learn more about evolution visit:
https://brainly.com/question/2725702?referrer=searchResults
_265Hs--->_16O+_9Be=_____?
Answer:
265hs+24.464536b+16o
Explanation:
265hs+16o+9b(2.718282)
=265hs+16o+24.464536b
=265hs+24.464536b+16o
2. In which state of matter do particles vibrate in place? *
1 point
A. gas
B. solid
C. liquid
solid.................
Answer:
b solid
Explanation:
i know for a fact
1. Here is a chemical equation: C2H2 + O2 → CO2 + H2O
• A Balance this chemical equation.
• B State what type of chemical reaction this is.
• C What will happen during this reaction besides just CO2 and H2O being released.
• D Discuss how your balanced chemical equation agrees with the law of conservation of mass.
2. Balance each of the reactions listed below. What type of reactions are they? Single-displacement, double-displacement, synthesis, decomposition, or combustion reaction.
• A Na + Cl2 → NaCl
• B Fe + O2 → FeO
Answer:
1) a) 2 C2H2 + 3O2 --> 2CO2 + 2H2O
b) Combustion Reaction
c) Bonds will be broken on the reactant side which will require energy.
d) It agrees with the law of conservation of mass because there are the same amount of molecules of each element on both sides of the equation, meaning mass was not created nor destroyed.
2) a) 2Na + Cl2 --> 2NaCl
Synthesis
b) 2Fe + O2 --> 2FeO
Synthesis
Hope this helps!
Explanation:
To calculate the atoms of an element in a given molecule, we need to multiply stoichiometry by the number that is written on the foot of that element. Therefore, the balanced equation is
2 C[tex]_2[/tex]H[tex]_2[/tex]+ 3O[tex]_2[/tex] [tex]\rightarrow[/tex] 2CO[tex]_2[/tex]+ 2H[tex]_2[/tex]O
What is Balanced equation?Balanced equation is the one in which the total number of atoms of a species on reactant side is equal to the total number of atoms on product side. The mass of the overall reaction should be conserved. There are so many types of chemical reaction reaction like combination reaction, displacement reaction.
a) 2 C[tex]_2[/tex]H[tex]_2[/tex]+ 3O[tex]_2[/tex] [tex]\rightarrow[/tex] 2CO[tex]_2[/tex]+ 2H[tex]_2[/tex]O is the balanced equation
b)Reaction is a Combustion Reaction
c) energy is required for the breaking of bond.
d) It agrees with the law of conservation of mass as the number of atoms of each element on reactant and product side is same.
Therefore, the balanced equation is
2 C[tex]_2[/tex]H[tex]_2[/tex]+ 3O[tex]_2[/tex] [tex]\rightarrow[/tex] 2CO[tex]_2[/tex]+ 2H[tex]_2[/tex]O
Learn more about the balanced equation, here:
https://brainly.com/question/7181548
#SPJ2
1. In a heterogeneous mixture, the substances
A. can be physically separated.
B. are chemically combined.
C. can only be separated through chemical
processes.
D. break down into new substances.
Please answer
Producers are the most numerous group in an ecosystem. Why?
-------------------------------------------------------------------------------------------------
Producers produce food energy for themselves and all the other levels. ⬜
Soil and temperature conditions in an ecosystem always favor producers. ⬜
As energy flows through the ecosystem, some energy is added at each step. ⬜
There is more room for small organisms than there is for large ones. ⬜
Answer:
The primary producer uses some of that energy. Because we lose energy each time we move up a trophic level, we have more producers than consumers, more herbivores than carnivores, more primary consumers than secondary consumers. See this Socratic answer for more detail.
Explanation:
Answer:
Producers produce food energy for themselves and all the other levels
Explanation:
why is extra vitamin C excreted in urine from the body but vitamin A in excess is retained in the body
Answer:
Vitamin C is water-soluble and not stored in your body
In contrast to fat-soluble vitamins, water-soluble vitamins do not get stored within the body. Instead, the vitamin C that you consume gets transported to your tissues via body fluids, and any extra gets excreted in urine ( 1 ).
Answer:
The reason vitamin C isn't stored well is because your body can't make it, and vitamin C is a water-soluble vitamin. This means it dissolves in water, and what your body doesn't use right away is excreted through urine. Thus, it is not stored in our body to a significant extent.
Explanation: