Answer:
c. When the meniscus is between marks, estimate the reading to the nearest tenth of a division (ie, estimate to 0.01 mL if buret has 0.1 ml divisions)
Explanation:
The meniscus is the mark that a liquid presents in a pipette. This measure is important for determining the volume of a solution, allowing the correct amounts of aqueous solutions to be used. The meniscus must be observed at eye level to avoid parallax errors. In this view, the border and center of the meniscus must be considered to determine the volume.
Suggest a reason why it is desirable to use an excess of barium ion in the precipitation.
Answer:
Hello your question is poorly written hence i will give you a more general answer
answer : The reason why it is desirable to use an excess of barium ion in the precipitation is to form the compound needed,
Explanation:
Natural Precipitation occurs when condensed atmospheric water vapor falls due to the gravitational pull exerted on it by the clouds. precipitation can be in various forms like ; rain , ice pellets and snow . e.t.c
Hence the reason why it is desirable to use an excess of barium ion in the precipitation is to form the compound needed,
Also in order to form the precipitation, we will also add excess of barium ion which will help form the required precipitate and also filter out the mass of Sulphate.
Calculate the number of moles of H2SO4 required to react with 0.93 moles of Al. Do not include units in your answer. Round to the tenths place or further.
Answer:
1.40 moles of H₂SO₄.
Explanation:
We'll begin by writing the balanced equation for the reaction. This is illustrated below below:
2Al + 3H₂SO₄ —> Al₂(SO₄)₃ + 3H₂
From the balanced equation above,
2 moles of Al reacted with 3 moles of H₂SO₄.
Finally, we shall determine the number of mole of H₂SO₄ required to react with
0.93 moles of Al. This can be obtained as follow:
From the balanced equation above,
2 moles of Al reacted with 3 moles of H₂SO₄.
Therefore, 0.93 moles of Al will react with = (0.93 × 3)/2 = 1.40 moles of H₂SO₄.
Thus, 1.40 moles of H₂SO₄ is needed for the reaction.
A student sets up a box with a flashlight that shines on a mirror located at position X. Other possible locations for objects in the box are labeled A-E.
How can the student place objects in the box to have all the light from the flashlight shine back on the flashlight?
Answer:
If all the objects are placed at the same angle.
Explanation:
If all the objects are placed at the same angle so all the light from the flashlight shine comes back to the flashlight. If the A object is placed at the specific location at which the mirror X reflects the light after hitting it, then the other E object is placed at the location where the light comes after reflecting the A object then the light comes back to the flashlight if the angle between objects placement is right.
Answer:
d
Explanation:
How many moles in 2.33E25 molecules of NO?
0.0258 mol
3.87E20 mol
38.7 mol
2.58E48 mol
please show work
Answer:
0.0258 mol Answer .......
forms of energy reflection
Answer:
any of these
Explanation:
kinetic energy: kinetic is motion, or released energy
Potential energy: porential energy is the energy of position or stored energy.
Thermal energy: is heat energy, it is stored energy that creats heat.
I NEED HALPPPPPP PLEASE
Question 1 options:
instant tea
water
Question 2 options:
instant tea
water
Question 3 options:
mixture
solution
question 1 water question 2 instant tea question 3 mixture
The 50:50 mixture of aspirin (Lit. MP: 135-136 oC) and 4-bromobenzoic acid (Lit. MP: 252-254 oC) will have the melting point in the range of:______.
Answer:
193.5-195 °C.
Explanation:
Hello!
In this case, since the mixture is 50:50, we can infer that an average may be used to compute the required range; thus, we first compute the the inner limit by using 135 °C and 252 °C:
[tex]\frac{135+252}{2} =193.5\°C[/tex]
And the upper limit:
[tex]\frac{136+254}{2} =195\°C[/tex]
Thus, the average melting point would be around 193.5-195 °C.
Best regards!
Which word best describes the relationship between polyps and algae
exoskeletal
Bleached
Photosynthetic
Symbiotic
Answer:
symbiotic
Explanation:
There like a close friendship
Calculate how many grams of BeCl2 are required to produce 0.52 grams of MnCl2
Answer:
65.0cp
Explanation:
looking at the pure subtances :water,oxygen,copper, can you tell by looking at them if it is pure or not ? explain your answer using example...
Answer:
Yes water is a pure, Water, H2O, is a pure substance, a compound made of hydrogen and oxygen. Although water is the most abundant substance on earth, it is rarely found naturally in its pure form. Most of the time, pure water has to be created. Pure water is called distilled water or deionized water.
Oxygen is a chemical element – a substance that contains only one type of atom. Its official chemical symbol is O, and its atomic number is 8, which means that an oxygen atom has eight protons in its nucleus. Oxygen is a gas at room temperature and has no colour, smell or taste
Usually by pure substances we mean either pure elements (all one type of atom), regular crystals (atoms arranged in a repeating pattern), or things made of only one type of molecule (a tightly bound structure of one or more types of atoms). So copper is a pure substance in any form (only copper atoms).
What is the major organic product obtained from the reaction of 2,2-dimethyl-1-propanol aqueous HBr at reflux
Answer:
See explanation
Explanation:
The mechanism involves SN1 nucleophilic substitution reaction. The -OH group of the alcohol is first protonated. Since water is a good leaving group, -OH2 leaves the substrate creating a primary carbo cation.
A 1,2 methyl shift now occurs to create a tertiary carbo cation which is more stable leading to the major product shown in the image attached to this answer.
Scientists classify rocks mainly according to which feature?
their color
how they form
their hardness
where they are found
Ethical Behavior Worksheet Situation 1. You are taking a very difficult chemistry course, which you must pass to maintain your scholarship and to avoid damaging your application for graduate school. Chemistry is not your strong suit, and, because of a just-below-failing average in the course, you will have to receive a grade of 90 or better on the final exam, which is two days away. A janitor, who is aware of your plight, informs you that he found the master for the chemistry final in a trash barrel and has saved it. He will make it available to you for a price, which is high but which you could afford. What would you do?
Answer:
I would not accept it.
Explanation:
Although it is tempting to accept the janitor's offer and save the scholarship, which is not easy to get, I would not accept his offer, as I do not believe in victories based on dishonesty and would be heavy on conscience if I did the opposite. Obviously, I would not like to lose my scholarship and for that reason, I would look for other ways that would be honest and help me improve my grade. If I could not improve and lose the scholarship, I would be extremely sad, but I would be at peace with my conscience.
In the morning, a paintball pressure tank is at 306 atm. The weather heats up over the
course of the day, and by 3 PM, the outside temperature is roasting at 38.5°C, and the
pressure inside the tank is 324 atm. What was the temperature (in degree Celsius) in the
morning?
3. Noble gases are sometimes called "inert gases." What can you infer about the meaning of the word "inert" in chemistry?
Answer:
Noble gases are sometimes called "inert gases." What can you infer about the meaning of the word "inert" in chemistry? It refers to substances that easily lose electrons. It refers to substances that do not react with other substances. It refers to substances that have strong electrochemical charges.
Explanation:
A) Suppose you separate a 3.02 g mixture of sand and salt. You recover 1.43 g of salt and 1.41 g of sand. What is the percent recovery of the mixture?
B) Suppose you separate a 3.02 g mixture of sand and salt. You recover 1.43 g of salt and 1.41 g of sand. What is the percent recovery of the mixture?
C) Calculate the percent by mass of a solution made from 15 g NaCl (the solute) and 69 g water.
D) What percent of 73.0 g is 26.1 g?
Answer:
A-B) 94 %.
C) 17.9 %.
D) 35.8 %.
Explanation:
Hello!
A-B) In this case, since the total mass of the mixture is 3.02 g and 1.43g+1.41g=2.84 g are recovered in total, we can compute the percent recovery as shown below:
[tex]\%rec=\frac{2.84g}{3.02g}*100\%\\\\\%rec=94\%[/tex]
C) Here, since the solution is made up of NaCl and water, we can say that the mass of the solution is 15g+69g=84g; thus, the percent by mass would be:
[tex]\%=\frac{15g}{84g}*100\%\\\\\%=17.9\%[/tex]
D) In this case, we simply divide 26.1 g by 73.0 g in order to obtain the percent:
[tex]\%=\frac{26.1g}{73.0g}*100\%\\\\\%=35.8\%[/tex]
Best regards!
The percentage in the cases are as follows;
A and B is; 94%C is; 17.9%D is; 35.8%Questions A and B are similar and can be solved as follows;
The total mass of the mixture is 3.02g.The recovered mass = 1.43g + 1.41g = 2.84g% recovery = (2.84/3.02) × 100%% recovery = 94%Question C can be solved as follows;
Total mass of solution = 15 + 69 = 84gMass of solute = 15g% by mass = (15/84) × 100%% by mass = 17.9%Question D can be solved as follows;
% = (26.1/73) × 100%% = 35.8%Read more:
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What a main difference between Earth and Jupiter?
A. Earth is an inner planet with a solid rock surface composition, while Jupiter is an outer planet with a gas surface composition.
B. Earth is an inner planet with a relatively long distance from the sun, while Jupiter is an outer planet with a relatively short distance from the sun.
C. Earth is an outer planet with a gas surface composition, while Jupiter is an inner planet with a solid rock surface composition.
D. Earth is an outer planet with a relatively short distance from the sun, while Jupiter is an inner planet with a long distance from the sun.
Answer: A. Earth is an inner planet with a solid rock surface composition, while Jupiter is an outer planet with a gas surface composition.
Answer: What a main difference between Earth and Jupiter?
Earth is an inner planet with a solid rock surface composition, while Jupiter is an outer planet with a gas surface composition.
Earth is an inner planet with a relatively long distance from the sun, while Jupiter is an outer planet with a relatively short distance from the sun.
Earth is an outer planet with a gas surface composition, while Jupiter is an inner planet with a solid rock surface composition.
Earth is an outer planet with a relatively short distance from the sun, while Jupiter is an inner planet with a long distance from the sun.
Explanation:
Please balance the equation, putting the correct coefficient in each box.
Do not leave any boxes blank! Enter "1" for formulas having a presumed
coefficient of 1.
Bi(OH)3 +
HNO3 →
H2O +
Bi(NO3)3
Answer: [tex]Bi(OH)_3+3HNO_3\rightarrow 3H_2O+Bi(NO_3)_3[/tex]
Explanation:
According to the law of conservation of mass, mass can neither be created nor be destroyed. Thus the mass of products has to be equal to the mass of reactants. The number of atoms of each element has to be same on reactant and product side. Thus chemical equations are balanced.
The balanced equation will be:
[tex]Bi(OH)_3+3HNO_3\rightarrow 3H_2O+Bi(NO_3)_3[/tex]
How to set up the rate expressions for the following mechanism?
A → B k1
B → A k2
B+C → D k3
If the concentration of B is small compared with the concentrations of A, C, and D, the steady-state approximation may be used to derive the rate law. Derive the rate law, and show that this reaction may follow the first-order equation at high pressures and the second-order equation at low pressures.
Answer:
Explanation:
From the given information:
A → B k₁
B → A k₂
B + C → D k₃
The rate law = [tex]\dfrac{d[D]}{dt}=k_3[B][C] --- (1)[/tex]
[tex]\dfrac{d[B]}{dt}=k[A] -k_2[B] -k_3[B][C][/tex]
Using steady-state approximation;
[tex]\dfrac{d[B]}{dt}=0[/tex]
[tex]k_1[A]-k_2[B]-k_3[B][C] = 0[/tex]
[tex][B] = \dfrac{k_1[A]}{k_2+k_3[C]}[/tex]
From equation (1), we have:
[tex]\mathbf{\dfrac{d[D]}{dt}= \dfrac{k_3k_1[A][C]}{k_2+k_3[C]}}[/tex]
when the pressure is high;
k₂ << k₃[C]
[tex]\dfrac{d[D]}{dt} = \dfrac{k_3k_1[A][C]}{k_3[C]}= k_1A \ \ \text{first order}[/tex]
k₂ >> k₃[C]
[tex]\dfrac{d[D]}{dt} = \dfrac{k_3k_1[A][C]}{k_2}= \dfrac{k_1k_3}{k_2}[A][C] \ \ \text{second order}[/tex]
Using the van der Waals equation, determine the pressure exerted by 4.30 mol Ar in 3.6 L at 325K.
Answer:
37.7 atm
Explanation:
Using the relation;
(P + an^2/V^2) (V - nb) = nRT
(P + an^2/V^2) = nRT/(V - nb)
a = 0.0341 atm dm^2 Mol^2
b = 0.0237 dm/mol
P = nRT/(V - nb) - an^2/V^2
P = [4.3 * 0.082 * 325 / (3.6 - (4.3 * 0.0237))] - (0.0341 * (4.3^2))/(3.6^2)
P = 114.595/(3.498) - 0.0487
P = 37.7 atm
when you hear organic what does it mean?
Answer:
The word “organic” refers to how a food is grown. ... However, without preservatives and fewer chemicals than regular produce, you might notice that organic foods taste fresher.
Answer:
The phrase hear, hear seems to have come into existence as an abbreviation of the phrase hear him, hear him, which was well-established in Parliament in the late seventeenth century. ... When you say hear, hear, you are in fact saying that you agree with something another person has just said.
Explanation:
hope it's help you
What is the difference between an introduced species and an invasive species?
Answer and Explanation:
The introduced species is, literally, a species that was introduced into an environment by human action. In other words, an introduced species is one that is not native to a region, does not occur naturally, but has been taken by humans to that region.
An invasive species, on the other hand, is one that was introduced naturally in an environment, but multiplied in a harmful way, causing a strong imbalance in the region.
1. What is the frequency of the following:
a. radio waves with wavelength 50 m?
b. gamma-ray with a wavelength of 45 m?
2.What is the wavelength of the following?
a. infrared light with frequency of 3 .5x 10° Hz?
b. ultraviolet light with frequency of 4.0x 10 * Hz
Answer:
its soooooo ezy
Explanation:
82828I 87is 818373773622771829383746171948468328933737373737378364737272828374736367181i3i46738100104848070792761527484930201834728the 8585949476425675666
Perform the following
mathematical operation, and
report the answer to the
appropriate number of
significant figures.
653.12 + 12.10247 = [?
Answer:
665.22
Explanation:
you see wich numbers after the decimal points have the least numbers, the one with the least u have to round your answer to that
After performing the required mathematical operation (addition), the answer is equal to 665.22.
What are significant figures?In Mathematics, significant figures can be defined as the number of single digits or numerical values in the coefficient of a mathematical expression that are important and meaningful.
Since "653.12" has two (2) significant figures, we must ensure that 12.10247 also has two (2) significant figures as follows:
12.10247 to 2 S.F = 12.10.
Next, we would perform the required mathematical operation (addition):
653.12 + 12.10 = 665.22.
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What is the apparent bond energy of a carbon–sulfur bond in cos?
This question is incomplete, the complete question is;
The enthalpy change for the reaction between two molecules of carbon oxysulfide (COS) to form one molecule of CO₂ and one molecule of CS₂, as shown below, is -3.2 x 10⁻²⁴ kJ per molecule of COS.
The bond energy for the C-S bond in C=S has been determined to be 552 kJ/mol.
What is the apparent bond energy of a carbon-sulfur bond in COS?
NOTE: A C=O bond adjacent to another double bond is not the same as a C=O bond that is not adjacent to another double bond.
Answer:
The apparent bond energy of a carbon–sulfur bond is 550.1 kJ/mole
Explanation:
Given the data in the question and the figure 8.122 in the image below;
the given reaction can be written as follows;
2COS -----→ CO₂ + CS₂
Δ[tex]H_{rxn}[/tex] = ∑ Bond Energy ( reactants) - ∑ Bond Energy (products)
= [ (2 × C=O) + (2 × C=S) ] - [ (2 × C=O) + ( 2 × C=S) ]
we know that;
Δ[tex]H_{rxn}[/tex] = -3.2 x 10⁻²⁴ kJ per molecule
= -3.2 x 10⁻²⁴ kJ × 2 × 6.023 × 10²³ kJ/mole
= -3.85 kJ/mole
Hence;
-3.85 kJ/mole = (2 × C=S)[tex]_{reactant}[/tex] - ( 2 × C=S)[tex]_{product}[/tex]
-3.85 kJ/mole = (2 × C=S)[tex]_{reactant}[/tex] - ( 2 × 552 kJ/mole)
(2 × C=S)[tex]_{reactant}[/tex] = -3.85 kJ/mole + 1104 kJ /mole
(2 × C=S)[tex]_{reactant}[/tex] = 1100.15 kJ/mole
2 × ( C=S)[tex]_{reactant}[/tex] = 1100.15 kJ/mole
( C=S)[tex]_{reactant}[/tex] = 1100.15 kJ/mole / 2
( C=S)[tex]_{reactant}[/tex] = 550.1 kJ/mole
Therefore, the apparent bond energy of a carbon–sulfur bond is 550.1 kJ/mole
The apparent bond energy of a carbon-sulfur bond in COS is equal to 550.08 kJ/mol.
Given the following data:
Enthalpy change of reaction = [tex]-3.2 \times 10^{-24}\;kJ/mol.[/tex]Bond energy of C=S = 552 kJ/mol.Scientific data:
Avogadro's number = [tex]6.02 \times 10^{23}[/tex]To determine the apparent bond energy of a carbon-sulfur bond in COS:
First of all, we would write a balanced chemical equation for the chemical reaction as follows:
[tex]2COS \rightarrow CO_2 + CS_2[/tex]
The enthalpy change of two (2) moles of COS is:
[tex]\Delta H_{rxn} = -3.2 \times 10^{-24}\times 2 \times 6.02 \times 10^{23}\\\\\Delta H_{rxn} =-3.85\;kJ/mol.[/tex]
Mathematically, the enthalpy change of a chemical reaction is given by this equation:
[tex]\Delta H_{rxn} = \sum Bond\;Energy_{(reactansts)} - \sum Bond\;Energy_{(products)}\\\\\Delta H_{rxn} = [(2\times C=O)+ (2\times C=S)]- [(2\times C=O)+ (2\times C=S)][/tex]
Substituting the parameters into the equation, we have;
[tex]-3.85 = (2\times C=S)- [2\times 552]\\\\(2\times C=S)=1104-3.85\\\\(2\times C=S)=1100.15\\\\(C=S)=\frac{1100.15}{2} \\\\(C=S)=550.08\;kJ/mol[/tex]
Therefore, the apparent bond energy of a carbon-sulfur bond in COS is equal to 550.08 kJ/mol.
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Complete Question:
The enthalpy change for the reaction between two molecules of carbon oxysulfide (COS) to form one molecule of [tex]CO_2[/tex] and one molecule of [tex]CS_2[/tex], as shown below, is [tex]-3.2 \times 10^{-24}[/tex] kJ per molecule of COS. The bond energy for the C-S bond in C=S has been determined to be 552 kJ/mol. What is the apparent bond energy of a carbon-sulfur bond in COS?
[Note: A C=O bond adjacent to another double bond is not the same as a C=O bond that is not adjacent to another double bond.]
Consider the reaction 2H2(g)+O2(g)→2H2O(l) 2 H 2 ( g ) + O 2 ( g ) → 2 H 2 O ( l ) What is the mass of water, H2O(l) H 2 O ( l ) , produced when 5.70 g g of O2(g) O 2 ( g ) reacts with excess H2(g) H 2 ( g ) ?hen 5.70 g g of O2(g) O 2 ( g ) reacts with excess H2(g) H 2 ( g ) ?
Answer:
mH₂O = 6.4116 g
Explanation:
Let's write the given reaction:
2H₂ + O₂ -------> 2H₂O
The problem states that 5.7 g of oxygen reacts with excess hydrogen, hence, the limiting reagent is the oxygen. With this mass of oxygen, we can determine the moles, and then, the moles of water with the mole ratio:
moles = mass / atomic weight AW of O₂ = 16 g/mol
Replacing we have:
moles O₂ = 5.70 / (16 * 2)
moles O₂ = 0.1781 moles
According to the balanced reaction, 1 mole of Oxygen produces 2 moles of water, so we have a mole ratio 1:2, therefore the moles of water would be twice the moles of oxygen:
moles H₂O = 0.1781 * 2 = 0.3562 moles
Finally the mass of water can be calculated solving for the mass from the expression of moles, and using molecular mass of water:
m = moles * MM MM H₂O = 18 g/mol
m = 0.3562 * 18
mH₂O = 6.4116 gHope this helps
Rank the following compounds in order of increasing stability, putting the least stable first. Group of answer choices II < I < III I < II < III III < II < I III < I < II
Hello. You forgot and show the compounds. The compounds are in the attached image.
Answer:
I < II < III
Explanation:
The stability of the presented compounds must be analyzed, taking into account the free electrons to form arrangements between the atoms. In this case, the molecules of greater stability follow the concept of valence and are characterized as those that manage to reach a large number of elements that manage to obey the octet rule.
Question 6 of 25
When nonionizing radiation is absorbed by matter, it usually becomes which
type of energy?
A. Thermal
B. Mechanical
C. Electromagnetic
O D. Chemical
Answer:
thermal
Explanation:
a p e x
How many electrons were transferred if the total charge of a process is 929.5 C?
Answer:
5746.25×e.
Explanation:
The electron is known as the subatomic particle which revolves around the nucleus by possessing the negative charge.
when the atoms are involved in the reaction or process these electrons are transferred are gained by the atoms.
Coulomb is the term used to express the charge of the electrons.
In normal 1 coulomb of charge possess 6.25× electrons.
So here the total charge of the process is 919.4c in order to find number of electrons transferred is found by the product of 919.4 × 6.25× = 5746.25 × .
Thus the number of electrons transferred is obtained. the transferred electrons are 5746.25 ×.
Question 8 of 25
What is alchemy?
O A. A scientific approach to research that uses observations and
measurements to test ideas
O B. An early form of chemistry that people used to try to turn metal
into gold
O c. A belief that chemistry forms the basis of all areas of science
O D. An ancient philosophy that taught that all matter was composed
of earth, fire, water, and air
SUBMIT
Alchemy is "an early form of chemistry that people used to try to turn metal into gold".
The development of a universal cure for illness, as well as the discovery of a way to indefinitely extend life, were the goals of mediaeval chemical research and speculative philosophy.
Boyle contributed to the evolution of chemistry from alchemy. He used the experimental approach from physics and applied it to chemistry. Boyle contributed to the comparison of these two fields of knowledge by demonstrating that chemistry is just as important to study as physics.
Therefore, the correct statement will be "An early form of chemistry that people used to try to turn metal into gold".
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