Answer:
The material properties of nanostructures are different from the bulk due to the high surface area over volume ratio and possible appearance of quantum effects at the nanoscale. ... Yu; they found that the structural distortions on the quantum dots depend both on the kind of dopant and on the size of the dots.
Explanation:
hope it helps
How do forces between particles in gases compare to forces in the other states of matter?
The forces in gases are weaker than forces in solids and liquids.
Because they have more kinetic energy that overcomes the force of attraction.
Gaseous methane will react with gaseous oxygen to produce gaseous carbon dioxide and gaseous water . Suppose 9.6 g of methane is mixed with 64.9 g of oxygen. Calculate the maximum mass of water that could be produced by the chemical reaction. Round your answer to significant digits.
Answer:
21.6 g
Explanation:
The reaction that takes place is:
CH₄ + 2O₂ → CO₂ + 2H₂OFirst we convert the given masses of both reactants into moles, using their respective molar masses:
9.6 g CH₄ ÷ 16 g/mol = 0.6 mol CH₄64.9 g O₂ ÷ 32 g/mol = 2.03 mol O₂0.6 moles of CH₄ would react completely with (2 * 0.6) 1.2 moles of O₂. As there are more O₂ moles than required, O₂ is the reactant in excess and CH₄ is the limiting reactant.
Now we calculate how many moles of water are produced, using the number of moles of the limiting reactant:
0.6 mol CH₄ * [tex]\frac{2molH_2O}{1molCH_4}[/tex] = 1.2 mol H₂OFinally we convert 1.2 moles of water into grams, using its molar mass:
1.2 mol * 18 g/mol = 21.6 gWhich diagram correctly depicts the trend in electronegativity?
a.
b.
c.
d.
The electronegativity increases across the period and decreases down the group. Thus, option B is correct.
Electronegativity can be defined as the tendency of an atom to gain or attract an electron. The electronegativity has been dependent on the size of the atom, as well as the atomic number and valence electrons.
The atom with the requirement of a less number of atoms to complete its octet can easily gain the electron and thereby have high electronegativity. The atomic size also plays a role in the electronegativity of the atom.
The atom with a bigger size has the lesser force of attraction from the nucleus and thus has difficulty attracting the electron, however, the smaller size atom can easily attract the electron with the attraction force from the nucleus.
Thus, the elements with smaller sizes and a high number of valence electrons are more electronegative. In the periodic table, on moving from left to right the valence electrons increase, thus the electronegativity increases.
On moving down the group, the element size increase, thus the electronegativity decreases down the group.
The electronegativity increases across the period and decreases down the group. Thus, option B is correct.
For more information about electronegativity, refer to the link:
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Which factors would increase the rate of a reaction?
1. Lowering the temperature
II. Increasing the concentration of readiants
JUL. Adding a catalyst
I and
Oland
O only
I only
Tony
Next
Adding a catalyst would increase the rate of a reaction
How many moles of hydrogen are in the sample?
Round your answer to 4 significant digits.
Answer:
1.56 mol H₂
Explanation:
Mg₃(Si₂O₅)₂(OH)₂
There are 4 Si moles per Mg₃(Si₂O₅)₂(OH)₂ mol. With that in mind we can calculate how many Mg₃(Si₂O₅)₂(OH)₂ moles are there in the sample, using the given number of silicon moles:
3.120 mol Si * [tex]\frac{1molMg_3(Si_2O_5)_2(OH)_2}{4molSi}[/tex] = 0.78 mol Mg₃(Si₂O₅)₂(OH)₂Then we can convert Mg₃(Si₂O₅)₂(OH)₂ moles into hydrogen moles, keeping in mind that there are 2 hydrogen moles per Mg₃(Si₂O₅)₂(OH)₂ mol:
0.78 mol Mg₃(Si₂O₅)₂(OH)₂ * 2 = 1.56 mol H₂Identify the type of reaction in the chemical reaction below:
2 P205 - 4P + 5 02
single replacement
synthesis
decomposition
combustion
double replacement
Complete question is;
Identify the type of reaction in the chemical reaction below:
2P205 ➡️ 4P + 502
single replacement
synthesis
decomposition
combustion
double replacement
Answer:
Decomposition
Explanation:
We. An see in the question that the compound 2P205 is broken down into simpler substances which are phosphorus (P) and oxygen (O).
Now, this is a decomposition reaction because a decomposition reaction is one in which a compound is broken down into simpler substances
A chemistry grad student measures the performance of the new pump in his lab. The result is:Convert to
Answer:
The correct answer is - 0.0188 mJ*s^-1.
Explanation:
In order to convert the kPA value to PA value--
and then convert PA unit to 1 kgm^-1s^-2
And in finally convert mm to m
The value that come should be convert from kgm^2s^-2 to and then convert J to mJ or kJ by dividing 100 or 100 subsequently.
As no question given this method can be followed for the answer.
Describe how you would prepare your assigned ester from a carboxylic acid and an alcohol. You do not need to include a detailed procedure, but you should include any necessary reagents or catalyst (solvents are not needed).
Answer:
The general preparation of esters( for example ethyl ethanoate) is through a process known as ESTERIFICATION.
Explanation:
The formation of an ester by the reaction between an alkanol and an acid is known as esterification. This reaction is extremely slow and reversible at room temperature, and is catalyzed by a high concentration of hydrogen ions.
In the preparation of one of the simpler esters known as ETHYL ETHANOATE the reactants include ethanol(an alcohol) and glacial ethanoic acid(a carboxylic acid) in the presence of concentrated tetraoxosulphate VI acid as a CATALYST. Note that, a catalyst is any substance that is able to increase the rate of a chemical reaction.
The mixture is warmed in a water bath( hot but not boiling) for about 25 minutes. The mixture is poured into a beaker partially filled with a sodium or calcium chloride to remove interacted ethanol. The ethyl ETHANOATE floats on the mixture as oily globules.
A soluble unknown has contaminated your sample. It absorbs the same wavelength as your analyte, Allura Red dye. How will this affect your results, and what type of error is introduced
Answer:
The explanation as per the given query is presented in the following paragraph.
Explanation:
The Allura Reds Pigment or coloring increases the absorption by absorbing at around a very similar wavelength as that of the analysis.Therefore, the approximated analysis concentration or its intensity seemed substantially higher than that of the authentic one. Some positive mistake is going to exist.Thus the above is the correct explanation.
The measured absorbance will be higher, thereby creating systematic error.
Absorbance can be defined as the value or quantity of light absorbed by a given sample.The presence of impurity with a similar absorption wavelength will increase the absorbance. Moreover, systematic error is a type of error that is repeated along with different processes of measurement.In conclusion, the measured absorbance will be higher, thereby creating systematic error.
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20. What intermolecular forces would affect the interactions of water molecules? Explain why.
Answer:
Water has strong hydrogen bond dipole-dipole intermolecular forces that give water a high surface tension and a high heat of vaporization and that make it a strong solvent
Suppose, in an experiment to determine the amount of sodium hypochlorite in bleach, you titrated a 23.92 mL sample of 0.0100 M K I O 3 with a solution of N a 2 S 2 O 3 of unknown concentration. The endpoint was observed to occur at 13.80 mL . How many moles of K I O 3 were titrated
Answer:
2.39x10⁻⁴ moles
Explanation:
As the problem asks us the number of moles of KIO₃ that were titrated, all that is required of us is to calculate how many moles of KIO₃ are there in 23.92 mL of a 0.0100 M solution (All moles in the samples are titrated).
We can do so by using the definition of molarity:
Molarity = moles / litersconverting 23.92 mL ⇒ 23.92 / 1000 = 0.02392 L
moles = 0.0100 M * 0.02392 Lmoles = 2.39x10⁻⁴ moles1. Calculate the percent recovery of benzoic acid, naphthalene and 3-nitroaniline if you were able to collect 10.75 g of benzoic acid, 5.41 g of naphthalene, and 7.81 g of 3-nitroaniline from a set of extractions. The starting mass of the mixture was 25.04 g. (0.6 pt) 2. Describe why it is important to use sodium hydroxide and hydrochloride acid in this experiment. Why was it necessary to initially start off with a 5% solution of the acid or base for this experiment
Explanation:
1.)
mass = 25.04
percentage recovery
[tex]benzoic acid = \frac{10.75}{25.04} = 0.4293*100 = 42.93%\\[/tex]
[tex]naphtalene =\frac{5.41}{25.04} = 0.2160*100 = 21.60\\3-nitroaniline=\frac{7.81}{25.04} =0.3119*100=31.19[/tex]
2. This experiment has these compounds, benzoic acid (which is an acid), naphthalene (this is neutral) and 3-nitroaniline (this is a base).
to extract, 5 percent of NaOH has to be used in order for benzoic acid to become with sodium hydroxide. the salt would then dissolve in H2O, the other two remaining are going to dissolve in organic layer. and this would make benzoic acid to leave the mix.
we make use of 5 percent of HCl so that the 3-nitroaniline will turn into ammonium salt with the hcl, then the ammonium salt would dissolve in water and naphtalene would become soluble in organic layer. when this happens we would then have the three compounds separated.
Do you think a single property is sufficient for conclusively identifying a substance?
Answer:
No
Explanation:A single property is insufficient for identifying a substance
In the reactionpyruvate lactatethat is catalyzed by the enzyme lactate dehydrogenase, the compound on which the enzyme works, pyruvate, is called the _______.
Answer:
Substrate
Explanation:
In biochemical sciences, a substrate is a substance that is acted upon by an enzyme to yield a product. Enzymes are known for catalyzing biochemical reactions. The substances that are usually worked with during this catalytic process are termed as SUBSTRATES.
Substrates, which are usually changed during the process, binds to the active site on the enzyme and form an enzyme-substrate complex.
According to this question, pyruvate is converted to lactate in a reaction that is catalyzed by the enzyme lactate dehydrogenase. This means that the compound on which the enzyme works, pyruvate, is called the SUBSTRATE.
Br NaOCH2CH3 + CH3CH-OH + NaBr CH3 CH3 a. Identify the mechanism of the reaction. b. Suggest steps for the mechanism of this reaction. Use curved arrows to show the electron motions. c. How would the rate be affected if the concentration of sodium ethoxide, NaOCH CH3 is increased? Justify your answer.
Answer:
a) The mechanism of the reaction is the Elimination Bimolecular or E2.
b) Steps for the mechanism of this reaction is given as follows,
c) Reaction rate = K[Organic compound][[tex]NaoCH_{2} CH_{3}[/tex]].
Explanation:
a) The mechanism of the reaction is the Elimination Bimolecular or E2.
c) This is an E2 reaction, so it depends on the concentration of both substrate and reactant. If we increase the concentration of [tex]NaoCH_{2} CH_{3}[/tex], the reaction rate will be increased.
Reaction rate = K[Organic compound][[tex]NaoCH_{2} CH_{3}[/tex]].
b) Steps for the mechanism of this reaction is given as follows,
write any two things that should be remembered while writing chemical equation
Answer:
the product and the reactant must be balanced
if u are required to give the mechanism if the reaction it must be written
Answer the following questions: (Questions about titration)
a. Why is it important to keep the NaOH solution covered at all times?
b. How will the molarity of NaOH solution be affected by its continued exposure to the atmosphere?
c. The pale pink color of the titration solution at the end point will fade to colorless after several minutes when exposed to the atmosphere. Account for this color change.
d. What volume (in mL) of 0.293 M Ba(OH)2 is required to neutralize 25.00 mL of 0.200M HNO3?
Answer:
Following are the solution to the given question:
Explanation:
For question a:
It is prevented that the atmospheric [tex]CO_2[/tex] through dissolving in the solution and make carbonic acid [tex](H_2CO_3)[/tex] which reacts with the [tex]NaOH:[/tex]
[tex]CO_2+ H_20\to H_2CO_3\\\\H_2CO_3 + NaOH \to NaHCO_3 +H_2O\\\\H_2CO_3 + 2 NaOH \to Na_2CO_3 + 2H_2O\\\\[/tex]
For question b:
For this, the [tex]NaOH[/tex] reacts with the dissolved [tex]CO_2[/tex] so, the molarity of the [tex]NaOH[/tex] will be decreased.
For question C:
In this, the Phenolphthalein is pink in the basic solution[tex](high \ pH)[/tex] and colorless throughout the acidic solution[tex](low\ pH)[/tex].
if the solution is exposed from the atmosphere, the [tex]CO_2[/tex] is from the air dissolving in the solution, and making the [tex]H_2CO_3[/tex] that gives the [tex]H^{+}\ ions[/tex]
[tex]\to[/tex] lower pH.
[tex]\to[/tex] colorless phenolphthalein
For question D:
[tex]Ba(OH)_2 + 2 HNO_3 \to Ba(NO_3)_2+ 2H_2O\\\\[/tex]
Calculating the moles of[tex]HNO_3 = volume \times \text{concentration of} HNO_3\\\\[/tex]
[tex]= \frac{25}{1000} \times 0.200\\\\= 0.005\ mol\\\\[/tex]
Calculating the moles of [tex]Ba(OH)_2= \frac{1}{2} \times\text{moles of}\ HNO_3\\\\[/tex]
[tex]=\frac{1}{2} \times 0.005\\\\= 0.0025 \ mol\\\\[/tex]
Calculating the volume of [tex]Ba(OH)_2=\frac{moles}{concentration\ of\ Ba(OH)_2}[/tex]
[tex]=\frac{0.0025}{0.0293}\\\\=0.08532\ L\\\\= 85.32 \ mL\\\\= 85.3\ mL[/tex]
g Elimination reaction simulation, Kim had tried to prepare cyclohexene from cyclohexanol using HCl as a catalyst, but he got a weird side product cyclohexyl chloride. Cyclohexyl chloride is formed possibly from the side reaction called A. SN1 substitution reaction B. E2 reaction C. E1 reaction D. SN2 substitution reaction
Answer:
SN1 substitution reaction
Explanation:
cyclohexanol is a secondary alkanol. The mechanism of acid catalysed dehydration of cyclohexanol involves the protonation of the -OH group.
This is followed by loss of water which is a good leaving group. At this stage, a proton could be abstracted to yield cyclohexene by E1 mechanism or an SN1 substitution reaction may occur to yield Cyclohexyl chloride.
The both reactions are equally likely.
Draw bond-line formulas of all monochloro derivatives that might be formed when 1,1-dimethylcyclobutane is allowed to react with Cl2 under UV irradiation. For each structure, indicate, with an asterisk, any stereocenters that might be present.
Answer:
Attached below
Explanation:
Diagram of Bond-line formulas of all monochloro derivatives formed when 1,1-dimethylcyclobutane is allowed to react with c12 under UV
attached below
name this organic compound
I don't need explaination just give the name
Answer:
Toluene
Explanation:
This compound is called toluene.
It is a phenyl group where it is bonded a methyl.
It is an aromatic compound.
IUPAC name can be, Methylbenzene.
As an organic compound it can not be dissolved in water.
This can be a reaction of synthesis:
C₆H₅H + CH₃Cl → C₆H₅CH₃ + HCl
Arrange these compounds by their expected boiling point. Highest boiling point Lowest boiling point CH3OH, CH3CI CH4.
Answer: The given compounds are arranged according to decreasing boiling point as [tex]CH_{3}OH > CH_{3}Cl > CH_{4}[/tex].
Explanation:
The temperature at which vapor pressure of a substance becomes equal to the atmospheric pressure is called boiling point.
Stronger is the intermolecular forces present the atoms of a molecule more heat will be required by it to break the bond between its atoms. Hence, more will the boiling point of the molecule.
In [tex]CH_{3}OH[/tex] (methanol), there is hydrogen bonding present which is a stronger force. So, it will have highest boiling point as compared to [tex]CH_{3}Cl[/tex] and [tex]CH_{4}[/tex].
In [tex]CH_{3}Cl[/tex] (chloroform), there is more electronegative atom attached (Cl) is attached to less electronegative atom (C and H). So, electrons are more pulled towards the chlorine atom. So, boiling point of [tex]CH_{3}Cl[/tex] is more than methane [tex](CH_{4})[/tex].
Thus, we can conclude that given compounds are arranged according to decreasing boiling point as [tex]CH_{3}OH > CH_{3}Cl > CH_{4}[/tex].
Classify each of the following as a strong acid or a weak acid and indicate how each should be written in aqueous solution. Classify ... In solution this acid should be written as: weak 1. hydrocyanic acid H3O CN- _______ 2. hydrobromic acid
Answer:
HCN, weak acid
H⁺, Br⁻, strong acid
Explanation:
Hydrocyanic acid is a weak acid, according to the following equation.
HCN(aq) ⇄ H⁺(aq) + CN⁻(aq)
Thus, it should be written in the undissociated form (HCN).
Hydrobromic acid is a strong acid, according to the following equation.
HBr(aq) ⇒ H⁺(aq) + Br⁻(aq)
Thus, it should be written in the ionic form (H⁺, Br⁻).
An ionic compound contains an unknown ion X and has the formula X3N2. Ion X contains 10 electrons. Write down the chemical symbol of X?
Answer:
Mg3N2
Explanation:
it would be magnesium as it would loss to electron so it would have 10 electron. you can see in the picture above .
hope this helps :)
Part A of the lab involved adding 4 mL increments of distilled water to 5.00 mL of antimony trichloride solution. The antimony trichloride solution contains 0.10 M SbCl3 in 4.5 M HCl. Calculate the concentrations of SbCl3 and H /Cl- in the test tube after 12.0 mL of distilled water has been added. Assume dilution only.
Answer:
0.0238M SbCl3, 1.07M H+, 1.14M Cl-
Explanation:
The total volume of the solution is:
4mL + 5.00mL + 12.0mL = 21mL
As the volume of the SbCl3 is 5.00mL, the dilution factor is:
21mL / 5.00mL = 4.2 times
The concentration of SbCl3 is:
0.10M SbCl3 / 4.2 times = 0.0238M SbCl3
The concentration of H+ = [HCl]:
4.5M / 4.2 times = 1.07M H+
The initial concentration of Cl- is:
3 times SbCl3 + HCl = 0.10M*3 + 4.5M =
3 times SbCl3 because 1 mole of SbCl3 contains 3 moles of Cl-
4.8M Cl- / 4.2 times = 1.14M Cl-
Nitrogen and hydrogen react to form ammonia, like this:N2(g)+3H2(g)→2NH3(g)Use this chemical equation to answer the questions below.Suppose 135, mmol of N₂ and 405, mmol of H₂ are added to an empty flask, How much N₂ will be in the flask at equilibrium? a. Noneb. Some, but less than 135, mmol.c. 135,mmold. More than 135, mmol.Suppose 235, mmol of NH₃ are added to an empty flask, How much N₂ will be in the flask at equilibrium? a. Noneb. Some, but less than 118, mmol.c. 118,mmold. More than 118, mmol.
Answer:
Option A is correct, there will be no N2 left in the flask
Explanation:
Step 1 : Data given
Number of moles of N2 = 135 mmol = 0.135 mol
Number of moles of H2 = 405 mmol = 0.405 mol
Step 2: The reaction
N2(g)+3H2(g)→2NH3(g)
Step 3:
For 1 mol N2 we need 3 moles H2 to produce 2 moles NH3
Both will completely react. There is no limiting reactant.
There will be produce 0.270 moles NH3.
Option A is correct, there will be no N2 left in the flask
determine the number of moles of Cl in 1.9 mol of CaCl2
Explanation:
In the formula of [tex]CaCl_2[/tex] we can see that there are 2mol Cl in 1 molecule of CaCl2. So, now we can do some math to find out how many mol of Cl there are in 1.9mol CaCl2!
[tex]1.9molCaCl_2*\frac{2molCl}{1molCaCl_2}[/tex]
So, there are 3.8mol Cl
A student conducted an experiment 4 times. His results were very close to each other each time he ran the experiment and
were very close to the true or actual value. His results showed
A. None of these answers are correct
B. poor accuracy and poor precision
C. good accuracy and good precision
D. poor accuracy and good precision
E. good accuracy and poor precision
Answer:
d is the answer have a good one
3. A 3.455-g sample of a mixture was analyzed for barium ion by adding a small excess of sulfuric acid to an aqueous solution of the sample. The resultant reaction produced a precipitate of barium sulfate, which was collected by filtration, washed, dried, and weighed. If 0.2815 g of barium sulfate was obtained, what was the mass percentage of barium in the sample
Answer:
[tex]Ba\ percentage\ in\ Mass=4.8\%[/tex]
Explanation:
From the question we are told that:
Mass of mixture [tex]m=3.455g[/tex]
Mass of Barium [tex]m_b=0.2815g[/tex]
Equation of Reaction is given as
[tex]Ba2+ + H2SO4 => BaSO4 + 2 H+[/tex]
Generally the equation for Moles of Barium is mathematically given by
Since
[tex]Moles of Ba^{2+} = Moles of BaSO_4[/tex]
Therefore
[tex]Moles of Ba^{2+} = \frac{mass}{molar mass of BaSO4}[/tex]
[tex]Moles of Ba^{2+} = \frac{0.2815}{233.39}= 0.0012061 mol[/tex]
Generally the equation for Mass of Barium is mathematically given by
[tex]Mass\ of\ Ba^{2+} = Moles * Molar mass of Ba^{2+}[/tex]
[tex]Mass\ of\ Ba^{2+} = 0.0012061 * 137.33 = 0.1656 g[/tex]
Therefore
[tex]Ba\ percentage\ in\ Mass = mass of Ba^{2+}/mass of sample * 100%[/tex]
[tex]Ba\ percentage\ in\ Mass= \frac{0.1656}{ 3.455 }* 100%[/tex]
[tex]Ba\ percentage\ in\ Mass=4.8\%[/tex]
Calculate the moles of H3PO4 that reacted (8). Consult the coefficients in the balance chemical reaction to obtain the mole ratio. Show your calculation here.
Answer:
The number of moles of H₃PO₄ that reacted is 0.000343 moles
Note: Some data is missing. Data from the attachment is used for the calculationsinnthe explanation below.
Explanation:
The reaction is a neutralization reaction between NaOH and H₃PO₄. The equation of the reaction is given as follows:
3 NaOH + H₃PO₄ ---> Na₃PO₄ + 3 H₂O
The molarity of the NaOH solution is 0.238 mol/L.
Average volume of NaOH used during the titration to arrive to endpoint = (4.6 + 3.9 + 4.5) mL / 3 = 4.33 mL
Molarity is defined ratio of the number of moles of solute to the volume of solution. Mathematically, molarity = number of moles/volume in Litres
Number of moles of NaOH reacted = 0.238 mol/L × (4.33mL × 1 L/1000 mL)
Number of moles of NaOH = 0.00103 moles
From the equation of the reaction, 3 moles of NaOH reacts with 1 mole of H₃PO₄
0.00103 moles of NaOH will react with 0.00103 x 1/3 moles of H₃PO₄ = 0.000343 moles of H₃PO₄.
Therefore, number of moles of H₃PO₄ that reacted is 0.000343 moles
Liquid A is poured into Liquid B and a single, clear layer results. More Liquid A is added and two distinct layers form. The solution is now_____and there is a_____equilibria occurring.
Answer:
Explanation:
Liquid A is poured into Liquid B and a single, clear layer results. More Liquid A is added and two distinct layers form. The solution is now unsaturated and there is a static equilibria occurring
