Answer:
Ci
Explanation:
because it is an electron effective nuclear charge
A 25.0 mL aliquot was taken from a 500.0 mL sample of tonic water containing an unknown amount of quinine and diluted to a volume of 200.0 mL. At 347.5 nm, the fluorescence intensity of the diluted sample was measured as 73.7 on an arbitrary scale. Under similar conditions, a 25.0 ppm standard quinine solution had a fluorescence intensity of 195 . Calculate the mass of quinine in the original tonic water sample.
The mass of quinine in the original tonic water sample is 37.8 mg.
What is the concentration of the diluted sample?The concentration of the diluted sample with a fluorescence intensity of 73.7 is calculated using the formula of Lambert-Beer's law as follows:
C₁/C₂ = A₁/A₂
where:
C₁ = 25 ppm or 25 mg/L
C₂ = ?
A₁ = 195
A₂ = 73.7
C₂ = 73.7 * 25 / 195
C₂ = 9.45 mg/L
To concentration of the original sample will be determined from the dilution formula:
C₁V₁ = C₂V₂
where;
C₁ = ?
V₁ = 25. 0 mL
C₂ = 9.45 mg/L
V₂ = 200 mL
C₁ = 9.45 * 200 / 25
C₁ = 75.6 mg/L
The volume of the stock sample was 500 mL or 0.5 L
The mass of quinine = 75.6 mg/L * 0.5 L
mass of quinine = 37.8 mg
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How many milliliters of a 2.59 M H2SO4 solution are needed to neutralize 47.50 mL of a 0.827 M KOH solution?
Given Data:
Concentration of acid, H2SO4 = 2.59 M
For, H2SO4, n-factor = 2, i.e., the number of [tex]H^{+}[/tex] ions on dissociation
Thus, the concentration in normality, N1 = 2.59 x 2 = 5.18 N
Concentration of base, KOH = 0.827 M
For, KOH, n-factor = 1, i.e., the number of [tex]OH^{-}[/tex] ions on dissociation
Thus, the concentration in normality, N2 = 0.827 x 1 = 0.827 N
Volume of base, V2 = 47.50 mL
Using the formula, N1 x V1 = N2 x V2, where, V1 = volume of acid
Thus, volume of acid required to neutralize, V1 = [tex]\frac{N_{2}X V_{2} }{N_{1} }[/tex] = [tex]\frac{0.827 X 47.50}{5.18}[/tex]
= 7.58 mL.
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10. When a metal atom combines with a nonmetal
atom, the nonmetal atom will
A. lose electrons and decrease in size
B. lose electrons and increase in size
C. gain electrons and decrease in size
D. gain electrons and increase in size
When a metal atom combines with a nonmetal atom, the nonmetal atom will gain electrons and decrease in size
What happen when metal react with non metal ?In a reaction between metals and non-metals, electrons are moved from the metal atoms to the non-metal atoms, resulting in the formation of ions. An ionic compound is the name given to the resulting substance.
Ions are created when metals and non-metals interact because the metal atoms' electrons are transferred to the non-metal atoms.The end result of this procedure is an ionic compound. Metal atoms provide their electrons to non-metal atoms. Metal atoms change into positive ions, whereas non-metal atoms change into negative ions.Learn more about Metals and non metal here:
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Question 16 of 25According to the Gibbs free energy equation, AG = AH-TAS, when is areaction always spontaneous?A. When AH and AS are both positiveB. When AH is negative and AS is positiveC. When AH is positive and AS is negativeD. When AH and AS are both negativeSUBMIT
Answer
B. When ΔH is negative and ΔS is positive
Explanation
The spontaneity of a reaction can be determined by the sign of the Gibbs free energy change. For a spontaneous reaction, the change in Gibbs free energy should be negative, that is:
[tex]\Delta G=\Delta H-T\Delta S[/tex]The spontaneity of a process can depend on the temperature. Since the temperature value here corresponds to the absolute temperature, this implies that T > 0 for any T. Therefore, to have a negative difference for any temperature value, the change in enthalpy (ΔH), should be negative and the change in entropy (ΔS) should be positive so that we always subtract a positive number from a negative number. This corresponds to a negative value in ΔG.
Hence, the
What is the electronic configuration of argon
Electronic configuration: this shows us the distribution of electrons in an atom. The chart below helps us find the electron configuration.
How many protons does argon have?
Argon has 18 protons.
The electronc configuration of argon is 1s2 2s2 2p6 3s2 3p6
A cheeseburger from a fast food restaurant contains 19 g of fat, 20 g of carbohydrates and 28 g of protein. How many kcal of energy does the cheeseburger contain? (Food caloric values are 9.0 kcal/g for fats, 4.0 kcal/g for carbohydrates and 4.0kcal/g for protein). Round the answer for each type of food to the nearest tens place. A. 70. kcal B. 360 calories C. 17 calories D. 630 calories
Answer:
Example:
Here, we want to get the kcal of energy contained in the cheeseburger
To do this, we multiply the caloric values of each food type by their masses and then sum
Mathematically, we have that as:
[tex]19(9)\text{ + 20\lparen4\rparen + 28\lparen4\rparen = 363 kcal}[/tex]To the nearest tens, we have that as 360 kcal
Assuming that each double-displacement reaction occurs, predict the products and write each balanced chemical equation.
a.
Sn(OH)2 + FeBry -*?
b. CsNO3 + KCI -* ?
The products of the double displacement reactions are given in the equations of the reaction below:
a. 3 Sn(OH)₂ (aq) + 2 FeBr₃ (aq) ---> 3 SnBr₂ (aq) + 2 Fe(OH)₃ (s)
Iron (iii) hydroxide is obtained as a precipitate
b. CsNO₃ (aq) + KCI (aq) ---> CsCl (aq) + KNO₃ (aq)
No double displacement reaction occurs as both products are soluble.
What are double displacement reactions?Double displacement reactions are reactions in which there is an exchange of radicals by two compounds when solutions of the compounds are added together.
In a double displacement reaction, an insoluble precipitate is obtained since one of the products of the double displacement reaction is insoluble in aqueous solutions.
The products of the double displacement reactions are given in the equations of the reaction below:
a. Reaction between Sn(OH)₂ and FeBr₃
3 Sn(OH)₂ (aq) + 2 FeBr₃ (aq) ---> 3 SnBr₂ (aq) + 2 Fe(OH)₃ (s)
Iron (iii) hydroxide is obtained as a precipitate
b. Reaction between CsNO₃ and KCI
CsNO₃ (aq) + KCI (aq) ---> CsCl (aq) + KNO₃ (aq)
No double displacement reaction occurs as both products are soluble.
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Dr. Lamar is performing an autopsy on a murder victim. What is he MOST likely to do during this procedure?
A.
Apply a Hematix strip to the fingertips to collect prints.
B.
Use the Kastle-Meyer test to examine blood samples.
C.
Collect hair samples from multiple places on the body.
D.
Scrape away any dried blood present on the body.
Collecting hair samples from multiple places on the body is most likely to be done during an autopsy.
What is Autopsy?This is referred to as a post-mortem examination which is done on a corpse so as to determine the cause of the sickness and for appropriate actions to be taken.
Hair is easily dispersed as a result of light weight and structure and its ability to easily attach to other substances. The hair will be most likely taken during this procedure, it helps to identify the race and sex of the suspect. It can also be used to identify the suspect through DNA analysis which is therefore the reason why option C was chosen as the correct choice.
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Answer: C
Explanation:
Classify the following compounds as alkane, alkene, alkyne based on the given structure
We have the next compounds
And we must classify them as alkane, alkene, alkyne.
We need to know that
- Alkane: They are the simplest hydrocarbons, containing only carbon and hydrogen held together by single bonds.
- Alkene: Alkenes are hydrocarbons that contain a double bond.
- Alkyne: Alkynes are hydrocarbons that contain a triple bond.
1. We can see that the structure has a double bond. So, it is an Alkene.
2. We can see that the structure has a triple bond. So, it is an Alkyne.
3. We can see that the structure has a double bond. So, it is an Alkene.
4. We can see that the structure has a triple bond. So, it is an Alkyne.
ANSWER:
1. Alkene
2. Alkyne
3. Alkene
4. Alkyne
Is NH4OH soluble or insoluble in water
Answer:
Ammonium hydroxide. Ammonium hydroxide is an inorganic herbicide, fungicide and microbiocide.It is non-volatile and highly soluble in water.
Explanation:
According to the concept of solubility, ammonium hydroxide is insoluble in water.
What is solubility?Solubility is defined as the ability of a substance which is basically solute to form a solution with another substance. There is an extent to which a substance is soluble in a particular solvent. This is generally measured as the concentration of a solute present in a saturated solution.
The solubility mainly depends on the composition of solute and solvent ,its pH and presence of other dissolved substance. It is also dependent on temperature and pressure which is maintained.Concept of solubility is not valid for chemical reactions which are irreversible. The dependency of solubility on various factors is due to interactions between the particles, molecule or ions.
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What is the final concentration when 288mL of water is added to 239mL of a 0.274M solution?
Answer:
0.124 M.
Explanation:
What is given?
Volume 1 (V1) = 239 mL,
Concentration 1 (C1) = 0.274 M,
Volume 2 (V2) = 239 mL + 288 mL = 527 mL.
What do we need? Concentration 2 (C2).
Step-by-step solution:
To solve this problem, we have to use the following formula:
[tex]C_1V_1=C_2V_2.[/tex]Where the initial concentration (C) and volume (V) are represented with subindex 1, and the final concentration and volume are represented with subindex 2.
The problem is telling us that we are adding 288 mL of water to 239 mL, so the final volume is the sum of these two volumes, i.e., 527 mL.
As we want to find the final concentration, C2, we just have to solve for this unknown value and replace the values that we have, like this:
[tex]\begin{gathered} C_2=\frac{C_1V_1}{V_2}, \\ \\ C_2=\frac{0.274\text{ M}\cdot239\text{ mL}}{527\text{ mL}}, \\ \\ C_2=0.124\text{ M.} \end{gathered}[/tex]The answer would be that the final concentration of the solution is 0.124 M.
A balloon has a volume of 1785 mL at 25°C, if the volume of balloon changes to 1.25 L, what is the new temperature in degree Celcius atconstant pressure and amount?
We work here with Charles' Law. The equation used here is:
V1/T1 = V2/T2 (1)
(pressure and amount constant)
V is for volume and T for temperature
V1 = 1785 mL
1 L = 1000 mL ==> V1 = 1.785 L
T1 = 25 °C = 25 °C + 273 = 298 K
V2 = 1.25 L
T2 = unknown
From (1) we clear T2:
T2 = V2 x T1/V1 = 1.25 L x 298 K/1.785 L = 209 K approx.
T2 = 209 K - 273 = -64 °C
Answer: T2 = -64 °C
3.0 x 10 ^23 atoms of calcium to moles
Answer:
[tex]0.5\text{ mole}[/tex]Explanation:
Here, we want to get the number of moles
Mathematically:
[tex]1\text{ mole has 6.02 }\times\text{ 10}^{23}\text{ atoms}[/tex]The number of moles in the question would be:
[tex]\frac{3.0\times10^{23}\text{ atoms}}{1}\times\frac{1\text{ mole}}{6.02\times10^{23}\text{ atoms}}\text{ = 0.5 mole}[/tex]The molecular formula of Allicin, The compound responsible for the characteristics smell of garlic, is C6H 10 OS2. A) what is the molar mass of a Allicin?B) how many moles of allicin are present in 4.20 mg of the substance?C) how many molecules of Allicin are in 4.20 mg of the substance?D) how many C atoms are present in 4.20 mg of allicin?
1) Molar mass of Allicin.
1.1- Write the formula.
[tex]C_6H_{10}OS_2[/tex]1.2- Look for the molar mass of each element in the formula.
C: 12.011 g/mol
H: 1.008 g/mol
O: 15.999 g/mol
S: 32.06 g/mol
1.3- Count how many atoms are there in the formula.
C: 6
H: 10
O: 1
S: 2
1.4- Set the equation.
[tex]TheMolarMass=(6*C)+(10*H)+(1*O)+(2*S)[/tex]Plug in the known values.
[tex]TheMolarMass=(6*12.011\text{ }g/mol)+(10*1.008\text{ }g/mol)+(1*15.999\text{ }g/mol)+(2*32.06\text{ }g/mol)[/tex][tex]MM=72.066\text{ }g/mol+10.08\text{ }g/mol+15.999\text{ }g/mol+64.12\text{ }g/mol[/tex][tex]MM=162.265\text{ }g/mol[/tex]The molar mass (MM) of Allicin (C6H10OS2) is 162.265 g/mol.
2) Moles of Allicin in the sample.
Allicin sample: 4.20 mg
The molar mass of Allicin (C6H10OS2) is 162.265 g/mol.
2.1- Convert mg to g.
1g = 1000 mg
[tex]g=4.20\text{ }mg*\frac{1\text{ }g}{1000\text{ }mg}=0.00420\text{ }g[/tex]2.2- Convert grams to moles.
The molar mass of Allicin (C6H10OS2) is 162.265 g/mol.
Allicin sample: 0.00420 g
[tex]mol\text{ }C_6H_{10}OS_2=0.00420\text{ }g\text{ }C_6H_{10}OS_2*\frac{1\text{ }mol\text{ }C_6H_{10}OS_2}{162.265\text{ }g\text{ }C_6H_{10}OS_2}=0.00002588\text{ }mol\text{ }C_6H_{10}OS_2[/tex]There are 0.00002588 moles of Allicin (C6H10OS2) in 4.20 mg of substance.
The result can also be expressed as 2.588*10^(-5) mol.
3) Molecules of Allicin in the sample.
The Avogadro's number is 6.022*10^(23).
1 mol C6H10OS2 = 6.022*10^(23) molecules C6H10OS2
Allicin sample: 0.00002588 mol.
[tex]molecules\text{ }of\text{ }C_6H_{10}OS_2=0.00002588\text{ }mol\text{ }C_6H_{10}OS_2*\frac{6.022*10^{23}\text{ }molecules}{1\text{ }mol\text{ }C_6H_{10}OS_2}=1.558*10^{19}\text{ }molecules\text{ }of\text{ }C_6H_{10}OS_2[/tex]There are 1.558*10^(19) molecules in the sample.
4) C atoms in the sample of Allicin.
The ratio of carbon in one molecule of Allicin is 6 C atoms: 1 molecule of Allicin.
Allicin sample: 1.558*10^(19) molecules C6H10OS2.
[tex]C\text{ }atoms=1.588*10^{19}\text{ }molecules*\frac{6\text{ }C\text{ }atoms}{1\text{ }molecule\text{ }C_6H_{10}OS_2}=9.35*10^{19}\text{ }C\text{ }atoms.[/tex]There are 9.35*10^(19) C atoms in the sample.
A gas mixture contains 1.26 g N2 and 0.76 g O2 in a 1.51 L container at 11 C. Calculate the partial pressure of N2?
When we have a mixture of gases, the pressure exerted by each depends on the number of moles present in the mixture, this contribution is called partial pressure. The sum of the partial pressures will be equal to the total pressure, this is called Dalton's law.
Partial pressure can be described by the following equation:
[tex]P_i=X_iP_T[/tex]Where,
Pi is the partial pressure
Xi is the molar fraction
Pt is the total pressure
The molar fraction is calculated by the following equation:
[tex]X_i=\frac{n_i}{n_T}[/tex]Where,
ni is the number of moles of the substance
nT is the total number of moles.
So, we have to find first the number of moles of each gas. We are given the grams of gases, to get the equivalent moles we must divide the mass by the molar mass.
Molar Mass N2=28.0134g/mol
Molar Mass O2=31.9988g/mol
[tex]\begin{gathered} molN_2=1.26g\times\frac{1molN_2}{28.0134gN_2}=0.045molN_2 \\ molO_2=0.76gO_2\times\frac{1molO_2}{31.9988gO_2}=0.024molO_2 \end{gathered}[/tex]Now, the partial pressure of N2 will be:
[tex]P_{N2}=\frac{0.045molN_2}{0.045molN_2+0.024molO_2}\times P_T[/tex][tex]P_{N2}=\frac{0.045molN_2}{0.069mol}\times P_T[/tex][tex]P_{N2}=0.652\times P_T[/tex]If we assume that the gas behavior is like an ideal gas, we can find the total pressure with the following equation:
[tex]\begin{gathered} PV=nRT \\ P_T=\frac{nRT}{V_T} \end{gathered}[/tex]Where,
n is the total number of moles, 0.069mol
R is a constant, 0.08206atm.L/mol.K
V is the volume of the gas, 1.51L
T is the temperature of the gas, K.284.15K
We replace the known data:
[tex]P_T=\frac{0.069mol\times0.08206\frac{atm.L}{mol.K}\times284.15K}{1.51L}=1.06atm[/tex]Now, the partial pressure of nitrogen will be:
[tex]P_{N2}=0.652*1.06atm=0.69atm[/tex]Answer: The partial pressure of N2 is 0.69atm
Balance the following equation:ZnO(s)⟶ΔZn(l)+O2(g) Express your answer as a chemical equation. Identify all of the phases in your answer.
Answer:2ZnO(s)→2Zn(l)+O2(g)
Explanation:
Select the correct answer.
Consider an atom that has an electron in an excited state. The electron falls to a lower energy level. What effect does that have on the electron?
The electron releases energy in the form of light.
Hope this helps!
4 Fe + 3 O2 = 2 Fe2O3How many grams of oxygen (O2) do you needto produce 75 g Fe203?
Answer
mass of oxygen = 22.54 g
Explanation
Given:
4 Fe + 3 O2 = 2 Fe2O3
Mass of Fe203 = 75 g
Required: Mass of O2
We know:
Molar mass of Fe2O3 = 159,69 g/mol
Molar mass of O2 = 31.998 g/mol
Solution:
Step 1: Calculate the moles of Fe2O3
n = m/M where n is the moles, m is the mass and M is the molar mass
n = 75g/159,69 g/mol
n = 0.469 mol
Step 2: Use the stoichiometry to find the moles of O2
The molar ratio between Fe2O3 and O2 is 2:3
Therefore moles of O2 = 0.469 mol x (3/2) = 0.704 mol
Step 3: Find the mass of O2
m = n x M
m = 0.704 mol x 31.998 g/mol
m = 22.54 g
Predict the shape and bond angles of the following molecules:
H2S
CF4
HCN
NF3
BCl3
NH2Cl
OF2
The shape and bond angle of the molecule will be, H2S =shape= bent, Bond angle =less than 109 degrees
2) CH4 = shape = tetrahedral
bond angle-=109 degrees
1)H2S =shape= bent
Bond angle =less than 109 degrees
2) CH4 = shape = tetrahedral
bond angle-=109 degrees
3) HCN = shape = Linear
Bond angle = 180 degrees
4) NF3 = shape = trigonal planar
Bond angle = less than 109 degrees
5) BCl3 = shape = trigonal planar
Bond angle = 120 degrees
6) NH2Cl = shape = trigonal pyramidal
Bond angle = 107 degrees
7) OF2 = shape = linear
Bond angle = 109 degrees
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A 45 mL sample of calcium chloride stock solution produces a 0.182 M diluted solution by adding 50. mL of water. What is the molarity of the stock solution?
A solution of Calcium Chloride was made, we are asked to find the concentration of the initial solution.
We will apply the following equation to find it:
[tex]C_1V_1=C_2V_2[/tex]Where,
C1 is the initial concentration we have to find
V1 is the initial volume, 45mL
C2 is the final concentration, 0.182M
V2 is the final volume, 50. mL
We clear C1 and replace the known data;
[tex]C_1=\frac{C_2V_2}{V_1}[/tex][tex]\begin{gathered} C_1=\frac{0.182M\times50.mL}{45mL} \\ C_1=0.202M \end{gathered}[/tex]The molarity of the stock solution is 0.202M
Answer: 0.202M
Calculate the percent by volume of 75 mL of concentrated juice if the juice is diluted with 200 mL of water.
The percent by volume is 27.27%
Why are chemical reactions used in the agricultural industry. Please cite all your sources.
Answer:
The objective of agricultural chemistry is to preserve or improve the fertility of soil, increase the agricultural yield and improve the quality of the crop. To reach those objectives the agricultural industry uses two types of chemicals.
- Fertilizers: increase soil fertility making crops more productive. They usually are compounds that contain three basic elements: P, K and N.
- Pesticides: control weeds (herbicides), insects (insecticides) and diseases from fungus (fungicides).
A 500 g sample of Al2(SO4)3 is reacted with 450 g of Ca(OH)2. A total of 596 g of CasO4 isproduced. What is the limiting reactant in this reaction, and how many moles of excess reactantare unreacted? Al2(SO4)3 (ag) + 3Ca(OH)2 (ag) -> 2Al(OH)3 (s) + 3CaSO4 (s)
ANSWER
[tex]undefined[/tex]EXPLANATION
Given that;
The mass of Al2(SO4)3 is 500 grams
The mass of Ca(OH)2 is 450 grams
The mass of CaSO4 is 596 grams
Follow the steps below to find the limiting reactant of the reaction
Step 1; Write the balanced equation of the reaction
[tex]\text{ Al}_2(SO_4)_{3(aq)}+\text{ 3Ca\lparen OH\rparen}_{2(aq)}\text{ }\rightarrow\text{ 2Al\lparen OH\rparen}_{3(s)}\text{ + 3CaSO}_{4(s)}[/tex]In the reaction above, 1 mole Al2(SO4)3 reacts with 3 moles Ca(OH)2 to give 2 moles Al(OH)3 and 3 moles CaSO4
Step 2; Determine the number of moles using the below formula
[tex]\text{ mole = }\frac{\text{ mass}}{\text{ molar mass}}[/tex]Recall, that the molar mass of Al2(SO4)3 is 342.15 g/mol and the molar mass of Ca(OH)2 is 74.093 g/mol
For Al2(SO4)3
[tex]\begin{gathered} \text{ Mole = }\frac{500}{\text{ 342.15}} \\ \text{ Mole = 1.461 moles} \end{gathered}[/tex]For Ca(OH)2
[tex]\begin{gathered} \text{ Mole = }\frac{\text{ 450}}{\text{ 74.093}} \\ \text{ Mole = 6.073 moles} \end{gathered}[/tex]Step 3; Find the limiting reactant of the reaction
To find the limiting reactant of the reaction, divide the moles of the reactant by the co-efficient of the compound
[tex]\begin{gathered} \text{ For Al}_2(SO_4)_3 \\ \text{ The mole ratio = }\frac{1.461}{1} \\ \text{ The mole ratio = 1.461 mol/wt} \\ \\ \text{ For Ca\lparen OH\rparen}_2 \\ \text{ The mole ratio = }\frac{\text{ 6.073}}{3} \\ \text{ The mole ratio = 2.024 mol/wt} \end{gathered}[/tex]Since the limiting reactant of the reaction is the reactant with the lowest number of mol/wt, then Al2(SO4)3 is the limiting reactant
[tex]\text{ The limiting reactant of the reaction is Al}_2(SO_4)_3[/tex]The excess reactant of the reaction is Ca(OH)2
Therefore, the no of moles of the excess reactant that is unreacted is
6.073 - 1.461 = 4.612 moles
Hence, the number of moles of the excess reactant that is unreacted is 4.621 moles
1. How would an element be classified?a. homogeneous mixtureb. pure substancec. solutiond. heterogeneous mixture
Hello
To solve this question, we should understand that an element is is the base form in which a particule exit. However, it can either be in a molecule, atom or in a compound. Elements are pure substance which form up the molecule, atom or compounds. An element can said to be an identity of a substance. Elements are generally classified using the periodic table into metals, non-metals, metalliods.
In this question, the most possibe defination is that an element is a pure substance
A homogenous mixture is a mixture that is said to have one phase of substance throughout. I.e the comprising substance are all in a single phase.
A solution is the mixture of a solute that is completely dissolved in a solvent.
A heterogeneous mixture is a solution that the substance are not in a single phase.
The answer to this question is option B
How can the bulk properties of a substance (macroscopic) such as electrical conductivity be caused by the microscopic such as electrical forces in the atoms?
The bulk properties of a substance (macroscopic) such as electrical conductivity can be caused by the microscopic such as electrical forces in the atoms through the movement of free electrons.
What is Conductivity?This is referred to as the measure or the degree in which a substance conducts electricity and how the electric current moves within a substance.
The electrical conductivity which is macroscopic can be caused by the microscopic such as electrical forces as a result of the electrons moving in the body. The movement of the electron is usually from the negative to the positive terminal of the body.
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In one demonstration of this reaction, 39.00 mL of H2 are collected over water at 25°C. Atmospheric pressure is 749.0 mmHg. How many grams of H2 are collected?
Taking into account the ideal gas law, a mass of 0.00314 grams of H₂ is collected.
Definition of ideal gas lawAn ideal gas is a theoretical gas that is considered to be composed of randomly moving point particles that do not interact with each other. Gases in general are ideal when they are at high temperatures and low pressures.
The pressure, P, the temperature, T, and the volume, V, of an ideal gas, are related by a simple formula called the ideal gas law:
P×V = n×R×T
where:
P is the gas pressure.V is the volume that the gas occupies.T is its temperature.R is the ideal gas constant. The universal constant of ideal gases R has the same value for all gaseous substances. The numerical value of R will depend on the units in which the other properties are worked.n is the number of moles of the gas. Mass of H₂In this case, you know:
P= 749 mmHg= 0.985526 atm (being 760 mmHg= 1 atm)V= 39 mL= 0.039 L (being 1000 mL= 1 L)n= ?R= 0.082 (atm×L)÷(mol×K)T= 25 C= 298 K (being 0 C= 273 K)Replacing in the ideal gas law:
0.985526 atm× 0.039 L = n× 0.082 (atm×L)÷(mol×K)× 298 K
Solving:
[0.985526 atm× 0.039 L]÷ [0.082 (atm×L)÷(mol×K)× 298 K]= n
0.00157 moles= n
Considering that the molar mass of H₂ is 2 g/mole, the mass can be calculated as:
mass= number of moles× molar mass
mass= 0.00157 moles× 2 g/mole
mass= 0.00314 grams
Finally, you collected a mass of 0.00314 grams.
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A gas occupies a constant volume at 35.0 celsius and 97 kPa. What is the pressure of the gas when the temperature is increased to 75 celsius?
For this question we are going to use Gay-Lussac's Law, which is an experimental gas law that shows the relationship between temperature and pressure in a gas. The formula is:
P1/T1 = P2/T2
We have:
P1 = 97 kPa
T1 = 308 K, we need to use Kelvin
P2 = ?
T2 = 348 K
Now we add these values into the formula:
97/308 = P2/348
0.315 = P2/348
P2 = 109.6 kPa, this will be new pressure
Calculate the pH if [H+] = 2.79 x 10^-11 M
Answer:
10.6.
Explanation:
What is given?
[H⁺] = 2.79 x 10⁻¹¹ M.
Step-by-step solution:
Let's see the formula of pH:
[tex]pH=-\log_{10}[H^+]=-\log_{10}[H_3O^+].[/tex]Where [H⁺] is the proton concentration in M. So we have to replace the given data in the formula:
[tex]pH=-\log_{10}{}\lbrack2.79\cdot10^{-11}]=10.55\approx10.6.[/tex]The pH of a [H⁺] = 2.79 x 10⁻¹¹ M solution would be 10.6.
What is the relationship between n, ℓ, and the total number of nodes?
The number of planar nodes = ℓ.
The number of spherical nodes = n - ℓ - 1.
The relationship between n, ℓ, and the total number of nodes is given by the expression; Number of spherical nodes = n - ℓ - 1.
What is the number of nodes?The number of nodes has to do with the points on the orbital where there is a zero electron density. It is the points along the orbital where there re no electrons. Recall that the orbitals are the regions in space where there is a high probability of finding an electron.
There are various orbitals and the number of nodes of each of the orbitals does vary. The s orbital has no nodes while the p orbital is known to have one node.
Learn more about orbital nodes:https://brainly.com/question/28100168
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Which statement describes the hydrogen bonds in an ethanol molecule? (image attached)thank you :)
Answer
Only the hydrogen atom attached to the oxygen atom is capable of forming hydrogen bonds. A dipole does not form between the hydrogen and the carbon atoms.
Explanation
The description of the hydrogen bonds in an ethanol molecule is that hydrogen bonding can occur between ethanol molecules, although not as effectively as in water. The hydrogen bonding is limited by the fact that there is only one hydrogen in each ethanol molecule with a sufficient δ+ charge.
Therefore only the hydrogen atom attached to the oxygen atom is capable of forming hydrogen bonds. A dipole does not form between the hydrogen and the carbon atoms.
The second option is the correct answer.