Answer:
Following are the response to the given question:
Explanation:
The number of shells
n = 4
Calculating the spectral line:
[tex]= \frac{n(n-1)}{2}\\\\ = \frac{4(4-1)}{2} \\\\= \frac{4\times 3}{2}\\\\ = \frac{12}{2}\\\\ = 6[/tex]
A sample of Kr gas is observed to effuse through a pourous barrier in 8.15 minutes. Under the same conditions, the same number of moles of an unknown gas requires 4.53 minutes to effuse through the same barrier. The molar mass of the unknown gas is ____________ g/mol.
Answer:
25.88 g/mol
Explanation:
Graham's law is a famous law which states that the diffusion rate or the effusion rate of any gas varies inversely to the square root of the molecular weight the gas.
So from Graham's law, we have,
[tex]$\frac{\text{time}}{M^{1/2}}=\text{constant}$[/tex]
Using the sample of Kr gas having M = 83.8
[tex]$\frac{8.15}{(83.8)^{0.5}}= \frac{4.53}{M^{0.5}}$[/tex]
[tex]$M^{0.5}= 5.088$[/tex]
M = 25.88 g/mol
Isotopes are: A. are only theoretical. B. only formed in laboratories. C. found in nature. D. found in the nuclear reactions in stars but not on Earth.
Answer:
B. only formed in laboratories
Explanation:
i know
Isotopes are only formed in Laboratories. hence, Option (B) is correct.
What are Isotopes ?
Each of two or more forms of the same element that contain equal numbers of protons but different numbers of neutrons in their nuclei, and hence differ in relative atomic mass but not in chemical properties; in particular, a radioactive form of an element is known as Isotope.
Isotopes are two or more types of atoms that have the same atomic number and position in the periodic table, and that differ in nucleon numbers due to different numbers of neutrons in their nuclei.
Therefore, Isotopes are only formed in Laboratories. hence, Option (B) is correct.
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The color cyan has a frequency of 5.902x10^14 What is the wavelength in nm ? Record your answer with 2
decimals.
The wavelength of the color cyan is 508 nm.
To solve the problem, we use the following equation that relates the frequency (ν) and the wavelength (λ) of a wave:
c = λ x ν
Given:
c = speed of light = 3.00 x 10⁸ m/s (is a constant)
ν = 5.902 x 10¹⁴ Hz = 5.902 s⁻¹
We introduce the data to calculate the wavelength in m:
λ = c/ν = (3.00 x 10⁸ m/s)/(5.902 s⁻¹) = 5.08 x 10⁻⁷ m
We know that 10⁻⁹m = 1 nm, so we convert λ to nm:
λ = 5.08 x 10⁻⁷ m x 1 nm/10⁻⁹m = 508 nm
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Which of the following substances can be used to neutralize HF?
A: HF
B: SO2
C: HCI
D: NaOH
Answer:
option (D) NaOH is right answer
A neutralization reaction is "a reaction in which an acid and a base react to form water and a salt and involves H+ ions and OH- ions to produce water.
What is an acid?An acid is "any hydrogen-containing substance that is capable of donating a proton or hydrogen ion to another substance".
What is base?Base is "a substance that gets dissociated in an aqueous solution to form hydroxide ions OH-".
Hence, NaOH can be used to neutralize HF.
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A capsule containing 0.500 L of air at 1.00 atm is compressed to 3.25 atm. At that point, what is the volume of the gas in the capsule?
Answer:
V₂ = 0.154 Liters
Explanation:
Pressure => P
Volume => V
Temperature => T
mass (moles) => n
This problem...
P₁ = 1.00 ATM P₂ = 3.25 ATM
V₁ = 0.500L V₂ = ?
T₁ = constant T₂ = T₁ = constant
n₁ = constant n₂= n₁ = constant
P₁V₁/n₁T₁ = P₂V₂/n₂T₂ => V₂ = V₁(P₁/P₂) = 0.500L (1.00ATM/3.25ATM) = 0.154 Liters
How does distance between two objects affect their gravitational force? (2 points)
a
Force increases as distance increases.
b
Force decreases as distance increases.
c
Force decreases as distance decreases.
d
Force is not related to distance.
Answer:
Option B: as the distance between the objects increases the Force of gravity decreases
What is Bose Einstein state of matter and their examples
Answer:
A BEC ( Bose - Einstein condensate ) is a state of matter of a dilute gas of bosons cooled to temperatures very close to absolute zero is called BEC.
Examples - Superconductors and superfluids are the two examples of BEC.
Explanation:
1. Explain the test for unsaturation.
2. Write down the balanced chemical equations for the complete and incomplete
combustion of octene
3. Explain how propanol, an alcohol, is formed from propene..
4. How is margarine formed?
Answer:
1)In organic chemistry, the bromine test is a qualitative test for the presence of unsaturation (carbon-to-carbon double or triple bonds), phenols and anilines. ... The more unsaturated an unknown is, the more bromine it reacts with, and the less coloured the solution will appear.
2)The equation for incomplete combustion of propane is: 2 C3H8 + 9 O2 → 4 CO2 + 2 CO + 8 H2O + Heat. If not enough oxygen is present for complete combustion, incomplete combustion occurs. The result of incomplete combustion is, once again, water vapour, carbon dioxide and heat. But it also produces carbon monoxide.
Explanation:
3)Propene, also known as propylene, is an unsaturated organic compound with the chemical formula {\displaystyle {\ce {CH3CH=CH2}}}. It has one double bond, and is the second simplest member of the alkene class of hydrocarbons. It is a colorless gas with a faint petroleum-like odor.
Formula: C3H6
IUPAC ID: Propene
4)Margarines are chemically created during hydrogenation which, until January 1, 2006, relied upon trans fats to solidify their vegetable oils. Food companies have been exploring options for replacing trans fat in partially hydrogenated margarine.
HELP ASAS 15 POINTS
When using the process of evaporation to separate a mixture, what is left behind in the evaporating dish?
A. None of these.
B. The liquid evaporates and the solid is left in the dish.
C. The mixture does not separate, and the entire mixture evaporates.
D. The mixture does not separate, and the entire mixture remains in the dish.
Answer:
liquid will be evaporated while solid remains
Tapeworm is grouped in the phylum Platyhelminthes
Answer:
Tapeworm, also called cestode, any member of the invertebrate class Cestoda (phylum Platyhelminthes), a group of parasitic flatworms containing about 5,000 species. ... Tapeworms also lack a circulatory system and an organ specialized for gas exchange.
calculate the total consumer surplus in the amusement park market if they a 12
Answer:
The total consumer surplus is 240.
Explanation:
If p=12 then q=20
0.5×(36−12)×20=240
here's the graph to help you see the change.
The specific heat capacity of lead is 0.13 J/g-K. How much heat (in J) is required to raise the temperature of 15 g of lead from 22 °C to 37 °C? a. 5.8 × 10-4 J b. 0.13 J c. 29 J d. 2.0 J e. -0.13 J
Answer:
c. 29 J
Explanation:
Step 1: Given data
Specific heat capacity of Pb (c): 0.13 J/g.K (= 0.13 J/g.°C)Mass of Pb (m): 15 gInitial temperature: 22 °CFinal temperature: 37 °CStep 2: Calculate the temperature change
ΔT = 37 °C - 22 °C = 15 °C
Step 3: Calculate the heat (Q) required to raise the temperature of the lead piece
We will use the following expression.
Q = c × m × ΔT
Q = 0.13 J/g.°C × 15 g × 15 °C = 29 J
The Nernst equation at 20oC is:
Eion= 58 millvolts/z. [log10 (ion)out/(ion)in]
Calculate the equilibrium potential for Cl- if the concentration of Cl- outside of the cell is 100 and the concentration inside of the cell is 10 mmol/liter.
a. 58 millivolts
b. +58 millivolts
c. -116 millivolts
d. 0
Answer:
a. -58 millivolts
Explanation:
The given Nernst equation is:
[tex]E_{ion} = 58 millivolts /z \Big[ log_{10} \Big( \dfrac{[ion]_{out}}{[ion]_{in}}\Big) \Big]}[/tex]
The equilibrium potential given by the Nernst equation can be determined by using the formula:
[tex]E_{Cl^-} = \dfrac{2.303*R*T}{ZF} \times log \dfrac{[Cl^-]_{out}} {[Cl^-]_{in}}[/tex]
where:
gas constant(R) = 8.314 J/K/mol
Temperature (T) = (20+273)K
= 298K
Faraday constant F = 96485 C/mol
Number of electron on Cl = -1
[tex]E_{Cl^-} = \dfrac{2.303*8.314*298} {(-1)*(96845)} \times log \dfrac{100} {10}[/tex]
[tex]E_{Cl^-} = - 0.05814 \ volts[/tex]
[tex]\mathsf{E_{Cl^-} = - 0.05814 \times 1000 \ milli volts}[/tex]
[tex]\mathsf{E_{Cl^-} \simeq - 58\ milli volts}[/tex]
Nucleophilic aromatic substitution involves the formation of a resonance-stabilized carbanion intermediate called a Meisenheimer complex as the nucleophile attacks the ring carbon carrying the eventual leaving group.
a. True
b. False
Answer:
True
Explanation:
Aromatic rings undergo nucleophillic substitution reactions in the presence of a electron withdrawing group which stabilizes the Meisenheimer complex.
When the nucleophile attacks the ring carbon atom carrying the eventual leaving group. A resonance-stabilized carbanion intermediate called a Meisenheimer complex is formed.
Subsequent loss of the leaving group from the intermediate complex yields the product of the reaction.
4. A sample of ammonia, NH3, contains 3.3 x 1021 hydrogen atoms. How many NH; molecules are in this sample?
Answer:
1.1 × 10²¹ NH₃ molecules
Explanation:
From the given information:
We were being told that the number of the hydrogen (H) atoms present in the sample of NH3 = 3.3 × 10²¹ hydrogen.
However, it signifies that each molecule of ammonia harbors 3hydrogen (H) atoms.
Hence, the number of molecules of NH₃ present;
[tex]\mathsf{=\dfrac{3.3\times 10^{21}}{3} \ molecules \ of \ {NH_3}}[/tex]
= 1.1 × 10²¹ NH₃ molecules
A sample of gas is held at constant volume. If the number of moles of this sample of gas is doubled and the pressure of this sample of gas is halved, what happens to the absolute temperature of the gas?
Select one
a. The absolute temperature is doubled.
b. The absolute temperature is halved.
c. The absolute temperature is quadrupled.
d. The absolute temperature is quartered.
e. The absolute temperature stays the same.
Answer:
number of moles of gas increases the volume also increases.
I need to know what is the median of the data
Answer:
The median is also the number that is halfway into the set. To find the median, the data should be arranged in order from least to greatest. If there is an even number of items in the data set, then the median is found by taking the mean (average) of the two middlemost numbers.
I hope it helps
Which of the following are examples of single replacement reactions? Select all that apply.
Answer:
Na2S(aq)+Cd(No3)2(aq)=CdS(s)+2NaNo3(aq)
Answer: it’s checkbox 2&3
The shape of a molecule is determined by:
A. All of these
B. The number of electron clouds around the atom.
C. The number of bonds.
D. Mutual repulsion between electrons.
How many neutrons does Carbon- 14 and Carbon -15 have? *
Answer: 8 for both
Explanation:
Hãy cho biết giá trị và ý nghĩa của số lượng tử n, l, m, ms khi mô tả trạng thái của electron trong nguyên tử?
At 445oC, Kc for the following reaction is 0.020. 2 HI(g) <--> H2 (g) + I2 (g) A mixture of H2, I2, and HI in a vessel at 445oC has the following concentrations: [HI] = 1.5 M, [H2] = 2.50 M and [I2] = 0.05 M. Which one of the following statements concerning the reaction quotient, Qc, is TRUE for the above system?
a. Qc = Kc; the system is at equilibrium.
b. Qc is less than Kc; more H2 and I2 will be produced.
c. Qc is less than Kc; more HI will be produced.
d. Qc is greater than Kc; more HI will be produced.
Explanation:
The given balanced chemical equation is:
[tex]2 HI(g) <--> H_2 (g) + I_2 (g)[/tex]
The value of Kc at 445oC is 0.020.
[HI]=1.5M
[H2]=2.50M
[I2]=0.05M
The value of Qc(reaction quotient ) is calculated as shown below:
Qc has the same expression as the equilibrium constant.
[tex]Qc=\frac{[H_2][I_2]}{[HI]^2} \\Qc=(2.50Mx0.05M)/(1.5M)^2\\Qc=0.055[/tex]
Qc>Kc,
Hence, the backward reaction is favored and the formation of Hi is favored.
Among the given options, the correct answer is option d. Qc is greater than Kc; more HI will be produced.
HELP!!!!! Substance A and substance B are mixed together. To separate the mixture, water is added, and substance A is filtered out. Then, the remaining liquid is heated to remove the water, leaving a residue of substance B. Which statement about substance A and substance B could be correct?
A. Substance A is rice, and substance B is sugar.
B. Substance A is alcohol, and substance B is salt.
C. Substance A is sand, and substance B is alcohol.
D. Substance A is sugar, and substance B is instant coffee.
The statement that "substance A is rice, and substance B is sugar" is correct.
WHAT IS A MIXTURE?
A mixture in chemistry is a substance that contains two or more different substances. One notable characteristics of a mixture is that it can easily be separated using physical means.According to this question, a mixture contains two substances A and B. Water is added to this mixture for easy separation.
Substance A is filtered out. This means that substance A is a solid that is insoluble in water. This substance is RICE. The remaining liquid is heated to remove the water content leaving a residue of substance B. This shows that substance B is also a solid but soluble in water. SUGAR best fits this description.Therefore, in the mixture of two substances A and B, substance A is rice, and substance B is sugar.
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what characterizes a homogeneous mixture?
Answer:
a mixture that doesn't really show the ingredients or things put into the material or food.
which of the following is is a chemical property of pure water
Answer:
Pure water has an acidity of about 7 on the pH scale. -is a chemical property of pure water. Pure water has an acidity of about 7 on the pH scale
Answer: không màu , không mùi không vị
Explanation:
Give the amino acid sequence in the following tetrapeptide using both 3-letter and 1-letter abbreviations for the amino acids. (Capitalize amino acid abbreviations appropriately.) ball
Answer:
ggggggggggggg
Explanation:
gggggggggggthyjum
Match each land resource to its use.
clay - used to make steel
iron ore - used to make batteries
salt - used to make pottery and tiles
aggregate - used in construction
graphite - used as a flavoring in food
i will give 10 points and brainliest!!!
Answer:
Explanation:
We are to match each land resource to what they are being used for.
Clay →→→ used to make pottery and tiles
iron ore →→→ used to make steel
Salt →→→ used as a flavoring in food
aggregate →→→ used in construction
graphite →→→ used to make batteries
Clay is a kind of soil particle that forms as a result of weathering processes. Examples include; pottery clays, glacial clays, and deep-sea clays e.t.c. The presence of one or more clay minerals, as well as variable quantities of organic and detrital components, characterizes all of them. Clay is usually sticky and moist when wet, but hard when dry. They are used in the making of tiles and potteries.
Iron ore: The iron ore deposits are found in the Earth's crust's sedimentary rocks. They're made up of iron and oxygen that mix during the chemical process in marine and freshwater. iron ores are used to produce almost every iron and steel product that we use today.
Aggregate: are utilized in construction activities. It is a material used to mix cement, gypsum, bitumen, or lime to produce concrete in the construction industry.
Graphite: Graphite is a mineral that occurs in both igneous and metamorphic rocks. It is generally generated on the earth's surface when carbon is exposed to high temperatures and pressures. It is mainly used in the production of batteries and electrodes,
If 50.0 g of sulfuric acid and 40.0 grams of barium chloride are mixed, how many grams of sulfuric acid and how many grams of barium chloride remain after the double replacement reaction is complete?
After the double replacement reaction is complete 0 grams of BaCl₂ and 31.16 grams of H₂SO₄ will remain.
First, we will write the balanced equation for the reaction
H₂SO₄ + BaCl₂ → BaSO₄ + 2HCl
This means 1 mole of BaCl₂ is needed to react completely with 1 mole of H₂SO₄ to give 1 mole of BaSO₄ and 2 moles of HCl
From the question, 50.0g of sulfuric acid is mixed with 40.0 grams of barium chloride. To determine the quantity of each substance remaining after the complete reaction, we will first determine the number of moles present in each of the reactant.
For H₂SO₄
mass = 50.0g
Molar mass = 98.079 g/mol
From the formula
Number of moles = Mass / Molar mass
∴ Number of moles of H₂SO₄ = 50.0g / 98.079 g/mol
Number of moles of H₂SO₄ = 0.5098 mol
For BaCl₂
mass = 40.0 g
Molar mass = 208.23 g/mol
∴ Number of moles of BaCl₂ = 40.0g / 208.23 g/mol
Number of moles of BaCl₂ = 0.1921 mol
Since the number of moles of H₂SO₄ is more than that of BaCl₂, then H₂SO₄ is the excess reagent and BaCl₂ is the limiting reagent (that is, it will be used up completely during the reaction)
From the equation, 1 mole of H₂SO₄ is needed to completely react with 1 mole of BaCl₂
∴ 0.1921 mol of H₂SO₄ will be needed to completely react with 0.1921 mol of BaCl₂.
Therefore, after the reaction is complete, 0 mole (i.e 0 grams) of BaCl₂ will remain and (0.5098 mole - 0.1921 mole) of H₂SO₄ will remain.
Number of moles H₂SO₄ that will remain = 0.5098 mole - 0.1921 mole = 0.3177 moles
Now, we will convert this to grams
From the formula
Mass = Number of moles × Molar mass
Mass of H₂SO₄ that will remain = 0.3177 moles × 98.079 g/mol
Mass of H₂SO₄ that will remain = 31.1597 g
Mass of H₂SO₄ that will remain ≅ 31.16 g
Hence, after the double replacement reaction is complete 0 grams of BaCl₂ and 31.16 grams of H₂SO₄ will remain.
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Tech A says that hydrocarbons are a result of complete combustion. Tech B says that a catalytic converter creates a chemical reaction, changing carbon monoxide and hydrocarbons to water and carbon dioxide. Who is correct
Answer:
Neither Tech A nor B is correct
Explanation:
Combustion is a chemical reaction that occurs when a chemical molecule(s) interacts quickly with oxygen and produces heat.
When hydrocarbon undergoes a complete combustion reaction, they produce water and CO2.
Tech B is also incorrect because the main purpose of a catalytic converter is to accelerate and speed up the chemical reaction rates, Hence, they are not involved in chemical reaction formation. Catalytic converters are utilized as a control device in exhaust emission to lessen the effect of toxic gas fumes.
A(n) _____, used as part of the stationary phase, has an affinity for the solvent and the chemical components of the mixture. adsorbent eluent Rf factor chromatogram
The Adsorbent is used as part of the stationary phase and has an affinity for the solvent and the chemical components of the mixture.
The adsorbent has a high affinity for solvent and the chemical components of the mixture.
Chromatography is a method of separation in which the mixture of substances is introduced into a mobile phase (solvent). The separation occurs as the solvent interacts with an adsorbent(stationary phase).
The extent of separation of the components of the mixture depends on the extent of interaction between the mobile and the stationary phase . This interaction also determines the retention factor (Rf) of the separation.
For a definition of chromatography, see
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