Explanation:
to find the number of moles for tetracycline you use the formula,
number of moles=mass/molar mass
the mass is given in the question which is 71.9g and the molar mass is 444.43(you find I by adding the number of atoms for each element in the compound,12×22+1×24+14×2+16×8)
n=71.9g/444.43
=0.16g/mol
I hope this helps
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
What is the hardest things in the world
Answer:
Diamond is the hardest things in the world
How many neutrons does Carbon- 14 and Carbon -15 have? *
Answer: 8 for both
Explanation:
công thức của định lý pytago
The sum of the squares of two sides of a right angle is equal to the square of the hypotenuse
#19.
An unknown sample weighs 45.2 g and takes 58.2 kJ to vaporize. What is
its heat of vaporization?
How many of shapes has the same number as the red oval.
The number of shapes that has the same number as the red oval is; 5
All the shapes has the same number as the red oval exempt the shape at the bottom right, this is because the text in the bottom right shape has one 8 missing at the end before 622.
Hence the number of shapes that has the same number as the red oval is 5
Learn more : https://brainly.com/question/24388778
The "Nutrition Facts" on a label of a 16 fluid ounce container of apple juice states that a serving size is 8 fluid ounces contains 176 Calories and 240 milligrams of potassium.
Nutrition Facts
Serving Size 8 fl. oz. (240mL)
Servings Per Container: 2
Amount Per Serving
Calories 176
% Daily Value*
Total Fat 0g 0 %
Sodium 32mg 1 %
Potassium 240mg 6 %
Total Carbohydrate 29g 10 %
Sugars 26g
Protein 0g
a) How many calories would 1 fluid ounce of apple juice contain?
b) How many milligrams of potassium would 1 fluid ounce of apple juice contain?
Answer:
a) 22 calories
b) 30 mg
Explanation:
Divide number of cal or mg of pot by 8 fl oz.
Select the number of valence electrons for hydrogen.
Answer:
Vanlency of hydrogen - 11
Electrons of hydrogen - 1
Answer:
The answer is: 1
Hope this helps :) <3
Explanation:
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]
Why does nitrogen not show allotropy?
Answer:
Nitrogen does not show allotropy because of its small size and high electronegativity. The single N-N bond is weaker than P-P bond because of high inter electronic repulsions among non-bonding electrons due to the small bond distance. Hence it does not show allotropy.
Answer:
The nitrogen atom has short inter-bond distance, hence highly electronegative in terms of magnitude. This creates no relation in energy varieties hence no allotropes formed.
Nitrogen atom is also very small.
PLEASE HELP I NEED THIS ASAP
Select all that apply.
The spectrum of Star S is compared to a reference hydrogen spectrum. What can be concluded about Star S?
Star S has radial motion.
Star S has transverse motion.
Star S is moving toward Earth.
Star S is moving away from Earth.
Answer:
I say Star S has radial motion
Explanation:
I'm not sure if it right but let me know if you have any other questions
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 have only a -C-O-C- functional group?
Answer:
B) ethers
Explanation:
The functional group of an organic compound defines its specificity. The functional group is responsible for the chemical behavior of an organic compound. For example, alkenes are known to have a carbon-carbon double bond (C=C) functional group.
Likewise, organic compounds known as ETHERS are known to possess an ethoxy functional group i.e. oxygen atom bonded to two alkyl groups (R- OR; where R is an alkyl group). Members of ether functional group includes dimethyl ether (CH3-O-CH3), diethyl ether (C2H5-O-C2H5).
Oxide is a combination of oxygen and another element. So is Water an oxide?
Answer:
Yah, it's a neutral oxide
Explanation:
[tex]{ \bf{2H_{2(g)} +O_{2(g)} \: →2H _{2}O _{(l)} }}[/tex]
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 13.4 mL sample of CO2 gas was collected in an experiment.
What is this volume in liters (L)? Use significant figures, do NOT include the units.
Explanation:
here's the answer to your question
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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The reversible reaction 2H2 CO <------> CH3OH heat is carried out by mixing carbon monoxide and hydrogen gases is a closed vessel under high pressure with a suitable catalyst . After equilibrium is established at high temperature and pressure, all three substances are present. If the pressure on the system is lower, with the temperature kept constant, what will be the result
Answer:
The amount of CH3OH present in the mixture would decrease
Explanation:
According to Le Cha-telier's principle, when a reaction is in equilibrium and one of the constraints that influence the rate of reactions is applied, the equilibrium would shift so as to neutralize the effects of the constraint.
In this case, looking at the equation of the reaction:
2H2 + CO <------> CH3OH + heat
the total number of moles on the reactant's (left hand) side is 3 (2+1) while on the product's (right hand) side, it is 1. If the pressure on the system is increased, more CH3OH (and less of H2 and CO) will be produced because its side has the lower number of moles out of the two sides.
If the pressure on the system is otherwise lowered, more of H2 and CO would be produced while the amount of CH3OH present would gradually decrease.
The element of the electron configuration is sodium. If it were to come near a fluorine atom, the sodium atom would give away its only valance electron to the fluorine atom have. That would make the sodium atom become positively charged and the fluorine atom become negatively charged.
Answer:
The answer is attached below
Explanation:
The answer is the photo attached
Test Question just answer random.
Answer:
U are a fool
Explanation:
Because you didn't even asked a question
Answer:
k.
Explanation:
A substance is made up of slow-moving particles that have very little space between them. Based on this information, what can most likely be concluded about this substance? O It is not a gas because its particles do not move continuously. It is a gas because its particles move continuously in a straight line. 0 It is not a gas because its particles do not have large spaces between them. It is a gas because its particles move in many different directions.
Answer:
o
Explanation:
it is not a gas because the particles do not move freely it may be a liquid or a solid partly and mostly liquidized.
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
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:
The standard free energy that is required for the sodium-potassium ATPase to pump two K ions into the cell and three Na ions is 43.8 kJ/mol but the standard free energy change of hydrolysis of ATP is only -32 kJ/mol. This apparent imbalance of free energy can be accounted for because ________.
Answer:
Explanation:
This apparent disparity of the free energy can be taken into account because:
the free energy produced by the hydrolysis of one ATP is adequate enough under psychological circumstances.
The Na-K ATPase aids the pumping of Na+ ions out of the cell and K+ ions into the cell. These actions occurring against their potential(concentration) gradients, which may be produced by hydrolyzing one ATP molecule.
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
Below is the structure of what should be the peptide Thr-Glu-Arg-Met. However, one of these residues has been drawn incorrectly. Identify this residue
Thr
Glu
Arg
Met
Answer:
the answer is glu and I know
The residue that has been drawn incorrectly is option (B) i.e. glu .
What is glutamate residue?Glutathione consists of a glutamate residue linked to cysteine via its γ-carboxyl rather than the α-carboxyl group and followed by a conventional peptide bond between cysteine and glycine.
It plays an important role in maintaining the proper ratio of oxidized to reduced forms of metabolically important thiols such as coenzyme A.
It also provides reducing equivalents that detoxify reactive oxygen species such as peroxides.
The tripeptide is regenerated through the concerted action enzymes in the so-called γ-glutamyl cycle.
The residue that has been drawn incorrectly is glutamate residue ,hence option (B) is correct.
Learn more about glutamate residue ,here:
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Enough of a monoprotic weak acid is dissolved in water to produce a 0.0118 M solution. The pH of the resulting solution is 2.32 . Calculate the Ka for the acid.
Answer:
1.94 × 10⁻³
Explanation:
Step 1: Calculate the concentration of H⁺ ions
We will use the definition of pH.
pH = -log [H⁺]
[H⁺] = antilog -pH = antilog -2.32 = 4.79 × 10⁻³ M
Step 2: Calculate the acid dissociation constant (Ka) of the acid
For a monoprotic weak acid, whose concentration (Ca) is 0.0118 M, we can use the following expression.
Ka = [H⁺]²/Ca
Ka = (4.79 × 10⁻³)²/0.0118 = 1.94 × 10⁻³
Given its formula and Avogadro's Number (6.02 x 10^23 molecules/mol), deduce how many molecules are present in 3 x 10^-16 grams of TCDD. Type in only a number without using scientific notation.
Answer:
5 × 10⁵ molecules (500,000 molecules)
Explanation:
Step 1: Convert 3 × 10⁻¹⁶ g to moles
We will use the molar mass of TCDD (321.97 g/mol).
3 × 10⁻¹⁶ g × 1 mol/321.97 g = 9 × 10⁻¹⁹ mol
Step 2: Convert 9 × 10⁻¹⁹ mol to molecules
The required conversion factor is Avogadro's number (6.02 × 10²³ molecules/mol).
9 × 10⁻¹⁹ mol × 6.02 × 10²³ molecules/1 mol = 5 × 10⁵ molecules
Why must oxidation be accompanied by a reduction?
A. The species being oxidized shares electron(s) with the species that is reduced
B. The species being oxidized takes electron(s) from some other
C. Electrons can be given up to free space. species being oxidized must transfer electron(s) to some othen
D. Electrons cannot just be given up to free space.
Answer:
A
Explanation:
because the species being oxidized shares electrons with the species that is reduced.making the oxidized element positively charged and the reduced element negatively charged.
I hope this helps
Alphabet:B. the species being oxidized takes electron from some other
how many moles of CO2 are formed from 3.0 mol of C2H2
Answer:
50.0 moles C02
Explanation:
First write down the CORRECTLY balanced equation. NOTE: The equation you provide is incorrect.
2C2H2(g) + 5O2(g) ==> 4CO2(g) + 2H2O(g) CORRECT EQUATION
Next, look at the stoichiometric ratio of C2H2 to CO2. You can see it is 2 moles C2H2 produces 4 moles CO2.
Thus, 25.0 moles C2H2 x 4 moles CO2/2 moles C2H4 = 50.0 moles CO2
