Answer:
4.515 × 10²³ atomsExplanation:
The number of atoms can be found by using the formula
N = n × L
where n is the number of moles
N is the number of entities
L is the Avogadro's constant which is
6.02 × 10²³ entities
From the question we have
N = 0.75 × 6.02 × 10²³
We have the final answer as
4.515 × 10²³ atomsHope this helps you
When an atom becomes charged what is transferred?
Answer:it becomes positively charged
Explanation:Some atoms can attract additional electrons so they become negatively charged.
3. Which of the following can be physically separated?
Answer:
mixture
Explanation:
an example of one is a salad you can separate the ingredients
THE DIAMETER OF A TAMBOURINE IS 10 INCHES.FIND THE AREA OF ITS SURFACE.USE π=3.14.
1.What is ask in the problem?
2.What are the given facts?
3.What operation to be used?
4.What is the number sentence
5.What is the answer?
Answer:
22/7 × [tex]10^{2}[/tex]
Explanation:
The area of a circle can be found out using π[tex]r^{2}[/tex]. Since r is the radius so if they multiply, they will give you an area of a square then multiply by 22/7 since it is a circle.
The surface area of the Tambourine at the given diameter of 10 inches is determined as 78.54 square inches.
Area of the TambourineA Tambourine has circular shape, and the area of the Tambourine can be determined by applying formula for area of a circle as shown below;
A = πr²
where;
r is the radius of the circleRadius of the Tambouriner = ¹/₂D
r = ¹/₂ x 10 in
r = 5 in
A = π(5)²
A = 25π in²
A = 78.54 in²
Thus, the surface area of the Tambourine at the given diameter of 10 inches is determined as 78.54 square inches.
Learn more about surface area here: https://brainly.com/question/76387
A buffer solution contains 0.475 M nitrous acid and 0.302 M sodium nitrite . If 0.0224 moles of potassium hydroxide are added to 150 mL of this buffer, what is the pH of the resulting solution
Answer: The pH of the resulting solution will be 3.001
Explanation:
Molarity is calculated by using the equation:
[tex]\text{Molarity}=\frac{\text{Moles}}{\text{Volume}}[/tex] ......(1)
We are given:
Moles of NaOH = 0.0224 moles
Molarity of nitrous acid = 0.475 M
Molarity of sodium nitrite = 0.302 M
Volume of solution = 150 mL = 0.150 L (Conversion factor: 1 L = 1000 mL)
Putting values in equation 1, we get:
[tex]\text{Moles of nitrous acid}=(0.475mol/L\times 0.150L)=0.07125mol[/tex]
[tex]\text{Moles of sodium nitrite}=(0.302mol/L\times 0.150L)=0.0453mol[/tex]
The chemical equation for the reaction of nitrous acid and NaOH follows:
[tex]HNO_2+NaOH\rightleftharpoons NaNO_2+H_2O[/tex]
I: 0.07125 0.0224 0.0453
C: -0.0224 -0.0224 +0.0224
E: 0.04885 - 0.0677
The power of the acid dissociation constant is the negative logarithm of the acid dissociation constant. The equation used is:
[tex]pK_a=-\log K_a[/tex] ......(2)
We know:
[tex]K_a[/tex] for nitrous acid = [tex]7.2\times 10^{-4}[/tex]
Using equation 2:
[tex]pK_a=-\log (7.2\times 10^{-4})=3.143[/tex]
To calculate the pH of the acidic buffer, the equation for Henderson-Hasselbalch is used:
[tex]pH=pK_a+ \log \frac{\text{[conjugate base]}}{\text{[acid]}}[/tex] .......(3)
Given values:
[tex][NaNO_2]=\frac{0.0677}{0.150}[/tex]
[tex][HNO_2]=\frac{0.04885}{0.150}[/tex]
[tex]pK_a=3.143[/tex]
Putting values in equation 3. we get:
[tex]pH=3.143-\log \frac{(0.0677/0.150)}{(0.04885/0.150)}\\\\pH=3.143-0.142\\\\pH=3.001[/tex]
Hence, the pH of the resulting solution will be 3.001
Write the molecular formula for the compound that exhibits a molecular ion at M+ = 112.0499. Assume that C, H, N, and O might be present, and use the exact masses below: Exact mass of carbon = 12.000 Exact mass of hydrogen = 1.0078 Exact mass of nitrogen = 14.003 Exact mass of oxygen = 15.995 (The order of atoms should be carbon, then hydrogen, then the others in alphabetical order. If there is more than one answer, just give one. ) Molecular formula:
Answer:
C₅H₈N₂O
Explanation:
The molecular formula denotes the various forms of atoms contained in a molecule at a particular fixed proportion.
The molecular ion M⁺ = 112.0499
and the exact mass values are given as follows:
C = 12.000
H = 1.0078
N = 14.003
O = 15.995
By assumption:
C = 12.000 × 5 = 60.0000
H = 1.0078 × 8 = 1.0078
N = 14.003 × 2 = 28.0060
O = 15.995 × 1 = 15.9950
= 112.0634
This is approximtely equal to 112.0499.
As such the Molecular formula for the compound = C₅H₈N₂O
Boric acid, B(OH)3, acts as an acid in water, but does not do so via ionization of a proton from boric acid. Use a balanced chemical equation to show why boric acid may be described as an acid in water.
Answer:
B(OH)₃ + H₂O = B(OH)₄⁻ + H⁺
Explanation:
Let's consider Arrhenius acid-base theory:
An acid is a substance that in aqueous media releases H⁺.A base is a substance that in aqueous media releases OH⁻.Boric acid, B(OH)₃ reacts with water according to the following equation.
B(OH)₃ + H₂O = B(OH)₄⁻ + H⁺
As we can see, boric acid releases H⁺ in aqueous media. Thus, it is an acid.
An atom has the electron configuration of 1s22s22p5 how many electrons are in that atom
Answer:
There are [tex]9[/tex] electrons in this atom.
Explanation:
Electron configuration of this atom: [tex]1s^2\, 2s^2\, 2p^5[/tex].
The electron orbitals of an atom are denoted as [tex]1s[/tex], [tex]2s[/tex], [tex]2p[/tex], [tex]3s[/tex], [tex]3p[/tex], etc. At any given time, an electron in this atom is located in exactly one orbital.
The electron configuration of an atom gives the number of electrons in each orbitals of this atom.
For example, in this atom, the superscript "[tex]2[/tex]" on the right of "[tex]1s[/tex]" means that there are two electrons in the [tex]1s\![/tex] orbital of this atom. Hence, [tex]1s^2\, 2s^2\, 2p^5[/tex] would translate to:
The [tex]1s[/tex] orbital of this atom contains [tex]2[/tex] electrons.The [tex]2s[/tex] orbital of this atom contains [tex]2[/tex] electrons.The [tex]2p[/tex] orbitals of this atom contain [tex]5[/tex] electrons.Hence, there would be [tex]2 + 2 + 5 = 9[/tex] electrons in total in this atom.
What happens when you increase the pressure on the following
reaction
2X(g) + 3Y(g) --> 5Z(g) + heat
Answer:
When pressure increases, there is no effect on the reaction because volume is constant.
A sample of carbon tetrachloride (CCl4) contains 3 moles of the substance. How many atoms are there in the sample?
Answer:
1.806 × 10²⁴ atoms
Explanation:
To obtain the number of atoms a substance contain, we have to multiply the number of moles in that substance (n) by Avogadro's number, which is 6.02 × 10²³.
According to this question, a sample of carbon tetrachloride (CCl4) contains 3 moles of the substance. The number of atoms in CCl4 is calculated thus:
number of atoms = 3 × 6.02 × 10²³
number of atoms = 18.06 × 10²³
number of atoms = 1.806 × 10²⁴ atoms.
Compound A has the formula C8H8. It reacts rapidly with acidic KMnO4 but reacts with only 1 equivalent of H2 over a palladium catalyst. On hydrogenation under conditions that reduce aromatic rings, A reacts with 4 equivalents of H2, and hydrocarbon B, C8H16, is produced. The reaction of A with KMnO4 gives CO2 and a carboxylic acid C, C7H6O2.
Required:
Draw the structure of compound B below.
Answer:
C8H16 (Ethylcyclohexane).
Explanation:
From the given information:
Compound A is an alkene because it interacts with 1 unit of hydrogen across a palladium catalyst.
Also, we are given another hint that:
Compound A needs 4 equivalence of H2 to hydrogenate under circumstances that decrease aromatic rings, indicating that it is a phenyl substituted alkene.
Compound A with formula C8H8 reacts instantly with KMnO4 to produce CO2, as well as carboxylic acid, points out that Compound acts as a terminal alkene.
Therefore, we can opine that compound A is a terminal phenyl substituted alkene whose formula = C8H8 (Styrene)
The diagrammatic expression of the compound can be seen below.
However, in the presence of the palladium catalyst, the reduction of Compound A with 4 units of hydrogen produces Compound B: C8H16 (Ethylcyclohexane).
171 g of sucrose ( MW of 342, melting point 186 oC, boiling point very high, and vapor pressure is negligible) is dissolved in one liter of water at 25 oC. At 25 oC the vapor pressure of water is 24 mmHg. Which value is closest to the vapor pressure (VP) of this solution at 25 oC?
The complete question is as follows: 171 g of sucrose ( MW of 342, melting point 186 oC, boiling point very high, and vapor pressure is negligible) is dissolved in one liter of water at 25 oC. At 25 oC the vapor pressure of water is 24 mmHg. Which value is closest to the vapor pressure (VP) of this solution at 25 oC?
a. 16mm Hg
b. 24mm Hg
c. 20mm Hg
d. 12mm Hg
Answer: The vapor pressure (VP) of this solution at [tex]25^{o}C[/tex] is closest to the value 24 mm Hg.
Explanation:
Given: Mass of sucrose = 171 g
Mass of water = 1 L = 1000 g
Vapor pressure of water = 24 mm Hg
As moles is the mass of substance divided by its molar mass. Hence, moles of water (molar mass = 18.02 g) is calculated as follows.
[tex]Moles = \frac{mass}{molar mass}\\= \frac{1000 g}{18.02 g/mol}\\= 55.49 mol[/tex]
Similarly, moles of sucrose (molar mass = 342 g/mol) is as follows.
[tex]Moles = \frac{mass}{molar mass}\\= \frac{171 g}{342 g/mol}\\= 0.5 mol[/tex]
Total moles = 55.49 + 0.5 mol = 55.99 mol
Mole fraction of water is as follows.
[tex]Mole fraction = \frac{moles of water}{total moles}\\= \frac{55.49}{55.99}\\= 0.99[/tex]
Formula used to calculate vapor pressure of the solution is as follows.
[tex]P_{i} = P^{o}_{i} \times \chi_{i}[/tex]
where,
[tex]P_{i}[/tex] = vapor pressure of component i over the solution
[tex]P^{o}_{i}[/tex] = vapor pressure of pure component i
[tex]\chi_{i}[/tex] = mole fraction of i
Substitute the values into above formula to calculate vapor pressure of water as follows.
[tex]P_{i} = P^{o}_{i} \times \chi_{i}\\= 24 mm Hg \times 0.99\\= 23.76 \\or 24 mm Hg\\[/tex]
Thus, we can conclude that the vapor pressure (VP) of this solution at [tex]25^{o}C[/tex] is closest to the value 24 mm Hg.
How does the law of conservation of mass relate to the number of atoms of each element that are present before a reaction vs. the number of atoms of each element that are present after a chemical reaction?
sino may kuyang palaging nambibira
Calcula la concentración de H+ de una sustancia que tiene pH 8.8
Answer:
[tex]pH = - log[H {}^{ + } ] \\ 8.8 = - log[H {}^{ + } ] \\ \: [H {}^{ + } ] = {10}^{ - 8.8} \\ [H {}^{ + } ] = 1.585 \times {10}^{ - 9} \: mol {dm}^{ - 3} [/tex]
The information code that an organism inherits can best be referred to as its -
O A genotype
B. territory
C. species
D. kingdom
Answer:
it will be no.A genotype
On another planet, the isotopes of titanium have the given natural abundances.
Isotope Abundance Mass (u)
46Ti 77.100% 45.95263
48Ti 17.100% 47.94795
50Ti 5.800% 49.94479
What is the average atomic mass of titanium on that planet?
Answer:
46.525 u
Explanation:
From the question given above, the following data were obtained:
Isotope A (⁴⁶Ti)
Abundance (A%) = 77.100%
Mass of A = 45.95263 u
Isotope B (⁴⁸Ti):
Abundance (B%) = 17.100%
Mass of B = 47.94795 u
Isotope C (⁵⁰Ti):
Abundance (C%) = 5.800%
Mass of C = 49.94479 u
Average atomic mass =?
The average atomic mass of titanium can be obtained as follow:
Average = [(Mass of A × A%)/100] + [(Mass of B × B%)/100] + [(Mass of C × C%)/100]
= [(45.95263 × 77.1)/100] + [(47.94795 × 17.1)/100] + [(49.94479 × 5.8)/100]
= 35.429 + 8.199 + 2.897
= 46.525 u
Therefore, the average atomic mass of titanium is 46.525 u
Please select the word from the list that best fits the definition
Include skin, the respiratory system, the circulatory system, and inflammation
A. antibody
B. antigen
C.Natural Defences
D.active immunity
Answer:
I choose D option because may be it's correct
I believe it is c
Explanation:
because if u think about it and also do some research you would see that the circulatory system is a strong part of your body which can help u through natural defences if this sounds weird it's all in research but if it ain't c dont blame me for ruining your life- lol but yeah I think its c
You have selected your two primers and added all of the PCR components to a test tube. Use the answer choices [A-C] to explain what will happen as the polymerase chain reaction proceeds. Answers may be used more than once or not at all.
Hi. You did not provide any response options. However, a PCR reaction proceeds as follows.
After the primers are added to the test tube containing the PCR components. This tube is placed in a device called a thermocycler. At that moment, the stage called denaturation will begin, where the thermocycler increases the temperature to the point of breaking the hydrogen bonds that hold the two strands of DNA together. The thermal cycler increases the temperature up to 96°C.
After that, the second step of the reaction begins. At that moment, the thermal cycler lowers the temperature to 55º - 65ºC, which is the ideal temperature for the primers to be able to attach themselves to the DNA strands, preparing them for the presence of the polymerase.
After that, the thermocycler raises the temperature to 72ºC, which is the ideal temperature for the DNA polymerase to work. At this stage, the DNA polymerase will use the DNA strand and the primer to build a new DNA strand, which will be annealed to the DNA strand used as a template.
These three steps will be repeated about 35 times, generating many copies of DNA.
An unknown element, X, has an atomic mass of 107.868 amu. The X-109 isotope (108.905 amu) is 48.16%. What is the amu of the other isotope (report final answer to the correct number of significant figures)
Answer:
106.905 amu is the mass of the other isotope
Explanation:
The atomic mass of an element is the sum of the masses of the isotopes multiplied by its abundance. The atomic mass of an element X with 2 isotopes is:
X = X-109*i + X-107*i
Where X is the atomic mass = 107.868 amu
X-109 = 108.905amu, i = 48.16% = 0.4816
X-107 = ?, i = 1-0.4816 = 0.5184
Replacing:
107.868amu = 108.905amu*0.4816 + X-107*0.5184
55.4194 = X-107*0.5184
106.905 = X-107
106.905 amu is the mass of the other isotopeThe energy released by a nuclear fusion reaction is produced when
A.
energy is converted to mass
B.
mass is converted to energy
C.
heat is converted to temperature
D.
temperature is converted to heat
The nuclear fusion results in the liberation of large amount of energy by the conversion of mass to energy. Thus, option B is correct.
The nuclear fusion has been a type of nuclear reaction in which the reaction of the two nuclei results in the nuclei with mass smaller than the reactants. In nuclear reactions, there has been the liberation of large amount of energy.
The energy released in the nuclear fusion has been formed by the conversion of the mass. Since, the formed product has nuclei with the mass smaller than the reactants, the remaining mass of the reactants has been converted to the energy.
Thus, in nuclear fusion, the energy released has been produced from the conversion of mass to energy. Thus, option B is correct.
For more information about the nuclear fusion, refer to the link:
https://brainly.com/question/16021285
Hydrogen bonds within liquid water are attractions between protons and hydroxide ions. are dipole-dipole attractions. are ion-induced dipole attractions. are attractions between protons and oxygen nuclei. are attractions between two hydrogen atoms.
Answer:
true because the bonds cannot be broken down
Write the molecular formula for the compound that exhibits a molecular ion at M+ = 112.0499. Assume that C, H, N, and O might be present, and use the exact masses below:
Exact mass of carbon = 12.000
Exact mass of hydrogen = 1.0078
Exact mass of nitrogen = 14.003
Exact mass of oxygen = 15.995
The order of atoms should be carbon, then hydrogen, then the others in alphabetical order.
Answer:
C₆H₁₀NO
Explanation:
In order to arrive at a molecular formula we have to make some assumptions and they are
Assuming there is one ( 1 ) N and one ( 1 ) O that is present in the said molecule
Total mass = 29.998
next step: subtract the total mass from 112.0499 = 82.501
next : assume the presence of 6 carbon atoms in said molecule
Total mass = 6 * 12 = 72
Mass of Hydrogens = 82.501 - 72 = 10.501
∴ number of hydrogens = 10.501 / 1.0078 ≈ 10
Hence Total mass = 29.998 + 82.501 ≈ 112.0499
Finally Molecular formula = C₆H₁₀NO
Suppose that you add 29.2 g of an unknown molecular compound to 0.250 kg of benzene, which has a K f of 5.12 oC/m. With the added solute, you find that there is a freezing point depression of 2.78 oC compared to pure benzene. What is the molar mass (in g/mol) of the unknown compound
Answer:
Suppose that you add 29.2 g of an unknown molecular compound to 0.250 kg of benzene, which has a K f of 5.12 oC/m. With the added solute, you find that there is a freezing point depression of 2.78 oC compared to pure benzene. What is the molar mass (in g/mol) of the unknown compound
Explanation:
The mass of nonvolatile solute added is ---- 29.2g
The mass of solvent benzene is ---- 0.250kg = 250g
The Kf value of benzene is ---- 5.12^oC/m.
Depression in the freezing point of the solution is --- 2.78^oC.
What is the molar mass of the unknown solute?
[tex]The depression in freezing point = Kf * molality of the solution\\molality of the solution = \frac{mass of solute}{molar mass of solute}*\frac{1}{mass of solvent in kg}[/tex]
Substitute the given values in this formula to get the molar mass of unknown solvent:
[tex]molality=\frac{29.2g}{M} * \frac{1}{0.250kg} \\depression in freezing point:\\2.78^oC=5.12^oC/m * \frac{29.2g}{M} * \frac{1}{0.250kg} \\\\=>M=5.12^oC/m * \frac{29.2g}{2.78^oC} * \frac{1}{0.250g} \\\\\\=>M=215.1g/mol[/tex]
Hence, the molar mass of unknown solute is --- 215g/mol.
Which of the following has the highest pH?
A. 0.01 M HCI
B. 0.1 M HCI
C. 1 M HCI
D. 0.001 M HCI
Answer:
D
Explanation:
pH=-log(x)
x=0.001M,pH=3
x=0.01M,pH=2
x=0.1M,pH=1
x=1M,pH=0
Highest pH is for option D
Answer:
D.
Explanation:
The highest pH is D because
0.01 M HCL => 2
0.1 M HCL => 1
1 M HCL => 0
0.001 M HCL => 3
so the answer is D.
Determine the electron geometry, molecular geometry, and idealized bond angles for each of the following molecules. CF4CF4 NF3NF3 OF2OF2 H2SH2S In which cases do you expect deviations from the idealized bond angle
Answer:
CF4
Molecular geometry- tetrahedral
Electron geometry- tetrahedral
NF3
-molecular geometry - trigonal pyramidal
Electron geometry - tetrahedral
OF2
Molecular geometry - bent
Molecular geometry - tetrahedral
H2S
Molecular geometry- bent
Electron geometry - tetrahedral
Explanation:
According to Valence Shell Electron Pair Repulsion Theory, the shape of a molecule depends on the number of electron pairs on the valence shell of the central atom in the molecule.
For all the compounds listed, the central atom has four points of electron density. This correspond to a tetrahedra electron pair geometry. The presence of lone pairs on the central atom of OF2,NF3 and H2S accounts for the departure of the observed molecular geometry from the geometry and idealized bond angle predicted on the basis of the VSEPR theory.
A 250ml sample of sir at 373.15k is warmed at 473.15 at constant pressure. What is the volume of the air sample at the new temperature
Answer:
317 mL.
Explanation:
From the question given above, the following data were obtained:
Initial volume (V₁) = 250 mL
Initial temperature (T₁) = 373.15 K
Final temperature (T₂) = 473.15 K
Pressure = Constant
Final volume (V₂) =?
The final volume of the air sample can be obtained by using the Charles' law equation as illustrated below:
V₁/T₁ = V₂/T₂
250 / 373.15 = V₂ / 473.15
Cross multiply
373.15 × V₂ = 250 × 473.15
373.15 × V₂ = 118287.5
Divide both side by 373.15
V₂ = 118287.5 / 373.15
V₂ = 317 mL
Therefore, the final volume of the air sample is 317 mL
50.00 mL of unknown calcium hydroxide solution is titrated with 0.250 M standard nitric acid solution. If 43.43 mL of the standard acid solution is required to reach a phenolphthalein endpoint, what is the molarity of the unknown calcium hydroxide solution
Answer: Molarity of the unknown calcium hydroxide solution is 0.217 M.
Explanation:
Given: [tex]V_{1}[/tex] = 50.00 mL, [tex]M_{1}[/tex] = ?
[tex]V_{2}[/tex] = 43.43 mL, [tex]M_{2}[/tex] = 0.250 M
Formula used is as follows.
[tex]M_{1}V_{1} = M_{2}V_{2}[/tex]
Substitute the values into above formula as follows.
[tex]M_{1}V_{1} = M_{2}V_{2}\\M_{1} \times 50.00 mL = 0.250 M \times 43.43 mL\\M_{1} = \frac{0.250 M \times 43.43 mL}{50.00 mL}\\= 0.217 M[/tex]
Thus, we can conclude that molarity of the unknown calcium hydroxide solution is 0.217 M.
C8H18+O2=CO2+H2O. Balance this equation and identify the number H2O molecules formed when 6 molecules of C8H18 react with 75 molecules of oxygen
Answer: 54 molecules of water will be formed in the reaction.
Explanation:
A balanced chemical equation is one where all the individual atoms are equal on both sides of the reaction. It follows the law of conservation of mass.
For the given unbalanced chemical equation, the balanced equation follows:
[tex]2C_8H_{18}+25O_2\rightarrow 16CO_2+18H_2O[/tex]
We are given:
Molecules of [tex]C_8H_{18}[/tex] = 6
Molecules of [tex]O_2[/tex] = 75
By the stoichiometry of the reaction:
If 2 molecules of [tex]C_8H_{18}[/tex] produces 18 molecules of water
So, 6 molecules of [tex]C_8H_{18}[/tex] will produce = [tex]\frac{18}{2}\times 6=54[/tex] molecules of water
Hence, 54 molecules of water will be formed in the reaction.
19. What is the molarity of a
solution that contains 6 liters
of solution and 2 moles of
solute?
a. 8 M
b. 0.3 mol/L
c. 12 mol/L
d. 3M
Answer:
b. 0.3 mol/L is the closest.
Explanation:
A molar solution of a substance contains 1 mole per liter of solution
So if we have 2 moles in 6 liters the there are 2/6 =1/3 of a mole in 1 liter.
Discuss the any two applications of Beer’s law with suitable justification.
Answer: It's used in chemistry to measure the concentration of chemical solutions.
Explanation:
Beer's Law is used in chemistry to measure the concentration of chemical solutions, to analyze oxidation, and to measure polymer degradation.
The law also describes the attenuation of radiation through the Earth's atmosphere
