Answer:
solubility is 1.984x10⁻⁹M
Explanation:
When CaCO₃ is in water, the equilibrium that occurs is:
CaCO₃(s) ⇄ Ca²⁺(aq) + CO₃²⁻(aq)
Kps = [Ca²⁺] [CO₃²⁻] = 4.96x10⁻⁹
If you have a 0.250M solution of Na₂CO₃, [CO₃²⁻] = 0.250M:
[Ca²⁺] [0.250M] = 4.96x10⁻⁹
Assuming you are adding an amount of CaCO₃:
[X] [0.250 + X] = 4.96x10⁻⁹
Where X is the amoun of CaCO₃ you can add, that means, solubility
X² + 0.250X - 4.96x10⁻⁹ = 0
Solving for X:
X = -0.25M → False answer, there is no negative concentrations.
X = 1.984x10⁻⁹M.
That means, solubility is 1.984x10⁻⁹M
Answer:
[tex]1.984x10^{-8}M[/tex]
Explanation:
Hello,
In this case, the equilibrium reaction for the solubility of calcium carbonate is:
[tex]CaCO_3(s) \rightleftharpoons Ca^{2+}(aq)+CO_3^{-2}(aq)[/tex]
In such a way, since 0.250 M sodium carbonate solution is the solvent, we assume an initial concentration of carbonate anion to be also 0.250 M since sodium carbonate is completely dissolved, for that reason the equilibrium equation turns out:
[tex]Ksp=[Ca^{2+}][CO_3^{2-}]\\\\4.96x10^{-9}=x*(0.250+x)[/tex]
Hence, solving for [tex]x[/tex] we have:
[tex]x=1.984x10^{-8}M[/tex]
Which corresponds to the molar solubility if calcium carbonate as well.
Regards.
Select all the correct answers.
What are three disadvantages of making and using plastic?
a. it pollutes the land and water
b. it requires cutting down trees from raw materials
c. it takes an incredibly long time to break down
d. it freely conducts heat and electricity
f. it isn't easy to recycle
Answer:
it is either a or c because they make the most sense
How many atoms are in a sample of 1.83 moles of potassium (K) atoms? How many atoms are in a sample of 1.83 moles of potassium (K) atoms?
Answer:
Avogadro's number represents the number of units in one mole of any substance. This has the value of 6.022 x 10^23 units / mole. This number can be used to convert the number of atoms or molecules into number of moles.
1.83 moles K (6.022 x 10^23 atoms / mole ) = 1.10 x 10^24 atoms K
Explanation:
1.83 moles K (6.022 x 10^23 atoms / mole ) = 1.10 x 10^24 atoms
1.What volume of 0.871 M oxalic acid contains 86.9 g of oxalic acid (H2C2O4)?
Answer:
1.11 L
Explanation:
Given data
Molarity of the oxalic acid solution (M): 0.871 MMass of oxalic acid (m): 86.9 gStep 1: Calculate the moles corresponding to 86.9 g of oxalic acid
The molar mass of oxalic acid is 90.03 g/mol.
[tex]86.9g \times \frac{1mol}{90.03g} = 0.965 mol[/tex]
Step 2: Calculate the volume of a 0.871 M solution that contains 0.965 moles of oxalic acid
The molarity is equal to the moles of solute (n) divided by the volume of the solution (V).
[tex]M = \frac{n}{V} \\V = \frac{n}{M} = \frac{0.965mol}{0.871 mol/L} =1.11 L[/tex]
The following reaction was performed in a sealed vessel at 734 ∘C : H2(g)+I2(g)⇌2HI(g) Initially, only H2 and I2 were present at concentrations of [H2]=3.75M and [I2]=2.15M . The equilibrium concentration of I2 is 0.0800 M . What is the equilibrium constant, Kc, for the reaction at this temperature? Express your answer numerically.
Answer:
128
Explanation:
Step 1: Write the balanced equation
H₂(g) + I₂(g) ⇌ 2 HI(g)
Step 2: Make an ICE chart
H₂(g) + I₂(g) ⇌ 2 HI(g)
I 3.75 2.15 0
C -x -x +2x
E 3.75-x 2.15-x 2x
Step 3: Find the value of x
Since the concentration of I₂ at equilibrium is 0.0800 M,
2.15M-x = 0.0800 M
x = 2.07 M
Step 4: Calculate the concentrations at equilibrium
[H₂] = 3.75-x = 3.75-2.07 = 1.68 M
[I₂] = 0.0800 M
[HI] = 2x = 2(2.07) = 4.14 M
Step 5: Calculate the equilibrium constant Kc
[tex]Kc= \frac{[HI]^{2} }{[H_2]\times [I_2]} = \frac{4.14^{2} }{1.68\times 0.0800} = 128[/tex]
Sodium (Na) reacts with chlorine gas to form the ionic compound NaCl. Which of the following statements is true? A The reaction leaves each atom more unstable. B Sodium gains electrons from the chlorine to form the sodium ion. C Sodium ions are anions in the ionic bond. D By reacting, each atom fills its outer energy level with electrons.
Answer:
D
Explanation:
When Na and Cl react, Na gives up one electron to Cl to fill both their valence electron shells. Both atoms are more stable, chlorine gains the electrons, and chloride is the anion.
Answer: D. After reacting, each ion has a stable octet. (For Gradpoint)
Explanation:
empirical formula for H2Cl2O6
Answer:
HClO₃
Explanation:
Empirical formula of a chemical compound is defined as the simplest ratio of atoms presents in the compound (In whole numbers).
For the H₂Cl₂O₆ the empirical formula could be obtained dividing in 2 the formula. That is:
HClO₃ → This is the simplest ratio of atoms presents in the compound, that is, the empirical formula
A mixture of krypton and argon gases, at a total pressure of 733 mm Hg, contains 3.97 grams of krypton and 6.34 grams of argon. What is the partial pressure of each gas in the mixture?
Answer:
Partial pressure of krypton= 167.12 mmHg
Partial pressure of argon = 565.88 mmHg
Explanation:
The partial pressure of a gas in a mixture of gasses is equal to the total pressure multiplied (Pt) by the mole fraction of the gas (X):
P= X Pt
The total pressure is Pt= 733 mmHg
The mole fraction is given by the following:
X = number of moles of gas/ total number of moles
For krypton (Kr) , the molecular weight is 83.8 g/mol and we calculate the number of moles by dividing the mass into the molecular weight as follows:
moles of Kr = 3.97 g/(83.8 g/mol)= 0.047 moles
For argon (Ar), the molesular weight is 39.9 g/mol, so we calculate the number of moles as follows:
moles of Ar = 6.34 g/(39.9 g/mol)= 0.159
Now, we calculate the total number of moles (nt):
nt= moles of Kr + moles of Ar = 0.047 moles + 0.159 moles = 0.206 moles
The mole fraction of each gas is now calculated:
X(Kr)= moles of Kr/nt = 0.047 moles/0.206 = 0.228
X(Ar)= moles of Ar/nt = 0.159 moles/0.206 = 0.772
Finally, with the mole fractions and the total pressure we calculate the partial pressure of each gas as follows:
P(Kr) = X(Kr) x Pt = 0.228 x 733 mmHg= 167.12 mmHg
P(Ar) = X(Ar) x Pt = 0.772 x 733 mmHg= 565.88 mmHg
If you touch a hot stove, the nervous system works closely with which other organ system to help your body react by pulling away quickly
1 Skeletal System
2 Muscular System
3 Digestive System
4 Circulatory System
Answer:
2. Muscular System
Explanation:
The muscular system is associated with body motion. Hence, the right answer is option 2.
NF3 Draw the molecule by placing atoms on the grid and connecting them with bonds. Include all lone pairs of electrons. +- CHONSPFBrClIXMore Request Answer Part B HBr Draw the molecule by placing atoms on the grid and connecting them with bonds. Include all lone pairs of electrons. +- CHONSPFBrClIXMore Request Answer Part C SBr2 Draw the molecule by placing atoms on the grid and connecting them with bonds. Include all lone pairs of electrons. +- CHONSPFBrClIXMore Request Answer Part D CCl4 Draw the molecule by placing atoms on the grid and connecting them with bonds. Include all lone pairs of electrons. +- CHONSPFBrClIXMore Request Answer Provide Feedback
Here is the correct question.
Draw the molecule by placing atoms on the grid and connecting them with bonds. Include all lone pairs of electrons.
NF3
SBr2
CCl4
Answer:
Explanation:
The objective here is to draw the molecule three molecules by placing atoms on the grids and connecting them with their respective bonds, therefore including all the lone pairs of electrons.
See the attachment below for the diagrams.
The first compound is know as Nitrogentrifluoride. A non-flammable greenhouse gas. It is majorly used for he production of semi conductors. It has a trigonal planar structure.
SBr2: Sulfur dibromide is a yellowish liquid toxic gas. It results as a reaction between SCl_2 and HBr. Its has a Bent Structure.
CCl_4 : carbon tetrachloride has the presence of a colourless liquid with a sweet smell. Carbon tetrachloride is used for different domestic uses such as: cleaning surfaces, fumigating, cleaning metals etc. It has a tetrahedral structure.
Which quantum number describes the energy level of an electron?
Spin quantum number
Principal quantum number
Magnetic quantum number
Angular momentum quantum number
Answer:
principle quantum number :)
Explanation:
I took the test and got it right
Quantum numbers are defined as the set of four numbers with the help of which we can get complete information about the electrons in an atom. The energy level of an electron is given by Principal quantum number. The correct option is B.
What is Principal quantum number?The Principal quantum number represents the main energy level or shell in which the electron is present. It also determines the average distance of the orbital or electron from the nucleus. It is denoted by the letter 'n' and can have any whole number values like 1, 2, 3, 4,....
The value of principal quantum number usually stand for different energy shells K, L, M, N .... the value of 'n' can be any integer with a positive value which is equal to or greater than 1.
The value of 'n' denotes the innermost electron shell of an atom which indicates the lowest energy state of an electron. It cannot be a negative value.
Thus the correct option is B.
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In the reaction of silver nitrate and sodium chloride to produce solid silver chloride, sodium ions and nitrate ions are ________. spectator ions gases solvents liquids molecules
Answer: spectator ions
Explanation:
A double displacement reaction is one in which exchange of ions take place. The salts which are soluble in water are designated by symbol (aq) and those which are insoluble in water and remain in solid form are represented by (s) after their chemical formulas.
Spectator ions are defined as the ions which does not get involved in a chemical equation or they are ions which are found on both the sides of the chemical reaction present in ionic form.
The total ionic chemical equation is:
[tex]Ag^+(aq)+NO_3^-(aq)+Na^+(aq)+Cl^-(aq)\rightarrow AgCl+Na^+(aq)+NO_3^-(aq)[/tex]
The ions which are present on both the sides of the equation are sodium and nitrate ions which are called as spectator ions and hence are not involved in net ionic equation.
A velocity vs time graph is a graph that shows the relationship between the velocity of an object over time___is plotted on the x-axis in seconds, and the___of the object is plotted on the y-axis in meters per second.
Answer:
i have the same question
Explanation:
A 10.17-g sample of solid sodium bicarbonate (the active ingredient in baking soda) completely decomposes into solid sodium hydroxide and carbon dioxide gas when heated. After the sodium hydroxide cools, it has a mass of 4.84 g. According to the law of conservation of mass, what mass of carbon dioxide must have been formed?
Answer:
5.33 g
Explanation:
Let's consider the balanced reaction for the complete decomposition of solid sodium bicarbonate to form solid sodium hydroxide and carbon dioxide gas when heated.
NaHCO₃(s) → NaOH(s) + CO₂(g)
According to Lavoisier's law of conservation of mass, the sum of the masses of the reactants is equal to the sum of the masses of the products. Then,
m(NaHCO₃) = m(NaOH) + m(CO₂)
m(CO₂) = m(NaHCO₃) - m(NaOH)
m(CO₂) = 10.17 g - 4.84 g
m(CO₂) = 5.33 g
An analytical chemist is titrating 60.5mL of a 0.8700M solution of benzoic acid HC6H5CO2 with a 0.3600M solution of KOH . The pKa of benzoic acid is 4.20 . Calculate the pH of the acid solution after the chemist has added 172.mL of the KOH solution to it. Note for advanced students: you may assume the final volume equals the initial volume of the solution plus the volume of KOH solution added. Round your answer to 2 decimal places.
Answer:
The correct answer is 12.6.
Explanation:
The formation of benzoate takes place when potassium hydroxide reacts with benzoic acid, due to the presence of a weak acid and its conjugated base the solution will act as a buffer. In the given question, the molarity of benzoic acid given is 0.8700 M and its volume is 60.5 ml. Therefore, the moles of benzoic acid will be,
Moles = molarity * volume of solution
= 0.8700 M * 60.5 ml = 52.365 m mol or 0.052365 moles
On the other hand, the molarity of KOH given is 0.3600 M and the volume given is 172 ml. Therefore, the moles of KOH added will be,
Moles = 0.3600 * 172 = 61.92 m moles or 0.06192 moles
Out of this 61.92 m mol, only 52.365 m mol of KOH will react with the benzoic acid. The moles of KOH, which remain unreactive is,
61.92 m moles - 52.365 m moles = 9.285 m moles or 0.009285 moles
The formula for calculating molarity is number of moles / volume of solution in liters
The total volume of the solution is 172 ml + 60.5 ml = 232.5 ml or 0.2325 L
The molarity of KOH will be,
Molarity = 0.009285 moles / 0.2325 L = 0.0395 M
The dissociation of KOH takes place completely to produce hydroxide ion.
pOH = -log[0.0395] = 1.4
pH + pOH = 14
pH = 14 - 1.4 = 12.6
In 1782 a French chemist named ________ proposed a systematic nomenclature for naming chemical compounds.
Answer:
Louis-Bernard Guyton De Morveau
Explanation:
He is who proposed the first systematic nomenclature for naming chemical compounds.
A solution is prepared by dissolving 0.5482 grams of iron(III) nitrate in enough water to make 100.0 mL of solution. A 10.00 mL aliquot (portion) of this solution is then diluted to a final volume of 250.0 mL. What is the concentration of Fe3 ions (M) in the final solution
Answer:
[tex]C_2=9.066x10^{-4}M[/tex]
Explanation:
Hello,
In this case, the first step is to compute the molarity of the first solution, for which we consider the molar mass of iron (III) nitrate that is 241.86 g/mol to compute the moles in 100.00 mL (0.1 L) of solution:
[tex]M=\frac{0.5482g*\frac{1mol}{241.86 g} }{0.1L}=0.0227 M[/tex]
Which is actually the concentration of iron (III) ions. Therefore, for 10.00 mL of such solution, the concentration until a dilution to 250.0 mL results being:
[tex]C_2=\frac{C_1V_1}{V_2} =\frac{0.0227M*10.00mL}{250.0mL} \\\\C_2=9.066x10^{-4}M[/tex]
Best regards.
A 5.000 g of Compound X with molecular formula C3H4 are burned in a constant-pressure calorimeter containing 15.00 kg of water at 25 °C. The temperature of the water is observed to rise by 3.688 °C. (You may assume all the heat released by the reaction is absorbed by the water, and none by the calorimeter itself.) Calculate the standard heat of formation of Compound X at 25 °C. Be sure your answer has a unit symbol, if necessary, and round it to the correct number of significant digits.
Answer:
THE STANDARD HEAT OF FORMATION FOR C3H8 IS 9.59 KJ/MOL.
Explanation:
Mass = 5 g of C3H4
Mass of water = 15 kg
Initial temperature of water = 25 C = 25 + 273 K = 298 K
Final temperature of water = 3.688 C = 3.688 + 273 K = 276.688 K
We may make the assumptions that:
1. the specific heat of water = 4.2 J/Kg K
2. total mass of the reaction mixture = 15 kg of water + 5 g of C3H8
= 15.005 Kg
Temperature change = 298 - 276.688 = 21.312 K
heat change for the reaction
Heat = mass * specific heat * change in temperture
Heat = 15.005 * 4.2 * 21.312
Heat = 1343.10 J
EQUATION
C3H8 + 5O2 -> 3CO2 + 4H2O + heat
Number of mole = mass / molar mass
Molar mass of HCl = 36.5 g/mol
Number of mole = 5 g/ 36.5 g/mol
Number of mole = 0.14 moles
5 g of C3H8 produces 1343.10 J of heat
0.14 mole of C3H8 produces 1343.10 J
1 mole of C3H8 will produce 1343.10 / 0.14 J of heat
= 9593.57 J
= 9.59 kJ of heat.
The standard heat of formation for C3H8 is 9.59 kJ/mol.
You have a 100 ml stock solution of 100 mg/ml ampicillin in deionized water. You want to make 30 ml of 25 mg/ml ampicillin in deionized water. How much ampicillin stock and how much deionized water are needed to make this
Answer:
The amount of ampicillin stock is [tex]V_3 = 7.5 mL[/tex]
The amount of deionized is 22.5 \ mL
Explanation:
From the question we are told that
The volume of stock solution of ampicillin in de-ionized water is [tex]V_0 = 100 mL[/tex]
The concentration (in mg ) of ampicillin in de-ionized is [tex]C_0 = 100 mg/mL[/tex]
The volume of ampicillin in deionized water to produce is [tex]V_2 = 30ml[/tex]
The concentration (in mg ) of ampicillin in de-ionized water to produce is [tex]C_2 = 25 mg/mL[/tex]
The chemical process can be mathematically represented as
[tex]V_3 100 = 30 * 25[/tex]
=> [tex]V_3 = \frac{30*25}{100}[/tex]
[tex]V_3 = 7.5 mL[/tex]
The amount of ampicillin stock is [tex]V_3 = 7.5 mL[/tex] and amount of 25 mL (30 - 7.5 = 22.5 mL ) of deionized water
You put scruffy can run up to 2 meters/sec on his fastest days scruffy has a mass of 8 KG what is his maximum kinetic energy on his fastest days?
Answer:
E = 16 J
Explanation:
We have,
You put scruffy can run up to 2 m/s on his fastest days scruffy has a mass of 8 kg
It is required to find the maximum kinetic energy on his fastest days. If v is the velocity, then kinetic energy is given by :
[tex]E=\dfrac{1}{2}mv^2[/tex]
Plugging all the values,
[tex]E=\dfrac{1}{2}\times 8\times 2^2 \\\\E=16\ J[/tex]
So, the maximum kinetic energy on his fastest day is 16 J.
What must be known to determine the nature of the salt formed from a weak acid and weak base?
a. the strength of the salt only
b. the strength of the acid only
c. the strength of the base only
d. the strength of both acid and base
why should we practice the local methods of separation?
Answer:
To obtain a desired component from the mixture
Explanation:
It is also important to be able to separate mixtures to be able to better understand how each component contributes to the properties, chemical and physical, of the resulting mixture.
How is the salt formed in a neutralization reaction written in a chemical reaction?
Answer:
A neutralization reaction between an acid and a base will produce a salt and water. In a neutralization reaction, the acid will produce H+ ions that react to neutralize the OH- ions produced by the base, forming neutral water. ... A weak acid + a strong base in an acid/base neutralization reaction will form a basic salt
Explanation:
explain which of benzene or naphthalene molecule would have equivalent carbon-carbon bond length
Answer:
Lengths. of. Naphthalene. Figure 3.20 shows that there are two equivalent ... all the carbon–carbon bonds of benzene are identical and are intermediate in length ... A typical carbon–carbon single bond has a length of 1.54 Å, and a double ... of how resonance can be used to explain or predict experimental observations.Explanation:
A geochemist in the field takes a 46.0 mL sample of water from a rock pool lined with crystals of a certain mineral compound X. He notes the temperature of the pool, 21·C, and caps the sample carefully. Back in the lab, the geochemist filters the sample and then evaporates all the water under vacuum. Crystals of X are left behind. The researcher washes, dries and weighs the crystals. They weigh 0.87 g. yes x10 1
Using only the information above, can you calculate the solubility of X in water at 21.° C?
a. yes
b. no
If you said yes, calculate it.
Be sure your answer has a unit symbol and the right number of significant digits.
Answer:
The correct answer is 1.89130 × 10⁻² g per ml.
Explanation:
Based on the given information, the volume of the water sample is 46 ml, the temperature given is 21 degree C. Weight of the compound mineral X is 0.87 grams obtained post evaporating, washing, and drying of the sample. Yes, on the basis of the given information, one can find the solubility of compound X in water at 21 degree C.
As 46 ml of water comprise 0.87 grams of the mineral compound X. Therefore, 1 ml of the water sample will comprise,
= 0.87/46 g of X
= 1.89130 × 10⁻² grams
Hence, the solubility of the compound X in the sample of water is 1.89130 × 10⁻² gram per ml.
The q,ß-unsaturated ketone A exchanges hydrogen atoms with deuterium at the two positions shown below to give product B. Provide a detailed, stepwise mechanism for the following transformation using proton transfer reactions.
Use curved arrows to show the movement of electrons.
O+D --------> D20 (solvent) D D
Complete Question
The complete question is shown on the first uploaded image
Answer:
The step wise mechanism is shown on the second uploaded image
Explanation:
Give the characteristics of a strong acid.
a.ionizes completely in aqueous solutions
b.has equilibrium far to the right
c.has a polar bond
d.has a weaker bond to hydrogen
e.all of the above
The characteristics of a strong acid is that it has a weaker bond to hydrogen. That is option D.
What is a strong acid?A strong acid is defined as the type of acid that completely dissociates in an aqueous solution during a chemical reaction.
Typical examples of strong acid include the following:
Hydrobromic Acid (HBr) Hydroiodic Acid (HI) Sulphuric Acid (H2SO4) Nitric Acid (HNO3) Perchloric Acid (HClO4).The characteristics of strong acids over weak acids is that they bond weakly with hydrogens.
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A ground state hydrogen atom absorbs a photon of light having a wavelength of 92.57 nm. It then gives off a photon having a wavelength of 954.3 nm. What is the final state of the hydrogen atom? Values for physical constants can be found in g
Answer:
the final state of the hydrogen atom = 3
Explanation:
From the given information;
Let first calculate the amount of energy by the ground state atom during the atoms absorbs photon light by using the formula:
[tex]E_{absorbs} = \dfrac{hc}{\lambda}[/tex]
where;
h = planck's constant = [tex]6.626*10^{-34 }\ \ Js[/tex]
c = speed of light = [tex]3.0*10^8 \ \ m/s[/tex]
λ = wavelength = 92.57 nm = 92.57 × 10⁻⁹ m
[tex]E_{absorbs} = \dfrac{6.626*10^{-34 }\ \ Js * 3.0*10^8 \ \ m/s}{92.57*10^{-9} \ \ m}[/tex]
[tex]E_{absorbs} = 2.15 *10^{-18} \ J[/tex]
The energy emitted by the hydrogen atom is calculated by using the same formula from above ; but here , the wavelength λ = 954.3 nm = 954.3 × 10⁻⁹ m
[tex]E_{absorbs} = \dfrac{6.626*10^{-34 }\ \ Js * 3.0*10^8 \ \ m/s}{954.3*10^{-9} \ \ m}[/tex]
[tex]E_{absorbs} = 2.08 *10^{-19} \ J[/tex]
The change in the energy absorbed is:
[tex]\Delta E= 2.15 *10^{-18} \ J - 2.08 *10^{-19} \ J[/tex]
[tex]\Delta E= 1.94 *10^{-18} \ J[/tex]
The final state of the atom can be determined by using the relation:
[tex]\Delta E = R_H [\dfrac{1}{1^2}-\dfrac{1}{n^2_f}][/tex]
where;
[tex]R_H[/tex] = Rydberg constant = 2.18 × 10⁻¹⁸ J
[tex]\dfrac{\Delta E}{R_H} = [\dfrac{1}{1^2}-\dfrac{1}{n^2_f}] \\ \\ \\ \dfrac{1.94*10^{-18} \ J}{2.18*10^{-18} \ J } = [\dfrac{1}{1^2}-\dfrac{1}{n^2_f}] \\ \\ \\ 0.889 = [\dfrac{1}{1^2}-\dfrac{1}{n^2_f}] \\ \\ \\ 1 - 0.889 = \dfrac{1}{n^2_f} \\ \\ \\ 0.111= \dfrac{1}{n^2_f} \\ \\ \\ {n^2_f} = \dfrac{1}{0.111} \\ \\ \\ {n^2_f} = 9 \\ \\ \\ {n_f} = \sqrt{9} \\ \\ \\ \mathbf{n_f = 3}[/tex]
Thus; the final state of the hydrogen atom = 3
[tex]E_a_b_s_o_r_b_e_d = (6.626 * 10^-^3^4 J.s) * (3.00 * 10^8 m/s) / (92.57 *10^-^9 m)[/tex]We can use the fact that the energy of the photon is given by the equation: to determine the final position of the hydrogen atom.
E = hc / λ
Where:
E is the energy of the photon,
h is Planck's constant [tex](6.626 * 10^-^3^4 J.s)[/tex],
c is the speed of light in a vacuum [tex](3.00 * 10^8 m/s)[/tex], and
λ is the wavelength of the photon.
Let's first determine the energy of the absorbed photon:
[tex]E_a_b_s_o_r_b_e_d = hc /[/tex]λ[tex]_a_b_s_o_r_b_e_d[/tex]
[tex]E_a_b_s_o_r_b_e_d = (6.626 * 10^-^3^4 J.s) * (3.00 * 10^8 m/s) / (92.57 *10^-^9 m)[/tex]
The energy of the photon released will then be determined by:
[tex]E_e_m_i_t_t_e_d = hc[/tex] / λ[tex]_e_m_i_t_t_e_d[/tex]
E[tex]_e_m_i_t_t_e_d[/tex] = [tex](6.626 * 10^-^3^4 J.s) * (3.00 * 10^8 m/s) / (945.3 *10^-^9 m)[/tex]
The energy difference between the absorbed and released photons must now be determined:
ΔE = [tex]E_e_m_i_t_t_e_d - E_a_b_s_o_r_b_e_d[/tex]
The energy levels of hydrogen are given by the equation:
ΔE = -13.6 eV *[tex](1 / n^2_f_i_n_a_l - 1 / n^2_i_n_i_t_i_a_l)[/tex]
Where
[tex]n_f_i_n_a_l[/tex] and [tex]n_i_n_i_t_i_a_l[/tex] are the principal quantum numbers of the final and initial states, respectively, and -13.6 eV is the ionization energy of hydrogen.
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Solution C is a 1.00 L buffer solution that is 1.420 M in acetic acid and 0.67 M in sodium acetate. Acetic acid has a pKa of 4.74. What is the pH change of this solution upon addition of 0.10100 mol of HCl? Enter a negative number to 3 decimal places.
Answer:
The correct answer is 0.10.
Explanation:
Based on the given question, in a buffer solution of 1 liter, the molarity of acetic acid is 1.420 M and the molarity of sodium acetate is 0.67. The pKa value of acetic acid given is 4.74, now the pH of buffer is,
pH of buffer = pKa + log ([CH3COONa]/[CH3COOH])
= 4.74 + log (0.67/1.420)
= 4.74 + (-0.326)
= 4.41
Now 0.10100 mol of HCl is added, the HCl reacts with sodium acetate to give,
CH3COONa + HCl = CH3COOH + NaCl
Now the concentration of CH3COONa becomes = 0.67-0.101 = 0.57 M, and the new concentration of CH3COOH becomes = 1.420 + 0.101 = 1.52 M
Now the new pH will be,
= pKa + log (0.57/1.52)
= 4.74 + (-0.426)
= 4.31
The pH change is 4.41-4.31 = 0.10
0.260 mol of octane is allowed to react with 0.760 mol of oxygen. How many moles of water are produced in this reaction? After the reaction, how much octane is left? Please, use conversion factors if possible.
Answer:
0.5472 moles of H₂O are produced
0.1992 moles of C₈H₁₈ were left
Explanation:
The reaction of octane (C₈H₁₈) with oxygen (O₂) is:
C₈H₁₈ + 25/2 O₂ → 8CO₂ + 9H₂O
Where 1 mole of octane reacts with 25/2 moles of oxygen to produce 8 moles of carbon dioxide and 9 moles of water
For a complete reaction of 0.760moles of oxygen there are needed:
0.760 mol O₂ ₓ (1 mole C₈H₁₈ / 25/2 moles O₂) = 0.0608 moles of C₈H₁₈
As you have 0.260 moles, the moles of octane that were left are:
0.260 mol - 0.0608 mol = 0.1992 moles of C₈H₁₈
Now, if 0.760 moles of O₂ react, the moles of water that are produced are:
0.760 mol O₂ ₓ (9 moles H₂O / 25/2 moles O₂) = 0.5472 moles of H₂O
Which energy conversion occurs in an operating voltaic cell? A) electrical energy to nuclear energy B) chemical energy to electrical energy C) chemical energy to nuclear energy D) electrical energy to chemical energy
Answer:
B) chemical energy to electrical energy
Explanation:
The correct option is B.
Which process occurs in a voltaic cell?A voltaic cell is an electrochemical cell that uses a chemical reaction to produce electrical energy. The important parts of a voltaic cell: The anode is an electrode where oxidation occurs. The cathode is an electrode where reduction occurs.
What kind of energy is converted in a galvanic cell?A galvanic cell is an electrochemical cell that converts the free energy of a chemical process into electrical energy. A photogalvanic cell is one that generates species photochemically which react resulting in an electrical current through an external circuit.
Learn more about energy conversion here https://brainly.com/question/961052
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