Answer:
The pKa of Glu is [tex]pK_a = 4.25[/tex]
Explanation:
From the question we are told that
The [tex]K_a[/tex] value of Glu is [tex]K_a = 5.62*10^{-5}[/tex]
The [tex]pKa[/tex] is mathematically represented as
[tex]pK_a = -log (K_a )[/tex]
substituting values
[tex]pK_a = -log (5.62 *10^{-5} )[/tex]
[tex]pK_a = 4.25[/tex]
A technician prepared a solution by heating 100 milliliters of distilled water while adding KCl crystals until no more KCl would dissolve. She then capped the clear solution and set it aside on the lab bench. After several hours she noticed the solution had become cloudy and some solid had settled to the bottom of the flask. Which statement best describes what happened?
A. As the solution cooled, evaporation of water increased the KCl concentration beyond its solubility
B. Water molecules, trapped with the KCl crystals, were released after heating
C. At lower temperatures the solubility of the KCl decreased and recrystallization occurred
D. At increased temperatures the solubility of KCl increased and remained too high after cooling
Answer:
At lower temperatures the solubility of the KCl decreased and recrystallization occurred
Explanation:
Solubility refers to the amount of solute that dissolves in one litre of water at a particular temperature. Solubility is a property referring to the ability for a given substance, the solute, to dissolve in a solvent. It is measured in terms of the maximum amount of solute dissolved in a solvent at equilibrium. The resulting solution is called a saturated solution.
Solubility is dependent on temperature. This is the reason why we must state the particular temperature at which a given solubility data was collected. Above or below the quoted temperature, the solubility data may no longer be accurate.
Let's return to the question, at elevated temperatures, we can see that the KCl is very soluble in water as evidenced by the clear solution obtained at high temperature. However, as the temperature decreases, the solubility of KCl also decreases accordingly and recrystallization of the solute occurred hence the formation of a cloudy solution and the settling of some solid at the bottom of the flask.
Answer:
C. At lower temperatures the solubility of the KCl decreased and recrystallization occurred
Explanation:
The volume measuring system for a gasoline pump at the service station is calibrated at 20.0°C. If the temperature of the gasoline drops to 10.0°C, what percentage extra amount of mass of gasoline do you receive when making a purchase? The coefficient of volume expansion for gasoline is 9.5 × 10-4/K.
Answer:
answer = -0.95
Explanation:
Determine the value of the equilibrium constant, Kgoal, for the reaction N2(g)+H2O(g)⇌NO(g)+12N2H4(g), Kgoal=? by making use of the following information: 1. N2(g)+O2(g)⇌2NO(g), K1 = 4.10×10−31 2. N2(g)+2H2(g)⇌N2H4(g), K2 = 7.40×10−26 3. 2H2O(g)⇌2H2(g)+O2(g), K3 = 1.06×10−10 Express your answer numerically.
Answer:
K = 1.79x10⁻³³
Explanation:
Using Hess's law, it is possible to fin K of a reaction by the algebraic sum of another related reactions.
In the reactions:
1. N2(g)+O2(g) ⇌ 2NO(g), K1 = 4.10×10−31 2.
2. N2(g)+2H2(g) ⇌ N2H4(g), K2 = 7.40×10−26
3. 2H2O(g)⇌2H2(g)+O2(g), K3 = 1.06×10−10
The sum of 1/2 (1) + 1/2 (2) produce:
N2(g) + 1/2O2(g) + H2(g) ⇌ 1/2N2H4(g) + NO(g)
And K' = √4.1x10⁻³¹×√7.4x10⁻²⁶ = 1.74x10⁻²⁸
Now, this reaction + 1/2 (3):
N2(g) + H2O(g) ⇌ NO(g) + 1/2N2H4(g)
And K of reaction is:
1.74x10⁻²⁸×√1.06x10⁻¹⁰ = 1.79x10⁻³³
Give 2 examples of a strong electrolyte
Answer:
Sodium Chloride, Potassium Chloride
Explanation:
Sodium Chloride, Potassium Chloride, are the most common example of a strong electrolyte. Most salts are strong electrolytes, such as hydrochloric acid, nitric acid, perchloric acid and sulphuric acid. Strong bases, such as sodium hydroxide and calcium hydroxide, are also potent electrolytes.
hope this helped!
If you can help answer the question if you can't then don't
a candle burning can be considered both chemical and physical change explain how is that possible ????
Answer:
Yes its both a physical and chemical change heres why.
When heated , the wax melts to form a liquid wax . The liquid wax then becomes a solid wax upon cooling ( Physical change )
When the candle is lit, the wax near the tip of the candle will melt . The wick then absorbs the liquid wax . The liquid wax then vapourizes due to the heat emitting from the flame . The wax vapour then burns to give off a black substance ( what we will to as CO₂ , soot ) , heat and water vapour
(Chemical change )
Brainliest ? Hope I answered your question
When 161.0 mL of water at 26.0°C is mixed with 41.0 mL of water at 85.0°C, what is the final temperature
Answer: The final temperature is [tex]38.0^0C[/tex]
Explanation:
The quantity of heat required to raise the temperature of a substance by one degree Celsius is called the specific heat capacity.
[tex]heat_{released}=heat_{absorbed}[/tex]
[tex]Q=m\times c\times \Delta T=m\times c\times (T_{final}-T_{initial})[/tex]
[tex]-[m_1\times c_1\times (T_{final}-T_1)]=[m_2\times c_2\times (T_{final}-T_2)][/tex]
[tex]-[m_1\times (T_{final}-T_1)]=[m_2\times (T_{final}-T_2)][/tex] (as [tex]c_1=c_2[/tex])
Q = heat absorbed or released
[tex]m_1[/tex] = mass of water at [tex]85.0^0C[/tex] = [tex]volume\times density=41.0ml\times 1g/ml=41.0g[/tex]
[tex]m_2[/tex] = mass of water at [tex]26.0^0C[/tex] = [tex]volume\times density=161.0ml\times 1g/ml=161.0g[/tex]
[tex]T_{final}[/tex] = final temperature = ?
[tex]T_1[/tex] = temperature of 41.0 ml of water = [tex]85.0^0C[/tex]
[tex]T_2[/tex] = temperature of 161.0 ml of water = [tex]26.0^0C[/tex]
Now put all the given values, we get
[tex]-[41.0\times (T_f-85.0)^0C]=161.0\times (T_f-26.0)^0C[/tex]
[tex]T_f=38.0^0C[/tex]
Thus the final temperature is [tex]38.0^0C[/tex]
Citric acid is one component of some soft drinks. Suppose that 8 L of solution are made from 0.24 g of citric acid, C6H8O7. What is the molarity of citric acid in the solution?
Answer:
The correct answer is 0.15 × 10⁻³ M.
Explanation:
C₆H₈O₇ is the molecular formula of citric acid. The mass of the one mole of the substance that comprise Avogadro's no of molecules is termed as the molar mass of the substance.
The molar mass of the citric acid (C₆H₈O₇) will be,
6 × atomic mass of carbon + 8 × atomic mass of hydrogen + 7 × atomic mass of oxygen = 6×12 + 8×1 + 7×16 = 192. Thus, the molar mass of citric acid is 192 g/mol.
The value of the solution given in the question is 8 L.
The mass of citric acid given is 0.24 g or 240 mg, which can also be written as 240/1000 g or 240 × 10⁻³ g.
The number of moles can be calculated by using the formula = mass / molar mass. Thus, by putting the values we get,
= 240 × 10⁻³ g / 192 g/mol
= 1.25 × 10⁻³ mol
The number of moles of the solute present in the 1 liter of the solution is termed as the molarity of the solution. The formula of molarity or M is,
= no of moles of solute / volume of solution in L
Now putting the values we get,
= 1.25 × 10⁻³ mol / 8 L
= 0.156 × 10⁻³ M
Hence, the molarity of citric acid in the given solution is 0.15 × 10⁻³ M
An equilibrium mixture of the three gases in a 7.40 L container at 535 K contains 0.313 M PCl5, 0.119 M PCl3 and 0.119 M Cl2. What will be the concentrations of the three gases once equilibrium has been reestablished, if the volume of the container is increased to 16.6 L?
Answer:
PCl₅: 0.1192M
PCl₃: 0.0734M
Cl₂: 0.0734M
Explanation:
Based on the reaction:
PCl₅ ⇄ PCl₃ + Cl₂
K of reaction is defined as:
K = [PCl₃] [Cl₂] / [PCl₅]
Replacing with concentrations of gases in equilibrium:
K = [0.119] [0.119] / [0.313]
K = 0.0452
Moles of each gas is:
PCl₅: 7.40L × (0.313mol / L) = 2.3162 moles
PCl₃: 7.40L × (0.119mol / L) = 0.8806 moles
Cl₂: 7.40L × (0.119mol / L) = 0.8806 moles
When the volume of the container is increased the system will produce more moles, (That is, produce more products) in order to keep constant the pressure of the container -Le Chatelier's principle-. In equilibrium, molarity of each gas is:
PCl₅: 2.3162 moles - x / 16.6L
PCl₃: 0.8806 moles + x / 16.6L
Cl₂: 0.8806 moles + x / 16.6L
Where X is reaction coordinate.
Replacing in K formula:
0.0452 = [0.05305 + X/16.6] [0.05305 + X/16.6] / [0.13953 - X/16.6]
6.3068x10⁻³ - 2.723x10⁻³ X = 0.0028143 + 0.00639157 X + 0.00362897 X²
0 = -0.0034925 + 0.00911457X + 0.00362897 X²
Solving for X:
X = -2.8 → False answer. There is no negative concentrations
X = 0.3378 moles
Replacing:
PCl₅: 2.3162 moles - 0.3378 / 16.6L = 0.1192M
PCl₃: 0.8806 moles + 0.3378 / 16.6L = 0.0734M
Cl₂: 0.8806 moles + 0.3378 / 16.6L = 0.0734M
Beeing these concentrations the concentrations in equilibrium of the three gases
Match the term to its description.
Gravitational energy
Answer 1
Mechanical energy
Answer 2
Nuclear energy
Answer 3
Thermal energy
Answer 4
Internal energy caused by vibrations of atoms and molecules
The potential energy of position
The energy of an object due to its movement
Energy stored in the nucleus of an atom
Answer:
Gravitational Energy: The energy of an object due to its movement
Mechanical Energy: The potential energy of position
Nuclear Energy: internal energy caused by vibrations of atoms and molecules
Thermal Energy: Energy stored in the nucleus of an atom
Answer:
radiant
nuclear
thermal
potential
Explanation:
The electron in a hydrogen atom, originally in level n = 8, undergoes a transition to a lower level by emitting a photon of wavelength 3745 nm. What is the final level of the electron? (c = 3.00 x 108m/s, h = 6.63 x 10−34 J • s, RH = 2.179 x 10−18 J)
a. 5
b. 6
c. 8
d. 9
e. 1
Answer:
The level is [tex]n_1 = 5[/tex]
Explanation:
From the question we are told that
The level of the hydrogen atom is [tex]n_2 = 8[/tex]
The wavelength of the photon is [tex]\lambda = 3745 nm = 3745 *10^{-9} \ m[/tex]
Generally the wave number is mathematically represented as
[tex]k = \frac{1}{\lambda }[/tex]
Now this wave number can also be mathematically represented as
[tex]k = R_{\infty} [\frac{1}{n_1^2} + \frac{1}{n_2^2} ][/tex]
This implies that
So
Here [tex]R_{\infty}[/tex] is the Rydberg constant, with a value [tex]1.097 * 10^7[/tex]
and [tex]n_1 \ and \ n_2[/tex] are the principal quantum levels
substituting values
[tex]0.0243= [\frac{1}{n_1^2} - \frac{1}{8^2} ][/tex]
[tex]0.0243= \frac{1}{n_1^2} - 0.015625[/tex]
[tex]0.0243 + 0.015625= \frac{1}{n_1^2}[/tex]
[tex]n_1 = 5[/tex]
In an ionic compound, the size of the ions affects the internuclear distance (the distance between the centers of adjacent ions), which affects lattice energy (a measure of the attractive force holding those ions together). Based on ion sizes, arrange these compounds by their expected lattice energy. Note that many sources define lattice energies as negative values. Please arrange by magnitude and ignore the sign.
Compunds: RbCl ,RbBr ,Rbl ,RbF
Answer:
The correct answer will be " RbF > RbCl > RbBr > Rbl".
Explanation:
The size of the given ions will be:
RbCl:
⇒ 689kJ/mol
RbBr:
⇒ 660kJ/mol
Rbl:
⇒ 630kJ/mol
RbF:
⇒ 785kJ/mol
Now according to the size, the arrangement will be:
⇒ (785kJ/mol) > (689kJ/mol) > (660kJ/mol) >(630kJ/mol)
⇒ RbF > RbCl > RbBr > Rbl
The bond among all opposite charging ions seems to be strongest whenever the ions were indeed small.
How many moles of water form when one mole of NH3 reacts according to this reaction 4 NH3+ 5 O2= 4NO+ 6 H20
moles ratio of NH3 to H2O is 4:6
if 4=6
1. ?
1 * 6 /4 = 1.5
1.5 moles of water
Be sure to answer all parts. Give the name and the formula of the compound formed from the following elements: (a) bromine and rubidium Name: (select) (select) Formula: (b) strontium and sulfur Name: (select) (select) Formula: (c) barium and chlorine Name: (select) (select) Formula
Answer:
These are the chemical names and molecular formula of the compounds formed from these elements:
Rubidium + Bromine = Rubidium bromide, RbBrStrontium + Sulphur = Strontium sulfide, SrSBarium and Chlorine = Barium chloride, [tex]BaCl_{2}[/tex]Write a chemical formula for each molecular model. (Blue ball represents nitrogen atom, red ball represents oxygen atom, white ball represents hydrogen atom, black ball represents carbon atom, yellow ball represents sulphur atom.)
Answer:
See answer below
Explanation:
In this case, you are missing the picture. Luckily I found one on another site, so I hope is the one you are asking for. If not, please post again with the picture.
According to the picture below, you need to write a chemical formula for each molecular model.
To do this, is just simple. Let's see each model per separate.
In the first model, we have a blue ball and three white balls. According to the nomenclature of the question a blue ball represents nitrogen atoms and white ball represents hydrogen, therefore, we have an atom of nitrogen bonded to three atoms of hydrogens, so, the chemical formula should be:
NH₃: This molecule corresponds to the Ammonia molecule.
The second picture, shows 4 black balls (representing an atom of carbon each) and each black ball holds a determinated number of white balls. The two of the middle have two white balls each, and the terminals have 3 white balls, therefore, the molecule should be the following:
CH₃ - CH₂ - CH₂ - CH₃: this corresponds to the butane
Finally, the last picture shows a yellow ball (which represents sulphur) and three red balls (representing oxygen each), so, the molecule that represents this would be:
SO₃: this is the sulfite ion.
What did Ernest Rutherford's work uncover?
Answer:
Ernest Rutherford is known in his work of pioneering studies of radioactivity and the specifics in the atom. He discovered that there are two types of radiation, which are alpha and beta particles, coming from uranium. He found that the atom consists mostly of empty space, with its mass concentrated in a central positively charged nucleus.
Explanation:
hope this helps
H3C-CH2-OH
What is the name of this
Answer:
H3C is the chemical name for the methyl group, and it can also be written as CH3
CH2 is a carbene
OH is hydroxide
Need help with these 7 problems
Answer:
1. 2.3
2. 4.5
3. 10.5
4. 5.6
5. 3.5
6. 3.9
7. 1.6
Explanation:
pH = - log [H+]
1. Lemon juice
[H+] = 0.005
pH = - log [H+]
pH = - log 0.005
pH = 2.3
2. Beer
[H+] = 3.16x10^-5
pH = - log [H+]
pH = - log 3.16x10^-5
pH = 4.5
3. Milk of Magnesia
[H+] = 3.16x10^-11
pH = - log [H+]
pH = - log 3.16x10^-11
pH = 10.5
4. Rain water
[H+] = 2.51x10^-6
pH = - log [H+]
pH = - log 2.51x10^-6
pH = 5.6
5. Soda
[H+] = 3.16x10^-4
pH = - log [H+]
pH = - log 3.16x10^-4
pH = 3.5
6. Tomatoes
[H+] = 1.23x10^-4M
pH = - log [H+]
pH = - log 1.23x10^-4
pH = 3.9
7. Bleach
[OH-] = 2.3x10^-2M
pOH = - log [OH-]
pOH = - log 2.3x10^-2
pOH = 1.6
If an experiment produces 5 g but should have made 500 g, what is the percent
yield?
Answer:
Percentage of yield = 1%
Explanation:
Given:
Amount of yield = 5g
Total amount of product = 500 gram
Find:
Percentage of yield = ?
Computation:
⇒ Percentage of yield = [Amount of yield / Total amount of product]100
⇒ Percentage of yield = [5g / 500g]100
⇒ Percentage of yield = [0.01]100
⇒ Percentage of yield = 1%
Next, a chemical reaction of interest was conducted in the same constant volume calorimeter. The neutralization reaction of HCl(aq) with NaOH(aq) caused the temperature of the calorimeter to rise by 2.46 °C. What is the change in internal energy ΔU of the neutralization reaction in kJ?
Answer:
A constant volume calorimeter (bomb calorimeter) was calibrated by performing in it a reaction in which 5.23 kJ of heat energy was released, causing the calorimeter to rise by 7.33 °C. What is the heat capacity Cy of the calorimeter
Explanation:
the heat capacity of the calorimeter is
[tex]C_v = \frac{q}{\Delta T} \\\\=\frac{5.23}{7.33} \\\\=0.714kJ /^\circ C[/tex]
Now that our heat capacity of the calorimeter is 0.714kJ/°C
we can easily calculate the change in internal energy ΔU of the neutralization reaction
[tex]\Delta U = C_v \ dt[/tex]
or
[tex]\Delta U = C_V \Delta T[/tex]
Δ T = 2.46 °C
[tex]C_v = 0.714 kJ/ ^\circ C[/tex]
[tex]\Delta U = 0.714*2.46\\\\=1.7564kJ[/tex]
A sample of 0.3220 g of an ionic compound containing the iodide ion (I-) is dissolved in water and treated with an excess of AgHCO3. If the mass of the AgI precipitate that forms is 0.235 g, what is the percent by mass of I in the original compound? The molar mass of AgI is 234.8 g.
Answer:
39.44 %
Explanation:
Step 1: Write the balanced equation
I⁻(aq) + AgHCO₃(aq) = AgI(s) + HCO₃⁻(aq)
Step 2: Calculate the moles corresponding to 0.235 g of AgI
The molar mass of AgI is 234.8 g/mol.
[tex]0.235g \times \frac{1mol}{234.8g} = 1.001 \times 10^{-3} mol[/tex]
Step 3: Calculate the moles of I⁻ that form 1.001 × 10⁻³ mol of AgI
The molar ratio of I⁻ to AgI is 1:1. The reacting moles of I⁻ are 1/1 × 1.001 × 10⁻³ mol = 1.001 × 10⁻³ mol
Step 4: Calculate the mass corresponding to 1.001 × 10⁻³ mol of I⁻
The molar mass of I⁻ is 126.90 g/mol.
[tex]1.001 \times 10^{-3} mol \times \frac{126.90g}{mol} = 0.1270 g[/tex]
Step 5: Calculate the percent by mass of I⁻ in the original compound
[tex]\frac{0.1270g}{0.3220g} \times 100 \% = 39.44 \%[/tex]
Since density depends on the mass and volume of an object, we need both of these values combined in the correct way to solve for density. Keep in mind that we may not be given the mass and volume directly, or the values may not be given in the units we want and we need to convert to the correct units before solving for density.When converting between metric units, use the prefixes to help you determine the magnitude of a value. The prefix k indicates kilo, 1000. Therefore 1000 g = 1 kg.A 11.0 kg iron weightlifting plate has a volume of 1400 cm3 . What is the density of the iron plate in g/cm3?Express your answer in grams per cubic centimeter to three significant figures.
Answer:
7.86 g/cm³
Explanation:
11.0 kg = 11,000 g
The density in g/cm³ is ...
(11,000 g)/(1,400 cm³) = 7.86 g/cm³
Compare a 3s orbital to a 3p orbital. Which of the following are true? I. The orbitals have the same shape. II. The orbitals have different shapes. III. The orbitals have the same energy. IV. The orbitals have different energies.
Answer:
II. The orbitals have different shapes.
IV. The orbitals have different energies.
Explanation:
1. Shapes
Below are pictures of a 3s and a 3p orbital.
The 3s orbital has a spherical shape, and the 3p orbital has a dumbbell shape.
2. Energies
For every element except H, the order of energies is
3s < 3p
For a hydrogen atom,
3s = 3p
What happens when a primary structure forms a secondary structure
Answer:
The oxygen atoms of the carbonyl groups and the hydrogen atoms attached to the nitrogen atoms form α-helices or β-pleated sheets. The order of the amino acids provides the R groups that interact to determine the tertiary structure
Explanation:
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Polymers are large molecules composed of simple units repeated many times. Thus, they often have relatively simple empirical formulas. Calculate the empirical formulas of the polyethylene: 86% C, 14% H. You must show all work for credit. Polymers are large molecules composed of simple units repeated many times. Thus, they often have relatively simple empirical formulas. Calculate the empirical formulas of the polystyrene: 92.3% C, 7.7% H. You must show all work for credit.
Answer:
A. CH2.
B. CH.
Explanation:
A. Determination of the empirical formula of polyethylene.
Data obtained from the question include:
Carbon (C) = 86%
Hydrogen (H) = 14%
The empirical formula of the polyethylene can be obtained as follow:
C = 86%
H = 14%
Divide by their molar mass
C = 86/12 = 7.17
H = 14/1 = 14
Divide by the smallest
C = 7.17/7.17 = 1
H = 14/7.17 = 2
Therefore, the empirical formula of the polyethylene is CH2.
B. Determination of the empirical formula of polystyrene
Data obtained from the question include:
Carbon (C) = 92.3%
Hydrogen (H) = 7.7%
The empirical formula of the polystyrene can be obtained as follow:
C = 92.3%
H = 7.7%
Divide by their molar mass
C = 92.3/12 = 7.69
H = 7.7/1 = 7.7
Divide by the smallest
C = 7.69/7.69 = 1
H = 7.7/7.69 =
Therefore, the empirical formula of the polystyrene is CH.
Write an equation that shows the formation of a magnesium ion from a neutral magnesium atom
Answer:
Mg ---> Mg^2+ + 2e^
Explanation:
hope it helps : )
Magnesium is a neutral atom that can lose two electrons two achieve stability and forms a cation. The magnesium ion is produced as, Mg ⇒ Mg²⁺ + 2e⁻.
What is a magnesium ion?Magnesium ion is a charged species that is produced as the result of the neutral magnesium donating its electron so as to achieve its stable and complete electronic configuration.
When an atom donates an electron to another atom then they themselves become positively charged whereas the other species that accepts the electron becomes negatively charged. The positive charge is called a cation.
The reaction of the neutral magnesium donating electrons to become ions is shown as,
Mg ⇒ Mg²⁺ + 2e⁻
Therefore, magnesium loses two electrons to become positively charged.
Learn more about magnesium ions here:
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What are the differences between HDL and LDL?
Answer:
LDL is
low density lipid
HDL is
high density lipid
Explanation:
HDL helps rid your body is excess cholesterol so so it won't end up in your arteries
LDL is also called "bad cholesterol" because it takes cholesterol to your arteries
A sample tube consisted of atomic hydrogen in their ground state. A student illuminated the atoms with monochromatic light, that is, light of a single wavelength. If only two separate emission lines in the visible region are observed, what is the wavelength (or wavelengths) of the incident radiation?
Answer:
The wavelength is [tex]\lambda =97.3 nm[/tex]
Explanation:
Generally the series whose emission line show on the visible spectrum is the
Balmar series so this two emission line seen on the visible spectrum could either be due to the move of electron from
[tex]n=3 \to \ n=2[/tex]
OR
[tex]n=4 \to n=2[/tex]
This implies that the first excitement is from [tex]n_i=1 \to \ n_f=4[/tex]
So the energy change due to the excitement is mathematically represented as
[tex]\Delta E = R_H [\frac{1}{n_i^2} -\frac{1}{n_f^2} ][/tex]
substituting values
[tex]\Delta E= R_H [\frac{1}{1^2} -\frac{1}{4^2} ][/tex]
[tex]\Delta E= \frac{15}{16} R_H[/tex]
This energy change can also be represented as
[tex]\Delta E = \frac{hc}{\lambda}[/tex]
So [tex]\frac{15}{16} R_H = \frac{hc}{\lambda}[/tex]
=> [tex]\lambda = \frac{16hc}{15 R_H}[/tex]
Where [tex]R_H[/tex] is the Rydberg constant with a value of [tex]R_H = 2.18 * 10^{-18} J.[/tex]
h is the Planck's constant with values [tex]h = 6.626 * 10^{-34} m^2 kg / s[/tex]
c is the speed of light with value [tex]c = 3.0*10^{8} \ m/s[/tex]
So
[tex]\lambda = \frac{16(6.626 *10^{-34})(3*10^{8})}{15 * (2.18*10^{-18})}[/tex]
[tex]\lambda = 9.73 *10^{-8} \ m[/tex]
[tex]\lambda =97.3 nm[/tex]
Under certain conditions the rate of this reaction is zero order in ammonia with a rate constant of 0.0089 M.s^-1:
2NH3(g) → N2(g)+ 3H2(g)
Suppose a 5.0 L flask is charged under these conditions with 400. mmol of ammonia. How much is left 2.0 s later? You may assume no other reaction is important.
Be sure your answer has a unit symbol, if necessary, and round it to 2 significant digits.
Answer:
Explanation:
The rate of reaction will not depend upon concentration of reactant . It will be always constant and equal to .0089M s⁻¹.
Initial moles of reactant = 400 x 10⁻³ mole in 5 L
molarity = 400 x 10⁻³ /5 M
= 80 x 10⁻³ M .
= .08M
no of moles reacted in 2 s = .0089 x 2
= .0178 M
concentration left = .08 - .0178 M
= .0622 M .
No of moles left in 5 L
= 5 x .0622 = .31 moles .
Draw the structure of the bromohydrin formed when (Z)-3-hexene reacts with Br2/H2O. Use the wedge/hash bond tools to indicate stereochemistry where it exists. If the reaction produces a racemic mixture, draw both stereoisomers. Separate multiple products using the sign from the drop-down menu.
Answer:
(3R,4R)-4-bromohexan-3-ol
Explanation:
In this case, we have reaction called halohydrin formation. This is a markovnikov reaction with anti configuration. Therefore the halogen in this case "Br" and the "OH" must have different configurations. Additionally, in this molecule both carbons have the same substitution, so the "OH" can go in any carbon.
Finally, in the product we will have chiral carbons, so we have to find the absolute configuration for each carbon. On carbon 3 we will have an "R" configuration on carbon 4 we will have also an "R" configuration. (See figure 1)
I hope it helps!
50 mL of CH3CH2Br (bromoethane) and 50 mL of water are poured into a separatory funnel. Bromoethane is a water‑insoluble compound with a density of 1.460gmL . The funnel is stoppered and the mixture is shaken vigorously. After standing, two layers separate. Which substance is in which layer? Explain. Bromoethane is more dense than water. Water is added second. The top layer is bromoethane and the bottom layer is water. The top layer is water and the bottom layer is bromoethane. Bromoethane has a higher molar mass than does water. b) Into the same funnel is poured carefully 50 mL of hexane (density = 0.660 g/mL) so that the other two layers are not disturbed. The hexane forms a third layer. The funnel is stoppered, and the mixture is shaken vigorously. After standing, two layers separate. Which compound(s) are in which layer? The top layer contains: The bottom layer contains:
Answer:
See explanation below
Explanation:
In this case, we can explain this in a very basic way.
We know that heavier objects will go always at the bottom when we are carrying two objects, one heavier than the other right?
In the same manner works the density of two liquids. In this case, we have a mix of water and bromoethane. Bromoethane is an organic compound and it's less polar than water which is extremely polar. When we mix these two liquids, we can see that both of them are insoluble, so no matter how much we shake the funnel, the liquids will not mix to form a solution.
Instead of that, both of them will be in the funnel, and they'll be gradually separating into two layers. The bromoethane has a higher density than water, this means that in the bottom layer we will have the bromoethane and in the top layer we will have the water.
In case you are wondering what happens if we added water first and then, the bromoethane?, it will happen the same, it does not matter the order you add the liquid, because density here is a very important factor, so when the water is added no matter which position, it will go to the top layer after the bromoethane is added.
Now when the hexane is added, it will form now three layers, and again, density plays an important factor. The higher density will go to the bottom, and the lowest to the top.
In this case, the order of layer will be:
Top layer: hexane (d = 0.66 g/mL)
Middle layer: water (d = 1 g/mL)
Bottom layer: bromoethane (d = 1.46 g/mL)
Hope this helps
