Answer:
Molality = 8.57 m
Explanation:
Given data:
Molarity of solution = 5.73 M
density = 0.9327 g/mL
Molality of solution = ?
Solution:
Molality = moles of solute / kg of solvent.
Kg of solvent:
Mass of 1 L solution = density× volume
Mass of 1 L solution = 0.9327 g/mL × 1000 mL
Mass of 1 L solution = 932.7 g
Mass of solute:
Mass of 1 L = number of moles × molar mass
Mass = 5.73 mol × 46.068 g/mol
Mass = 263.97 g
Mass of solvent:
Mass of solvent = mass of solution - mass of solute
Mass of solvent = 932.7 g - 263.97 g
Mass of solvent = 668.73 g
In Kg = 668.73 /1000 = 0.6687 Kg
Molality:
Molality = number of moles of solute / mass of solvent in Kg
Molality = 5.73 mol / 0.6687 Kg
Molality = 8.57 m
Considering the definition of molality , you obtain that the molality of a 5.73 M ethanol (C₂H₅OH) solution whose density is 0.9327 g/mL is 8.57 [tex]\frac{moles}{kg}[/tex].
Molality is the ratio of the number of moles of any dissolved solute to kilograms of solvent.
The Molality of a solution is determined by the expression:
[tex]Molality=\frac{number of moles of solute}{kilogramof solvent}[/tex]
You have a 5.73 M ethanol (C₂H₅OH) solution whose density is 0.9327 g/mL.
Molarity is the number of moles of solute that are dissolved in a certain volume.
In this case, taking into account that the volume considered is 1 L, the number of moles of solute is 5.73 moles.
On the other side, density is the ratio of the weight (mass) of a substance to the volume it occupies. So, being 1 mL= 0.001 L, 0.9327 g/mL means that you have 0.9327 grams per 1 mL or 932.7 g per 1 L.
So, being the mass of solution calculated as number of moles multiplied by the molar mass, and being the mass of the solution 932.7 grams in 1 L, the mass of water is:
Mass of solvent = mass of solution - mass of solute
Mass of solvent = mass of solution - number of moles× molar mass
Mass of solvent = 932.7 g - 5.73 mol× 46.068 g/mol
Mass of solvent = 932.7 g - 263.97 g
Mass of solvent = 668.73 g= 0.66873 kg
Then, the molality can be calculated as:
[tex]Molality=\frac{5.73 moles}{0.66873 kg}[/tex]
Solving:
molality= 8.57 [tex]\frac{moles}{kg}[/tex]
Finally, the molality of a 5.73 M ethanol (C₂H₅OH) solution whose density is 0.9327 g/mL is 8.57 [tex]\frac{moles}{kg}[/tex].
Learn more about:
density: brainly.com/question/952755?referrer=searchResults brainly.com/question/1462554?referrer=searchResults molalitybrainly.com/question/20366625?referrer=searchResults brainly.com/question/4580605?referrer=searchResults molarity with this example: brainly.com/question/15406534?referrer=searchResultsPhenylephrine is a nasal decongestant and is the active ingredient in Sudafed, which contains phenylephrine hydrochloride (PEHCL). The conjugate acid (PEH+) of phenylphrine has a pKa = 5.5. At a physiological pH of 7.4. what is the ratio of concentrations, [PE]/[PEH+]?
Answer:
The ratio of concentrations is 79.4
Explanation:
Using Henderson-Hasselbalch equation we can solve the [PE]/[PEH+] ratio:
pH = pKa + log [A-] / [HA]
Where pH is 7.4
pKa of the phenylphrine is 5.5
[A-] is the weak base = [PE]
And [HA] is the conjugate acid [PEH+]
Replacing:
7.4 = 5.5 + log [PE] / [PEH+]
1.9 = log [PE] / [PEH+]
79.4 = [PE] / [PEH+]
The ratio of concentrations is 79.4
The rearrangement which most likely occurs in the following reaction can be described as a
HBr
(CH3)2CHCH=CH2 →
a. hydride shift from C-2 to C-1.
b. hydride shift from C-3 to C-2.
c. proton shift from C-2 to C-1.
d. methyl group shift from C-3 to C-2.
Answer:
b. hydride shift from C-3 to C-2.
Explanation:
Markovnikov's rule states that *in the addition of a protic acid HX or other polar reagent to an asymmetric alkene, the acid hydrogen (H) or electropositive part gets attached to the carbon with more hydrogen substituents, and the halide (X) group or electronegative part gets attached to the carbon with more alkyl substituents* (wikipedia).
This rule implies that the hydrogen of HBr will be attached to C-1 and the carbocation will be on C-2. Remember that the order of stability of carbocations is tertiary > secondary > primary > methyl. A hydride shift can yield a tertiary carbocation.
C-3 is a tertiary carbon atom. If the hydride on carbon 3 shifts to carbon 2, a tertiary and more stable carbocation is formed. This accounts for the major product in the reaction.
A solution of sulfuric acid (H2SO4, 25.00 mL) was titrated to completion with 34.55 mL of 0.1020 M sodium hydroxide. What was the concentration of the sulfuric acid
Answer:
0.0705 M
Explanation:
We'll begin by writing the balanced equation for the reaction. This is given below:
H₂SO₄ + 2NaOH —> Na₂SO₄ + 2H₂O
From the balanced equation above,
The mole ratio of the acid, H₂SO₄ (nA) = 1
The mole ratio of the base, NaOH (nB) = 2
Next, data obtained from the question. This include the following:
Volume of acid, H₂SO₄ (Va) = 25 mL
Volume of base, NaOH (Vb) = 34.55 mL
Molarity of base, NaOH (Mb) = 0.1020 M
Molarity of acid, H₂SO₄ (Ma) =?
The molarity of the acid, H₂SO₄ can be obtained as follow:
MaVa / MbVb = nA/nB
Ma × 25 / 0.1020 × 34.55 = 1/2
Ma × 25 / 3.5241 = 1/2
Cross multiply
Ma × 25 × 2 = 3.5241
Ma × 50 = 3.5241
Divide both side by 50
Ma = 3.5241 / 50
Ma = 0.0705 M
Therefore, the concentration of the acid, H₂SO₄ is 0.0705 M
Answer:
C=0.140964M
Explanation:
M1V1=M2V2
DATA
M1=?
M2=0.1020M
V1=25.00ML
V2=34.55ML
M*25.00ML=(0.1020M)*(34.55ML)
M*25.00ML=3.5241M*ML
M=3.5241M*ML/25.00ML
M=0.140964M
Therefore, concentration of sulfuric acif is 0.140964M
Which of the following salts will be less soluble in 0.10 M NaCl than it is in pure water?
PbF2
CaCO3
All of the options are less soluble in 0.10 M NaCl than in pure water.
PbCl2
The less soluble salt : PbCl₂
Further explanationGiven
0.1 M NaCl
Required
The less soluble salt
Solution
If we see from the answer option, the salt that is more difficult to dissolve in NaCl is PbCl₂ because it has the same ion (Cl)
When PbCl₂ is dissolved in water, ionization will occur
PbCl₂ ⇒ Pb²⁺+ 2Cl⁻
So, when dissolved in NaCl, NaCl itself will be ionized
NaCl ⇒ Na⁺ + Cl⁻
Based on the principle of equilibrium, the addition of an ion (one of the ions is enlarged), the reaction will shift towards the ion that was not added. In addition to this Cl ion, the reaction will shift to the left so that the solubility of PbCl₂ will decrease (the reaction to the right decreases)
What is the reducing agent in the following reaction
5Fe2+(aq) + MnO4-(aq) + 8H+(aq) → 5Fe3+(aq) + Mn2+(aq) + 4H2O(I)
A. MnO4-
B. Fe3+
C. Mn2+
D. Fe2+
E. H+
Answer: [tex]Fe^{2+}[/tex] is the reducing agent
Explanation:
Oxidation reaction : When there is an increase in oxidation state number.
Reduction reaction : when there is a decrease in oxidation state number.
[tex]5Fe^{2+}(aq)+MnO_4^-(aq)+8H^+(aq)\rightarrow 5Fe^{3+}(aq)+Mn^{2+}(aq) +4H_2O(l)[/tex]
Fe has undergone oxidation, as its oxidation state is changing from+2 to +3.
Mn has undergone reduction, as its oxidation state is changing from +7 to +2.
The chemical agent which itself get oxidized and reduce others is called reducing agent. [tex]Fe^{2+}[/tex] is a reducing agent.
The chemical agent which itself get reduced and oxidize others is called oxidizing agent. [tex]MnO_4^-[/tex] is an oxidizing agent.
.
PLEASE HELP QUICK!
Your organ systems do not function
independently. Consider the following
scenarios, and explain how different
organ systems are working together.
a) You step on hot pavement in the
summer and quickly pull your foot
back.
(b) after running up the stairs you
breathe a little harder.
(c) A friend has a cold, and three days
later you have a cold too.
Answer:A
Explanation:
Your muscular system is at work
If you ingest a chemical from lab, immediately drink plenty of milk, then contact your instructor and wait for his/her response.
a. True
b. False
Answer:
False
Explanation:
The correct answer would be false.
If a chemical is ingested while working in the lab, the correct thing to do would be to contact the lab instructor right away as eating or drinking of any kind is prohibited in the laboratory.
While drinking milk may help in some cases depending on the nature and amount of the chemical ingested, only the lab instructor has the technical know-how to analyze the situation and administer first aids. Milk has the capacity to act as a buffer in some cases pending the time the victim would be able to get adequate medical attention.
To be considered a source of water pollution, the source must include a chemical.
Please select the best answer from the choices provided
ОТ
OF
Answer:
it is true because i just took the test and i did research on it
Explanation:
i study this and because i did research
Answer:
trueeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeee
Explanation: eeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeee
Which describes the number of protons in the atom of a particular element
Answer:
Atomic Number
Explanation:
The number of protons an atom has is unique to that element. The number of protons is noted as the atomic number for that element on the periodic table.
Deuterium is the isotope of hydrogen of mass number 2, with a proton and a neutron in its nucleus. The chemistry of deuterium is nearly identical to the chemistry of hydrogen, except that C−D bond is slightly (5.0KJ/mole) stonger than the C−H bond. Reaction rates tend to be slower if a C−D bond as opposed to a C−H bond is broken in a rate limiting step. This effect on the rate is called a kinetic isotope effect.
a. True
b. False
Answer:
True
Explanation:
We know that the zero-point-energy of a C-D system is quite lower than the zero point energy of the C-H bond so the C-D bond is stronger.
Kinetic isotope effect refers to the change in the rate of reaction owing to a change of one of the atoms of the reactants by replacing it with one of its isotopes.
Since we know that the C-D bond is stronger than the C-H bond, when we replace hydrogen with deuterium in a reaction's rate determining step we experience a little lag in the rate of reaction. This is referred to as the kinetic isotope effect in physical organic chemistry.
Which statements describe density? Check all that apply.
O Density is a chemical property of an object.
O The density of an object is constant.
O Density is a derived unit of measure.
D Density is the sum of the mass and volume of an object.
I The density of an object determines whether it will sink or fioat.
Answer:
2,3,5
Explanation:
Got correct on EDG
How many protons are in an element with an atomic number of 8 and mass number of 18
Answer:8
Explanation:
Atomic number = 8
Mass number = 18
The number of protons and the number of electrons is equal to the atomic number.
The number of neutrons in the nucleus is given by the difference in mass number and atomic number.
So, number of protons are 8
number of electrons = 8
number of neutrons = 18 - 8 = 10
Write a complete chemical formula, including physical state symbol, for each element listed below in its standard state.The first row of the table has been completed.Element FormulaIron Fe(s)Phosphorus Neon Chlorine
Answer:
Phosphorus P (s)
Neon Ne (g)
Chlorine Cl (g)
Explanation:
Iron: Fe(s) - The (s) denotes that iron is in its solid state.
Phosphorus: P(s) - The (s) indicates that phosphorus is in its solid state.
Neon: Ne(g) - The (g) signifies that neon is in its gaseous state.
Chlorine: Cl₂(g) - The (g) indicates that chlorine exists as a diatomic gas, with the formula Cl2, in its standard state.
Iron (Fe):
Iron is a chemical element commonly found in its solid state under standard conditions. The chemical symbol for iron is Fe, which is derived from the Latin word "ferrum." Iron is a lustrous, silvery-gray metal and is known for its strength and ability to be magnetized. In its standard state, iron exists as a solid, denoted by the (s) symbol. Therefore, the complete chemical formula for iron in its standard state is Fe(s).
Phosphorus (P):
Phosphorus is an element that exists in various forms, with the most common form being a solid known as white phosphorus. Under standard conditions, white phosphorus is the most stable and prevalent form. It is a waxy, white-to-yellowish solid that is highly reactive and combustible. The chemical symbol for phosphorus is P, and it is represented by the (s) symbol to indicate its solid state. Therefore, the complete chemical formula for phosphorus in its standard state is P(s).
Neon (Ne):
Neon is a chemical element that exists as a gas under standard conditions. It is a noble gas and is known for its bright red-orange glow when used in signs and lighting. Neon is chemically inert, meaning it does not readily react with other substances. The chemical symbol for neon is Ne, and it is represented by the (g) symbol to indicate its gaseous state. Therefore, the complete chemical formula for neon in its standard state is Ne(g).
Chlorine (Cl):
Chlorine is a halogen element that exists as a diatomic gas under standard conditions. It is a highly reactive and corrosive substance with a yellowish-green color and a pungent odor. Chlorine exists as a molecule with two chlorine atoms bonded together, forming Cl₂. The (g) symbol is used to indicate that chlorine exists as a gas. Therefore, the complete chemical formula for chlorine in its standard state is Cl₂(g).
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Perform the following operation
and express the answer in
scientific notation.
4.3x102 -7.0x 102
Answer:
-2.7 ×10²
Explanation:
Scientific notation is the way to express the large value in short form.
The number in scientific notation have two parts.
. The digits (decimal point will place after first digit)
× 10 ( the power which put the decimal point where it should be)
for example the number 6324.4 in scientific notation will be written as = 6.3244 × 10³
Given measurements = 4.3×10² - 7.0 ×10²
= -2.7 ×10²
How many centimeters make an inch?
Answer:
2.54 Centimeters.
I REALLY NEED HELP can someone help me please I’ll mark you brainliest! :)
Answer:
A
Explanation:
What is the motion of the particles in this kind of wave?
A hand holds the left end of a set of waves. The waves themselves make a larger set of waves in the same direction as that of the smaller waves. A label Wave motion is above the series of waves and an arrow next to the label points right.
The particles will move up and down over large areas.
The particles will move up and down over small areas.
The particles will move side to side over small areas.
The particles will move side to side over large areas.
Answer:
D
Explanation:
The particles will move side to side over large areas.
Answer:
The particles will move side to side over large areas.
Explanation:
What do u call a snowman in the summer
Answer:
A puddle
Explanation:
BAHAHAHAHA
if you are using a formula where you need the change in temperature, explain why it is not important whether your temperatures are both in Kelvin or Celsius?
Answer:
This is because, Kelvins and Celcius degrees both agree at fixed points i.e; the lower fixed point and upper
Acids are substances that surround us in our everyday life. The uses of acids range from providing essential nutrients for our bodies to dissolving metals. Some acids are safe to handle with our bare hands or even use in food preparation. Other acids will severely burn human skin. Why these substances can all be acids and yet have such different properties?
Answer: Strong and Weak Acids
Explanation:
Acids, also known as electrolytes, are compounds that break down into cations (positively charged ions) and anions when dissolved in water (negatively charged ions). Solid Electrolytes (Acids) fully ionize,
Whereas weak electrolytes (acids) only partly ionize.
What would humans need to live on another planet?
Answer:
In its astrobiology roadmap, NASA has defined the principal habitability criteria as "extended regions of liquid water, conditions favorable for the assembly of complex organic molecules, and energy sources to sustain metabolism". In August 2018, researchers reported that water worlds could support life.
What is the purpose of the cooling tower?
A. pumps cool water into the reactor
B. reduces heat pollution to the environment
C. cools down the electric generator
Answer:
id say c though im not sure
Explanation:
Cooling towers are primarily used for heating, ventilation, and air conditioning (HVAC) and industrial purposes.
Answer:
c
Explanation:
i had this on my test
Ethanol has the chemical formula C2H5OH. Write and balance the chemical reaction for the combustion of ethanol
Answer:
C2H5OH(l)+3O2(g)⟶2CO2+3H2O(l)
Explanation:
The balanced equation for the combustion of ethanol will be
[tex]C_{2}H_{5}OH+3O_{2}------- > 2CO_{2}+3H_{2}O[/tex]. According to this carbon dioxide and water will be the product.
What is combustion?
Combustion is a chemical process during which a material reacts quickly with oxygen and generates heat.
The original substance is referred to as the fuel, and the supplier of oxygen is referred to as the oxidizer. The fuel can be solid, liquid, or gas, but it is usually a liquid for airplane propulsion.
Combustion is a chemical reaction between two or more substances, usually involving oxygen, that produces light and heat in the form of a flame.
The products of complete ethanol combustion are carbon dioxide and water, as well as the start releasing of light and heat.
The equation will be:
[tex]C_{2}H_{5}OH+3O_{2}------- > 2CO_{2}+3H_{2}O[/tex]
Thus, in this way, the combustion of ethanol occurs.
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What mass of carbon monoxide gas (CO) would occupy a volume of 4.30 L at STP? Explain how you got the answer.
Answer:
5.38 g of CO.
Explanation:
From the question given above, the following data were obtained:
Volume of CO = 4.3 L
Mass of CO =?
Next, we shall determine the number of mole of CO that occupied 4.3 L at STP. This can be obtained as follow:
Recall = 1 mole of any gas occupy 22.4 L at STP.
1 mole of CO occupied 22.4 L at STP.
Therefore, Xmol of CO will occupy 4.3 L at STP i.e
Xmol of CO = 4.3 / 22.4
Xmol of CO = 0.192 mole.
Thus, 0.192 mole of CO occupy 4.3 L at STP.
Finally, we shall determine the mass of CO as follow:
Mole of CO = 0.192 mole.
Molar mass of CO = 12 + 16 = 28 g/mol
Mass of CO =?
Mole = mass /Molar mass
0.192 = mass of CO / 28
Cross multiply
Mass of CO = 0.192 × 28
Mass of CO = 5.38 g.
Therefore, 5.38 g of CO occupied 4.3 L at STP.
what is the answer i need help
so it is necessary to place the coefficient 2 in the front of HCL to balance the chemical equation to prove that
we have two CL and two H atoms in the products and one Cl and one H atom in the reactants so if we dont put 2 in front of HCL the chemical equation will not be balanced
how will we know that a chemical reaction happened if we cant see atoms??
we can do soo by noticing any colour change, or by the formation of an insoluble precipitate or by the evolution of a gas.
PLEASE HELP!!! WILL MARK BRIANLIST DO NOT GUESS I HAVE ATTEMPTED THREE TIMES
I want to prepare 4 Liters of 0.25 M aqueous sodium chloride solution. How many grams of the salt will I need to weigh out?
Answer:
Mass = 58.5 g
Explanation:
Given data:
Volume of solution = 4 L
Molarity of solution = 0.25 M
Grams of NaCl required = ?
Solution:
Formula:
Molarity = number of moles / volume in L
By putting values,
0.25 M = number of moles / 4 L
Number of moles = 0.25 mol/L × 4 L
Number of moles = 1 mol
Mass in gram:
Mass = number of moles × molar mass
Mass = 1 mol × 58.5 g/mol
Mass = 58.5 g
The half-life for a first-order reaction is 32 s. What was the original concentration if, after 2.0 minutes, the reactant concentration is 0.062 M?
Answer:
0.834 M.
Explanation:
Hello!
In this case, since this is a first-order reaction, we can infer that the half-life and the rate constant are related via:
[tex]t_{1/2}=\frac{ln(2)}{k}[/tex]
Thus, we are able to compute the rate constant:
[tex]k=\frac{ln(2)}{t_{1/2}} =\frac{ln(2)}{32s}\\\\k=0.0217s^{-1}[/tex]
Next, since we have the resulting concentration of the reactant and we need the initial one, we proceed as shown below with the rate law:
[tex]A=A_0exp(-kt)\\\\A_0=\frac{A}{exp(-kt)} \\\\A_0=\frac{0.062M}{exp(-0.0217s^{-1}*2.0min*\frac{60s}{1min} )}\\\\A_0=0.834M[/tex]
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How many joules of heat are given off when 5.00g of water cool from 348.0K to 298.0K?
Answer:
Q = -1045 J
Explanation:
Given data:
Mass of water = 5.00 g
Initial temperature = 348.0 K
Final temperature = 298.0 K
Heat given off = ?
Solution:
Specific heat capacity:
It is the amount of heat required to raise the temperature of one gram of substance by one degree.
Specific heat capacity of water is 4.18 J/g.K
Formula:
Q = m.c. ΔT
Q = amount of heat absorbed or released
m = mass of given substance
c = specific heat capacity of substance
ΔT = change in temperature
ΔT = 298.0 K - 348.0 K
ΔT = - 50 K
Q = 5.0 g ×4.18 J/g.K× - 50 K
Q = -1045 J