Answer:
pH → 1.83
Explanation:
Let's write the lactic acid as HLac, because it is a monoprotic weak acid.
HLac + H₂O ⇄ H₃O⁺ + Lac⁻ Ka
Initially we have 0.25 moles, so x amount has reacted. At the end, when the equilibrium is finished, we may have (0.25 - x) moles of acid, x moles of protons have been released and x moles of lactate were formed.
In order to find x, we use the acid constant, Ka. The expression for Ka is:
Ka = [H₃O⁺] . [Lac⁻] / [HLac]
8.3×10⁻⁴ = x² / (0.25-x)
8.3×10⁻⁴ (0.25 - x) = x²
8.3×10⁻⁴ . 0.25 - 8.3×10⁻⁴x - x² → this is a quadractic function
a = -1, b = 8.3×10⁻⁴, c = 2.07×10⁻⁴
We solve: (-b - √(b² - 4ac) / (2a)
(-8.3×10⁻⁴ - (√ ((8.3×10⁻⁴)² - 4 (-1) (2.07×10⁻⁴) ) / (2 . -1) = 0.0148
[H₃O⁺] = 0.0148 M
- log [H₃O⁺] = pH → - log 0.0148 = 1.83
The pH is defined as the power of Hydrogen. The pH of a 0.25 M solution of lactic acid is 1.83.
[tex]\bold { CH_3COOH \rightarrow CH_3 COO + H^+\ \ \ \ \ \ \ \ \ \ \ \ (Ka = 8.3 x 10 -4 ).}[/tex]
Initial concentration of lactic acid is 0.25 M, So, [tex]x[/tex]. At the end of equilibrium [tex]x[/tex] amount of lactic acid dissociates.
So, concentration of the Hydrogen ion in the (0.25 - [tex]x[/tex])
[tex]x[/tex] can be found out by using the dissociation constant formula,
[tex]\bold {Ka = \dfrac {[H^+][CH_3COO^-]}{[Ch_3COOH]}}\\[/tex]
[tex]\bold {8.3x10^-^4= \dfrac {[x][x]}{[2.5- x]}}\\\\\bold {8.3x10^-^4= \dfrac {[x^2]}{[2.5- x]}}\\\\\bold {x^2= 8.3x10^-^4\times [2.5- x]}}\\\\\bold {8.3x10^-^4 \times 0.25 - 8.3x10^-^4 x - x^2 = 0}[/tex]
The equation above is a quadratic equation, solving it we get,
The concentration of protons = 0.0148 M
Put this into the pH formula,
[tex]\bold {pH = -log [H^+]}[/tex]
[tex]\bold {pH = -log [ 0.0148]}\\\\\bold {pH = 1.83}[/tex]
Therefore, the pH of a 0.25 M solution of lactic acid is 1.83.
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Air is made up mostly of O2, N2, and CO2. If the total pressure of air is 765mmHg and P(N2) = 0.79 atm and P(CO2) = 0.05 atm, then what is the partial pressure of the O2?
Answer:
the partial pressure of the O2 is 0.167 atm
Explanation:
The computation of the partial pressure of the O2 is shown below:
As we know that
P = P_N2 + P_O2 + P_CO2
P_O2 = P - P_N2 - P_CO2
= (1.007 - 0.79 - 0.05)
= 0.167 atm
Hence, the partial pressure of the O2 is 0.167 atm
we simply applied the above formula
If both samples contain the same amount of gas, which sample has a greater volume? use your knowledge of gas laws to explain your answer
Answer:A modern statement is: Avogadro's law states that "equal volumes of all gases, at the same temperature and pressure, have the same number of molecules." For a given mass of an ideal gas, the volume and amount (moles) of the gas are directly proportional if the temperature and pressure are constant.
Explanation:
The Avogadro's law is used here to determine the volume of the gas. Here the both samples have equal volume since they contain the same amount of gas.
What is Avogadro's law?The Avogadro's law states that equal volumes of all gases under similar conditions of temperature and pressure contain equal number of molecules. Mathematically the law can be expressed as:
V ∝ n
The gases show great uniformity in their behaviour irrespective of their nature. Some useful generalisations have been deduced from the behaviour of gases which are known as gas laws.
The Avogadro's law follows that the volume of a gas is directly proportional to the number of molecules. But the number of molecules (N) of any gas is directly proportional to its number of moles (n).
So here if both samples contain the same amount of gas, both of them have the equal volumes. We cannot determine one with greater volume.
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Explain how low atomspheric oxygen levels affected alligators growth in terms of celluar respiration
Answer:
Answer: Hyperoxic alligators show significantly lower breathing rates than their siblings in normoxic and hypoxic groups. Conversely, each breath supports greater oxygen consumption in hyperoxic animals than in other groups. Statistical significance between groups was calculated by ANOVA with post hoc Tukey-Kramer
The explanation regarding the less atmospheric oxygen levels impacted the alligators growth should be because of Hyperbolic alligators.
What is Hyperbolic alligators?There should be less breathing rate and the consumption of the oxygen should be high per breath.
The compensatory cardiopulmonary remodeling, the growth of the hypnotic alligators should be constrained by the less temperature with respect to the supply of the oxygen that should limited the food utilization capacity.
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Given two balanced equations, each representing a reaction:
(1) Equation 1 shows 2.2 X 105 times more energy being absorbed. (\
2) Equation 2 shows 2.2 X 105 times more energy being absorbed.
(3) Equation 2 shows 2.2 X 105 times more energy being released.
(4) Equation 1 shows 2.2 X 105 times more energy being released.
Answer:
There is a hack in forms that forms gives u the answer hold ctrl + u, and scrool to the bottom he read the part with the question and there will be an answer.
Mark as brainliest if im right good luck
I need help ASAP
Extra points & brainlest:)
Answer:
it is c
Explanation:
Answer:
Lysosome
Explanation:
The lysosome of a cell removes waste and deports it to the Golgi Apparatus to remove completely
What does what does c6h12o6+6o2→6co2+6h2o+energy equal to?
Answer: c6h12o6+6o2→6co2+6h2o= C6H12O6 + 6O2 -> 6CO2 + 6H2O Yields 2755 kJ/mole of glucose. The reverse of this reaction – combing carbon dioxide and water to make sugar is known as photosynthesis. Photosynthesis is the process responsible for storing all the energy we extract from fossil fuels, crops, and all of our food. We will also see that it is part of a globally important cycle affected by our consumption of fossil fuels. Photosynthesis How is photosynthesis able to run the reaction above in the reverse direction? Somehow it must come up with 2755 kJ of energy to make each mole of glucose. Where does that energy come from? The short answer: photons of sunlight. The long answer: When the pigment chlorophyll inside the chloroplasts of a photosynthetic organism (phytoplankton, trees, other plants) absorbs sunlight, it becomes energetically ‘excited’ and grabs the hydrogen atoms away from a water molecule, leaving the oxygen atoms to escape as O2 gas. This is called ‘splitting water.’ The hydrogen atoms are then split into their component protons and electrons. The electrons are used to reduce carbon dioxide, in a series of many steps requiring more absorption of sunlight by chlorophyll, to glucose. When carbon dioxide receives those electrons, the extra negative charge attracts protons from elsewhere, creating hydrogen atoms attached to the carbon atom. This process is called reduction. When those reduced carbon dioxide molecules are combined together in a larger molecule, the result is glucose. This ‘combing together’ of small molecules requires an input of energy, which is provided by the ATP molecules made by the protons diffusing through the membrane of the chloroplast. The ATP molecule is simply a molecule that biology uses to store energy for later use. In this case, the mechanical energy created by the protons diffusing across the membrane turns a sort of molecular turbine that smashes together its precursors.
PLEASE HELP ILL MARK BRAINLIEST
Answer:
1. true
2. existing matter
3. the materials simply turn into gases you cannot see
hope that helps! ☺
plz mark Brainliest!
3. Students measured the mass of the reactants and products for a combustion reaction they observed.
When they measured the mass of the products, they discovered the products had a greater mass than
the reactants. How did this unexpected change in mass occur?
A. Stadents made a measurement error, because ending with more products is impossible.
B. The reactants had hidden materials within them that had no mass until the reaction was complete.
C. The products of reactions often have greater mass, because the law of conservation is not
applicable in all chemical reactions.
D. The reaction occurred in an open system, so during the reaction a gas interacted with the reactants.
The mass of the gas could not be measured before the reaction.
Answer:
A. Students made a measurement error, because ending with more products is impossible.
Explanation:
The law of conversation of matter tells us that in a chemical reaction, matter is never created or destroyed, it's simply converted from one form to another. So the mass of reactants should always equal the mass of the products in a chemical reaction. If there is excess mass in the product, the students have made an error of some kind.
what is a molecule??
Answer:
molecule is a group of atoms bonded together representing the smallest fundamental unit of a chemical reaction
Calculate the volume of a 0.15 mol dm-3 Ba(OH)2 solution required to completely neutralize 45 cm3 of a 0.29 mol dm-3 HNO3 solution. Note: Ba(OH)2 + 2HNO3 --> Ba(NO3)2 + 2H2O
Answer:
[tex]V_{base}=43.5cm^3[/tex]
Explanation:
Hello there!
In this case, given the neutralization chemical reaction of barium sulfate and nitric acid, it is possible to evidence the 1:2 mole ratio between them; thus, at the equivalence point we have:
[tex]2n_{base}=n_{acid}[/tex]
Which in terms of molarities and volumes is:
[tex]2M_{base}V_{base}=M_{acid}V_{acid}[/tex]
In such a way, by solving for the volume of base, we proceed as follows:
[tex]V_{base}=\frac{M_{acid}V_{acid}}{2M_{base}} \\\\V_{base}=\frac{45cm^3*0.29mol*dm^{-3}}{2*0.15mol*dm^{-3}} \\\\V_{base}=43.5cm^3[/tex]
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What type of reproduction requires uniform population.
Answer:
Asexual reproduction .
Explanation:
Asexual reproduction is a type of reproduction that does not involve the fusion of gametes or change in the number of chromosomes. The offspring that arise by asexual reproduction from either unicellular or multicellular organisms inherit the full set of genes of their single parent.
Please help me with this
how is it proved that carbon is present in sugar?
Answer:
In all living organisms, in substances like carbohydrate, starch, urea etc. To prove sugar contains carbon, take a little amount of sugar in spoon and heat it gently till it melts and turned into yellowish color. On further heating it changes into brown colored mass and then black, which is charcoal.
Take a small bit of sugar on a spoon and slowly heat it until it melts and turns a yellowish tint to demonstrate that it contains carbon. As it continues to heat up, it transforms into charcoal, which is a black mass first.
What is Charcoal ?Strongly heating wood with little oxygen produces charcoal, a light black carbon residue that has been stripped of all water and volatile components.
Since the beginning of time, charcoal has been used for a wide variety of reasons, including art and healing, but its most significant usage has been as a metallurgical fuel. The typical fuel for a blacksmith's forge and other uses requiring high heat is charcoal.
Sugar breaks down into carbon and water when it is heated. Water is still a chemical, but it can't be heated
Thus, As it continues to heat up, it transforms into charcoal, which is a black mass first.
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If 5 moles of sugar was added to a kilogram of water, the new boiling point would be _____ degrees C.
Write your answer to the nearest hundredth.
Answer: 102.56
Explanation: I just took the K12 test and this is my answer.
If the Earth were to spin half as fast as it does now, how many hours would be in one day (one complete spin)?
(Science)
Answer:
12hrs
Explanation:
Hope this helps
Answer:
12 hours
Explanation:
it's half of the time in a day now
Which of the following is a potential disadvantage of using wind energy? (2 answers)
A)It has potential to kill fish caught in the turbines
B)The source of energy can sometimes be inconsistent
C)It alters migratory bird routes
D)It is influenced by the amount of cloud cover
E)It releases high amounts of carbon dioxide when used
Answer:
It's probably b
Explanation:
(I'm wrong aren't I)
Which of the nine substances are made of three elements?
Answer: You are made of mostly 6 elements: Oxygen, Carbon, Hydrogen, Nitrogen, Calcium, and Phosphorus. Some of these elements combine to form compounds in your body.
Explanation:
Does a animal cell have cytolysis?
Answer:
The presence of a cell wall prevents the membrane from bursting,so cytolysis only occurs in animal and protozoa cells which do not have cell walls.
Explanation:
how can water become more acidified than normal due to
atmospheric pollutants
Answer:
The water can become acidified than normal because all the pollution such as when carbon dioxide can dissolve in sea waters causing the water be polluted because of the bad air.
Explanation:
Help ASAP POINTS ARE ADDED !!!!!!due in 3 minutes
Proton:
Positive
Found in Nucleus
Mass of 1 AMU
Neutron:
Neutral
Found in Nucleus
Mass of 1 AMU
Electron:
Negative
Found in orbitals
Mass of 0 AMU
1. Which of the following is not an example of a form of carbon?
O fullerenes
O graphite
salt
diamond
Reference page.
What happens when you mix hydrogen, oxygen and fire together?
Answer:
this could result to things like wild fires a tornadoes
Explanation:
25. The ability of one substance to dissolve in another at a given temperature and
pressure is known as:
a. Solubility
b. Freezing point
c. Melting point
d. Concentration
Answer:
Melting point
Explanation:
And here is your answer hope it would be correct
UGRENT! Please help showing all work
Answer:
wait I AM TRYING..................
this is limiting reactant
Pls help will give brainlist
Answer:
D. 5
Explanation:
The coefficient will almost always be the whole number in front of the variable.
example
5(x)= 7
The coefficient would be 5.
What would happen to Earth's temperature if the energy absorbed from the sun (solar radiation) was less than the emitted (thermal) energy leaving the Earth?
Answer:
The Earth would become cooler until it probably attains a new equilibrium between absorbed solar energy and emitted solar energy.
Explanation:
The earth's energy balance refers to the balance between the energy absorbed from the sun (solar radiation) and the emitted (thermal) energy leaving the Earth. This balance ensures that the earth's surface temperature remains fairly constant.
When energy from the sun reaches the earth, it is absorbed and used by various features of the earth which uses it for their energy needs. Eventually, any excess radiant energy is sent back or emitted from the earth back into space such that the balance between absorbed and emitted energy is maintained.
However, if there is an imbalance whereby more energy is emitted than is absorbed, this would result in the earth losing more heat than it receives. This would result in the earth becoming more significantly colder until it probably attains a new equilibrium between absorbed solar energy and emitted solar energy.
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Why is water called.compound
Answer:
because it's composed of two elements, hydrogen and oxygen. water is technically a molecular compound tho, for it has two hydrogens.
Describe what happens when a bond is created between magnesium and bromine. Be specific and explain in terms of electrons.
Answer: Magnesium and Bromine/MgBr2 = Ionic compounds
Explanation: When atoms form together they can form between Ionic Compounds and molecules; this could depend on if they're joined by Covalent bonds as well because when atoms form with Covalent bonds, it forms Molecules.
I need help please i need to turn this in today
Answer:
Natural phenomena such as melting glaciers is due to the rise in temperature. This will result to extinction of flora and fauna. Moreover it can cause extreme flooding due to rise in water level in other water bodies such as rivers, lakes
Balancing chemical equation:
_Na+_MgF2—>_NaF+_Mg
Na= ? Na= ?
Mg= ? Mg= ?
F= ? F= ?
2Na + MgF2 → 2NaF + Mg