In a zero-order reaction, k was found to be a decrease of 0.0064 absorbance units per hour at ambient temperature. If the initial concentration defined by absorbance units was 0.85, how long will it take the initial concentration to degrade by 50%?
Answers
It will take approximately 66.4 hours for the initial concentration of 0.85 absorbance units to degrade by 50% at ambient temperature. In a zero-order reaction, the rate constant k was found to be a decrease of 0.0064 absorbance units per hour at ambient temperature.
If the initial concentration defined by absorbance units was 0.85, we can determine how long it will take the initial concentration to degrade by 50% using the following steps:
1. Calculate the final concentration after a 50% decrease: 0.85 * 0.5 = 0.425 absorbance units.
2. Calculate the total decrease in absorbance units: 0.85 minus 0.425 = 0.425 absorbance units.
3. Determine the time it takes for the reaction to degrade by 50%. Time (T) = (total decrease in absorbance units) / (k), where k = 0.0064 absorbance units per hour.
4. Calculate the time: T = 0.425 / 0.0064 = 66.4 hours.
So, in a zero-order reaction, it will take approximately 66.4 hours for the initial concentration of 0.85 absorbance units to degrade by 50% at ambient temperature.
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Related Questions
Dos moléculas de Clorato de Potasio en estado sólido, al aplicarle calor se descompone en dos moléculas de Cloruro de Potasio en estado sólido y tres moléculas diatómicas de Oxígeno en estado gaseoso ¿como se representan?
Answers
Answer:
2KClO3 (s) -------> 2KCl (s) + 3O2 (g)
Explanation:
Una ecuación de reacción química es una representación simbólica de lo que sucede en un recipiente de reacción.
Al escribir la ecuación de reacción química para una reacción particular, se utilizan los símbolos químicos de todas las especies involucradas.
Por la reacción. en el cual dos moléculas de Clorato de Potasio en estado sólido, al aplicar calor se descompone en dos moléculas de Cloruro de Potasio en estado sólido y tres moléculas diatómicas de Oxígeno en estado gaseoso, la ecuación de reacción se escribe así;
2KClO3 (s) -------> 2KCl (s) + 3O2 (g)
La regla para escribir ecuaciones de reacción química balanceada es que el número de átomos de cada elemento en el lado derecho de la ecuación de reacción debe ser el mismo que el número b de átomos del mismo elemento en el lado izquierdo de la ecuación de reacción.
Si realizamos un conteo de átomos simple en ambos lados de la ecuación de reacción, la regla se cumple
A buffer resists change in ph when ___________ amount of acid or base is added to it.
Answers
A buffered solution will resist changes in pH when small amounts of acid or base are added.
How does a buffer withstand pH changes?Buffers are solutions that resist pH changes when small amounts of acid or base are added. They are able to do so because they contain an acidic component, HA, which neutralises OH- ions, and a basic component, A-, which neutralises H+ ions. Because Ka is a constant, the [H+] will be directly proportional to the [HA]/[A-] ratio. Buffer, as defined, is a conjugate acid-base pair that can withstand pH changes when small amounts of strong acids or bases are added. When a strong base is added, the buffer's acid neutralises the hydroxide ions (OH -start superscript, start text, negative, end text, end superscript).The strong acid reacts with the weak base in the buffer to form a weak acid, which produces few H ions in solution and therefore only a little change in pH.To learn more about A buffer resists change in ph refer to
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The table below shows the organisms in a prairie ecosystem. It also shows where they get energy from?
Based on the table above, which food chain below is NOT present in the prairie ecosystem?
Sun> grass> grasshopper >meadow frog
Sun> chicory>pocket gopher> weasel
Sun> grass>ground squirrel >coyote
Sun> coyote> ground squirrel> grass
Answers
Answer:
the 4th food chain i guess
Answer:
The Correct Answer is D
Explanation:
they are all out of order
which elements are created in stellar nucleosynthesis? (select all that apply.) carbon nitrogen oxygen calcium iron hydrogen helium
Answers
Elements created in stellar nucleosynthesis are carbon, oxygen, iron, calcium .
What is stellar nucleosynthesis ?
Stellar nucleosynthesis is a process involving nuclear reactions in which new atomic nuclei are synthesized from existing nuclei or nucleons. The first stage of nucleosynthesis occurred in the hot early universe, producing H, He, and trace amounts of Li-7 (primordial nucleosynthesis). In today's universe, nucleosynthesis takes place as follows.
(1) thermonuclear reaction and explosion inside the star (nucleus formation up to the Fe peak), (2) neutron capture and explosion inside the star (nucleus formation above the Fe peak), (3) stars Spallation reactions in interstitial matter, where light nuclei (Li, Be, and B) arise from the fragmentation of heavy nuclei (C, N, and O).
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What is the mass of 6.023×10^23 molecules of hydrogen
Answers
Answer:So, the mass of 6.023×1023 6.023 × 10 23 molecules of HCl is 36.46 g.
Explanation:
Explanation
The chemical formula for water is H₂O. Sometimes two water molecules can bump into each other and
form the ions H30* and OH".
H₂O
H*
H₂O
What is happening in the chemical equation above?
Why is one ion positive and the other ion negative?
H₂O*
+
OH
Answers
Water is h2O, a clear, colorless, odorless, tasteless liquid that freezes into ice below 0 degrees centigrade and boils above 100 degrees centigrade.
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Some analytes must be derivatized to increase their column retention or detectability. Derivatization means Group of answer choices altering the chemical structure of the analyte to increase detection and specificity. adding fluorescent labels or combining the analyte with chiral reagents or other chemicals to increase detectability. removing dissolved gases in the solvent to produce a clear chromatogram. using multiple detectors to assist in identification.
Answers
Derivatization means adding fluorescent labels or combining the analyte with chiral reagents or other chemicals to increase detectability.
Some analytes must be derivatized to increase their column retention or detectability.
Retention time can be referred to as the amount of time a solute spends in the stationary and mobile phases of a column.
Detectability is the ability of an analyte to get detected in the mobile phase of chromatography.
The refractometer, fluorescence detector, and UV detector are the three most popular liquid chromatography detectors. These detectors increase the detectability.
For derivatization, the fluorescence detector are used.
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Calculate the number of atoms in 0.6984 moles in silver.
Answers
There are approximately 4.201 x 10^23 atoms in 0.6984 moles of silver.
How to calculate the number of atoms in a given number of moles of a substance ?First we can use Avogadro's number, which is the number of particles atoms, molecules, etc. in one mole of a substance. Avogadro's number is approximately 6.022 x 10^23 particles per mole.
The number of atoms in a given number of moles of a substance is equal to the number of moles multiplied by Avogadro's number. So, to find the number of atoms in 0.6984 moles of silver, we can use the following equation:
Number of atoms = Number of moles x Avogadro's number
Number of atoms = 0.6984 moles x 6.022 x 10^23 atoms/mole
Number of atoms = 4.201 x 10^23 atoms
Therefore, there are approximately 4.201 x 10^23 atoms in 0.6984 moles of silver.
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Four students wrote different analogies to describe an electron before the formation of an ionic bond. Student a: a tug of war between two wrestlers each weighing 460 lbs student b: a dog and his owner tugging at a frisbee student c: a big, greedy dog stealing away a bone from a smaller dog student d: children exchanging their orange and strawberry flavored popsicles which student presented a correct analogy? a b c d.
Answers
Student C: A big, greedy dog stealing away a bone from a smaller dog. This analogy describes an electron before the formation of an ionic bond.
What does the term "ionic bonding" mean?The main interaction in ionic compounds is ionic bonding, a form of chemical bonding that includes the electrostatic attraction between two atoms or ions with dramatically differing electronegativities. Along with covalent bonding and metallic bonding, it is one of the principal forms of bonding.
How does an ionic bond form?Ionic bonds are formed for a number of reasons, one of which being the stark disparities in electronegativity between atoms, which draw other atoms near them for the exchange of electrons. In contrast to other forms of bonds, this chemical interaction of electrons results in a strong bonding between the atoms.
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compound a, c10h16 reacts with 1 molar equivalent(s) of hydrogen upon catalytic hydrogenation. a undergoes reaction with ozone, followed by zn treatment, to give:
Answers
In summary, compound a reacts with hydrogen to undergo catalytic hydrogenation, and then undergoes ozonolysis followed by Zn treatment to produce an aldehyde or ketone.
Compound a, C10H16, is a hydrocarbon that undergoes catalytic hydrogenation when it reacts with 1 molar equivalent of hydrogen. This means that the hydrogen gas is added across the double bonds in the compound, resulting in a saturated compound with no double bonds.
A undergoes reaction with ozone, which is an oxidative process that cleaves double bonds in organic compounds. This produces a mixture of ozonides, which are unstable compounds that can be further treated with a reducing agent such as zinc (Zn). The Zn treatment is a step in the process of reducing the ozonides to aldehydes or ketones, depending on the structure of the starting hydrocarbon.
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Because water is a [x] molecule, it can act to disrupt the bonds of ionic salts, resulting in free ions in solution which can then undergo a double displacement reaction.
A.)precipitate
B.)solvate
C.)polar covalent
D.)dissociate
E.)net ionic equation
Answers
Because water is a polar covalent molecule, it can act to disrupt the bonds of ionic salts, resulting in free ions in solution which can then undergo a double displacement reaction. The correct answer is C.) polar covalent.
Polar covalent bondA polar covalent bond is a chemical bond between atoms where the electrons are shared unequally. Electronegativity is a measure of an atom's ability to attract electrons. If two atoms with distinct electronegativities are bonded together, the shared electrons will be more closely linked to the more electronegative atom. As a result, the more electronegative atom in a bond develops a partially negative charge, and the less electronegative atom develops a partially positive charge, which creates a polar molecule. For example, water is a polar molecule.
The bond between hydrogen and oxygen in water is polar due to the oxygen atom's higher electronegativity. Water's chemical formula is H2O, indicating that it is made up of two hydrogen atoms and one oxygen atom. It is known as a polar covalent molecule because oxygen is more electronegative than hydrogen. In the water molecule, the oxygen atom has a partial negative charge, while the two hydrogen atoms have a partial positive charge.
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In what part of the renal tubule does parathyroid hormone (pth) promote the reabsorption of calcium ions?
Answers
The distal convoluted tubule (DCT) part of the renal tubule does parathyroid hormone (PTH) promote the reabsorption of calcium ions.
What is PTH?PTH, short for parathyroid hormone, is the name of the four microscopic glands in the neck that regulate the body's calcium levels. Each gland is about the size of a grain of rice, weighing in at around 30 milligrams, and measuring 3–4 millimeters in diameter. PTH increases the body's capacity to absorb calcium from meals after ingestion by dissolving bone and releasing calcium. This increases the blood calcium level.
The main goal of these parathyroid glands is to maintain stable, healthy blood levels of calcium and phosphorus. For instance, the parathyroid gland will respond by secreting more PTH if the blood calcium level drops. After the excess PTH raises the calcium level, binding of calcium to the calcium-sensing receptor lowers the production and secretion of PTH, bringing the calcium level back to normal. This exchange of reciprocal benefits continues successfully up until renal failure sets in.
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Balancing equations help please !!!
Answers
6=H2O(I)
1=C6H12O6(s)
6=O2(g)
What is the major organic product obtained from the following reaction LiAlH4 H3O?
Answers
The major organic product obtained from the reaction between LiAlH₄ and H₃O⁺ is an alcohol.
LiAlH4, also known as lithium aluminum hydride, is a powerful reducing agent commonly used in organic synthesis. It can reduce a variety of functional groups, such as carbonyl compounds, to their corresponding alcohols. In this reaction, LiAlH₄ first reduces the carbonyl group (C=O) to a hydroxyl group (C-OH), resulting in the formation of an alkoxide intermediate. Then, the addition of H₃O⁺ (water) hydrolyzes the alkoxide, converting it into an alcohol.
The specific alcohol product will depend on the starting carbonyl compound used. For example, if the starting compound is a ketone, the major product will be a secondary alcohol. If the starting compound is an aldehyde, the major product will be a primary alcohol, it is important to note that LiAlH₄ is a strong reducing agent and should be handled with care due to its reactivity. So therefore the major organic product obtained from the reaction between LiAlH₄ and H₃O⁺ is an alcohol.
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5. calc 'ate the mass of an atom of (a) helium, (b) iron, and (c) lead. give your answers in atomic mass units and in grams. the atomic weights are 4. 56, and 207. respectively, for the atoms given.
Answers
Answer:
a) 4.0026 amu
b) 55.845 amu
c) 207.20 amu
Explanation:
To find the mass of an atom, it is excellent to look at the periodic table of elements.
What is the periodic table of elements?
A periodic table of elements shows a repeating pattern of properties of the elements crucial and known in the world of chemistry.
Reading the periodic table can be difficult but easy to manage with the correct amount of understanding. There are 118 elements known to science today, and all of them are contained with 4 main sectors:
Chemical Symbol: this is what differentiates the chemical and is an abbreviation. This is what we look for when we are trying to find information about an element. Name: The name of the element is written under the chemical symbol.Atomic Number: the atomic number is the number of protons in the nucleus of an atom of that element. Atomic Mass: This number indicates the average mass of that atom of all the isotopes in that element.Using this information, we need to find the atomic mass of Helium, Iron, and Lead. Consulting the periodic table of elements, the abbreviations of those elements are respectfully He, Fe, and Pb. We can find these on the periodic table to find the atomic mass, which is usually under the name of the element. It is measured in atomic mass units, or amu.
HELLPPPPPP!
Why does the freezing of water, exothermic process,become spontaneous at temperatures below 0° C even though the entropy of liquid water decreases during the phase change?
Answers
Answer:
Because the melting of ice as a spontaneous process (or reaction).
Explanation:
Here is an example:
Take a ice on a plate and leave it for half an hour (conditions). After half an hour, we notice water instead of ice.
This process took place without any intervention from your side. Heat absorbed by the ice from surrounding is due to set of conditions not due to your intervention.
So, we can consider melting of ice as a spontaneous process (or reaction).
which of these are considered to be macrominerals? i. c ii. ca iii. cl iv. co v. cu
Answers
The elements considered to be macrominerals are: i. C - Carbon, ii. Ca - Calcium and iii. Cl - Chloride
Calcium, phosphorus, magnesium, sodium, potassium, chloride, and sulfur are the macrominerals. Iron, manganese, copper, iodine, zinc, cobalt, fluoride, and selenium are the trace minerals. The other elements mentioned are:
iv. Co - Cobalt
v. Cu - Copper
While cobalt and copper are essential trace elements, they are not classified as macrominerals. Macrominerals are needed in larger amounts in the body, and calcium and chloride are among them.
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A 22 g sample of water is heated until it reaches a temperature of 73 °C. This sample
is placed in a calorimeter that contains 23 mL of H20 at 41 °C (use dH20 = 1.0 g/mL).
If the Cs of water is 4.18 J/g°C what is the final temperature of the water? (assume
that all the heat of the hot water goes into heating up the cold water until the two are
at thermal equilibrium and no heat is lost to the environment)
Answers
Answer:
56.64°c
Explanation:
its obtained from facts that heat gained by water=heat lost by calorimeter
Q. Give reasons for the following: 1. Graphite has a very high melting point. 2. Graphite is a non-metal but conducts electricity. Answer the question according to the class 9th student.
Answers
Explanation:
1.Graphite has a very high melting point because its structure consists of carbon atoms which are held together by strong covalent bonds
2.It has delocalised electrons.
someone anyone give me tips to finish online homework because i have 30 assignments to do
Answers
Answer:
Ok! I have four tips!
Explanation:
Create A Time Table.
Gather Information For Your Online Assignments Beforehand.
Make Notes As You Read The Course Materials.
Start Doing Your Online Assignment In Advance.
The table describes how some substances were formed.
Substance
P.
Q
Description
Formed by boiling pure water
Formed by combining three hydrogen atoms to every nitrogen atom
Formed by adding 5 g of sugar to 1 L of water
Formed by compressing carbon under high pressure
R
S
Based on the given descriptions, which substance is most likely a mixture?
P
Q
R
S
Answers
Explanation:
Which is a pure substance?
1. soda
2. gasoline
3. salt water
4. carbon dioxide
carbon dioxide
Bromine, a liquid at room temperature, has a boiling point of 58°C and a melting point of -7.2°C. Bromine can be classified as a
1. compound.
2. impure substance.
3. mixture.
4. pure substance.
pure substance.
Answer:
the answer is
Explanation:
Sugar and water make a homogeneous mixture (the same proportions of its components throughout any given sample).
Anyone help please more & you get extra points
Answers
Answer:
qns-4
1-multicellular organism
2-unicellular organism
3-unicellular organism
4-multicellular organism
5-unicellular organism
6-multicellular organism
7-unicellular organism
What is the density of an object with a mass of 130 g and a volume of 5 cm^3? please explain or im gonna fail 7th grade science
Answers
Answer:
26 g/cm³
Explanation:
Given data:
Mass of object = 130 g
Volume of object = 5 cm³
Density of object = ?
Solution:
Formula:
d = m/v
d = density
m = mass
v = volume
d = 130 g/ 5cm³
d = 26 g/cm³
Its a pick and HELP FASTS!!!!!
Answers
The cellular organization of human body starts from the cells itself and tissues then organ and organ systems. Here the the image in third box is cell or a tissue the first level and they joined together to form the second level as seen in the second box then heart and the human body.
What is organ system?Human body is made of various organ systems. Organ systems are a group of organs joined to perform one more functions. Different organ systems include digestive system, respiratory system, circulatory system etc.
The organ system including heart is circulatory system by which blood flow throughout the body. Cells are the basic level of this organization. Cells combines to form tissues asin the second image.
Tissue combines to form an organ as heart in first image and then the organ system and human body as seen in the last image.
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Hydrogen and nitrogen react to produce ammonia gas as shown in the following chemical
equation.
N2 + 3H2 - 2NH:
How many grams of hydrogen must react to produce 31.5 grams of ammonia?
Answers
Explanation:
\(31.5 \: g \: aommnia \: \times \: \frac{1 \: mol \: ammonia}{8 \: g \: ammonia \: } \: \times \frac{3 \: mol \: hydrogen}{2 \: mol \: ammonia} \: \times \frac{1 \: g \: hydrogen}{1 \: mol \: hydrogen} = \: 5.90625 \: g \: hydrogen \: must \: react \: \)
compute the number-average molecular weight for a polystyrene for which the degree of polymerization is 25,000.
Answers
The number-average molecular weight for the given polystyrene is 2,600,000 g/mol.
The number-average molecular weight (Mn) is a measure of the average molecular weight of the polymer chains in a sample. In the case of polystyrene, the degree of polymerization (DP) refers to the number of monomer units (styrene molecules) that are linked together to form a polymer chain. In this example, the degree of polymerization is given as 25,000. The molecular weight of the monomer (Mm) is an essential parameter required to calculate the Mn.
For polystyrene, the molecular weight of the monomer is approximately 104 g/mol. By multiplying the degree of polymerization by the molecular weight of the monomer, we obtain the number-average molecular weight of 2,600,000 g/mol for the given polystyrene sample.
The number-average molecular weight (Mn) of a polymer can be calculated using the formula:
Mn = (DP) × (Mm)
Where:
DP = Degree of polymerization
Mm = Molecular weight of the monomer
Mn = (25,000) × (104 g/mol)
Mn = 2,600,000 g/mol
Therefore, the number-average molecular weight for the given polystyrene is 2,600,000 g/mol.
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please help me on this question
Answers
Answer:
B
Explanation:
That seem the most locigal to me
how many grams are represented by 1.45 moles of Koh? Determine your answer to the correct number of significant figures.
Answers
Answer:
\(\boxed {\boxed {\sf 81.4 \ g\ KOH}}\)
Explanation:
We are asked to convert 1.45 moles of potassium hydroxide (KOH) to grams.
1. Molar MassThe molar mass is the mass in grams of 1 mole of a substance. The values are found on the Periodic Table. They are the same as the atomic masses but the units are grams per mole (g/mol) instead of atomic mass units (amu).
We have the compound KOH. Look up the molar masses of the individual elements.
Potassium (K): 39.098 g/mol Oxygen (O): 15.999 g/mol Hydrogen (H): 1.008 g/molThe formula for the compound has no subscripts, so there is 1 mole of each element in 1 mole of the compound. We can simply add the molar masses.
KOH: 39.098 + 15.999 + 1.008 =56.105 g/mol2. Convert Moles to GramsBased on the molar mass, there are 56.105 grams of KOH in 1 mole. Create a ratio using this information.
\(\frac {56.105 \ g\ KOH}{ 1 \ mol \ KOH}\)
We are converting 1.45 moles of KOH to grams, so we multiply by this value.
\(1.45 \ mol \ KOH *\frac {56.105 \ g\ KOH}{ 1 \ mol \ KOH}\)
The units of moles of KOH cancel.
\(1.45\ *\frac {56.105 \ g\ KOH}{ 1 }\)
\(81.35225 \ g\ KOH\)
3. RoundThe original measurement of moles has 3 significant figures, so our answer must have the same.
For the number we calculated, that is the tenths place. The 5 in the hundredths place (81.35225) tells us to round the 3 up to a 4.
\(81.4 \ g\ KOH\)
Approximately 81.4 grams of potassium hydroxide are represented by 1.45 moles.
1) Kilogram
Abbreviation
Answers
Answer: Kilogram (Kg)
Explanation:
Use the sample data to construct a 90% confidence interval estimate of the percentage of cell phone users who develop cancer of the brain or nervous system. %
Answers
Using this formula, we can calculate the confidence interval once we have the sample data, without the sample data, it is not possible to provide an accurate confidence interval estimate.
To construct a 90% confidence interval estimate of the percentage of cell phone users who develop cancer of the brain or nervous system, we would need the sample data, specifically the number of cell phone users and the number of users who developed cancer. Without the sample data, it is not possible to provide an accurate confidence interval estimate.
However, if we assume that we have the necessary sample data, we can proceed with the calculation. The formula for calculating a confidence interval for a proportion is:
Confidence interval
\(=�^±�×�^(1−�^)�Confidence interval= p^ ±z× np^ (1− p^ ) where:�^p^\)
is the sample proportion (number of users with cancer divided by the total number of cell phone users).
\(�\)
z is the z-score corresponding to the desired confidence level (90% confidence level corresponds to a z-score of approximately 1.645).
\(�\)
n is the sample size (total number of cell phone users).
Using this formula, we can calculate the confidence interval once we have the sample data.
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