Answer:
Explanation:
O B. Hypothesizing how pieces of ancient pottery were used
Two samples of the same rainwater are tested using two indicators at an environrnental lab. The first indicator, Methyl Orange, reveals a distinct yellow color when added to the sample. The second indicator, Litmus, turns red when placed in contact with the water sample.
Required:
a. Identify a possible pH value for the rainwater.
b. Explain, in terms of hydronium ions and hydroxide ion concentrations, the pH value of the rainwater.
Answer:
A. The pH value of rainwater is acidic about 4.4
B. The molar concentrations of the Hydronium ions are more than that of the hydroxide ions. That is why the rainwater is acidic with a pH of less than 7
Explanation:
A. Methyl orange is an acid indicator that is used to detect acidic solutions which have pH values that fall within the range of about 4.4 to 7. The distinct yellow colour change that was shown by the methyl orange as it was added to the water shows that the pH value is acidic, with a value above 4.4. (it has to be like this before methyl orange changes to yellow colour)
B. The Hydronium ( H30+) ion concentrations and the hydroxide (OH-) ion concentrations are used to measure the pH values of substances.
We can tell that the Hydronium ( H30+) ion concentrations are more than the hydroxide (OH-) ion concentrations in the sample of rainwater tested. This can be detected from the colour change that both the methyl orange and the litmus paper gave. The indicators showed that the rainwater solution was indeed acidic. Hence, the pH value will be less than 7, but greater than 4.4.
why does Portland have moderate climate
Answer:
Due to its location, Portland has a moderate climate. Also, which portland are you talking about? Portland Oregon or Portland Maine. Portland Oregon has a much more rainy climate, so I would say Maine has a better climate.
Explanation:
Asbestosis is a lung disease caused by inhaling asbestos fibers. The US Department of Health and Human Services considers a particular form of asbestos to be a carcinogen. The composition of this form of asbestos is 26.31% Mg, 20.20% Is, 1.45% H and the rest of the mass is due to oxygen. The molar mass of the compound is 277 g/mol. What is the molecular formula for the carcinogenic form of asbestos
Answer: The molecular formula for the carcinogenic form of asbestos [tex]Mg_3Si_2H_4O_9[/tex]
Explanation:
a) If percentage are given then we are taking total mass is 100 grams.
So, the mass of each element is equal to the percentage given.
Mass of Mg = 26.31 g
Mass of Si= 20.20 g
Mass of H= 1.45 g
Mass of O= (100-(26.31+ 20.20+ 1.45)) = 52.04 g
Step 1 : convert given masses into moles
Moles of Mg=[tex]\frac{\text{ given mass of Mg}}{\text{ molar mass of Mg}}= \frac{26.31g}{24g/mole}=1.10moles[/tex]
Moles of Si=[tex]\frac{\text{ given mass of Si}}{\text{ molar mass of Si}}= \frac{20.20g}{28g/mole}=0.72moles[/tex]
Moles of H=[tex]\frac{\text{ given mass of H}}{\text{ molar mass of H}}= \frac{1.45g}{1g/mole}=1.45moles[/tex]
Moles of O=[tex]\frac{\text{ given mass of O}}{\text{ molar mass of O}}= \frac{52.04g}{16g/mole}=3.25moles[/tex]
Step 2 : For the mole ratio, divide each value of moles by the smallest number of moles calculated.
For Mg = [tex]\frac{1.10}{0.72}=1.5[/tex]
For Si =[tex]\frac{0.72}{0.72}=1[/tex]
For H=[tex]\frac{1.45}{0.72}=2[/tex]
For O =[tex]\frac{3.25}{0.72}=4.5[/tex]
The ratio of Mg : Si: H: O = 1.5 : 1 : 2 : 4.5
Converting them into whole numbers :
The ratio of Mg : Si: H: O = 3 : 2 : 4 : 9
Hence the empirical formula is [tex]Mg_3Si_2H_4O_9[/tex]
Empirical mass =[tex]3\times 24+2\times 28+4\times 1+9\times 16=276g[/tex]
Molecular mass = 277 g
[tex]n= \frac{\text {Molecular mass}}{\text {Empirical mass}}=\frac{277}{276}=1[/tex]
Thus molecular formula =[tex]1\times Mg_3Si_2H_4O_9=Mg_3Si_2H_4O_9[/tex]
Given the equation:
н
H
H
H
H H H H H H
1
H H
7
C=C
/
H H
+
+
C=C
...
... -
C=C
/
Н.
с C-C-...
|
TI
H H H H H H
I-O-I
I-O-I
1
Н
H
н
Which type of reaction is represented by this equation?
1.
combustion
2.
esterification
3.
polymerization
4
substitution
Submit Answer
Answer:
The type of reaction is Polymerization
Answer:
combustion?
Explanation:
Yo, like what is that question.
List three ways the rate of solvation of sodium chloride in water may be
increased
Answer:
1) Increasing temperature
2) Stirring
3) Increasing surface area of salt by grinding it
what type of bond is most likely form between 2 gold atoms
Answer:
Metallic
Explanation:
"Metallic bonding is a type of chemical bonding that rises from the electrostatic attractive force between conduction electrons and positively charged metal ions. It may be described as the sharing of free electrons among a structure of positively charged ions." -Wikipedia
Please help! (:
question above — how much money would you need to buy 7.0 lb of arugula? If 27lb of arugula cost $16
Answer:
$11.81
Explanation:
27 lb cost $16
27/16=$1.69 per pound
$1.69*7=$11.81 for 7 lbs
One compound in the list below is a gas at room conditions, while all of the others are liquids or solids. For each compound, indicate whether it is the gas or the force most responsible for it being a liquid or solid.
First list:
A. CH3OH
1. a gas2. dispersion forces 3. dipolar forces4. hydrogen bonds5. ionic bonds6. covalent bondsB. CH4
1. a gas2. dispersion forces 3. dipolar forces4. hydrogen bonds5. ionic bonds6. covalent bondsC. CaCO3
1. a gas2. dispersion forces 3. dipolar forces4. hydrogen bonds5. ionic bonds6. covalent bondsD. C6H14
1. a gas2. dispersion forces 3. dipolar forces4. hydrogen bonds5. ionic bonds6. covalent bondsSecond list:
A. H2O
B. C2H2
C. CCl4
D. KCl
Answer:
First list
A. CH3OH----hydrogen bonds
CH4----dispersion forces
CaCO3---ionic bonds
C6H14----dispersion forces
Second list
H2O------ liquid----hydrogen bonds
C2H2----gas---dispersion forces
CCl4---liquid---dispersion forces
KCl----solid---ionic bonds
Explanation:
For every compound, the intermolecular forces decide whether the substance will be solid liquid or gas. Molecules are known to associate with each other in any particular state of matter. These molecules are held together by different intermolecular interactions with varying degrees of strength. The strength of the intermolecular interaction between the molecules of a substance will decide if the substance will be a solid, liquid or gas.
When the intermolecular forces are very strong such as in ionic solids and covalent network solids, the substance exists as a solid. When the intermolecular forces are not so strong such as dispersion forces and hydrogen bonds, the substance exists as a liquid. However, very weak intermolecular dispersion forces are found in gases hence the molecules are relatively free when compared to molecules of liquids and solids.
How would I find the quantity of heat absorbed or released when 2.0g of LiOH is dissolved in 100g of H₂0 when the enthalpy of the solution is -23.6KJ/mol?
Answer:
1.97kJ of energy are released.
Explanation:
The dissolution of LiOH in water is:
LiOH(s) → Li⁺(aq) + OH⁻(aq) ΔH = -23.6kJ
That means, when 1 mole of LiOH is dissolved, there are released (Because of the - in the enthalpy) 23.6kJ
2.0 g of LiOH (Molar mass: 23.95g/mol) are:
2.0g LiOH × (1 mol / 23.95g) =0.0835 moles of LiOH.
As 1 mole of LiOH release 23.6kJ, 0.0835moles release:
0.0835moles × (-23.6kJ / 1mole) = 1.97kJ of energy are released
What did John Dalton publish?
Answer:
An early theory describing properties of atoms.
Explanation:
Apex
Reactive oxygen species (ROS) are unstable, or reactive, compounds that result from the partial reduction of oxygen. ROS can cause damage to molecules, including membrane lipids and nucleic acids, and may be associated with some diseases. Which of these compounds are reactive oxygen species? Choose all that apply.
a. OH
b. OH-
c. O2-
d. H2O
e. H2O2
f. H-
Suppose that a wave has a period of 0.03 seconds what is its frequency be sure to show the steps for your work
Answer:
f = 33.34 Hz
Explanation:
A wave has a period of 0.03 seconds. It is required to find the frequency of a wave. The relation between time period and frequency is inverse. The time period of a wave is given by :
T = 1/f, f = frequency of wave
[tex]f=\dfrac{1}{T}\\\\f=\dfrac{1}{0.03}\\\\f=33.34\ Hz[/tex]
So, the frequency of the wave is 33.34 Hz.
Indicate whether the following represents a Chemical or Physical change: Gasoline burns in air
Answer:
Chemical
Explanation:
Whenever "burns" is being used, most of the time it is a chemical change
Answer:
chemical change
Explanation:
it's a chemical change because when gas burn it produces water and carbon dioxide
You are trying to recrystallize compound X. You consider using ethyl acetate as your recrystallizing solvent and test a small amount of compound X with ethyl acetate. You find that compound X is soluble in ethyl acetate at room temperature and at boiling. Is ethyl acetate a good recrystallization solvent? No, the sample needs to be insoluble or sparingly soluble at room temperature so that the maximum amount of purified crystals form at room temperature and in the ice bath. Yes, you want the sample to fully dissolve at room temperature and boiling so that it will crystallize in the ice bath. Yes, you can only be sure that all the impurities dissolved if the sample is soluble at room temperature
Answer:
No, the sample needs to be insoluble or sparingly soluble at room temperature so that the maximum amount of purified crystals form at room temperature and in the ice bath.
Explanation:
For a solvent to be adequate it must completely dissolve the substance to be purified when it is hot, that is, at boiling temperature only. It should be practically insoluble when the solvent is cold or at room temperature. This must occur in this way since impurities must be removed by hot filtering or dissolved in the mother liquor.
When vinylcyclohexane is treated with in dichloromethane, the major product is (2-bromo ethylidene)cyclohexane . Account for the formation of this product by drawing the structure of the most stable radical intermediate. Include all valence lone pairs in your answer. Include all valence radical electrons in your answer.
Answer:
Explanation:
Vinylcyclohexane is an example of a cyclic hydrocarbon where the vinyl group (-CH=CH₂ ) attaches itself to an end of a cyclohexane in ring form thereby giving rise to a vinylcyclohexane. The vinyl group are ethylene with a reduction in one hydrogen atom given them the name vinyl.
SOo, when vinylcyclohexane is treated with NBS ( i.e N-Bromosuccinimide a chemical reagent used in organic reactions) ; the bromine in the NBS reacts with the cyclohexane thereby giving rise to a allyl radical first. The allyl radical is resonance stabilized radical with an unpaired electron on the allylic carbon . As a result of stabilization ; a more stable substituted cycloalkene is formed as an intermediate .
This stable substituted cycloalkene intermediate then finally react with a bromine ion to give a major product known as ; (2-bromo ethylidene)cyclohexane.
The diagram emphasizing more on the above explanation can be seen in the attached image below
What are the relations between Electrochemistry and Cancer?
Answer: if im not wrong the relations are that the electrochemistry can detect the cancer and any other sickness
just like it does with chemical phenomena
=)
Which of the following best describes isotopes?
An element with the same number of neutrons, but a different number of protons.
An element with the same number of protons, but a different number of electrons.
An element with the same number of electrons, but a different number of neutrons
An element with the same number of protons, but a different number of neutrons
Answer: An element with the same number of protons, but a different number of neutrons
Explanation:
The # of protons in an atom is what determines what atom it is (hydrogen has 1 proton, helium has 2 protons, etc ...). You cannot change the number of protons in an atom without changing what element the atom is.
The number of electrons in atoms varies greatly because electrons are constantly gained, lost, and shared during chemical reactions.
An isotope is a variation of the same element (so they must have the same # of protons) that have different masses (and therefore a different number of neutrons).
The answer is the fourth choice, "An element with the same number of protons, but a different number of neutrons"
The isotopes refer to an element that consists of a similar number of protons but have a distinct no of neutrons.
What are isotopes:It is considered to be the members of the family with respect to the elements that consist of a similar number of protons but have a distinct no of neutrons. The no of protons in the nucleus measured the atomic number of elements based on the periodic table.
Therefore, the fourth option is correct.
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Magnesium and nitrogen react in a combination reaction to produce magnesium nitride:
3 Mg + N2 → Mg3N2
In a particular experiment, a 8.33-g sample of N2 reacts completely. The mass of Mg consumed is ________ g.
Answer:
21.7 g
Explanation:
Step 1: Write the balanced equation
3 Mg + N₂ → Mg₃N₂
Step 2: Calculate the moles corresponding to 8.33 g of nitrogen
The molar mass of N₂ is 28.01 g/mol.
[tex]8.33 g \times \frac{1mol}{28.01g} =0.297mol[/tex]
Step 3: Calculate the moles of magnesium that reacts with 0.297 moles of nitrogen
The molar ratio of Mg to N₂ is 3:1. The reacting moles of Mg are 3/1 × 0.297 mol = 0.891 mol
Step 4: Calculate the mass corresponding to 0.891 moles of magnesium
The molar mass of Mg is 24.31 g/mol.
[tex]0.891 mol \times \frac{24.31g}{mol} = 21.7 g[/tex]
Answer:
[tex]m_{Mg}=21.7 g Mg[/tex]
Explanation:
Hello,
In this case, considering the given reaction, we are able to compute the mass of magnesium that is consumed by considering its molar mass (24.31 g/mol), the molar mass of diatomic nitrogen (28.02 g/mol), the initial mass of nitrogen (8.33 g) and the 3:1 molar ratio of magnesium to nitrogen in the reaction.
Hence we compute it by applying the shown below stoichiometric procedure:
[tex]m_{Mg}=8.33 gN_2*\frac{1molN_2}{28.02gN_2} *\frac{3molMg}{1molN_2} *\frac{24.31gMg}{1molMg} \\\\m_{Mg}=21.7 g Mg[/tex]
Regards.
Which of the following is a chemical property of iron? It
Answer:
is capable of combining with oxygen to form iron oxide
Suppose that while you're in the lab performing a simple distillation you encountered one of the following errors: The components within the mixture, isopropanol and dichloromethane, distilled well below their boiling point. Poor separation between isopropanol and dichloromethane was observed. The initial volume of the distillation mixture has decreased significantly, almost dry, but no distillate was collected.
Answer:
Isopropanol and dichloromethane, distilled well below their boiling point.
Explanation:
The best way to separate isopropanol and dichloromethane is the method of fractional distillation. In this method, different compounds separate from each other due to difference in boiling. The boiling point of dichloromethane is 39.6 degree Celsius which is lower than the boiling point of isopropanol which is 82.5 degree Celsius. So dichloromethane will be evaporated when the temperature reaches to 40 degree Celsius and separated from isopropanol before reaching its boiling point.
How could the government enforce ethical standards of scientific
experiments?
A. The government could encourage scientists to make up their own
minds about ethics.
B. The government could take away research funds if ethical
standards are not met.
C. The government could let scientists monitor each other to
encourage ethical behavior.
D. The government could encourage the public to take a stand
against unethical scientists.
Answer: D. The Government could take away research funds if ethical standards are not met
The government enforce ethical standards of scientific experiments
B. The government could take away research funds if ethical
standards are not met.
Ethical standards are a set of principles established by the founders of the organization to communicate its underlying moral values. This code provides a framework that can be used as a reference for decision making processes.
How does the government control scientific research?Politicians and bureaucrats control scientific research and research outcomes by selectively funding projects that look for potential disasters, ideally global disasters.
What are the 8 ethical standards?This analysis focuses on whether and how the statements in these eight codes specify core moral norms (Autonomy, Beneficence, Non-Maleficence, and Justice), core behavioral norms (Veracity, Privacy, Confidentiality, and Fidelity), and other norms that are empirically derived from the code statements.
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Calculate the number of moles of magnesium, chlorine, and oxygen atoms in 4.90 moles of magnesium perchlorate, Mg(ClO4)2.]\
Answer:
4.90 moles of [tex]Mg(ClO_4)_2[/tex] will produce (9.8) moles of [tex]Cl^{-}[/tex] ,
(4.90) moles of [tex]Mg^{2+}[/tex] and
(39.2) moles of [tex]O^{2-}[/tex]
Explanation:
From the question we are told that
The number of moles of is [tex]n = 4.90 \ mols[/tex]
The formation reaction of [tex]Mg(ClO_4)_2[/tex] is
[tex]Mg^{2+} + 2 Cl^{-} + 8O^{2+} \to Mg(ClO_4)_2[/tex]
From the reaction we see that
1 mole of [tex]Mg(ClO_4)_2[/tex] is formed by 2 moles of [tex]Cl^{-}[/tex] 1 mole of [tex]Mg^{2+}[/tex] and 4 [tex]O^{2-}[/tex]
This implies that
4.90 moles of [tex]Mg(ClO_4)_2[/tex] will produce (2 * 4.90) moles of [tex]Cl^{-}[/tex] ,
(1 * 4.90) moles of [tex]Mg^{2+}[/tex] and
(8 * 4.90) moles of [tex]O^{2-}[/tex]
So
4.90 moles of [tex]Mg(ClO_4)_2[/tex] will produce (9.8) moles of [tex]Cl^{-}[/tex] ,
(4.90) moles of [tex]Mg^{2+}[/tex] and
(39.2) moles of [tex]O^{2-}[/tex]
Answer:
- [tex]n_{Mg}=4.90molMg[/tex]
- [tex]n_{Cl}=9.6molCl[/tex]
- [tex]n_{O}=38.4molO[/tex]
Explanation:
Hello,
In this case, for the given 4.90 moles of magnesium perchlorate, we can compute the moles of each atom by identifying the subscript each atom has in the molecule as shown below:
- Moles of magnesium atoms: here, one mole of magnesium perchlorate has only one mole of magnesium atom (subscript is one), this the moles of magnesium atoms are also 4.90 moles.
- Moles of chlorine atoms: here, one mole of magnesium perchlorate has two moles of chlorine atoms as it has a two out of the parenthesis enclosing the perchlorate anion, thus, we have:
[tex]n_{Cl}=4.80molMg(ClO_4)_2*\frac{2molCl}{1molMg(ClO_4)_2} =9.6molCl[/tex]
- Moles of oxygen atoms: here, one mole of magnesium perchlorate has eight moles of oxygen atoms as it has a four in the oxygen subscript and a two out of the parenthesis enclosing the perchlorate anion, thus, we have:
[tex]n_{O}=4.80molMg(ClO_4)_2*\frac{8molO}{1molMg(ClO_4)_2} =38.4molO[/tex]
Best regards.
Based on VSEPR theory and your observations from the Molecular Geometry lab consider the following questions What is the predicted hybridization at an atom which is surrounded by a double bond and two single bonds?
a) Sp
b) sp^2
c) sp^3
Answer:
b) sp^2
Explanation:
Hybridization refers to the concept that atomic orbitals fuse to form newly hybridized orbitals, which in turn, influences molecular geometry and bonding properties. In chemistry, orbital hybridisation (or hybridization) is the implies the mixing of atomic orbitals to form hybrid orbitals (with different energies, shapes, etc., different from that of the component atomic orbitals) suitable for the pairing of electrons to form chemical bonds according to the principles of the valence bond theory.
In 1931 Linus Pauling proposed the idea of “mixing” the orbitals or “hybridizing” them to account for certain observed bonding patterns. Pauling proposed a sort of a combination of the orbitals giving you an orbital that has partial characters.
Hybridization is merely a mathematical construct. It is never an actual “process” that occurs within orbitals . Hybridization is a mathematical model that describes how the atomic orbitals would’ve looked like based on the observable molecular orbitals.
sp2 hybridization leads to the formation of a double bond. sigma bonds may also be formed depending on the valency of the central atom. In alkenes, an sp2 hybridized carbon atom forms a double bond in addition to two sigma bonds to other atoms.
The predicted hybridization is:
b) [tex]sp^2[/tex]
What does Hybridization tell us?It is the integration of atomic orbitals to shape new orbitals with exclusive energies and shapes than the unique orbitals.
Given: An atom that's surrounded with the aid of using a double bond and unmarried bonds.
[tex]sp^2[/tex] hybridization ends in the formation of a double bond. sigma bonds can also be shaped relying at the valency alkenes, an [tex]sp^2[/tex]sigma bonds to different atoms.
Thus, correct option is b.
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Classify the following unbalanced chemical reaction Fe(s) + Cl2(aq) = Fe2+(aq) + Cl-(aq)
1. Acid-Base Reaction
2. Precipitation Reaction
3. Oxidation-Reduction Reaction
4. Combustion Reaction
Answer:
3. Oxidation-Reduction Reaction
Explanation:
Fe(s) + Cl2(aq) = Fe2+(aq) + Cl-(aq)
Fe(s) -2e- ----> Fe2+(aq) oxidation
Cl2(aq) + 2e- -----> 2Cl-(aq) reduction
The given unbalanced chemical reaction is the oxidation-reduction reaction. Therefore, option (3) is correct.
What is an oxidation-reduction reaction?Redox reactions can be defined as oxidation-reduction chemical reactions in which the reactants of the reaction undergo a change in their oxidation states. All the redox reactions are further broken down into two different processes: a reduction process and an oxidation process.
The oxidation and reduction reactions take place simultaneously in an Oxidation-Reduction reaction. The substance that is getting reduced in a reaction is known as the oxidizing agent, while a substance that is getting oxidized is the reducing agent.
The given chemical reaction is:
[tex]Fe(s) + Cl_2(aq) \longrightarrow Fe^{2+}(aq) + Cl^-(aq)[/tex]
The oxidation reaction for this reaction is: Fe (s) → Fe²⁺ (aq) + 2e⁻
The reduction reaction: Cl₂ (g) + 2e⁻ → 2Cl⁻ (aq)
Therefore, the given reaction between the iron and chlorine gas is the oxidation-reduction reaction or redox reaction.
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A 5.00-L tank contains helium gas at 1.50 atm. What is the pressure of the gas in mmHg
Answer:
1140 mmHg
Explanation:
1 atmosphere is 760 mmHg, so 1.5 atmospheres is ...
1.5×760 mmHg = 1140 mmHg
5. Rubbing alcohol is a commonly used disinfectant and has a cooling effect when applied to the skin. The active ingredient in rubbing alcohol is isopropanol. In drugstores, the most common concentration of rubbing alcohol sold contains 70% (vol/vol) isopropanol in water. Assuming the rubbing alcohol manufacturer uses a 100% isopropanol solution, what volume of pure isopropanol is required to produce a 200-mL bottle of rubbing alcohol
Answer:
Explanation:
70% (vol/vol) means
cotnaimns 70 %(vol/vol) 70 ml of isoprapnol is there in 100 ml of Rubbing sold alcohol.
if it is 200 ml then obvouly it has the 70*2 =140 ml of isoproanol required.
Alcohol is an organic compound that when rubbed on the skin it evaporates quickly leaving a cool effect on the skin. The reason why it evaporates is because it has loosely bound molecules and a low boiling temperature.
The volume of pure isopropanol required to produce a 200-ml bottle of rubbing alcohol is 140 ml
From the question:
Alcohol sold contains 70%(vol/vol). This means 70 ml of the solute of isopropanol can be found in 100 ml of solution.
Hence:
100ml of solution = 70ml of isopropanol
200ml of solution = ?
Cross Multiply
200 ml x 70 ml / 100 ml
= 140 ml
Therefore, the volume of pure isopropanol required to produce a 200-ml bottle of rubbing alcohol is 140 ml
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Which statement BEST describes how a golf club does "work" on a golf ball?
(A) When the club hits the ball the club transfers all of its kinetic energy to the ball.
(B) All of the kinetic energy from the club is transferred to the ball as they both move through the air.
(C)
Some of the kinetic energy from the golf club is transferred to the ball and some transforms into sound
and heat, but the total energy remains the same.
(D) The golf club loses kinetic energy when it hits the ball and the ball gains kinetic energy from the air as it
travels
Answer:
C
Explanation:
It looks pretty reasonable to me
How many moles would 1.204x1024 atoms of oxygen be? (Remember Avogadro's number is 6.022x1023
Answer:
7.25 x 10^47
Explanation:
1.204 x 10^24 moles*6.022 x 10^23 avogadro's number= 7.25 x 10^47
The core of the pyruvate dehydrogenase complex is made up of eight catalytic________that make up the_______component.
a. monomers; E1b. dimers; E2c. dimers; E3d. trimers; E2
Answer:
(D.)
The core of the pyruvate dehydrogenase complex is made up of eight catalytic trimers that make up the E2 component.
Explanation:
Eight trimers assemble as a hollow truncated cube, which forms the core of the multi-enzyme complex, known as the E2 complex in human pyruvate dehydrogenase complex.
Find the age ttt of a sample, if the total mass of carbon in the sample is mcmcm_c, the activity of the sample is AAA, the current ratio of the mass of 14 6C 614C to the total mass of carbon in the atmosphere is rrr, and the decay constant of 14 6C 614C is λλlambda. Assume that, at any time, 14 6C 614C is a negligible fraction of the total mass of carbon and that the measured activity of the sample is purely due to 14 6C 614C. Also assume that the ratio of mass of 14 6C 614C to total carbon mass in the atmosphere (the source of the carbon in the sample) is the same at present and on the day when the number of 14 6C 614C atoms in the sample was set. Express your answer in terms of the mass mamam_a of a 14 6C 614C atom, mcmcm_c, AAA, rrr, and λλlambda. View Available Hint(s)
Answer:
Explanation:
An artifact is found in a desert cave. The anthropologists who found this artifact would like to know its age. They find that the present activity of the artifact is 9.25 decays/s and that the mass of carbon in the artifact is 0.100 kg. To find the age of the artifact, they will need to use the following constants:
r=1.2
The activity of carbon 14 is
[tex]A=A_0e^{\lambda t}[/tex]
where,
[tex]A_0[/tex] is the initial activity of the compound
Solve for t
[tex]-\lambda t=In\frac{A}{A_0}[/tex]
[tex]t=-\frac{1}{\lambda} In(\frac{A}{A_0} )[/tex]
[tex]=-\frac{1}{\lambda} In(\frac{A}{\lambda r(\frac{m_c}{m_a} )} )[/tex]
since,
[tex]A_0=\lambda r(\frac{m_c}{m_a} )[/tex]
[tex]=-\frac{1}{\lambda} In(\frac{A\ m_a}{\lambda r m_c} )[/tex]
Now, the age of the artifact is
[tex]=-\frac{1}{\lambda} In(\frac{A\ m_a}{\lambda r m_c} )[/tex]
[tex]=-\frac{1}{1.21\times 10^{-4}} In(\frac{(9.25)(2.32\times 10^{-26}}{1.21\times 10^{-4}(\frac{1}{3.15569\times10^7} )(1.2\times 10^{-12})(0.100)}} )\\\\=6303.4 \ years[/tex]
to two significant figure = 6300 years