Answer:
5x10⁶ atoms of platium have to be laid side by side
Explanation:
1 atom of platium has a radius of 139pm = 139x10⁻¹²m. The distance that occupies 1 atom of platinum is 2 times its ratio:
139x10⁻¹²m*2 = 2.78x10⁻¹⁰m
Assuming there is no distance between to atoms of platinum, just its ratio. The amount of atoms necessary to occupy 1.39mm = 1.39x10⁻³m is:
1.39x10⁻³m / 2.78x10⁻¹⁰m =
5x10⁶ atoms of platium have to be laid side by sideClassify each cation as a weak acid or pH neutral (neither acidic nor basic).
a. Na+
b. Ni2+
c. NH4+
Answer:
a. Na+ is pH neutral
b. Ni2+ = weak acid
c. NH4+ = Weak acid
Explanation:
To know the nature of the cation we need to find the nature of its conjugate base.
If the conjugate base of the ion is a strong base, the ion is neutral.
If the conjugate base is a weak base, the ion is a weak acid:
a. Conjugate base Na+ = NaOH
Sodium hydroxide is a strong base:
Na+ is pH neutral
b. Conjugate base Ni²⁺: Ni(OH)2 is a weak base because is not completely soluble in water. That means:
Ni2+ = weak acid
c. Conjugate base NH4+: NH4OH. Weak base:
NH4+ = Weak acid
Name the compound CuI2
Answer:
Copper iodide. I think
Answer:
copper iodide(Cul2)hope it helps
stay safe healthy and happy..
Which event would be impossible to explain by using John Dalton's model of the atom?
Answer:
That is, the atom is a solid and indivisible mass. However, the fenomenom by which an iron atom emits particles when it is struck by light (known as the photoelectric effect) can not be explaind by this indivisible atom model.
Suppose an enzyme and its substrate obey the lock and key model of enzyme catalysis. Which of the following would be true of the enzyme?
a. only one substrate could be converted to product by the enzyme
b. the active site of the enzyme must be rigid
c. the entire enzyme must be rigid
d. the active site of the enzyme must be flexible
e. the enzyme could bind different substrates if the substrates shared a common motif somewhere in their structures
Answer:
only one substrate could be converted to product by the enzyme
Explanation:
If an enzyme obeys the lock and key model, it then follows that the design of the enzyme is unique to a particular substrate.
Just as only the correct key can effectively fit into a lock, only the appropriate substrate whose design matches that of the enzyme can fit into the enzyme.
Owing to the lock and key model of enzyme activity, only one enzyme could interact with a substrate to yield particular product.
bio-chemisty of protain
Answer:
Protein biochemistry is the study of proteins. Protein biochemistry is a scientific field dedicated to the study of proteins, complex chains of amino acids which make up the building blocks of all living organisms.
Explanation:
I hope that helped
Copy and Pasted!
Answer:
Listen to what guy said on top.
Explanation:
polypeptide structures consisting of one or more long chains of amino acids residue.....
or my answer
Give your familiarity for following terms
1. roasting 2. smelting 4. zone refining 5. polling
Answer:
The roasting process is a delicate combination of art and science . Roasters are familiar with how the beans look and the smells Well, familiarity with the machine makes things much easier to predict, but the best way is to do many different tests .Well, familiarity with the machine makes things much easier to predict, but the best way is to do many different tests.Smelting is a process of applying heat to ore in order to extract a base metal. It is a form of extractive metallurgy. It is used to extract many metals from their ores, including silver, iron, copper, and other base metals.In zone refining, solutes are segregated at one end of the ingot in order to purify the remainder, or to concentrate the impurities. For example, in the preparation of a transistor or diode semiconductor, an ingot of germanium is first purified by zone refining. In zone refining, solutes are segregated at one end of the ingot in order to purify the remainder, or to concentrate the impurities. ... For example, in the preparation of a transistor or diode semiconductor, an ingot of germanium is first purified by zone refining.Polling is the process where the computer or controlling device waits for an external device to check for its readiness or state, often with low-level hardware. For example, when a printer is connected via a parallel port, the computer waits until the printer has received the next character.Explanation:
hope it heloed
How many molecules in each sample?
64.7 g N2
83 g CCl4
19 g C6H12O6
Answer:
1.39x10²⁴ molecules N₂.25x10²³ molecules CCl₄6.38x10²² molecules C₆H₁₂O₆Explanation:
First we convert the given masses into moles, using the compounds' respective molar mass:
64.7 g N₂ ÷ 28 g/mol = 2.31 mol N₂83 g CCl₄ ÷ 153.82 g/mol = 0.540 mol CCl₄19 g C₆H₁₂O₆ ÷ 180 g/mol = 0.106 mol C₆H₁₂O₆Then we multiply each amount by Avogadro's number, to calculate the number of molecules:
2.31 mol N₂ * 6.023x10²³ molecules/mol = 1.39x10²⁴ molecules0.540 mol CCl₄ * 6.023x10²³ molecules/mol = 3.25x10²³ molecules0.106 mol C₆H₁₂O₆ * 6.023x10²³ molecules/mol = 6.38x10²² moleculesWhat mass of NaOH would need to be dissolved in 500.0 mL of water to produce a solution with a pH of 12.40
Answer:
0.5024 g
Explanation:
Step 1: Calculate the concentration of H⁺
We will use the definition of pH.
pH = -log [H⁺]
[H⁺] = antilog -pH = antilog -12.40 = 3.981 × 10⁻¹³ M
Step 2: Calculate the concentration of OH⁻
We will use the ionic product of water expression.
[H⁺] [OH⁻] = 10⁻¹⁴
[OH⁻] = 10⁻¹⁴/[H⁺] = 10⁻¹⁴/3.981 × 10⁻¹³ = 0.02512 M
Step 3: Calculate the initial concentration of NaOH
NaOH is a strong base and the molar ratio of NaOH to OH⁻is 1:1. Thus, the initial concentration of NaOH is 1/1 × 0.02512 M = 0.02512 M.
Step 4: Calculate the moles of NaOH
We will use the definition of molarity.
M = moles of NaOH/liters of solution
moles of NaOH = M × liters of solution
moles of NaOH = 0.02512 mol/L × 0.5000 L = 0.01256 mol
Step 5: Calculate the mass of 0.01256 moles of NaOH
The molar mass of NaOH is 40.00 g/mol.
0.01256 mol × 40.00 g/mol = 0.5024 g
Which Group is in the second column of the periodic table?
O A. Noble gases
O B. Alkaline earth metals
O C. Alkali metals
O D. Halogens
Answer:
O B. Alkaline earth metals
Explanation:
Noble gases → 8th column.
Alkali metal → first column.
Halogen → 7th
Answer:
B. Alkaline earth metals
Explanation:
Alkaline-earth metals: The alkaline-earth metals make up Group 2 of the periodic table, from beryllium (Be) through radium (Ra). Each of these elements has two electrons in its outermost energy level, which makes the alkaline earths reactive enough that they're rarely found alone in nature. But they're not as reactive as the alkali metals. Their chemical reactions typically occur more slowly and produce less heat compared to the alkali metals.
How is each triglyceride different from the others?
Each triglyceride is different from the others on the basis of presence of fatty acids in it.
What are triglycerides?Triglycerides is a kind of fat and derivative of ester which is formed by the combination of glycerol and three fatty acids.
So in the triglyceride molecule three sub divided parts are present due to the presence of three fatty acids groups and these fatty acids will make difference in each triglyceride molecules.
Hence of fatty acids in triglyceride molecule makes it different from other.
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Answer:
It has different fatty acids.
Explanation:
This is a signature of triglycerides
A compound was analyzed and found to contain 76.57% carbon, 6.43% hydrogen, and 17.00% oxygen by mass. Calculate the empirical formula of the compound. If the molar mass of the compound is 94.11 g/mol, what is the molecular formula of the compound?
A second compound is composed of 53.30% Carbon 11.19% Hydrogen and 35.51% Oxygen by mass.Please Calculate the empirical formula of the compound of the molar mass of the compound is 90.12g/mol, what is the molecular formula for that compound?
Answer:
See explanation
Explanation:
First we divide the percentage by mass of each element by it's relative atomic mass then we divide the quotients obtained by the lowest ratio obtained in the first step.
C- 76.57/12, H= 6.43/1, O = 17.00/16
C- 6.38/1.06, H= 6.43/1.06, O= 1.06/1.06
C- 6, H- 6, O- 1
Empirical formula: C6H6O
[(12 ×6) + (6 × 1) + (16 × 1)]n=94.11
[72 + 6 +16]n = 94.11
n = 94.11/94
n= 1
Molecular formula = C6H6O
2)
C- 53.30/12, H- 11.19/1, O- 35.51/16
C- 4.44/2.22, H- 11.19/2.22, O- 2.22/2.22
C- 2, H- 5, O- 1
Empirical formula: C2H5O
[(2×12) + (5× 1) + (1×16)]n = 90.12
[24 + 5 + 16] n = 90.12
n= 90.12/45
n= 2
Molecular formula = C4H10O2
When Hg2+ concentration is 6.35x10^-4 M, the observed cell potential at 298K for an electrochemical cell with the following reaction is 1.499V. What is the Cr3+ concentration?
3H^2+ (aq) + 2Cr(s)= 3Hg(l) + 2Cr^3+(aq)
Answer:
10.5 × 10^5 M
Explanation:
E°cell = E°cathode - E°anode
E°cell = 0.85 - (-0.74) = 1.59 V
From Nernst's equation;
Ecell = E°cell - 0.0592/n log Q
1.499 = 1.59 - 0.0592/6 log [Cr^3+]/6.35x10^-4
1.499 - 1.59 = - 0.0592/6 log [Cr^3+]/6.35x10^-4
-0.091 = -0.00987 log [Cr^3+]/6.35x10^-4
-0.091/ -0.00987 = log [Cr^3+]/6.35x10^-4
9.22 = log [Cr^3+]/6.35x10^-4
Antilog (9.22) = [Cr^3+]/6.35x10^-4
1.66 × 10^9 = [Cr^3+]/6.35x10^-4
[Cr^3+] = 1.66 × 10^9 × 6.35x10^-4
[Cr^3+] = 10.5 × 10^5 M
A scientist is conducting a Sanger's sequencing experiment to determine the number of polypeptides present in an oligomeric protein. The molecular weight of the protein is 18000 g/mol . After the reaction of 520 mg of the protein with 1‑fluoro‑2,4‑dinitrobenzene, the peptide bonds were hydrolyzed with an acid. As a result, the scientist obtained 39 mg of 2,4‑dinitrophenyl serine. What is the number of the polypeptide chains present in the oligomer?
Answer:
Depends on molecule.
Explanation:
The number of the polypeptide chains present in the oligomer depends on the molecule. Some molecules have more polypeptide chains whereas some of them have less polypeptide chains. For example, Hemoglobin is a oligomer that consists of four Polypeptide Chains, two of these Polypeptide Chains are α-globin molecules, each comprise of 141 amino acids, and the other two are (β, γ, δ, or ε) globins, each consist of 146 amino acids.
What is the theoretical yield of cyclohexene (in grams) that could be formed from 0.105 moles of cyclohexanol and 0.0444 moles of 85% phosphoric acid
Answer:
3.65 g of cyclohexene
Explanation:
Cyclohexanol + phosphoric acid ----> cyclohexene
The reaction is 1:1 hence the limiting reactant is phosphoric acid.
Hence,
1 mole of phosphoric acid yields 1 mole of cyclohexene
0.0444 moles of phosphoric acid yields 0.0444 moles of cyclohexene
Theoretical yield = number of moles of cyclohexene × molar mass of cyclohexene
Theoretical yield = 0.0444 moles of cyclohexene × 82.143 g/mol
Theoretical yield = 3.65 g of cyclohexene
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The pKa of an acid can be determined through _____ (reduction, titration, filtration) with a strong base.
Gradually increase the volume of the base, stopping _____ (before, as, after) the equivalence point is reached.
The pKa of the acid is equal to the pH at the _____ (equivalence point, midway volume to the equivalence point, maximum volume).
Answer:
The pKa of an acid can be determined through titration with a strong base.
Gradually increase the volume of the base, stopping before the equivalence point is reached.
The pKa of the acid is equal to the pH at the midway volume to the equivalence point.
Explanation:
An acid HA dissociates in water as follows:
HA ⇄ H⁺ + A⁻ Ka
So, it produces hydrogen ions (H⁺) and a conjugate base (A⁻). The concentrations of HA, H⁺ and A⁻ at equilibrium determine the constant Ka. The pKa is calculated as:
pKa = -log Ka
The relationship between the pH of the solution and the pKa of the acid is described by the Henderson-Hasselbalch equation:
pH = pKa + log ([A⁻]/[HA])
The pKa can be experimentally determined by acid-base titration, in which a strong base is added to the acid solution. As the base is added, the acid HA is neutralized and the conjugate base A⁻ is formed. Thus, the concentration of the acid ([HA]) increases and the concentration of the conjugate base ([A⁻] decreases. The equivalence point is reached when the total amount of acid is neutralized with the added base. Before reaching the equivalence point, at the halfway point, half of the acid is neutralized and converted into the conjugate base. Thus:
[A-] = [HA] ⇒ log [A-]/[HA] = log 1 = 0 ⇒ pH = pKa
We measure the pH at that point and it is equal to the pKa of the acid.
Use the heating curve of 60.0 grams of ice and the list of values to answer the question.
A heating curve with the y -axis showing temperatures between -20 degrees Celsius and 15 degrees Celsius and the x-axis showing time. The plot starts at Point A at -20 degrees Celsius and moves diagonally upward and to the right until it reaches Point B, which measures 0 degrees Celsius. Next, the line runs horizontally to the right until it reaches Point C. From Point C the line moves up and to the right to Point D, which measures at 15 degrees Celsius.
© 2019 StrongMind
specific heat of ice = 2.10 J/(g·°C)
specific heat of water = 4.18 J/(g·°C)
specific heat of water vapor = 2.07 J/(g·°C)
latent heat of fusion of ice = 333.4 J/g
latent heat of vaporization of water = 2256 J/g
How much energy was added to the ice between Point A and Point D?
25 kJ
150 J
154 J
26 kJ
Answer:
Changes of state occur at segment
✔ B–C
and segment
✔ D–E
Explanation:
got it right on edge :)
The amount of energy added to the ice between Point A and Point D is approximately 25 kJ.
To calculate the amount of energy added to the ice between Point A and Point D, we need to consider the different stages of the heating curve.
Heating the ice from -20°C to 0°C:
The energy required to raise the temperature of the ice can be calculated using the specific heat of ice (2.10 J/(g·°C)) and the mass of the ice (60.0 g). The temperature change is from -20°C to 0°C, which is a total of 20 degrees.
Energy = mass × specific heat × temperature change
Energy = 60.0 g × 2.10 J/(g·°C) × 20°C
Energy = 2520 J
Melting the ice at 0°C:
The energy required to melt the ice can be calculated using the latent heat of fusion of ice (333.4 J/g) and the mass of the ice (60.0 g).
Energy = mass × latent heat of fusion
Energy = 60.0 g × 333.4 J/g
Energy = 20,004 J
Heating the water from 0°C to 15°C:
The energy required to raise the temperature of the water can be calculated using the specific heat of water (4.18 J/(g·°C)) and the mass of the water (60.0 g). The temperature change is from 0°C to 15°C, which is a total of 15 degrees.
Energy = mass × specific heat × temperature change
Energy = 60.0 g × 4.18 J/(g·°C) × 15°C
Energy = 3753 J
The total energy added to the ice between Point A and Point D is the sum of the energy calculated in each step:
Total Energy = Energy (Heating ice) + Energy (Melting ice) + Energy (Heating water)
Total Energy = 2520 J + 20,004 J + 3753 J
Total Energy = 25,277 J
Converting this energy to kilojoules (kJ):
Total Energy = 25,277 J ÷ 1000
Total Energy = 25.277 kJ
Therefore, the amount of energy added to the ice between Point A and Point D is approximately 25 kJ.
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Cal is titrating 57.7 mL of 0.311 M HBr with 0.304 M Ba(OH)2. How many mL of Ba(OH)2 does Cal need to add to reach the equivalence point?
Answer:
118.06 mL
Explanation:
The neutralization reaction between HBr (acid) and Ba(OH)₂ (base) is the following:
2HBr + Ba(OH)₂ → BaBr₂ + 2H₂O
According to the equation, 2 moles of HBr react with 1 mol Ba(OH)₂. Thus, at the equivalence point the moles of acid and base react completely:
2 moles HBr = 1 mol Ba(OH)₂
We can replace the moles by the product of the molar concentration (M) and volume (V):
2 x (M HBr) x (V HBr) = M Ba(OH)₂ x V Ba(OH)₂
Now, we introduce the data in the equation to calculate the volume in mL of Ba(OH)₂:
V Ba(OH)₂ = (2 x (M HBr) x (V HBr))/M Ba(OH)₂
= (2 x 0.311 M x 57.7 mL)/(0.304 M)
= 118.06 mL
Therefore, 118 mL of Ba(OH)₂ are needed.
Consider the balanced chemical equation below.
3 A ⟶ C + 4 D
How many moles of C would be produced if 7 moles of A were used?
Answer:
2.33 mol C
Explanation:
Step 1: Write the balanced generic chemical equation
3 A ⟶ C + 4 D
Step 2: Establish the appropriate molar ratio
According to the balanced equation, the molar ratio of A to C is 3:1.
Step 3: Calculate the number of moles of C produced from 7 moles of A
We will use the previously established molar ratio.
7 mol A × 1 mol C/3 mol A = 2.33 mol C
Help pls!!!
For groups 13 through 18, the number of valence electrons is equal to the group number
a. minus 10
b. minus the period number
c. plus 1
d. plus the period number
Answer:
a. minus 10
Explanation:
An element in group 13 = Boron ,valence electrons = 3 , therefore, valence electrons in group 13 = group no. -10
An element in group 18 = Neon, valence electrons = 8 , therefore, valence electrons in group 18 = group no. - 10
For groups 13 through 18, the number of valence electrons in an atom is equal to the group number minus 10. Therefore, option (A) is correct.
What is a valence electron?Valence electrons in an atom can be described as the electrons occupying the outer most electron shell of an atom while the electrons in the inner shell are core electrons. Lewis structures can be helpful to calculate the number of valence electrons.
Valence electrons can be filled in several electron shells as they are caused interaction between atoms and responsible for the formation of chemical bonds. Only valence electrons can contribute to the formation of a chemical bond and decide the reactivity of the element.
The general electronic configuration of group 13 is ns²np¹ has three valence electrons. It can be determined as group number - 10 = 13 - 10 = 3.
The general electronic configuration of group 18 is ns²np⁶ has eight valence electrons. It can be determined as group number - 10 = 18 - 10 = 8.
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Why the catalytic and optical properties of nanomaterial are different from bulk material
Answer:
The material properties of nanostructures are different from the bulk due to the high surface area over volume ratio and possible appearance of quantum effects at the nanoscale. ... Yu; they found that the structural distortions on the quantum dots depend both on the kind of dopant and on the size of the dots.
Explanation:
hope it helps
To insert a thermometer into an adapter, use ______ to prepare the thermometer. Then, hold the thermometer ______ the adapter and _____ the thermometer into the adapter.
Answer:
mineral oil; close to; slowly turn
Explanation:
Temperature can be defined as a measure of the degree of coldness or hotness of a physical object. It is measured with a thermometer and its units are Celsius (°C), Kelvin (K) and Fahrenheit (°F).
Generally, temperature measures the average kinetic energy of particles in a particular substance.
A thermometer can be defined as a device used for measuring the temperature (degree of hotness or coldness) of a body or substance is. It is a thin glass having a bulb on one of its end and typically contains either colored alcohol or mercury.
A thermometer adapter is used with a temperature probe in the distillation process, in order to determine readings.
To insert a thermometer into an adapter, use mineral oil to prepare or make suitable the thermometer. Then, hold the thermometer close to the adapter and slowly turn the thermometer into the adapter.
Determine the percentage of carbon and hydrogen in ethane C2H6 if the molecular weight is 30.
Answer:
Percentage of carbon:
[tex] { \tt{ = \frac{24}{30} \times 100\%}} \\ = 80\%[/tex]
Percentage of hydrogen:
[tex]{ \tt{ = \frac{6}{30} \times 100\%} } \\ = 20\%[/tex]
Whate the mass percentage of Sulphure in Na2so4 ?
Answer:
Water H2O + SULPHATE OXIDE
The majority of metals are found within
The majority of metals are found in ores.
But a few such as copper, gold, platinum, and silver frequently occur in the free state because they do not readily react with other elements.
The following statements either define or are closely related to the terms periodic law, period, or group. Match the terms to the appropriate statements.1. This is a vertical arrangement of elements in the periodic table. 2. This is a horizontal arrangement of elements in the periodic table. 3. The properties of the elements repeat in a regular way as the atomic numbers increase. 4. Element 19 begins this arrangement in the periodic table 5. The chemical properties of elements 12, 20, and 38 demonstrate this principle.
Answer:
Please find the complete solution in attached file.
Explanation:
Periodic law is the the properties of the elements that repeat in a regular way as the atomic numbers increase.
What is periodic table?Periodic chart organized collection of all chemical elements arranged roughly according to increasing atomic weight. The periodic recurrence of several features in the elements was originally identified by Dmitry I. Mendeleyev in 1869.
1. This is a vertical arrangement of elements in the periodic table group
2. This is a horizontal arrangement of elements in the periodic table period
3. The properties of the elements repeat in a regular way as the atomic numbers increase periodic law
4. Element 19 begins this arrangement in the periodic table period
5. The chemical properties of elements 12, 20, and 38 demonstrate this principle. periodic law
Therefore, periodic law is the the properties of the elements that repeat in a regular way as the atomic numbers increase.
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Consider an acid-base titration in which the base is dispensed from a burette into a flask containing an acid. If any drops of the base adhere to the inner walls of the flask, but do not actually mix with the solution, the calculated acid concentration would be
Answer:
Higher than the actual value
Explanation:
Titration is a volumetric process in which a known volume of solution is dispensed from a burette to react with a known volume of solution in a conical flask.
When acid-base titration is carried out in such a way that the base is in the burette and the acid is in the conical flask and drops of the base adhere to the inner walls of the flask, but do not actually mix with the solution, the calculated acid concentration would be higher than the actual value.
This is because;
From CA= CBVBnA/VAnB
When VB(volume of base) that reacted is lower than the actual volume recorded, then the calculated volume of CA(concentration of acid) is much higher than the actual value since drops of the base adhere to the inner walls of the flask.
Identify the substance that conducts electricity.
a. Rubbing alcohol.
b. KBr dissolved in water.
c. Solid KBr.
d. Solid baking soda
e. Sugar dissolved in water.
Answer:
KBr dissolved in water.
Explanation:
A substance conducts electricity as a result of the presence of mobile ions in the substance.
An ionic substance such as KBr when dissolved in water releases free ions which become charge carriers in solution hence the solution conducts electricity. Solid ionic substances such as solid KBr and solid baking soda do not conduct electricity because the ions are strongly bound to each other in the crystal lattice.
Molecular substances such as sugar and alcohol do not conduct electricity even in solution.
The metal thallium becomes superconducting at temperatures below 2.39K. Calculate the temperature at which thallium becomes superconducting in degrees Celsius. Round your answer to decimal places.
Answer:
-270.76°C
Explanation:
Given that metal Thallium becomes superconducting below the temperature of 2.39 kelvin i.e. this temperature is critical temperature for Thallium and below critical temperature a metal offers no resistance to the flow of electric current. Also the metal below its critical temperature expels the magnetic field in such a way that they do not penetrate the metal and pass through its surface only.
We have the relation between kelvin scale and degree Celsius scale of temperature measurement as:
[tex]C = K - 273.15[/tex]
[tex]C=2.39-273.15\\ C=-270.76^{o}C[/tex]
Organic foods do not contain chemicals.
True
Or
False
Answer:
True
Explanation:
The word Organic refers to the methods used to cultivate and process farm agricultural products. Organic foods are edible and nutritious substances consumed (both plants and animals) that are free from the use of synthetics and chemicals. In plants, the include the use of organic manure that serves as fertilizers and carrying out the weeding process by hand weeding. In animals, diseases can be prevented by maintaining a clean house or rotational grazing.
The benefit of organic foods are to produce food substances with no chemical substances.