Answer:
That would be 4.17742995 * 10^13 :)
Explanation:
3. What is the molar mass of O2? Round to nearest whole number.
8
O
16
32
64
Answer:
Molar mass of O is = 16
Molar mass of O2 = 32
Given a sample of poly[ethylene-stat-(vinyl acetate)] A.Calculate the mean repeat unit molar mass for a sample of poly[ethylene-stat-(vinyl acetate)] that comprises 12.9 wt% vinyl acetate repeat units.B.Given that its number-average molar mass is 39,870 g/mol, calculate the number-average degree of polymerization of the copolymer.
Answer:
a) The mean repeat unit molar mass for PEVA is 30.72 g/mol
b) degree of polymerization of the copolymer is 1300
Explanation:
Given that;
the wt% of copolymer consist of 12.9 wt% of vinyl acetate and 87.1 wt% Ethylene.
Basis: 100 g of PEVA consist of 12.9 of vinyl acetate and 87.1g of Ethylene.
now we calculate the mole fraction of vinyl acetate Ethylene in the copolymer;
the molecular weights of vinyl acetate and ethylene are 86.09 g/mol and 28.05 g/mol respectively
so
moles of vinyl acetate = wt. of vinyl acetate / molecular weights of vinyl acetate
moles of vinyl acetate = 12.9 g / 86.09 g/mol
moles of vinyl acetate = 0.1498 mol
moles of Ethylene = wt. of Ethylene / molecular weights of Ethylene
moles of Ethylene = 87.1 g / 28.05 d/mol
moles of Ethylene = 3.1052 mol
Total moles = 0.1498 mol + 3.1052 mol = 3.255 mol
Next we calculate the mole percent;
mole percent of vinyl acetate [tex]X_{V}[/tex] = moles of vinyl acetate / total moles
[tex]X_{V}[/tex] = (0.1498 mol / 3.255 mol) × 100
[tex]X_{V}[/tex] = 4.6%
mole percent of Ethylene [tex]X_{E}[/tex] = moles of Ethylene / total moles
[tex]X_{E}[/tex] = (3.1052 mol / 3.255 mol) × 100
[tex]X_{E}[/tex] = 95.397% ≈ 95.4%
we know that, mean repeat unit molar mass for a sample = ∑[tex]X_{i}[/tex][tex]M_{i}[/tex]
where [tex]X_{i}[/tex] is the fraction ratio and [tex]M_{i}[/tex] is the molecular weight
so or the PEVA
mean repeat unit molar mass M = ( [tex]X_{V}[/tex][tex]M_{V}[/tex]) + ( [tex]X_{E}[/tex][tex]M_{E}[/tex])
so we substitute
M = ( 4.6% × 86.09) + ( 95.4% × 28.05 )
M = 3.96014 + 26.7597
M = 30.72 g/mol
Therefore, The mean repeat unit molar mass for PEVA is 30.72 g/mol
b)
Degree of polymerization
[tex]DP_{n}[/tex] = [tex]\frac{M_{n} }{M}[/tex]
where [tex]M_{n}[/tex] is the number average molecular weight ( 39,870 g/mol )
so we substitute
[tex]DP_{n}[/tex] = 39,870 g/mol / 30.72 g/mol
[tex]DP_{n}[/tex] = 1297.85 ≈ 1300 { 3 significance figure }
Therefore, degree of polymerization of the copolymer is 1300
What causes lightning?
A. Build up of electric charges in the clouds
B. Flow of electric charges among clouds
C. Light energy created in the clouds
D. Reflection of light by the clouds
Answer:
B.
Explanation:
Not sure if this is correct if not sorry.
What is the equilibrium constant for the reaction
SO2(g) + NO2(9) = SO3(g) + NO(g)?
А. Keq: [S03)(S02]
[NO][NO2]
B. Keq: [SO2)(NO2]
[SO3)(NO]
C. Keq: [SO3)3(NO]
[SO2)2(NO2)2
D. Keq: [SO3)(NO]
[SO2]NO2]
Answer:
D. Keq: [SO3][NO] /[SO2]NO2]
Explanation:
Hello!
In this case, according to the process to set up equilibrium expressions for chemical reactions at equilibrium, we realize we need to write up the concentration of products on top and that of reactants on bottom; thus, for there chemical reaction herein specified, we obtain:
[tex]Keq=\frac{[SO_3][NO]}{[SO_2][NO_2]}[/tex]
Thereby, the answer is D. Keq: [SO3][NO] /[SO2]NO2].
Best regards!
Answer:
D
Explanation:
What is the number of nitrogen molecules that reacted with excess hydrogen to make 2x10^10 molecules of ammonia
According to stoichiometry and mole concept,1×10¹⁰ molecules reacted with excess hydrogen to make 2 x 10¹⁰ molecules of ammonia.
What is stoichiometry?Stoichiometry is the determination of proportions of elements or compounds in a chemical reaction. The related relations are based on law of conservation of mass and law of combining weights and volumes.
Stoichiometry is used in quantitative analysis for measuring concentrations of substances present in the sample.It is important while balancing chemical equations.
In the given example, as 1 molecule of nitrogen produces 2 molecules of ammonia
∴2 x 10¹⁰ molecules of ammonia will be produced when 2 x 10¹⁰×1/2=1×10¹⁰ molecules .
Thus, 1×10¹⁰ molecules reacted with excess hydrogen to make 2 x 10¹⁰ molecules of ammonia.
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PLEASE HELP! Will mark Brainly if correct!
Answer:
6.591
explanation
mass of weight is 1.092 , and mass of weight boat and sample = 7.683
mass of the solid sample= (mass of weight boat and sample) - (weight of the boat) = (1.092-7683) = 6.591 g
hence, the mass of the solid sample is 6.591 g
Is CaO binary or polyatomic?
Answer:
It is going to be binary
Explanation:
What would be the wavelength of light that has a frequency of 3 X
10-4 Hz in a vacuum?
Answer:
[tex]\lambda=10^{12}\ m[/tex]
Explanation:
Given that,
The frequency of the light, [tex]f=3\times 10^{-4}\ Hz[/tex]
We need to find the wavelength of the light.
The relation between frequency, wavelength and the speed of light is given by :
[tex]c=f\lambda\\\\\lambda=\dfrac{c}{f}\\\\\lambda=\dfrac{3\times 10^8}{3\times 10^{-4}}\\\\\lambda=10^{12}\ m[/tex]
So, the wavelength of the light is [tex]10^{12}\ m[/tex].
The wavelength of light will be "[tex]10^{12} \ m[/tex]"
Given:
[tex]f = 3\times 10^{-4} \ Hz[/tex][tex]c = 3\times 10^8[/tex]By using the relation,
→ [tex]\lambda = \frac{c}{f}[/tex]
By putting the values, we get
→ [tex]= \frac{3\times 10^8}{3\times 10^{-4}}[/tex]
→ [tex]= 10^{12} \ m[/tex]
Thus the above response is right.
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Which of the following is a true statement?
Often, fossil remains of a large complex animal are complete.
Often, fossil remains of a small simple animal are complete.
Often, fossil remains of a large complex animal are incomplete.
Often, fossil remains of a small simple animal are incomplete.
Answer:
i think its C
Explanation:
What common instrument is used for hair comparison?
Comparison Microscope
Telescope
O Compound Microscope
Answer:
comparison microscope
Explanation:
please follow me
5) Calculate the molality of 0.210 mol of KBr dissolved in 0.075kg pure
water?
Answer:
2.8 m
Explanation:
From the question given above, the following data were obtained:
Number of mole KBr = 0.210 mole
Mass of water = 0.075 kg
Molality of KBr =?
Molality is simply defined as the mole of solute per unit kg of water. Mathematically, it can be expressed as follow:
Molality = mole of solute / Kg of water.
With the above formula, we can obtain the molality of the KBr solution. This can be obtained as follow:
Number of mole KBr = 0.210 mole
Mass of water = 0.075 kg
Molality of KBr =?
Molality = mole of solute / Kg of water.
Molality = 0.210 / 0.075
Molality = 2.8 m
Therefore, the molality of the KBr solution is 2.8 m.
What is the sum of the coefficients when the equation is balanced with the smallest whole numbers? __BaCl2 + __Fe2(SO4)3 → __FeCl3 + __BaSO4 *?
Explanation:
Hphphphphphphphohoohohhpph
The Rock Cycle moves in a specific order. True or
False
Answer:
it is false
Explanation:
it goes in different ways not in order
Please help, and if you could also give me a step by step that would be awesome!!
Answer:
4.4 g
Explanation:
Step 1: Write the balanced equation
Cu + 4 HNO₃ ⇒ Cu(NO₃)₂ + 2 NO₂ + 2 H₂O
Step 2: Calculate the moles corresponding to 3.2 L of NO₂ at STP
At standard temperature and pressure, 1 mole of NO₂ occupies 22.4 L.
3.2 L × 1 mol/22.4 L = 0.14 mol
Step 3: Calculate the moles of Cu needed to produce 0.14 moles of NO₂
The molar ratio of Cu to NO₂ is 1:2. The moles of Cu needed are 1/2 × 0.14 mol = 0.070 mol.
Step 4: Calculate the mass corresponding to 0.070 moles of Cu
The molar mass of Cu is 63.55 g/mol.
0.070 mol × 63.55 g/mol = 4.4 g
explain how liquid can enter the gas phase without reaching its boiling point
HELP!!!! Which of the following substances is a major component in acid rain?
A) KOH
B) NH3
C) SO2
D) NaOH
Answer:
(C) SO2.
SO2 is known as sulfur dioxide.
The below information about acid rain and SO2’s involvement is from epa.gov:
“Acid rain results when sulfur dioxide (SO2) and nitrogen oxides (NOX) are emitted into the atmosphere and transported by wind and air currents. The SO2 and NOX react with water, oxygen and other chemicals to form sulfuric and nitric acids. These then mix with water and other materials before falling to the ground.”
Explanation:
What is the normal pH range of a Base?
Answer:
7.35 - 7.45
Explanation:
The pH scale ranges from 0 (strongly acidic) to 14 (strongly basic or alkaline). A pH of 7.0, in the middle of this scale, is neutral. Blood is normally slightly basic, with a normal pH range of about 7.35 to 7.45. Usually, the body maintains the pH of blood close to 7.40.
Hope this helps
Answer:
The normal pH range if a base is more than 7
Explanation:
Basideally the pH range goes from 0-14 in which
Acidic range is :0-7
Neutral :7
Base : 7 - 14
solve this .......,..,.,.,..,.,,.,.,.,.,.,.,.,.,..,.,.,.,.z.,.,.,.,..,.,.,.,.,,.,.,.,
Answer: Molecular formula of copper (II) bromide is [tex]CuBr_2[/tex]
Molecular formula of aluminium (III) nitrate is [tex]Al(NO_3)_3[/tex]
Molecular formula of calcium (II) phosphate is [tex]Ca_3(PO_4)_2[/tex]
Molecular formula of iron (III) sulphide is [tex]Fe_2S_3[/tex]
Molecular formula of mercury (II) chloride is [tex]HgCl_2[/tex]
Molecular formula of magnesium (II) acetate is [tex](CH_3COO)_2Mg[/tex]
Explanation:
The name of the ionic compounds is written by writing the name of the cation first followed by its oxidation state in round brackets and then the name of the anion is written without any suffix. Thus the cation is written first followed by the oxidation state and then the anion.
For formation of a neutral ionic compound, the charges on cation and anion must be balanced. Thus they combine and their oxidation states are exchanged and written in simplest whole number ratios to give neutral compound.
Molecular formula of copper (II) bromide is [tex]CuBr_2[/tex]
Molecular formula of aluminium (III) nitrate is [tex]Al(NO_3)_3[/tex]
Molecular formula of calcium (II) phosphate is [tex]Ca_3(PO_4)_2[/tex]
Molecular formula of iron (III) sulphide is [tex]Fe_2S_3[/tex]
Molecular formula of mercury (II) chloride is [tex]HgCl_2[/tex]
Molecular formula of magnesium (II) acetate is [tex](CH_3COO)_2Mg[/tex]
There is a 2 percent defect rate at a specific point in a production process. If an inspector is placed at this point, all the defects can be detected and eliminated. The inspector would cost $10 per hour and could inspect units in the process at the current production rate of 48 per hour.
If no inspector is hired and defects are allowed to pass this point, there is a cost of $11 per defective unit to correct the defects later on.
Assume that the line will operate at the same rate (i.e., the current production rate) regardless of whether the inspector is hired or not.
a. If an inspector is hired, what will be the inspection cost per unit? (Round your answer to 3 decimal places.)
Inspection cost per unit _____________$
b. If an inspector is not hired, what will be the defective cost per unit? (Round your answer to 3 decimal places.)
Defective cost per unit _____________$
c. Should an inspector be hired based on costs alone?
Answer:
A) $0.208 per unit
B) $0.220 per unit
C) An inspector should be hired
Explanation:
percentage of defect rate = 2% = 0.02
cost of inspector = $10 per hour
production rate = 48 per hour
cost of not hiring an inspector = $11
A) Determine the inspection cost per unit if an inspector is hired
= cost of inspector / production rate
= 10 / 48 = $0.208 per unit
B) Determine the defective cost per unit if an Inspector is not hired
= cost of not hiring an inspector * percentage of defect rate
= 11 * 0.02
= $0.220 per unit
C) Inspection cost < defective cost i.e. $0.208 < $0.220 hence an inspector should be hired
a hypothesis is tested by ___.
a. proposing a theory
b. conducting an experiment
c. making further observations
d. talking with other scientists
Answer:
A.
Explanation:
because a theory is like a prediction and a prediction is like a hypothesis.
Which of the following compounds are held together by ionic bonds? Select all that apply.
O A. CaCl2
OB. CH4
OC. Naci
D. sodium bromide
E. carbon dioxide
F. FeBr3
Answer:
Explanation:
All of above except carbon dioxide
The compound that is held together by ionic bonds are CaCl₂, NaCl, sodium bromide, and FeBr₃. The correct options are A, C, D, and F.
What are ionic bonds?Ionic bonds are electrovalent bonds. These bonds are formed when two or more atoms lose electrons or gain electrons to form an ion. Ions are opposite charges that attract each other. Ionic bonds are formed in both metals and non-metals.
CaCl₂, calcium chloride, is formed between metals and non-metals. Some more examples are NaOH – Sodium Hydroxide, NaHCO₃—Sodium Hydrogen Carbonate, etc.
An example is NaCl, is sodium has 11 atomic numbers. Chloride has 6 electrons in its outermost shell. They will share electrons with each other to make the noble gas configuration.
Thus, the correct options are A. CaCl₂, C. NaCl, D, sodium bromide, and F. FeBr₃.
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How did Dmitri Mendeleev arrange the periodic law?
a. Each set of elements was arranged in special columns based on their mass.
b. Each set of elements was arranged in special columns based on their diameter.
c. Each set of elements was arranged in special periods based on their qualities.
d. Each set of elements was arranged in alphabetical order.
Answer:
a. Each set of elements was arranged in special coloumns based on their mass.
What is a number at the bottom right of an element in a chemical equation called?
Answer:an element in a chemical equation is called a subscript.
Explanation:
it represents the the number of atoms of that element present in the compound. hope this helps have a great day yall
The number at the bottom right of an element in a chemical equation is called a subscript.
Subscripts represent the number of atoms of that particular element in a molecule or formula unit. They indicate the ratio of atoms or ions present in a compound. Subscripts are written in a smaller font size and appear slightly below the element's symbol.
For example:
In the chemical compound water [tex](H_2O)[/tex],the subscript '2' indicates that there are two atoms of hydrogen (H) bonded to one atom of oxygen (O). The subscript specifies the ratio of elements in the compound, indicating that there are two hydrogen atoms for every one oxygen atom in water.
Therefore, the term subscript refers to the number on the right of an element in a chemical equation.
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Difference between n-propyl and isopropyl radicals.
Answer:
Isopropyl has the specific orientation of being attached to a central carbon atom with two CH3 molecules attached (so in IUPAC naming it can become dimethylethyl), whereas propyl is three carbons all attached in a line branching off the main carbon chain, so it's two CH2 molecules and one CH3 molecule.
Explanation:
n-propane are longer chain hydrocarbon whereas isopropane is branched hydrocarbon. Isopropyl radical is more stable than n-propyl radical.
What are radicals ?Radicals are reaction intermediates containing one unpaired electron. They are highly reactive species . The stability of radicals depends on the structure and reaction condition.
n -propyl radical is CH₃-CH₂-CH₂·
Isopropyl radical is written as CH₃-CH·-CH₃
The isopropyl group contains a branch in the second carbon and its makes the central carbon with secondary structure.
The stability of tertiary radicals is greater than secondary which is greater than primary. Therefore, isopropyl radical is more stable than n -propyl radical.
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A sample of metal has a mass of 16.12 g, and a volume of 4.87 mL. What is the density of this metal?
Answer:
3.31 g/cm³
Explanation:
1000cm³ = 1L
4.87mL = 4.87 × 10^-3 × 1000 = 4.87 cm³
density = mass/volume = 16.12/4.87 = 3.31 g/cm³
7. Consider an element with 2
electrons on the 1st shell and 4
electrons on the 2nd shell. What
element is likely to have that Bohr
model?
Answer:
Carbon (C)
Explanation:
The electron configuration of Carbon is 2-4.
How do you name ethers in chemistry?
Answer:
Common names of ethers simply give the names of the two alkyl groups bonded to oxygen and add the word ether. The current practice is to list the alkyl groups in alphabetical order (t-butyl methyl ether), but older names often list the alkyl groups in increasing order of size (methyl t-butyl ether).
Explanation:
Hope it is helpful.......
How to frick a chicken...
Answer:uhhhhh should I be concerned
Explanation:
Answer:
hmmm o_O Maybe you... shouldnt
there is no such thing as a universal solvent- explain? I’ll mark brainiest!!!
Answer:
A true universal solvent does not exist. Although water is considered to be a the "universal solvent" it only dissolves other polar molecules. It does not dissolve nonpolar molecules, including organic compounds such as fats and oils. It is only called so because it can dissolve many more than other liquids.
I would like to get some examples of Newtons 1st,2nd, and 3rd Law
Answer:
Explanation:
Newtons 1st law:
If you slide a hockey puck on ice, eventually it will stop, because of friction on the ice. It might also stop if a hockey player places their stick in front of it.
Newton's 2nd law:
If the mass of an object is 20 kg and it's acceleration is 5 m/s, the force acting upon it is (m*a or 20*5) 100 N.
Another example that proves that force is dependent upon mass is that if you were to move a car and a truck (that were both previously stationary) at the same speed, the car would take less force/effort to move than the truck.
Newton's 3rd law:
If a book on a table, the table is exerting a force on it that is equal and opposite to the force of gravity.
If two soccer balls of the same mass collide, one moving and one stationary, then they would both apply an equal and opposite force onto each other, causing the moving ball to stop and the previously stationary ball to move at the speed of the previously moving ball.