Answer:
(A) 0.80 M
(B) 0.64 g
(C) 0.050 M
(D) 1.6 M
Explanation:
(A)
Convert 4.0 g to moles with molar mass. Convert 125 mL to L.
4.0 g x (1 mol/39.998 g) = 0.100 mol
125 mL x (1 L/1000 mL) = 0.125 L
Molarity = mol/L
Molarity = 0.100 mol/0.125 L = 0.80 M
(B)
Find moles of NaOH with the molarity you just found. And convert 20 mL to L.
Molarity = mol/L
0.80 M = mol/0.020 L
mol = 0.016
Convert moles to grams with molar mass.
0.016 mol x (39.998 g/1 mol) = 0.64 g
(C)
You know the molarity of a NaOH solution (Part A). 30 mL initial volume and 480 mL final volume are given. Dilution question so use the dilution formula.
M1V1 = M2V2
(0.80 M)(30 mL) = (M2)(480 mL)
M2 = 0.050 M
(D)
Dilution question again, use the dilution formula.
M1V1 = M2V2
(0.80 M)(200 mL) = (M2)(100 mL)
M2 = 1.6 M
Question
What is the name of the covalent compound with the formula P2N3?
Answer:
P2N5
Explanation:
you have to plus it 2 times
What is the pH and pOH of a 2.2 x 10^-3 HBr solution?
Answer:
The pH and pOH of a 2.2*10⁻³ HBr solution is 2.66 and 11.34 respectively.
Explanation:
pH - short for hydrogen potential - is a measure of the acidity or alkalinity of a solution. So the pH is a parameter that indicates the concentration of hydrogen ions [H]⁺ that exist in a solution.
The pH is expressed as the negative base 10 logarithm of the hydrogen ion concentration. This is represented by:
pH= - log [H⁺]
pH is measured on a scale of 0 to 14. On this scale, a pH value of 7 is neutral, which means that the substance or solution is neither acidic nor alkaline. A pH value of less than 7 means that it is more acidic, and a pH value of more than 7 means that it is more alkaline.
HBr is a strong acid. Then, in aqueous solution it will be totally dissociated. So the proton concentration is equal to the initial concentration of acid:
[H⁺]= [HBr]= 2.2*10⁻³ M
So:
pH= - log (2.2*10⁻³)
pH= 2.66
On the other hand, pOH is a measure of the concentration of hydroxyl ions in a solution. The sum of pH and pOH equals 14:
pH + pOH= 14
2.66 + pOH= 14
pOH= 14 - 2.66
pOH= 11.34
The pH and pOH of a 2.2*10⁻³ HBr solution is 2.66 and 11.34 respectively.
The energy needed to overcome intermolecular forces is called?
Answer:
vaporization.
Explanation:
13. The element with the following electron configuration [Kr] 4d105s25p2 belongs to
Group of answer choices
actinide.
metal.
transition element.
nonmetal.
lanthanide.
14. Which is a physical change?
Group of answer choices
KNO3 dissolves in water
A firecracker explodes
Popcorn pops when placed in a microwave
A nail rusts
A piece of wood is burned
The element with the following electron configuration [Kr] 4d105s25p2 belongs to transition element.
The given electron configuration belongs to an element with atomic number 52. It can be written as 1s22s22p63s23p63d104s24p64d105s25p2. It belongs to the transition element as the electrons are filled in d orbital. KNO3 dissolves in water is a physical change.A physical change refers to a change in the state or properties of matter without any modification in its composition. The given options that are physical change and rest is a chemical change.KNO3 dissolves in water is a physical change as the salt is still KNO3 and has not been modified into something else. It simply separated into smaller particles to mix uniformly with the solvent, which in this case is water.A firecracker explodes, when popcorn pops when placed in a microwave and a piece of wood is burned are all examples of chemical change.A nail rusts is also a chemical change.
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How many molecules are in 3.01 g of H2O
A. 0.167 molecules
B. 54.18 molecules
C. 1.01x10^23 molecules
D. 6.022x10^23
Answer:
Option C
Explanation:
No. of Molecules=(Given Weight/Molar weight)*Avagadro No.
Given weight of H2O=3.01g
Molar weight of H2O=18g
On applying the formula, we get:
No. of Molecules=(3.01/18)*6.023*10²³=1.01*10²³
Emu
Sparrow
How are emus and sparrows alike?
A. Both birds build nests in trees.
B. Both birds are taller than humans.
C. Both birds catch small animals while flying.
U
D. Both birds have a beak for breaking apart food.
PLSSSSSS ANSWERRRRR???
Answer:
( j ) should be the correct option because atomic number of fluorine is 9 so, no. of electrons and protons should be same I.e. 9
HELP ASAP 30 POINTS
IS THIS CORRECT?
answer: yes I believe so
explain: I just think it is I have done this before
What is the oxidation state of copper in Cu(C2H3O2)2? +2 -1 -2 +4 +1
Identify the parts of a wave using the illustration and the function below.
Answer: 1. Crest 2. Trough 3. Wave Length 4. Amplitude
Explanation:
Please help me ASAP I’m almost done.
Answer:
i think the answer is c
Explanation:
sorry if im wrong i am most likely wrong but ye
using the equation e=(hcrh)(1n2)=(−2.18×10−18j)(1n2) calculate the energy of an electron in the hydrogen atom when n=2 .
When n=2, the energy of an electron in the hydrogen atom is calculated using the equation e = (-2.18 × 10^-18 J)(1/n^2). Plugging in the values, the energy is found to be -5.45 × 10^-19 J.
The energy of an electron in the hydrogen atom when n=2 can be calculated using the equation e=(hcR_H)(1/n^2), where e represents energy, h is the Planck constant (6.62607015 × 10^-34 J·s), c is the speed of light (2.998 × 10^8 m/s), R_H is the Rydberg constant for hydrogen (1.0973731568539 × 10^7 m^-1), and n is the principal quantum number. Plugging in the values, we get e = (-2.18 × 10^-18 J)(1/n^2). When n=2, the energy can be calculated as e = (-2.18 × 10^-18 J)(1/2^2) = -5.45 × 10^-19 J.
The explanation of the calculation involves substituting the given values into the equation. First, the Planck constant (h) is multiplied by the speed of light (c) and the Rydberg constant for hydrogen (R_H). Then, we multiply the result by 1 divided by the square of the principal quantum number (n^2). In this case, n is given as 2. Thus, we calculate 1/2^2, which is 1/4. Multiplying this value by the previously calculated expression, we find the energy to be -5.45 × 10^-19 J. The negative sign indicates that the energy is bound, meaning the electron is in a lower energy state within the hydrogen atom.
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Kathy is trying to conduct an experiment she wants an element that is
very reactive, which of these should she use?
evidence concerning crystallized and fluid intelligence shows that
Evidence concerning crystallized and fluid intelligence shows the diverse nature of intellectual development.
Research on both crystallized and fluid intelligence suggests that there are different stages of intellectual development. Crystallized intelligence reflects the sum of knowledge, abilities, and experience obtained through education and life events. It includes vocabulary, factual knowledge, and problem-solving abilities that rely on previously learned information.
In contrast, the ability to reason logically, solve unexpected issues, and adapt to changing circumstances is referred to as fluid intelligence. It calls on abilities like pattern recognition, spatial imagery, and abstract reasoning. Studies have revealed that individuals can have varying levels of crystallized and fluid intelligence, and these skills can vary across different periods of life due to factors like education, environmental effects, and cognitive aging.
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Classify the two amino acids below according to their effective polarity in proteins at pH=7.4. n= Nonpolar up = Uncharged polar cp= Charged polar 1. 2. Classify the two amino acids below according to their effective polarity in proteins at pH=7.4. n= Nonpolar up = Uncharged polar cp= Charged polar 1. 2. Cysteine (Cys or C ) Polarity
At pH = 7.4, Cysteine (Cys or C) can be classified as up = Uncharged polar. Cysteine is a polar amino acid with a sulfhydryl group.
Cysteine is a non-polar amino acid that is made up of an aliphatic side chain containing a sulfhydryl group (–SH). This polar cysteine side chain's polarity enables the formation of disulfide bridges with other cysteine side chains in other proteins and amino acids. The polar amino acid cysteine can form a disulfide bond with another cysteine in an amino acid chain, which gives a high degree of stability to the protein molecules. This amino acid contributes to the stabilization of protein molecules by forming hydrogen bonds and disulfide bonds. The electronegative sulfur atom is responsible for its polar nature. Cysteine can be classified as an uncharged polar amino acid at pH = 7.4. Nonpolar amino acids are hydrophobic (water-repelling) and do not interact well with water. Conversely, charged amino acids are hydrophilic (water-attracting) and interact well with water.
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Pls help if you can, Thx! Describe ozone creation and loss in the ozone layer. Does one occur more than the other?
Ozone was created millions of years ago from a natural process frozen in ice during the ice age, the gases that make up the ozone layer were formed naturally from oxygen atoms accompanied by a reaction of ultraviolet radiation and molecular oxygen which was frozen in the ice during the time of the ice age was released over years as the ice melted.
What is an atom?An atom is defined as the smallest unit of matter which forms an element. Every form of matter whether solid,liquid , gas consists of atoms . Each atom has a nucleus which is composed of protons and neutrons and shells in which the electrons revolve.
The protons are positively charged and neutrons are neutral and hence the nucleus is positively charged. The electrons which revolve around the nucleus are negatively charged and hence the atom as a whole is neutral and stable due to presence of oppositely charged particles.
Atoms of the same element are similar as they have number of sub- atomic particles which on combination do not alter the chemical properties of the substances.
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Which sodium salt(s) of an amphiprotic ion will produce a basic solution when added to pure water? 1. NaHSO4 (Ka = 1.03 x10^-2; K, = 9.71 x10^-13) 2. NaHCO3 (KA = 4.69 x10^-11, Kg = 2.24 x10^-8) 3. NaHSO3 (Kg = 6.73 x10^-8; Ky = 7.19 x10^-13) a. I and 2
b. l only c. 2 only d. I and 3
e. 3 only
Amphiprotic ion refers to any species that can act as both a proton acceptor and a proton donor. The amphiprotic salt reacts with water and produces either basic or acidic solutions depending on the salt's amphiprotic ion's strength as an acid or base.
The amphiprotic ion of NaHCO3 is bicarbonate ion (HCO3–), and the amphiprotic ion of NaHSO3 is bisulfite ion (HSO3–). The bicarbonate ion is a weak base that reacts with water to form an alkaline solution, while the bisulfite ion is a weak acid that reacts with water to form an acidic solution.NaHSO4 has the strong conjugate base SO4^2-, which will not donate protons to water and produce a basic solution. Therefore, the only sodium salt(s) of an amphiprotic ion that produces a basic solution when added to pure water are NaHCO3 and Na2CO3. Hence, the correct option is (c) 2 only.
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what simple machine would be best for lifting a couch through a 3rd floor apartment window?
Answer:
Pully
Explanation:
I would think that a pully would be most effective for lifting it Up and into the apartment (at least if you have a suitable spot to put the pully)
2.0 L of a gas is at STP. What is the new pressure in kPa if the volume changes to 10.5 L and the temperature and # of molecules remain constant?
Answer:
What is the new volume if the temperature is constant? V=2.50L. P = lookPa. P2=40k Pa. V2 = x. PV = P2 ... If a sample of gas occupies 6.8 L at 327°C
HCl (aq) + NaOH (aq) = NaCl (aq) + H2O (l)
What type of reaction is the above?
Answer:
Neutralization reaction
Explanation:
It is a reaction between an acid and a base
all of the following are ways that reduce the environmental impact of meat production except _______.
All of the following are ways that reduce the environmental impact of meat production except Raising beef cattle in feedlots. The correct option is A.
A traditional way of producing meat that often has a greater environmental impact than alternative methods is raising beef cattle in feedlots.
Feedlots pack a lot of animals into a small area, which can cause problems like water pollution from manure runoff, overuse of antibiotics, and significant greenhouse gas emissions.
Thus, the correct option is A.
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Your question seems incomplete, the probable complete question is:
Option B, D, and E, on the other hand, all help to lessen the environmental impact of meat production. Option B, pasture-based beef cattle production, permits more natural grazing and lessens the need for extensive feeding operations.
All of the following are ways that reduce the environmental impact of meat production except A.) Raising beef cattle in feedlots B.) Raising beef cattle in pastures C.) Decreasing the demand for meat D.) Developing meat substitutes E.) Raising beef cattle on rangelands
A 25.0 mL sample of 0.150M hydrocyanic acid is titrated with a 0.150M NaOH solution. What is the pH before any base is added? The Ka of hydrocyanic acid is 4.9 X 10^-10.
The pH before any base is added to the hydrocyanic acid solution is approximately 0.82.
Before any base is added, the pH of the hydrocyanic acid solution can be calculated using the Ka value and the initial concentration of the acid. The pH of a solution is determined by the concentration of H+ ions present. Hydrocyanic acid (HCN) is a weak acid that partially dissociates in water. The dissociation can be represented as follows: HCN ⇌ H+ + CN-. The Ka value of hydrocyanic acid (HCN) is given as 4.9 x 10^-10.
To find the pH before any base is added, we can assume that the dissociation of HCN is negligible compared to its initial concentration. Therefore, the concentration of H+ ions can be considered equal to the initial concentration of HCN. Using the given concentration of hydrocyanic acid (0.150M), we can calculate the pH by taking the negative logarithm (pH = -log[H+]). The concentration of H+ ions is 0.150M, and thus the pH is determined as the negative logarithm of 0.150, which is approximately 0.82.
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why do you think we have chosen reagents that generate bromine in situ instead of using liquid bromine br2 as a reagent?
The main reason for choosing reagents that generate bromine in situ instead of using liquid bromine Br₂ as a reagent is safety and ease of handling.
Using reagents that generate bromine in situ offers several advantages over using liquid bromine Br₂ directly. First, bromine is a highly reactive and corrosive liquid, posing safety risks during handling. It can cause severe burns and has toxic fumes, requiring careful precautions and specialized equipment. By generating bromine in situ, we can minimize the direct exposure and risks associated with handling liquid bromine.
Reagents that generate bromine in situ are often more stable, easier to store, and have a longer shelf life compared to liquid bromine. They can be prepared and used as needed, eliminating the need for storing and handling potentially hazardous quantities of liquid bromine. Overall, the use of in situ generated bromine reagents provides a safer and more convenient approach for conducting chemical reactions that require bromine.
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T/F. In an aqueous and diethyl ether extraction the aqueous will be the top layer?
The statement is True. In an aqueous and diethyl ether extraction, the aqueous layer will be the top layer. This is due to the difference in density between water and diethyl ether.
Water has a higher density compared to diethyl ether, which causes it to settle at the bottom layer. Diethyl ether, being less dense, will form the top layer. During the extraction process, immiscible solvents like water and diethyl ether are used. Since these solvents do not mix together, they form separate layers based on their densities. Water, being denser, will settle at the bottom while diethyl ether, being lighter, will float on top. This allows for the separation of compounds or substances that are preferentially soluble in either of the solvents. By carefully extracting the top or bottom layer, depending on the desired component, one can isolate specific compounds from a mixture.
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what is the volume of 9.783 x 1023 atoms of he at 9.25 atm and 512k?
The volume of 9.783 x 10^23 atoms of helium at 9.25 atm and 512 K is approximately 1.97 liters.
To calculate the volume of gas, we can use the ideal gas law equation:
PV = nRT
Where:
P is the pressure (in atmospheres)
V is the volume (in liters)
n is the number of moles
R is the ideal gas constant (0.0821 L·atm/(mol·K))
T is the temperature (in Kelvin)
Given:
Number of atoms of helium (n) = 9.783 x 10^23 atoms
Pressure (P) = 9.25 atm
Temperature (T) = 512 K
First, we need to convert the number of helium atoms to moles. Since 1 mole contains Avogadro's number (6.022 x 10^23) of particles:
Number of moles (n) = Number of atoms / Avogadro's number
Number of moles (n) = 9.783 x 10^23 atoms / 6.022 x 10^23
Number of moles (n) ≈ 1.625 moles
Now, we can rearrange the ideal gas law equation to solve for the volume (V):
V = (nRT) / P
V = (1.625 moles * 0.0821 L·atm/(mol·K) * 512 K) / 9.25 atm
V ≈ 1.97 liters
Therefore, the volume of 9.783 x 10^23 atoms of helium at 9.25 atm and 512 K is approximately 1.97 liters.
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Which of the following would produce the most fluid lipid bilayer?
Choose one:
A. phospholipids with fully saturated tails of 20 carbon atoms
B. phospholipids with fully saturated tails of 18 carbon atoms
C. large amounts of cholesterol
D. phospholipids with tails of 18 carbon atoms and two double bonds
E. phospholipids with tails of 20 carbon atoms and two double bonds
Phospholipids with tails of 18 carbon atoms and two double bonds would produce the most fluid lipid bilayer
Option (D) is correct.
The fluidity of a lipid bilayer is influenced by the composition of the phospholipids that make up the membrane. The presence of unsaturated fatty acid tails, indicated by the presence of double bonds, increases the fluidity of the lipid bilayer.
phospholipids with tails of 18 carbon atoms and two double bonds, would produce the most fluid lipid bilayer among the given choices. The presence of double bonds in the fatty acid tails introduces kinks in the hydrocarbon chains, which prevent them from packing tightly together. This increases the fluidity of the lipid bilayer by allowing the phospholipids to move more easily.
Therefore, the correct option is (D).
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1. Assume that the top of your head has a surface area of 25cm x 25 cm. How many newtons of force push on your head at sea level? 2. If you estimate this area to be 100 in^2 what is the force in pounds
1. Approximately 6333.125 newtons of force push on your head at sea level. Given that the surface area of the top of your head is 25 cm x 25 cm = 625 cm², we can convert it to square meters:
To calculate the force pushing on your head at sea level, we need to use the formula for pressure:
Pressure = Force / Area
Area = 625 cm² × (1 m / 100 cm)^2 = 0.0625 m²
At sea level, the standard atmospheric pressure is approximately 101,325 Pascals (Pa) or 101.325 kilopascals (kPa). Therefore, the force pushing on your head can be calculated by multiplying the pressure by the area:
Force = Pressure × Area
Force = 101,325 Pa × 0.0625 m² = 6333.125 N (to three decimal places)
2.If the area of your head is estimated to be 100 square inches, approximately 1468.276 pounds of force push on your head at sea level.If we estimate the area to be 100 square inches, we can convert it to square meters:
Area = 100 in² × (0.0254 m / 1 in)^2 = 0.064516 m²
Using the same atmospheric pressure, the force pushing on your head can be calculated:
Force = Pressure × Area
Force = 101,325 Pa × 0.064516 m² = 6530.645 N (to three decimal places)
To convert this force into pounds, we can use the conversion factor of 1 N = 0.2248 lb:
Force in pounds = 6530.645 N × 0.2248 lb/N = 1468.276 lb (to three decimal places)
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A student dilutes 50.0 mL of a 0.10 mol/L to 0.010 mol/L. Which statement is true?
Pressure is inversely proportional to which of the following, assuming all other variables are constant? Select the correct answer below O force area O both force and area O neither force or area
According to the statement, Pressure is inversely proportional to the area. Therefore, the correct answer is "Area."
According to the Physics, the pressure exerted by an object is defined as the force applied per unit area of the surface on which the force is applied. Mathematically, it can be written as,P = F / A. Where P is the pressure, F is the force and A is the area on which the force is applied.
From this equation, we can understand that the pressure exerted is inversely proportional to the area on which the force is applied. Therefore, if the area on which the force is applied is increased, then the pressure exerted by the object is decreased and vice versa. In addition, there are several factors that affect the pressure exerted by an object, including the magnitude of force applied, the area of contact, and the angle of application of the force. If all other variables are constant, then the pressure is solely dependent on the force and area of contact. Thus, pressure is inversely proportional to the area.
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Name the compound and determine the number of moles present. SHOW YOUR WORK.
17.4 g Na
17.4 grams of Sodium
Na= 1 mole.