Is the fractional distillation of liquefied air a physical or chemical change?
Answer:
Physical Chanhe is the answer : )
What is the pH of a buffer solution prepared by mixing 20.0 mL of 0.0800 molL−1NaOH with 20.0 mL of 0.130 molL−1 cacodylic acid?
Answer:
pH = 6.20
Explanation:
The pKa of cacodylic acid is 6.
To solve this question we must use Henderson-Hasselbalch equation:
pH = pKa +log [A⁻] / [HA]
Where pKa is the pKa of the weak acid = 6
And [] could be taken as the moles of A⁻ the conjugate base, and HA, the weak acid.
The moles of the NaOH added to the solution of the weak acid are = Moles A⁻
And moles HA = Initial moles HA - Moles NaOH added
Initial moles HA:
0.0200L * (0.130mol / L) = 0.00260 moles
Moles NaOH:
0.0200L * (0.0800mol / L) = 0.00160 moles = [A⁻]
Moles HA =
0.00260 moles - 0.00160 moles = 0.00100 moles = [HA]
pH = 6 +log [0.00160 moles] / [0.00100 moles]
pH = 6.20The pH of the resulting solution is 1.6.
Let cacodylic acid be HA, mixing cacodylic acid and NaOH, the following occurs;
HA(aq) + NaOH(aq) ------> NaA(aq) + H2O(l)
Number of moles of NaOH = 0.0800 molL−1 × 20.0/1000 = 0.0016 moles
Number of moles of HA = 20.0/1000 × 0.130 = 0.0026 moles
We can see that the HA is in excess, Number of moles of excess acid =
0.0026 - 0.0016 = 0.001 moles
Total volume of solution = 20.0 mL + 20.0 mL = 40 mL or 0.004 L
Molarity of excess acid = 0.001 moles/0.004 L = 0.025 M
pH = -log[H^+]
pH = -log[0.025 M]
pH = 1.6
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HELPPPP!!!!
Four students were asked to identify the part of an atom that determines the atom's identity and chemical properties. The student's responses are shown in the chart below. Which of the student's responses is correct?
Answer:
The number of protons is what determines a atoms identity.
This means that student 3 is correct.
Explanation:
Name two chemical used to disinfect water
Answer:
chlorine and I think maybe sulphur. but check the internet
Answer:
chlorine I think so . sorry if it ain't the right answer
What type of reaction occurs when potassium iodide is combined with lead (II) nitrate?
A. single replacement
b. double replacement
c. synthesis
d. combustion
Answer:
double replacement occurs
what is change in science
Answer:
Scientific change is: "Any change in the scientific mosaic, i.e. a transition from one accepted theory to another or from one employed method to another. "
Explanation:
give an example of competition in an ecosystem
hbzjaj
Explanation:
competition for food
How many moles of steam are produced when 5.74 moles of octane (C8H18) react?
In a warehouse, the workers sometimes slide boxes along the floor to move them. Two boxes were sliding toward each other and crashed. The crash caused both boxes to change speed. Based on the information in the diagram, which statement is correct? In your answer, explain what the forces were like and why the boxes changed speed.
Box 1 has more mass than Box 2.
Box 1 and Box 2 are the same mass.
Box 1 has less mass than Box 2.
Answer:
Box 1 and Box 2 are the same mass.
Explanation:
Because they both change speed due to having the same mass!
Hope this helps! :) BRAINLIEST PLZ
Judge Joe is looking over a list of expert witnesses that must be summoned to court. Which one of the following actions would he take pretrial to ensure they appear? A. Issue an arrest warrant. B. Conduct a jury poll. C. Send out subpoenas. D. Interpret case law.
the equation of 3times x is 38
Answer is 38/3 or 12.67
3x=38
x=38/3
therefore answer is the one mentioned above
true or false. a less reactive halogen will displace a more reactive halogen from an aqueous solution of its salt.
Answer:
I think the answer is false
Select all of the answers that apply.
multiple selection answer
Surface currents are driven by _____.
salinity
density
wind
temperature
the moon
[tex]\mathfrak{\huge{\orange{\underline{\underline{AnSwEr:-}}}}}[/tex]
Actually Welcome to the Concept of the Geography.
Surface currents in a ocean or a sea are driven by Winds.
Answer:
winds :)
Explanation:
2 NH3(g) → N2(g) + 3 H2(g)
What type of reaction is shown above?
A)
single replacement
B)
decomposition
C)
double replacement
D)
synthesis
Answer:
Decomposition Reaction
Explanation:
In the provided reaction, we can see that Ammonia is getting decomposed into Nitrogen and Hydrogen gas.
Another way to think about it is that Decomposition is nothing but one thing giving rise to 2 or more than 2 things.
Since our Ammonia is giving rise to 2 gases, this reaction is an example of Decomposition reaction
The formula for photosynthesis is shown.
64,0 + 600, → CH2+ 60,
What are the reactants of photosynthesis? (7.5A)
A.water and carbon dioxide
B.
oxygen and water
C.
glucose and oxygen
D.carbon dioxide and glucose
how do i make chrystals
Answer:
1. In the beaker, stir 1/2 cup of Epsom salts with 1/2 cup of very hot tap water for at least one minute. ...
2. Add a couple drops of food coloring if you want your crystals to be colored.
3. Put the beaker in the refrigerator.
4. Check on it in a few hours to see a beaker full of epsom salt crystals!
Explanation:
Which of the following would have three iron atoms in its formula? Iron oxide, iron Ill oxideiron phosphide, or iron phosphide.
Answer:
1 and 4 and 24
Explanation:
I know this because i passed 1st grade
please help! Question is on the bottom
A swimmer is moving at a speed of 2.0 meters/second. How long will it take for the swimmer to go 100 meters?
The primary role of ATP is to _______ by transferring a phosphate group to a molecule and forming ADP.
A
provide energy for cellular work
B)
produce heat energy
C)
reduce the activation energy of a reaction
D)
take energy from cellular work
Answer:
A) provide energy for cellular work
Explanation:
The Adenosine triphosphate (ATP) molecule is the nucleotide known in biochemistry as the "molecular currency" of intracellular energy transfer; that is, ATP is able to store and transport chemical energy within cells. ATP also plays an important role in the synthesis of nucleic acids.
ATP always GIVES ENERGY
We need a 3.0M aqueous HCl solution to dissolve the middle of a penny which is made of nickel. What mass of HCl is contained in 2.40 L of a 3.0M solution?
Answer:
262.8 g
Explanation:
Molarity = 3.0M
Mass = ?
Volume = 2.40L
The relationship between these quantities is given as;
Molarity = Number of moles / Volume
Number of moles = Molarity * Volume
Number of moles = 3 * 2.4 = 7.2 mol
Mass = Number of moles * Molar mass
Molar mass of HCl = 1 + 35.5 = 36.5 g/mol
Mass = 7.2 * 36.5 = 262.8 g
Answer:
262.44 grams of HCl is contained in 2.40 L of a 3.0 M solution.
Explanation:
Molarity (M) or Molar Concentration is the number of moles of solute that are dissolved in a certain volume.
Molarity is calculated as the number of moles divided by the volume of the solution:
[tex]Molarity=\frac{number of moles of solute}{volume of solution}[/tex]
Molarity is expressed in units [tex]\frac{moles}{liter}[/tex].
In this case:
Molarity= 3 MNumber of moles of solute= ?Volume of solution= 2.4 LReplacing:
[tex]3 M=\frac{number of moles of solute}{2.40 L}[/tex]
and solving you get:
number of moles of solute= 3 M* 2.40 L
number of moles of solute= 7.2 moles
Being the molar mass of HCl 36.45 g/mole, then you can apply the following rule of three: if 1 mole has 36.45 grams, 7.2 moles how much mass does it have?
[tex]mass of HCl=\frac{7.2 moles*36.45 grams}{1 mole}[/tex]
mass of HCl= 262.44 grams
262.44 grams of HCl is contained in 2.40 L of a 3.0 M solution.
HELP PLEASE ||Suppose you add water to a 6 g of sugar to make a solution with a concentration of 3 g/L. What is the total volume of the solution?
Answer:
2 L
Explanation:
Divide the mass by the concentration to find the volume.
(6 g)/(3g/L) = 2 L
According to the concept of solubility, in order to make solution of sugar the total volume of solution is 2 g/L.
What is solubility?Solubility is defined as the ability of a substance which is basically solute to form a solution with another substance. There is an extent to which a substance is soluble in a particular solvent. This is generally measured as the concentration of a solute present in a saturated solution.
The solubility mainly depends on the composition of solute and solvent ,its pH and presence of other dissolved substance. It is also dependent on temperature and pressure which is maintained.Concept of solubility is not valid for chemical reactions which are irreversible. The dependency of solubility on various factors is due to interactions between the particles, molecule or ions.
In order to calculate total volume of solution divide mass/ concentration that is 6/3=2 g/L.
Thus, the total volume of the solution is 2 g/L.
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how do you make fried chicken im white and don't know how to season
Answer:
lol you use batter use flour salt pepper thats what gives it the fried and crispy taste
Explanation:
which image of earth is more recent?
Answer:
b
Explanation:
Answer:
2
Explanation:
its has more space now cause of The to contemplates
5. Keratin and collagen are examples of *
li
Answer:
Structural proteins
Explanation:
Glad I could Help Pls Brainliest
4 Al + 3 O₂ --> 2 Al2Ol₃ Given 6 moles of aluminum, how many grams of aluminum oxide will be produced?
Answer:
305.88 g
Explanation:
4 Al + 3 O₂ → 2 Al₂O₃
First, we convert 6 moles of aluminum (Al) into moles of aluminum oxide (Al₂O₃), using the stoichiometric coefficients:
6 mol Al * [tex]\frac{2molAl_2O_3}{4molAl}[/tex] = 3 mol Al₂O₃
Finally we convert 3 moles of aluminum oxide into grams, using its molar mass:
3 mol Al₂O₃ * 101.96 g/mol = 305.88 g
What is the approximate elevation above sea level at which atmospheric pressure is 10-1 atmosphere
Answer:
The answer is 17km
Is this balanced ?CsH12 + 702 → 5 CO2 + 6H2O
Answer:
Nope
Explanation:
Answer: nope, it should be : C5H12 + 8O2 → 5CO2 + 6H2O
Calculate the volume which 1.00 mole of a gas occupies at STP.
Answer:
22.4 L
Explanation:
A gas at STP will possess the following;
Pressure (P) = 1 atm
Temperature (T) = 273K
General gas constant (R) = 0.0821 Latm/molK
Using the general gas law formula to calculate the volume a gas of 1 mol will contain;
PV = nRT
V = nRT/P
V = 1 × 0.0821 × 273 ÷ 1
V = 22.41/1
V = 22.4 litres
2) You start with 3.8 x 1021 gold atoms, how many moles is this?
Answer:
0.0063mol
Explanation:
Number of moles (n) in a substance can be calculated by dividing the number of atoms (nA) of that substance by Avagadro's number i.e. 6.02 × 10^23. That is; n = nA ÷ 6.02 × 10^23
1 mol of Gold = 6.02 × 10^23 atoms
Therefore, 3.8 x 10^21 atoms of Gold will be;
3.8 x 10^21 ÷ 6.02 × 10^23
= 3.8 ÷ 6.02 × 10^ (21 - 23)
= 0.6312 × 10^-2
= 0.0063mol of Gold