Option A is correct.
This is because atoms get compressed when the pressure increases and takes less space, on the other hand, the atoms get expanded when pressure decreases and hence take more space.
A piece of wood has a mass of 36g and measures 3cm X 6cm X 4cm. What is the density of the wood? Would the piece of wood float or sink in water?
Answer:
Explanation:
The density is
1.1 g c m 3 .
The following data were obtained by gas-liquid chromatography on a 40-cm packed column:
Compound tR, min W, min
Air 1.9 —
Methylcyclohexane 10 0.76
Methylcyclohexene 10.9 0.82
Toluene 13.4 1.06
Calculate:
a. an average number of plates from the data.
b. the standard deviation for the average in (a).
c. an average plate height for the column.
Answer:
a)
For Methylcyclohexane N₁ = 2770
For Methylcyclohexene N₂ = 2827
For Toluene N₃ = 2557
b) the standard deviation for the average in (a) is 143.31
c)
For Methylcyclohexane; H₁ = 0.01444 cm
For Methylcyclohexene; H₂ = 0.01415 cm
For Toluene; H₃ = 0.01564 cm
Explanation:
Given the data in the question;
Gas-liquid chromatography on a 40-cm packed column:
Compound tR, min W, min
Air 1.9 —
Methylcyclohexane 10.0 0.76
Methylcyclohexene 10.9 0.82
Toluene 13.4 1.06
a)
an average number of plates from the data;
To get the Number of plates N, we use the following expression;
N = 16( tR / W )², we use it for Methylcyclohexane, Methylcyclohexene and Toluene
-
For Methylcyclohexane N₁ = 16( 10 / 0.76 )² = 16( 173.13 ) = 2770.08 ≈ 2770
-
For Methylcyclohexene N₂ = 16( 10.9 / 0.82 )² = 16( 176.7 ) = 2827.2 ≈ 2827
-
For Toluene N₃ = 16( 13.4 / 1.06 )² = 16( 159.8078 ) = 2556.9 ≈ 2557
b) standard deviation for the average in (a).
First we get the mean;
Mean N" = ( N₁ + N₂ + N₃ ) / 3 = ( 2770 + 2827 + 2557 ) / 3 = 8154 / 3 = 2718
Next we determine the deviation
d₁² = (N₁ - N")² = (2770 - 2718)² = (52)² = 2704
d₂² = (N₂ - N")² = (2827 - 2718)² = (109)² = 11881
d₃² = (N₃ - N")² = (2557 - 2718)² = (-161)² = 25,921
∴ ∑d²[tex]_i[/tex] = 40506
Standard Deviation S = √( ∑d²[tex]_i[/tex] / ( n-1 ) )
Standard Deviation S = √( 40506 / ( 3-1 )
Standard Deviation S = √( 40506 / 2 )
Standard Deviation S = √( 20253 )
Standard Deviation S = 143.31
Therefore, the standard deviation for the average in (a) is 143.31
c)
an average plate height for the column
Given that; Gas-liquid chromatography on a 40-cm packed column, L = 40 cm
-
For Methylcyclohexane; H₁ = L/N₁ = 40 / 2770 = 0.01444 cm
-
For Methylcyclohexene; H₂ = L/N₂ = 40 / 2827 = 0.01415 cm
-
For Toluene; H₃ = L/N₃ = 40 / 2557 = 0.01564 cm
What is the molarity of a solution that contains 152 g NaCl in 4.00 L solution?
Answer:
200.0lg
Explanation:
please give a brainliest
Which of the following is the BEST description of a budget? *
10
Answer:
A budget is an estimation of revenue and expenses over a specified future period of time and is usually compiled and re-evaluated on a periodic basis. Budgets can be made for a person, a group of people, a business, a government, or just about anything else that makes and spends money.
A solution is prepared by dissolving 16.90 g of ordinary sugar (sucrose, C12H22O11, 342.3 g/mol) in 40.90 g of water. Calculate the boiling point of the solution. Sucrose is a nonvolatile nonelectrolyte.
Answer:
Explanation:
The boiling point will increase due to dissolution of sugar in water . Increase in boiling point ΔT
ΔT = Kb x m , where Kb is molal elevation constant water , m is molality of solution
Kb for water = .51°C /m
moles of sugar = 16.90 / 342.3
= .04937 moles
m = moles of sugar / kg of water
= .04937 / .04090
= 1.207
ΔT = Kb x m
= .51 x 1.207
= .62°C .
So , boiling point of water = 100.62°C .
The masses of carbon and hydrogen in samples of four pure hydrocarbons are given above. The hydrocarbon in which sample has the same empirical formula as propene, C3H6
Sample Mass of carbon Mass of hydrogen
A 60g 12g
B 72g 12g
C 84g 10g
D 90g 10g
a. Sample A
b. Sample B
c. Sample C
d. Sample D
Answer:
Sample B
Explanation:
In this case, we need to determine the empirical formula for each sample. The one that match the formula of the propene would be the sample.
Let's do Sample A:
C: 60 g; H: 12 g
1. Calculate moles:
We need the atomic weights of carbon (12 g/mol) and hydrogen (1 g/mol):
C: 60 / 12 = 5
H: 12 / 1 = 12
2. Determine number of atoms in the formula
In this case, we just divide the lowest moles obtained in the previous part, by all the moles:
C: 5 / 5 = 1
H: 12 / 5 = 2.4 or rounded to two
3. Write the empirical formula:
Now, the prior results, represent the number of atoms in the empirical formula for each element, so, we put them with the symbol and the atoms as subscripted:
C₁H₂ = CH₂
Therefore, sample A is not the same as propene.
Sample B:
C: 72 g H: 12 g
Following the same steps, let's determine the empirical formula for this sample
C: 72 / 12 = 6 ---> 6 / 6 = 1
H: 12 / 1 = 12 ----> 12 / 6 = 2
EF: CH₂
Sample C:
C: 84 g H: 10 g
C: 84 / 12 = 7 ----> 7 / 7 = 1
H: 10 / 1 = 10 ----> 10 / 7 = 1.4 or just 1
EF: CH
Sample D
C: 90 g H: 10 g
C: 90 / 12 = 7.5 -----> 7.5 / 7.5 = 1
H: 10 / 1 = 10 -------> 10 / 7.5 = 1.33 or just 1
EF: CH
Neither compound has the same empirical formula as C3H6, but C3H6 is a molecular formula, so, if we just simplify the formula we have:
C3H6 -----> CH₂
Therefore, sample B is the one that match completely. Sample B would be the one.
Hope this helps
The chemical equation below is unbalanced.
NaOH + H3PO4 -> Na3PO4 + H2O
When the equation is correctly balanced, what will be the coefficient of H2O?
Answer:
3 NaOH (aq) + H3PO4 (aq) → Na3PO4 (aq) + 3 H2O (l)
Explanation:
This is an acid-base reaction (neutralization): NaOH is a base, H3PO4 is an acid.
When the equation is balanced, and the coefficient of H₂O is 3.
To balance the chemical equation:
NaOH + H₃PO₄ ⇒ Na₃PO₄ + H₂O
The number of atoms of each element is the same on both sides of the equation.
Balance the hydrogen atoms. There are three hydrogen atoms on the left side and two hydrogen atoms on the right side. To balance the hydrogen atoms, multiply H₂O by a coefficient of 3:
NaOH + H₃PO₄ ⇒ Na₃PO₄ + 3H₂O
If the oxygen (O) atoms are balanced. There are four oxygen atoms on the right side, but only two oxygen atoms on the left side. To balance the oxygen atoms, we need to multiply NaOH by a coefficient of 2.
To learn more about the chemical equation, follow the link:
https://brainly.com/question/28792948
#SPJ6
The exhaust from car engines spreads throughout our atmosphere and adds to pollution. What is this an example of?
A.
An increase in enthalpy
B.
An increase in thrust
C.
An increase in thermodynamics
D.
An increase in entropy
(D is the correct answer!)
Answer: When exhaust from car engines spreads throughout our atmosphere and adds to pollution then it is an example of increase in entropy.
Explanation:
A degree of randomness in the molecules of a substance is called entropy.
When exhaust from car engines spreads throughout our atmosphere then it means the molecules are moving at a faster speed due to which they spread into the atmosphere rapidly.
This means that the entropy of exhaust is increasing.
Thus, we can conclude that when exhaust from car engines spreads throughout our atmosphere and adds to pollution then it is an example of increase in entropy.
An increase in entropy
Convert a pressure of 250 torr to atm a) 0.266 atm b) 0.279 atm c) 0.329 atm d) 0.297 atm
Answer:
C
Explanation:
1atm=760torr
X=250torr
Cross multiply
760torrX=250torr*atm
Divide both sides by 760torr
X=250torr*atm/760torr
X=0.32895atm
X=0.329atm
Option C is collect
How much energy is contained in the six-cookie serving size recommended on the label?
Monounsaturated Fat 1g
a sample of mg(hco3)2 contains 1.8 moles of oxygen atom find the number of carbon atoms in the given sample
please solve fast very much urgent
Answer:
0.60 moles of atoms of carbon
Explanation:
Step 1: Given data
Chemical formula of the compound: Mg(HCO₃)₂Moles of oxygen atoms: 1.8 molesStep 2: Calculate the number of carbon atoms in the given sample
According to the chemical formula of the compound, the molar ratio of C to O is 2:6, that is, there are 2 moles of atoms of C every 6 moles of atoms of O. The number of moles of atoms of C is:
1.8 mol O × 2 mol C / 6 mol O = 0.60 mol C
When liquid water freezes into solid ice in the freezer,
Answer:
What about it? I don't get the question
The elements in the periodic table are not always represented by
the first one or two letters in their names. What are some examples of
this (list three)?
Unnillium (101)
Unnilbium (102)
Unniltrium (103)
Unnilquadium (104)
Unnilpentium (105)
Unnilhexium (106)
Unnilseptium (107)
Unniloctium (108)
Unnilennium (109)
Ununnillium (110)
Using stoichiometry, you predict that you should be able to use 314.0 g of Al to produce 1551 g of AlCi3. In your lab
exercise you actually produced 1400.0 g of aluminum chloride. What is your % yield for this reaction?
CORRECT ANSWER IS: 90.26% but what are the steps on how to get this answer ?
Answer:
90.26%
Explanation:
From the question given above, the following data were obtained:
Theoretical yield of AlCl₃ = 1551 g
Actual yield of AlCl₃ = 1400 g
Percentage yield =?
The percentage yield of the reaction can be obtained as follow:
Percentage yield = Actual yield / Theoretical yield × 100
Percentage yield = 1400 / 1551 × 100
Percentage yield = 140000 / 1551
Percentage yield = 90.26%
Thus, the percentage yield of the reaction is 90.26%
What is the usable form of nitrogen that is found in the ground?
Question 6
4 pts
6) Chromium crystallizes in a body-centered cubic unit cell. If the length of an edge of the unit cell
is 289 pm, what is the density (in g/cm3) of chromium?
Show your work on a paper and upload it here.
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Answer:
7.15g/cm³
Explanation:
To solve this question we must know that a body-centered cubic unit cell contains 2 atoms.
The volume of the unit cell is:
289pm = (289x10⁻¹²m)³ =
2.414x10⁻²⁹m³ * (1cm³ / 1x10⁻⁶m³) = 2.414x10⁻²³cm³
And the mass is -Molar mass Chromium = 51.9961g/mol:
2atoms * (1mol / 6.022x10²³atoms) * (51.9961g / mol) =
1.727x10⁻²²g
The density is:
1.727x10⁻²²g / 2.414x10⁻²³cm³ =
7.15g/cm³Calculate the mass of sucrose needed to prepare a 2000 grams of 2.5% sucrose solution.
Answer:
50 g Sucrose
Explanation:
Step 1: Given data
Mass of solution: 2000 gConcentration of the solution: 2.5%Step 2: Calculate the mass of sucrose needed to prepare the solution
The concentration of the solution is 2.5%, that is, there are 2.5 g of sucrose (solute) every 100 g of solution. The mass of sucrose needed to prepare 2000 g of solution is:
2000 g Solution × 2.5 g Sucrose/100 g Solution = 50 g Sucrose
In volcanic areas, groundwater heated by magma is a source of
a.
lava flows.
b.
silica.
c.
geothermal energy.
d.
pyroclastic flows.
Answer:I believe it is c.
Explanation:
Answer:
C., or "geothermal energy."
Determine how many pennies are in the stack on the left in the photograph at the beginning of this module. Create a conversion factor to calculate how many pennies are in the photo, knowing that there are 12 stacks of pennies.
Answer:
I had the answer
Explanation:
Moles to particles Now suppose you want to determine how many particles of sucrose are ... Driving Question Board Have students revisit the DQB to remind themselves of the Unit and Module questions.
What element in group 1 is not considered an alkali metal?
A. Hydrogen (H)
B. Lithium (Li)
C. Potassium (K)
D. Cesium (Cs)
Answer:
A
Explanation:
Hydrogen isn't an alkali metal
Answer:
hydrogen
Explanation:
hydrogen is a gas not a metal
What is the mass of 1.2 x 1023 atoms of arsenic?
Answer:
14.93 g
Explanation:
First we convert 1.2 x 10²³ atoms of arsenic (As) into moles, using Avogadro's number:
1.2 x 10²³ atoms ÷ 6.023x10²³ atoms/mol = 0.199 mol AsThen we can calculate the mass of 0.199 moles of arsenic, using its molar mass:
0.199 mol * 74.92 g/mol = 14.93 gThus, 1.2x10²³ atoms of arsenic weigh 14.93 grams.
Sample A: 300 mL of 1M sodium chloride
Sample B: 145 mL of 1.5 M sodium chloride
Which sample contains the larger concentration of sodium chloride?
Answer:
Sample A
Explanation:
Molarity of a solution can be calculated using the formula:
Molarity = number of moles (mol) ÷ volume (vol)
For Sample A:
V = 300ml = 300/1000 = 0.3 L
Molarity = 1M
n = number of moles (mol)
1 = n/0.3
n = 0.3moles
For Sample B:
V = 145 mL = 145/1000 = 0.145L
Molarity = 1.5 M
n = number of moles
1.5 = n/0.145
n = 1.5 × 0.145
n = 0.22 moles
Based on the above results (moles), sample A with 0.3 moles contains the larger concentration of sodium chloride.
If the nucleus of an atom
contained 6 protons and 7
neutrons, what would be its
mass
Answer:
13
Explanation:
1 proton/neutron has an atomic mass of 1. We ignore the electrons because they are too small. Protons and Neutrons have the same atomic mass, therefore the answer s 6+7=13
I’m confused and I don’t understand this, can someone help?
Wilma- tt
Wilbur- TT
c) 100% chance
d) 100% chance
it has been a while since I've done this so it could be wrong but im pretty sure its correct
Wilbur's family claims it is pure so they have TT
and his wife simply has big eyes so its tt
so the chances of their children having either eye shape is 100%
I'm sorry- im not too good at explaining it ><
How many moles of iron are needed to produce 10 moles of Fe2O3
Answer:
20 moles of Iron are needed
Explanation:
In 1 mole of Iron (III) oxide, Fe₂O₃, there are 2 moles of Iron, Fe. The equation that we can write is:
2 moles Fe = 1 mole Fe₂O₃
To find the moles of iron that are needed to produce 10 moles of Fe₂O₃ we must use this equation as follows:
10 moles of Fe₂O₃ * (2 moles Fe / 1mole Fe₂O₃) =
20 moles of Iron are neededHow many sigma bond and pi bond are present
If 56.8 g of FeCl, are formed, how many grams of Fe reacted?
(Explain or show work plz)
Answer:
the molar mass for Fe and Cl
What is matter?
O A. Anything that has energy and motion
B. Anything that takes up space and has mass
C. Anything that can be seen
D. Anything that can be measured
Answer:
B.Anything that takes up space and has mass
What does a velocity measurement include that a speed measurement does not?
time
direction
distance
acceleration
Give an example to illustrate the difference between "paying more in taxes ” and paying a higher tax rate .