Answer: 0.05
Explanation:Divide the length (1.5 cm) by the number of turns (30)
The direct proportion rule allows you to find that the correct answer for the result of the thickness of the copper wire is:
0.05 cm
Copper is a strong material with which the cross section is constant, therefore the copper wire has a constant thickness, which is why when making a full turn it advances the same amount
When Jade wound thirty times (n = 30) it has the same diameter each time, therefore with a direct rule of proportions we can find the thickness of the wire.
If in 30 laps we have 1.5 cm, in one lap we have?
[tex]x= 1 turn ( \frac{1.5 cm}{30 turn} )[/tex]
x = 0.05 cm
In conclusion using a direct rule of proportions we can that the correct answer for the result of the thickness of the copper wire is:
0.05 cm
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How many atoms of titanium are there in 0.125 mole of each of the following?a. ilmenite, FeTiO3b. titanium(IV) chloridec. Ti2O3d. Ti3O5
Answer:
a. 7.528x10²² atoms Ti
b. 7.528x10²² atoms Ti
c. 1.5055x10²³ atoms Ti
d. 2.258x10²³ atoms Ti
Explanation:
Using the molecular formula of the structures, we can determine the moles of titanium in 0.125 moles of each compound. With moles of titanium we can convert these to atoms using Avogadro's number as follows:
a. FeTiO₃: 1 mole of Ti per mole of FeTiO₃.
Moles of Ti are 0.125 moles. Atoms are:
0.125 moles Ti * (6.022x10²³ atoms / 1 mole) =
7.528x10²² atoms Tib. Titanium (IV) chloride = TiCl₄: 1 mole of Ti per mole of TiCl₄.
Moles of Ti are 0.125 moles. Atoms are:
0.125 moles Ti * (6.022x10²³ atoms / 1 mole) =
7.528x10²² atoms Tic. Ti₂O₃: 2 moles of Ti per mole of Ti₂O₃.
Moles of Ti are 2*0.125 moles = 0.25 moles. Atoms are:
0.25 moles Ti * (6.022x10²³ atoms / 1 mole) =
1.5055x10²³ atoms Tia. Ti₃O₅: 3 mole of Ti per mole of Ti₃O₅.
Moles of Ti are 3*0.125 moles = 0.375 moles of Ti. Atoms are:
0.375 moles Ti * (6.022x10²³ atoms / 1 mole) =
2.258x10²³ atoms TiFrom the formula for calculating number of atoms, the number of atoms of Ti in 0.125 moles of the compounds FeTiO₃, TiCl₄, Ti₂O₃, Ti₃O₅ are 7.528 * 10²² atoms Ti, 7.528 x 10²² atoms Ti, 1.5055 * 10²³ atoms Ti and 2.258 * 10²³ atoms Ti respectively.
What is the number of atoms present in the compounds?The number of atoms present in a substance is calculated using the formula:
Number of atoms = Number of moles * 6.022 * 10³Moles of Titanium in the compounds:
a. FeTiO₃ contains 1 mole of Ti per mole of FeTiO₃.
Moles of Ti are 0.125 moles.
number of atoms = 0.125 * 6.022x10²³ atoms
number of atoms = 7.528 * 10²² atoms Ti
b. 1 mole of Titanium (IV) chloride TiCl₄ contains 1 mole of Ti per mole of TiCl₄.
Moles of Ti are 0.125 moles.
Atoms of titanium = 0.125 * 6.022x10²³ atoms / 1 mole)
number of atoms = 7.528 x 10²² atoms Ti
c. 1 mole of Ti₂O₃ contains 2 moles of Ti per mole of Ti₂O₃.
Moles of Ti are 2 * 0.125 moles = 0.25 moles
number of atoms = 0.25 * 6.022x10²³ atoms
number of atoms = 1.5055 * 10²³ atoms Ti
d.1 mole of Ti₃O₅ contains 3 mole of Ti per mole of Ti₃O₅.
Moles of Ti are 3 * 0.125 moles = 0.375 moles of Ti.
number of atoms = 0.375 * 6.022x10²³ atoms
number of atoms = 2.258 * 10²³ atoms Ti
Therefore, the number of atoms of Ti in 0.125 moles of the compounds FeTiO₃, TiCl₄, Ti₂O₃, Ti₃O₅ are 7.528 * 10²² atoms Ti, 7.528 x 10²² atoms Ti, 1.5055 * 10²³ atoms Ti and 2.258 * 10²³ atoms Ti respectively.
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What contributions led to the acceptance of the heliocentric model of the solar system
Answer:
It was just on a way and scienticts cant really "delete" it from galaxy so they descided accepting it and study it.
Explanation:
Answer:
In 1543 he further developed the heliocentric model. Copernicus was able to work out the arrangement of the known planets and how they move around the sun.
Explanation:
hope this helps:)
If 6.09 g of sodium chloride are mixed with 35.50 g of water, what is the mass % (w/w%) salt in the solution
Answer:
14.6 %
Explanation:
Step 1: Given data
Mass of sodium chloride (solute): 6.09 g
Mass of water (solvent): 35.50 g
Step 2: Calculate the mass of solution
We will use the following expression.
m(solution) = m(solute) + m(solvent)
m(solution) = 6.09 g + 35.50 g
m(solution) = 41.59 g
Step 3: Calculate the percent by mass of the salt
We will use the following expression.
%w/w = mass of NaCl / mass of solution × 100%
%w/w = 6.09 g / 41.59 g × 100%
%w/w = 14.6 %
Can a smoothie be separated by physical means ?
Answer:
No because the sugar that went to it dissolved and the fruits are very blended in. It depends what smoothie it is because you can evaporate a strawberry smoothie and have only the strawberry mix instead of the water or milk.
Explanation:
What is an extensive property? *
A property that changes if temperature changes
A property that will NOT change if temperature changes
A property that changes if the amount of substance changes
A property that does NOT change if the amount of substance changes
Help :( pls
Answer:
A property that changes if the amount of substance changes
Explanation:
An extensive property is a property that depends on the amount of matter in a sample.
A runner competed in a 5-mile run. How many yards did she run?
a-8800 yards
b-8800 miles
с-8657 yards
What is the correct answer with the appropriate significant digits?6.25 x 19.50
How far will you travel in 180 seconds running at a rate of 6 m/s?
Answer:
1080 meters.
Explanation:
When 1 carbon atom combines with 2 oxygen atoms, the resulting substance is called a
Answer:
Carbon Dioxide
Explanation:
Which is a compound:)
I need these questions answered
Answer:
Three objects with kinetic energy
A ball rolling down the street
Moving Car
Bullet
Law of Conservation of Energy states that the total energy of an isolated system remains constant; it is said to be conserved over time.
Though technically there are limitless forms of both types of energy, officially there's five types of kinetic energy: radiant, thermal, sound, electrical and mechanical and potential energy adds gravitational, nuclear, and elastic.
Calculate the mass of sucrose necessary to make a 5% by mass sucrose solution if the solution contains 50.0 ml of distilled water. (Hint: the total mass of the solution is the mass of sucrose plus the mass of water.)
Answer:
2.6 g
Explanation:
Percent concentration = 5%
Volume of water = 50ml
Since 1ml of water = 1g of water
Mass of water= 50g
Let the mass of sucrose be x
Mass% = mass of solute/mass of solute + mass of solvent × 100
5= x/x+ 50 ×100
5/100 = x/x + 50
0.05 = x/x + 50
0.05(x + 50) = x
0.05x + 2.5 = x
2.5 = x - 0.05x
2.5 = 0.95x
x= 2.5/0.95
x=2.6 g
Ignore my writing, but I’m so confused on this. Please help me
Before this it was talking about sig figs, so I’m not sure if you’re supposed to use sig figs in this or not.
Explanation:
You are suppose to use sig figs.
It takes 330 joules of energy to raise the temperature of 24.6 gbenzene from 21 degrees Celsius to 28.7 degrees Celsius at constantpressure. What is the molar hear capacity of benzene at constantpressure?
Given :
Energy , E = 330 J .
Initial temperature , [tex]T_i=21^oC[/tex] .
Final temperature , [tex]T_f=24.6^oC[/tex] .
Mass of benzene , m = 24.6 g .
To Find :
The molar hear capacity of benzene at constant pressure .
Solution :
Molecular mass of benzene , M = 78 g/mol .
Number of moles of benzene :
[tex]n=\dfrac{24.6}{78} \ mol\\\\n=0.32 \ mol[/tex]
Energy required is given by :
[tex]q=nC_p\Delta T\\\\330=0.32\times C_p\times (28.7-21)\\\\C_p=\dfrac{330}{0.32\times 7.7}\ J\ mol^{-1}^oC^{-1} \\\\C_p=133.9\ J\ mol^{-1}^oC^{-1}[/tex]
Hence , this is the required solution .
HELP FAST!!!
As a roller coaster car travels down a hill, which type of change in energy allows
it to speed up?
a) potential energy changing into heat energy
b) potential energy changing into kinetic energy
c) kinetic energy changing into heat energy
d) kinetic energy changing into potential energy
Answer:
B
Explanation:
A liquid has a volume of 4mL and a mass of 24 grams. What is the density of the liquid?
Answer:
the density is 6
Explanation:
mass divided by volume equals density
What sequence should be followed when conducting a laboratory investigation? Make observations, gather experimental data, form a conclusion, state a problem Define a problem, form a hypothesis, gather experimental data, form a conclusion. Form a hypothesis, form a conclusion, gather experimental data, define a problem Gather experimental data, make observations, form a conclusion, for a hypothesis.
Answer:
Define a problem, form a hypothesis, gather experimental data, form a conclusion
Answer:
Make observations, gather experimental data, form a conclusion, state a problem Define a problem, form a hypothesis, gather experimental data, form a conclusion.
Explanation:
How do you determine the last digit in any measured number
Answer:
Explanation:
The last number in a measured number is always an estimated digit.
Calculate the mass of forsterite that contains a million oxygen atoms. Be sure your answer has a unit symbol if necessary, and round it to significant digits.
Answer:
2.33×10¯¹⁶ g of forsterite
Explanation:
From Avogadro's hypothesis, we understood that 1 mole of any substance contains 6.02×10²³ atoms. This equally means that 1 mole of forsterite (Mg2SiO4) contains 6.02×10²³ atoms.
1 mole of forsterite (Mg2SiO4) = (24×2) + 28 + (16×4)
= 48 + 28 + 64
= 140 g
Finally, we shall determine the mass of forsterite that contains a million oxygen atoms.
140 g of forsterite (Mg2SiO4) contains 6.02×10²³ atoms.
Therefore, Xg of forsterite (Mg2SiO4) will contain 1×10⁶ atoms of oxygen i.e
Xg of forsterite (Mg2SiO4) =
(140 × 1×10⁶) /6.02×10²³
= 2.33×10¯¹⁶ g
Therefore, 2.33×10¯¹⁶ g of forsterite contains a million oxygen atoms..
The mass of forsterite that contains a million oxygen atoms is 5.67 × 10^-17 g.
The chemical formula of forsterite is Mg2SiO4. Now, molar mass of forsterite is; 2(24) + 28 + 4(16) = 140 g/mol
Next, we have to obtain the number of oxygen atoms that are found in 1 mole of forsterite as follows;
Number of oxygen atoms in 1 mole = 1 × 4 × 6.02 × 10^23 = 24.08 × 10^23 atoms
Now;
If 1 mole of forsterite contains 24.08 × 10^23 atoms oxygen atoms
x moles of forsterite contains 1 × `10^6 atoms
x = 1 mole × 1 × `10^6 atoms/24.08 × 10^23 atoms
x = 4 × 10^-19 moles
Mass of forsterite that contains a million oxygen atoms = 4 × 10^-19 moles
× 140 g/mol = 5.67 × 10^-17 g
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Hydrogen reacts with nitrogen monoxide to form dinitrogen monoxide (laughing gas) according to the equation: H2O(g) + 2NO(g) rightarrow O + H2O(g)NO (M) 0.30 0.60 0.60H2 (M) 0.35 0.35 0.70Rate (M/L/s) 3.822 x 103 1.529 x 10-2 3.058 x 10-2 A) Determine the rate law according to the following data. B) Determine the rate constant (in mol-2. L2. s-1).C) Determine the orders with respect to each reactant.
Answer:
A. [tex]r=k[NO]^2[H_2][/tex]
B. [tex]k=0.121\frac{L^2}{mol^2*s}[/tex]
C. Second-order with respect to NO and first-order with respect to H₂
Explanation:
Hello,
In this case, for the reaction:
[tex]H_2O(g) + 2NO(g) \rightarrow N_2O + H_2O(g)[/tex]
The rate law is determined by writing the following hypothetical rate laws:
[tex]3.822x10^{-3}=k[0.3]^m[0.35]^n\\\\1.529x10^{-2}=k[0.6]^m[0.35]^n\\\\3.058x10^{-2}=k[0.6]^m[0.7]^n[/tex]
Whereas we can compute m as follows:
[tex]\frac{3.822x10^{-3}}{1.529x10^{-2}} =\frac{[0.3]^m[0.35]^n}{[0.6]^m[0.35]^n} \\\\0.25=(0.5)^m\\\\m=\frac{log(0.25)}{log(0.5)} \\\\m=2[/tex]
Therefore, the reaction is second-order with respect to NO. Thus, for hydrogen, we find n:
[tex]\frac{1.529x10^{-2}}{3.058x10^{-2}} =\frac{[0.6]^2[0.35]^n}{[0.6]^2[0.7]^n} \\\\0.5=(0.5)^n\\\\n=\frac{log(0.5)}{log(0.5)}\\ \\n=1[/tex]
A) Therefore, the reaction is first-order with respect to H₂. In such a way, we conclude that that the rate law is:
[tex]r=k[NO]^2[H_2][/tex]
B) Rate constant is computed from one kinetic data:
[tex]k=\frac{1.529x10^{-2}\frac{mol}{L*s} }{(0.6\frac{mol}{L} )^2(0.35\frac{mol}{L})}\\\\k=0.121\frac{L^2}{mol^2*s}[/tex]
C. As mentioned before, reaction is second-order with respect to NO and first-order with respect to H₂.
Best regards.
The order with respect to NO has been 2, while the order with respect to water has been 1.
The rate law has been the representation of the chemical concentration responsible for determining the rate of the reaction. The balanced chemical equation has been:
[tex]\rm H_2O\;+\;2\;NO\;\rightarrow\;N_2O\;+\;H_2O[/tex]
A. The rate equation for the reaction has been:
Rate = Rate constant [tex]\rm [H_2O]^m\;[NO]^n[/tex]
Where, m and n are the rate of the respective reactants.
The rate with respect to NO from the given data can be given as:
The ratio of Rate 1 to rate 2 with concentration of NO
[tex]\rm \dfrac{3.822\;\times\;10^-^3}{1.529\;\times\;10^-^2}[/tex] = [tex]\rm \dfrac{[0.3]^m\;[0.35]^n}{[0.6]^m\;[0.35]^n}[/tex]
m = 2
The rate of reaction with respect of NO has been 2.
The rate of reaction with water concentration has been:
[tex]\rm \dfrac{1.529\;\times\;10^-^2}{3.058\;\times\;10^-^2}[/tex] = [tex]\rm \dfrac{[0.6]^m\;[0.35]^n}{[0.6]^m\;[0.7]^n}[/tex]
n = 1
The rate of reaction with respect of water has been 1.
The rate law for reaction has been:
Rate = k [tex]\rm [H_2O]^1\;[NO]^2[/tex]
B. The rate constant can be given as:
Rate = 3.822 [tex]\rm \times\;10^-^3[/tex]
Concentration of NO = 0.6
Concentration of water = 0.35
The rate constant from the rate law can be given as:
3.822 [tex]\rm \times\;10^-^3[/tex] = k [tex]\rm [0.6]^2\;[0.35][/tex]
k = 0.121 [tex]\rm mol^-^2\;L^2\;s^-^1[/tex]
C. The order with respect to NO has been 2, while the order with respect to water has been 1.
For more information about the rate of reaction, refer to the link:
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Which tool can be used to measure the volume of liquid?
an electronic balance
a meniscus
a caliper
a beaker
Answer:
The answer is D a beaker
Explanation:
Hope this helps :D
Use the observation in the first column
Observation Questions
At 4 °C, Substance E has a Which has a higher boiling point
vapor pressure of 86. torr and Substance A. Substance E
F has a vapor pressure of 136. torr. B. Substance F
C. Neither, E and F have the
same boiling point.
The enthalpy of vaporization of Substance At any temperature where both
C is smaller than that of Substance D. substances are liquid which has
has the higher vapor pressure?
A. Substance C
B. Substance D
C. Neither, C and D have the
same vapor pressure
Which has a higher vapor pressure?
At 1 atm pressure Substance A boils at A. Substance A
129. °C and Substance B B. Substance B
boils at 154. °C. C. Neither, A and B have the
same vapor pressure.
Answer:
A. Substance E
A. Substance C
A. Substance A
Explanation:
Given that:
At 4 °C, Substance E has a vapor pressure of 86. torr and Substance F has a vapor pressure of 136. torr
Which has a higher boiling point?
A. Substance E
B. Substance F
C. Neither,EandF have the same boiling point
The vapor pressure varies inversely proportional to the boiling point.
[tex]\mathbf{vapor \ pressure \ \ \alpha \ \ \dfrac{1}{boiling \ point}}[/tex]
Therefore, the lower the vapor pressure, the higher the boiling point.
At 4°C, Substance E with a lower vapor pressure of 86. torr will have a higher boiling point from the given information.
2.
Recall that :
[tex]\mathbf{vapor \ pressure \ \ \alpha \ \ \dfrac{1}{enthalpy \ of \ vaporization}}[/tex]
therefore, the lower the enthalpy of vaporization, the higher the vapor pressure at any given temperature.
Given that:
Substance C has an enthalpy of vaporization smaller than that of substance D. Then, substance C has a higher vapor pressure.
3.
We've earlier said that:
The vapor pressure varies inversely proportional to the boiling point.
[tex]\mathbf{vapor \ pressure \ \ \alpha \ \ \dfrac{1}{boiling \ point}}[/tex]
Therefore, the lower the vapor pressure, the higher the boiling point.
As such, Substance A will have a higher boiling point.
Which of the following DOES NOT have 2 significant
figures?
11,000,000,000
0.11
1.001
0.0000011
Answer:
1.001
Explanation:
The Significant Figures are 1 0 0 1, This answer has 4 Significant figures, while the other three have only 2 significant figures
3y= 4y^3
Write a verbal sentence to represent each equation.
Answer:
See explanation
Explanation:
To write a verbal sentence to represent an equation, we must look at the equation closely in order to capture its essence.
For this equation, 3y= 4y^3, we can write it in words as:
Three multiplied by y is equal to four multiplied by y raised to power three.
A solution is made by dissolving
42.3 g of potassium hydroxide
(KOH) in 329 g of water.
What is the molality of the solution?
Answer:
2.29 m.
Explanation:
The following data were obtained from the question:
Mass of KOH = 42.3 g
Molar mass of KOH = 56.11 g/mol
Mass of water = 329 g
Molality of KOH = ?
Next, we shall determine the number of mole in 42.3 g of KOH. This can be obtained as follow:
Mass of KOH = 42.3 g
Molar mass of KOH = 56.11 g/mol
Mole of KOH =?
Mole = mass /Molar mass
Mole of KOH = 42.3/56.11
Mole of KOH = 0.754 mole
Next, we shall convert 329 g of water to kilogram (kg). This can be obtained as follow:
1000 g = 1 kg
Therefore,
329 g = 329 g /1000 g × 1 kg
329 g = 0.329 kg
Therefore, 329 g of water is equivalent to 0.329 kg
Finally, we shall determine the molality of the KOH solution ad follow:
Molality is defined as the mole of solute per unit kilogram of solvent (water) i.e
Molality = mole/ mass (kg) of water
Mole of KOH = 0.754 mole.
Mass of water = 0.329 kg.
Molality = mole/ mass (kg) of water
Molality = 0.754/0.329
Molality = 2.29 m
Therefore, the molality of the KOH solution is 2.29 m.
Answer:
2.29
Explanation:
A buffer contains 0.010 moles of lactic acid (pKa = 3.86) and 0.050 mol of sodium lactate per liter.
(a) Calculate the pH of the buffer.
(b) Calculate the change in pH when 5 mL of 0.5 M HCl is added to 1 L of the buffer.
(c) What pH change would you expect if you added the same quantity (5 mL) of HCl to 1 L of pure water?
Answer:
a. pH = 4.56
b. Change in pH = 0.85
c. Change in pH = 5.4
Explanation:
a. The pKa of lactic buffer is: 3.86.
Using Henderson-Hasselbalch formula for the lactic buffer:
pH = 3.86 + log [Lactate] / [Lactic acid]
Where [] is molarity of each compound but could be taken as moles
Replacing:
pH = 3.86 + log [0.050 moles] / [0.010 moles]
pH = 4.56
b. The HCl added reacts with Lactate producing lactic acid. Moles of HCl are:
5x10⁻³L * (0.5mol /L) = 0.025 moles HCl
Moles of lactate: 0.050moles - 0.025 moles = 0.025 moles
Moles lactic acid: 0.010 moles + 0.025 moles = 0.035 moles
pH = 3.86 + log [0.025 moles] / [0.035 moles]
pH = 3.71
Change in pH = 4.56 - 3.71 = 0.85
c. 1L of pure water has a pH of 7. 0.025 moles of HCl = 0.025 moles H⁺ in 1.005L:
0.025 mol / 1.005L = 0.0249M = [H⁺]
As pH = -log [H⁺]
pH = 1.6
Change in pH = 7.0 - 1.6 = 5.4
At a certain temperature this reaction follows first-order Kinetics with a rate constant of 0.0660
2H1 (g)----------> H2, (g)+I2
Suppose a vessel contains HI at a concentration of 0.310 M. Calculate how long it takes for the concentration of HI to decrease to 0.0558 M. You may assume no other reaction is important. Round your answer to 2 significant digits.
Answer:
After 26.0s, the concentration of HI decreases from 0.310M to 0.0558M.
Explanation:
Based on the reaction of the problem, you have as general kinetic law for a first-order reaction:
ln[HI] = -kt + ln [HI]₀
Where [HI] is actual concentration after time t,
k is rate constant
and [HI]₀ is initial concentration of the reactant.
Initial concentration of HI is 0.310M,
K is 0.0660s⁻¹,
And the actual concentration is 0.0558M:
ln[HI] = -kt + ln [HI]₀
ln[0.0558M] = -0.0660s⁻¹*t + ln [ 0.310M]
-1.7148 = -0.0660s⁻¹*t
26.0s = t
After 26.0s, the concentration of HI decreases from 0.310M to 0.0558M
Rank the following atoms in order of increasing electronegativity.a. Se, O, S b. P, Na, Cl c. Cl, S, F d. O, P, N
Answer:
a)- Se, S, O
b)- Na, P, Cl
c)- S, Cl, F
d)- P, N, O
Explanation:
We can solve this problem by looking at the Periodic Table. In a group, electronegativity increases from bottom to top; whereas in periods it increases from left to right.
Thus, we order the elements from lower to higher electronegativity as follows:
a. Se, O, S ⇒ order: Se, S, O
Because they are all in the same group. Se is near the bottom, followed by S and O is at the top.
b. P, Na, Cl ⇒ order: Na, P, Cl
They are in the same period. Na is at the left, followed by P and Cl is nearest the right.
c. Cl, S, F ⇒ order: S, Cl, F
P and Cl are in the same period, and P is at the left, so it has the lowest electronegativity. F is in the same group of Cl, but at the top. F has the highest electronegativity.
d. O, P, N ⇒ order: P, N, O
N and P are in the same group, but P is at the bottom so it has the lower electronegativity. N and O are in the same period, but O is at the right, so it is the most electronegative.
Photosynthesis by land plants leads to the fixation each year of about 1 kg of carbon on the average for each square meter of an actively growing forest. The atmosphere is approximately 20% O2 and 80% N2, but contains 0.039% CO2 by weight.
A) How much carbon is present in the entire atmosphere lying above each square meter of the earth's surface?
B) At the current rate of utilization, how long would it take to use all the CO2
in the entire atmosphere directly above a forest?
Answer:
a) mass of carbon directly above 1 ( each) square meter of the earth is 1.65kg
b) all CO₂ will definitely be used up from the atmosphere directly above a forest in 1.65 years
Explanation:
first we calculate the moles of carbon
moles = mass/molar mass
= 1kg/12gmol⁻¹
= 1000g/12gmol⁻¹
= 83.33 mol
now using the ideal gas equation
we find the volume of co₂required based on 83.33 moles
PVco₂ = nRT
Vco₂ = nRT/P
Vco₂ = (83.22mol × 0.0821L atm k⁻¹ mol⁻¹ 298 K) / 1 atm
Vco₂ = 2083.73 L
so since CO₂ in air is 0.0390% by volume in the atmosphere, we find the the total amount of air required to obtain 1kg carbon
therefore
Vair × 0.0390/100 = 2038.73L
Vair = (2038.73L × 100) / 0.0390
Vair = 5.23 × 10⁶L
therefore 5.23 × 10⁶ L of air will be required to obtain 1kg carbon
a)
Here we calculate the mass of air over 1 square meter of surface.
Remember that atmospheric pressure is the consequence of the force exerted by all the air above the surface; 1 bar is equivalent to 1.020×10⁴kgm⁻²
NOW
mass of air = 1.020×10⁴kgm⁻² × 1m²
= 1.020×10⁴kg
= 1.020×10⁷g [1kg = 10³g]
we now find the moles of air associated with it
moles = mass/molar mass
= 1.020 × 10⁷g / ( 20%×Mo₂ + 80%×Mn₂)
= 1.020 × 10⁷g / ( 20%×32gmol⁻¹ + 80%×28gmol⁻¹)
= 1.020 × 10⁷g / 28.8 gmol⁻¹
= 354166.67mol
so based on the question, for each mole (air), there is 0.0390% of CO₂
now to calculate the moles of CO₂ we say;
MolesCo₂ = 0.0390/100 × 354166.67mol
= 138.125 moles
Now we calculate mass of CO₂ from the above findings
Moles = mass/molar mass
mass = moles × molar mass
= 138.125 moles × 12gmol⁻¹
= 1657.5g
we covert to KG
= 1657.5g / 1000
mass = 1.65kg
therfore mass of carbon directly above 1 ( each) square meter of the earth is 1.65kg
b)
to find the number years required to use up all the CO₂, WE SAY
Number of years = total carbon per m² of the forest / carbon used up per m² from the forest per year
Number of years = 1.65kgm⁻² / 1kg²year⁻¹
Number of years = 1.65 years
Therefore all CO₂ will definitely be used up from the atmosphere directly above a forest in 1.65 years
Disadvantage of dot structure
The enthalpy of sublimation of iodine is 60.2 kJ/mol, and its enthalpy of vaporization is 45.5 lz.1/mol. What is the enthalpy of fusion of iodine?
Answer:
ΔH = 14,7kJ/mol
Explanation:
It is possible to make algebraic sum of several chemical process to obtain enthalpy of a determined reaction (Hess's law).
Sublimation of iodine is (Transition from solid to gas):
I₂(s) → I₂(g) ΔH = 60.2kJ/mol
Vaporization of iodine (From liquid to gas):
I₂(l) → I₂(g) ΔH = 45.5kJ/mol
Fusion of iodine (From solid to liquid can be obtained subtracting the sublimation process - Vaporization process:
I₂(s) → I₂(g) ΔH = 60.2kJ/mol
I₂(g) → I₂(l) ΔH = -45.5kJ/mol
I₂(s) → I₂(l) ΔH = 60.2kJ/mol - 45.5kJ/mol
ΔH = 14,7kJ/mol