Answer:
Increasing the temperature of 1 mol of C8H18(l) requires more energy
Explanation:
To answer this question, we need to define molar heat capacity that is the amount of heat required to increase in 1K the temperature of 1 mole of substance.
That means the substance with higher molar heat requires more energy to increase its temperature
Molar heat of octane, C8H18 is 255.68J/Kmol
Molar heat of water is 75.38J/Kmol
That means increasing the temperature of 1 mol of C8H18(l) requires more energy
How many π electrons are there in adenine? State which atoms contribute one electron to the π MOs and which atoms contribute two electrons?
Answer:
12 π electrons.
Explanation:
The structure of adenine can be seen below.
From the diagram, the total number of electrons in adenine is 70 electrons where 20 of them are core electrons.
Also from this same structure, we will notice that we have a total number of 12 π electrons.
i.e.
Each one of these five atoms described takes part in the π electron. These are N-1, N-3, N-7 which comprise of 2σ bonds, and also each of three N contributes one π electron.
Similarly, N-9 and N-10 contain 3σ bonds; Hence, each of them donates two electrons.
Thus;
5C = 5π electrons
3N = 3π electrons
2N = 4π electrons
= 12π electrons
How many Stars are In the Milky way Galaxy
Answer:
100 thousand million stars
Explanation:
Answer:
100 to 400 billion stars
Find the pH of the equivalence point and the volume(ml) of 0.125M HCl needed to reach the point in titrations of: a) 65.5ml of 0.234M NH3.b) 21.8 mL of 1.11 M CH3NH2.
Answer:
a. 122.6 mL / pH = 4.03
b. 193.6 mL / pH = 5.73
Explanation:
In the equivalence point we know: mmoles acid = mmoles base- And the pH in a titration between a weak base and a strong base, is acid, at the equivalence point. For the volume, we can replace the equation with the data given.
a. 0.125M . volume of acid = 65.5 mL . 0.234M
Volume of acid = (65.5 . 0.234) / 0.125 = 122.6 mL
Total volume at the equivalence point = 188.1 mL
b. 0.125M . volume of acid = 21.8 mL . 1.11 M
Volume of acid = (21.8 . 1.11) / 0.125 = 193.6 mL
Let's calculate the pH. In the equilavence point we have a neutralization reaction.
a. NH₃ + HCl → NH₄Cl
All the mmoles of protons (65.5 mL . 0.234M) react to ammonia, to obtain ammonium.
New concentration is: 15.32 mmoles / 188.1 mL = 0.0814 M
This is the [NH₄⁺] to determine the pH in the acid base equilibrium.
NH₄⁺ + H₂O ⇄ NH₃ + H₃O⁺ Ka
Expression for Ka = [NH₃] . [H₃O⁺] / [NH₄⁺]
5.6×10⁻¹⁰ = x² / (15.32 - x)
(We can avoid the quadratic equation 'cause Ka is so small)
√(5.6×10⁻¹⁰ . 15.32) = x → [H₃O⁺] = 9.26×10⁻⁵
pH = - log [H₃O⁺] → 4.03
b. CH₃NH₂ + HCl → CH₃NH₃Cl
All the mmoles of protons (21.8 mL . 1.11M) react to methylamine, to obtain methylammonium.
New concentration is: 24.2 mmoles / 193.6 mL = 0.125 M
This is the [CH₃NH₃⁺] to determine the pH in the acid base equilibrium.
CH₃NH₃⁺ + H₂O ⇄ CH₃NH₂ + H₃O⁺ Ka
Expression for Ka = [CH₃NH₂] . [H₃O⁺] / [CH₃NH₃⁺]
2.7×10⁻¹¹ = x² / (0.125 - x)
(We can avoid the quadratic equation 'cause Ka is so small)
√(2.7×10⁻¹¹ . 0.125) = x → [H₃O⁺] = 1.84×10⁻⁶
pH = - log [H₃O⁺] → 5.73
The pH of the equivalence point of 0.125M HCl with NH₃ is 4.03 and with CH₃NH₂ is 5.73.
What is equivalence point?In the acid - base titration, at the equivalence point equal moles of acid as well as of base are present.
First we calculate the volume of HCl by using the below equation as:
M₁V₁ = M₂V₂, whereM₁ = molarity of NH₃ = 0.234 M
V₁ = volume of NH₃ = 65.5 mL
M₂ = molarity of HCl = 0.125 M
V₂ = volume of HCl = ?
V₂ = (65.5 . 0.234) / 0.125 = 122.6 mL
Total volume at the equivalence point = 188.1 mL
Chemical reacion will be written as:
NH₃ + HCl → NH₄Cl
All moles of protons react with moles of ammonia, so new moles (n) will be calculated as:
n = molarity × volume
n = 65.5 mL × 0.234M = 15.32 moles
Now, concentration in terms of molarity will be 15.32 mmoles / 188.1 mL = 0.0814 M
pH in the acid-base reaction due to [NH₄⁺], as:
NH₄⁺ + H₂O ⇄ NH₃ + H₃O⁺
Value of Ka for this reaction is = 5.6×10⁻¹⁰
According to the ICE table, Ka equation will be written as-
5.6×10⁻¹⁰ = x² / (15.32 - x)
x = [H₃O⁺] = 9.26 × 10⁻⁵
pH = - log [H₃O⁺] = 4.03
Again we calculate the volume of HCl with the CH₃NH₂ as:0.125M . volume of acid = 21.8 mL . 1.11 M
Volume of acid = (21.8 . 1.11) / 0.125 = 193.6 mL
Total volume at the equivalence point = 215.4 mL
Chemical reacion will be written as:
CH₃NH₂ + HCl → CH₃NH₃Cl
All moles of protons react with moles of ammonia, so new moles (n) will be calculated as:
n = 21.8 mL . 1.11M = 24.2 moles
Now, concentration in terms of molarity will be 24.2 moles / 215.4 mL = 0.11M
pH in the acid-base reaction due to [CH₃NH₃⁺], as:
CH₃NH₃⁺ + H₂O ⇄ CH₃NH₂ + H₃O⁺
Value of Ka = 2.7×10⁻¹¹
According to the ICE table, Ka equation will be written as-
2.7×10⁻¹¹ = x² / (0.11 - x)
x = [H₃O⁺] = 5.4×10⁻⁶
pH = - log [H₃O⁺] = 5.73
Hence the value of pH will be 4.03 and 5.73 respectively.
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Use what you’ve learned about Lewis structures and formal charges to predict which of the following sulfur-containing molecule(s) would be least likely to exist.
SO2
H2S2
SCl2
HS
HSOH
Answer:
its DDDDDDDDDDDDDDDDDD
The structure that is least likely to exist is HS.
Sulfur is an element in group 16. Sulfur is a divalent element that has two lone pairs of electrons. This means that sulfur forms compounds in which it is bonded to two atoms or groups.
All the molecules listed can exist because they consists of structures in which sulfur is bonded to two atoms or groups. The only structure that can not exist is HS because it does not satisfy the valency of sulfur.
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Which of the following covalent bonds is the most polar (i.e., highest percent ionic character)?
A) Al I
B) Si I
C) Al Cl
D) Si Cl
E) Si P
Answer:
answer d is correct that works
1. What is the flame color of sodium?
yellow-orange
purple
green
blue-green
Orange is the color of Sodium
Which statement describes how phase changes can be diagrammed as a substance is heated?
The phase is on the y-axis and the temperature is on the x-axis.
The temperature is on the y-axis and the phase is on the x-axis.
The time is on the y-axis and the temperature is on the x-axis.
The temperature is on the y-axis and the time is on the x-axis.
Answer:
The temperature is on the y-axis and the time is on the x-axis.
Explanation:
Which statement describes how phase changes can be diagrammed as a substance is heated? (D is the answer)
The phase is on the y-axis and the temperature is on the x-axis.
The temperature is on the y-axis and the phase is on the x-axis.
The time is on the y-axis and the temperature is on the x-axis.
The temperature is on the y-axis and the time is on the x-axis.
Which statement describes the appearance of a temperature-vs.-time graph? (C is the answer)
A horizontal line shows that the temperature increases at a constant rate over time.
A vertical line shows that the temperature decreases at a constant rate over time.
Horizontal lines where the temperature is constant during phase changes connect upward-sloping lines where the temperature increases.
Horizontal lines where the temperature increases are connected by upward-sloping lines where the temperature is constant for each phase.
A sheet of aluminum measures 55.0 cm by 23.3 cm. If the volume is 2.90 cm^3 what is the thickness of the foil?
Express your answer with the appropriate units.
Answer:
0.0023 cm
Explanation:
The following data were obtained from the question:
Length (L) = 55 cm
Breadth (B) = 23.3 cm
Volume (V) = 2.9 cm³
Thickness (T) =?
Thus, we can obtain the thickness of the aluminum foil as illustrated below:
V = L × B × T
2.9 = 55 × 23.3 × T
2.9 = 1281.5 × T
Divide both side by 1281.5
T = 2.9/1281.5
T = 0.0023 cm
Therefore, the thickness of the aluminum foil is 0.0023 cm
How can energy from the Sun be used to heat water? What
things will affect how well the sunlight heats water?
Answer:
Water is heated as it travels through flat, glazed panels known as solar collectors, which are normally situated on the roof of the building. The heated water is then stored in an insulated storage tank.
what is the mass of 16.6 x 10^23 molecules of barium nitrate
The mass of 16.6 × 10²³ molecules of barium nitrate is 718.7g
The number of moles of a substance can be calculated by dividing the mass by its molar mass. That is;no. of moles = mass(g) ÷ molar mass (g/mol)no. of moles of Ba(NO3)2 = 16.6 × 10²³ ÷ 6.02 × 10²³no. of moles = 2.75 × 10⁰no. of moles = 2.75moles. Molar mass of Ba(NO3)2 = 261.34g/molmass of Ba(NO3)2 = 261.34 × 2.75Mass of Ba(NO3)2 = 718.7gTherefore, the mass of 16.6 × 10²³ molecules of barium nitrate is 718.7g.Learn more at: https://brainly.com/question/15743584?referrer=searchResults
Describe the potential energy of a chemical reaction and how the energy is accessed?
Explanation:
The energy released due to breakage of bond or we can say that protons and electrons go from a structure of higher potential energy to lower potential energy. During this change, potential energy is converted to kinetic energy in form of heat.
Generally chemical potential energy is accessed in form heat, which the difference between the potential energies of reactant and product.
Given the following balanced equation, determine the rate of reaction with respect to [Cl2]. If the rate of Cl2 loss is 4.64 × 10-2 M/s, what is the rate of formation of NOCl? 2 NO(g) + Cl2(g) → 2 NOCl(g)
Answer:
[tex]r_{NOCl}=9.28x10^{-2}M[/tex]
Explanation:
Hello!
In this case, given the balanced chemical reaction:
[tex]2 NO(g) + Cl_2(g) \rightarrow 2 NOCl(g)[/tex]
Since there is 1:2 mole ratio between chlorine and NOCl, based on the rate proportions, we can write:
[tex]\frac{1}{-1}r_{Cl_2} =\frac{1}{2}r_{NOCl}[/tex]
It means that for the formation of NOCl, we obtain:
[tex]r_{NOCl}=\frac{2}{-1}r_{Cl_2} \\\\r_{NOCl}=\frac{2}{-1}(-4.64x10^{-2}M)\\\\r_{NOCl}=9.28x10^{-2}M[/tex]
Notice that chlorine is disappearing, which means its rate is negate.
Best regards!
A) A solution of c6h2o4 in c2h5oh has a boiling point of 80.38 Celsius. what is the molality of the solution ?
B) what is the approximation of concentration of dissolved solution in blood, if the osmotic pressure is 7.65 atm at 37Celsius.
a. molality-m=1.623
b. molarity-M=0.3
Further explanationa. Boiling point
[tex]\tt \Delta Tb=Kb\times m[/tex]
Kb for ethanol=1.22 °C/m
Boiling point for ethanol = 78.4 °C
ΔTb=80.38-78.4=1.98
[tex]\tt 1.98=1.22\times m\\\\m=\dfrac{1.98}{1.22}=1.623[/tex]
b. osmotic pressure
[tex]\tt \pi =MRT[/tex]
π = 7.65 atm
R = 0.08205 L/atm K
T = 37 + 273 = 310 K
[tex]\tt M=\dfrac{\pi}{RT}=\dfrac{7.65}{0.08205\times 310}=0.3~M[/tex]
12. When the frequency of a wave increases, what happens to the wavelength?
A. The wavelength is not directly affected by the frequency of a wave
B. The wavelength increases
C. The wavelength decreases
D. More specific information is needed to form a conclusion
Answer:
C. The wavelength decreases
Explanation:
This is because frequency is how often the wave hits the top (peak) and the bottom (through). The more it hits the less wavelength it will have because it is moving faster and has more energy.
of the element listed wich
has the largest atomic rodius?
Calcium Cas Copper (ca)
Chromium (Cr)
Cobalt (co)
The atomic radius trend on the Periodic Table is as follows:
- Atomic radius increases down a column (or group)
- Atomic radius decreases across rows (or periods) from left to right
Looking at my Periodic Table, calcium, chromium, cobalt and copper are in that order from left to right in the same period, which simplifies things significantly.
Since these elements are in the same period, and given that we know atomic radius decreases across periods from left to right, we can see that calcium has the largest atomic radius.
Which of these mixtures would NOT be separated by using simple distillation?
Ink and water
Salt and water
Sand and water
There is a golden role of solubility, polar solute dissolve in polar solvent and non polar solute dissolve in non polar solvent. Therefore, the correct option is option B that is Salt and water.
What is solution?Solutions are a homogeneous mixture of two or more substances. A solution is a homogeneous mixture of solvent and solute molecules. Solvent is a substance that is in large amount in solution. solute is the substance which is in small amount in a solution. There are two types of mixture that is homogeneous and heterogeneous. Solution is a homogeneous solution.
Salt and water because salt is transparent and will dissolve into the water among given solute, salt NaCl is a polar solute which will dissolve in polar solvent that is water.
Therefore, the correct option is option B that is Salt and water.
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Robert was changing the oil in his truck. He dumped the used oil on the ground in his yard. He didn't know it, but Robert was hurting the environment because the oil-
HELP FAST
Answer:
goes deep into the ground and pollutes the groundwater.
plz help me... my ppr is gonig on......
In first line of Lyman Series, wave number is
1 point
82.26 x 10^5
97.49 x 10^5
109.678 x 10^5
none
Answer:
geruow0irghvn3p0unhie0ghik
Explanation:
1. A baseball pitcher won 75% of the games he pitched. If he pitched 43 ballgames, how many games
did he win?
Answer:
He won 32 games.
Explanation:
Another way of expressing 75% is 75/100.
To calculate how many games the baseball pitcher won, we multiply the total of games played (43, in this case) by the percent won:
43 * 75/100 = 32.25 ≅ 32
So the baseball pitcher won 32 games.
Identify the place which has the highest boiling point of water. Identify the place which has the highest boiling point of water. Denver, Colorado, 5280 feet Death Valley, 282 feet below sea level New Orleans, sea level Mt. Everest, 29035 feet A pressurized passenger jet, 35,000 feet
Answer:
B. because if it was to change so would the amount of wieght that gravity puts on us.
Explanation:
A. might seem right but it's not 35,000 under seal level is the OPPOSITE of 35,000 above sea level.
C. water pressure can change where you are at because of the speed or the type of body of water.
D. it does not make any sense.
hope this helps!!!
what is the number of each element and the total number of atoms for vinegar?
how fast is a formula 1 car? (For my chemistry project)
Answer:
it's 200 mph fast........
If 75J of heat are applied to 8.4 L of a gas at 732 mmHg and 298K, what is the final temperature, in K, of the gas? Cp for an ideal gas is 20.79 J/mol*K.
Answer:
309 K
Explanation:
Step 1: Convert the pressure to atm
We will use the conversion factor 1 atm = 760 mmHg.
732 mmHg × 1 atm/760 mmHg = 0.963 atm
Step 2: Calculate the moles (n) of the ideal gas
We will use the ideal gas equation.
P × V = n × R × T
n = P × V/R × T
n = 0.963 atm × 8.4 L/0.0821 atm.L/mol.K × 298 K
n = 0.33 mol
Step 3: Calculate the temperature change
We will use the following expression.
Q = n × Cp × ΔT
ΔT = Q/n × Cp
ΔT = 75 J/0.33 mol × 20.79 J/mol.K
ΔT = 11 K
Step 4: Calculate the final temperature
T = 298 K + 11 K = 309 K
how many atoms does sodium hypochlorite have?
Answer:
NaClO; the contained elements ae Na, Cl, O.
Which of these lead (II) salts will dissolve to the greatest extent in water?
a. PbSO4, Ksp = 1.7x10^-8
b. PbI2, Ksp = 6.5x10^-9
c. PbCrO4, Ksp = 1.8x10^-14
d. PbS, Ksp = 2.5x10^-27
e. Pb3(AsO4)2, Ksp = 4.0x10^-36
Answer:
a. PbSO4, Ksp = 1.7x10^-8.
Explanation:
Hello!
In this case, since the solubility product indicates how likely a solid is able to ionize and consequently dissolve in water, we can infer that the larger the solubility product Ksp, the more ions are able dissolve in water; therefore the proper answer goes with the largest Ksp, which is a. PbSO4, Ksp = 1.7x10^-8 since the power goes closer to 1 than the other options.
Best regards!
The chemical reaction between iron (Fe) and oxygen (O) results in the loss of electrons from iron. This reaction is an example of _____.
A) respiration
B) sublimation
C) oxidation
D) combustion
Answer:
d combustion because iron and oxegen need eachother
Answer:
The Correct answer would be Oxidation.
Explanation:
How do you know your cell's are working
If the net force acting on an object is 0 N, the forces are
Since the forces equal to 0, it's balanced because the object isn't moving.
The closer to 7 a substance measures on the pH scale, the ______ the compound fill in the blank
Explanation:
If the PH is greater than 7 then the solution is basicIf the PH is less than 7 then the solution is acidicIf the PH is equal to 7 then the solution is neutral1. 2Al(s) + 3H2SO4(aq) → Al2(SO4)3(aq) + 3H2(g) a. Determine the volume (mL) of 15.0 M sulfuric acid needed to react with 45.0 g of aluminum to produce aluminum sulfate. b. Determine the % yield if 112 g of aluminum sulfate is produced under the above conditions.
Answer:
a. 167 mL b. 39.27 %
Explanation:
a. From the chemical equation. 2 mole of Al reacts with 3 mole H₂SO₄ to produce 1 mol Al₂(SO₄)₃.
Now, we calculate the number of moles of Al in 45.0 g Al.
We know number of moles, n = m/M where m = mass of Al = 45.0 g and M = molar mass of Al = 26.98 g/mol.
So n = 45.0 g/26.98 g/mol = 1.668 mol
Since 2 mole of Al reacts with 3 mole H₂SO₄, then 1.668 mole of Al reacts with x mole H₂SO₄. So, x = 3 × 1.668/2 mol = 2.5 mol
So, we have 2.5 mol H₂SO₄.
Now number of moles of H₂SO₄, n = CV where C = concentration of H₂SO₄ = 15.0 M = 15.0 mol/L and V = volume of H₂SO₄.
V = n/C
= 2.5 mol/15.0 mol/L
= 0.167 L
= 167 mL of 15.0 M H₂SO₄ reacts with 45.0 g Al to produce aluminum sulfate.
b. From the chemical reaction, 2 mol Al produces 1 mol Al₂(SO₄)₃
Therefore 1.668 mol Al will produce x mol Al₂(SO₄)₃. So, x = 1 mol × 1.668 mol/2 mol = 0.834 mol
So, we need to find the mass of 0.834 mol Al₂(SO₄)₃. Now molar mass Al₂(SO₄)₃ = 2 × 26.98 g/mol + 3 × 32 g/mol + 4 × 3 × 16 g/mol = 53.96 g/mol + 96 g/mol + 192 g/mol = 341.96 g/mol.
Also number of moles of Al₂(SO₄)₃, n = mass of Al₂(SO₄)₃,m/molar mass Al₂(SO₄)₃, M
n =m/M
So, m = nM = 0.834 mol × 341.96 g/mol = 285.2 g
% yield = Actual yield/theoretical yield × 100 %
Actual yield = 112 g, /theoretical yield = 285.2 g
So, % yield = 112 g/285.2 g × 100 %
= 0.3927 × 100 %
= 39.27 %
The volume (mL) of 15.0 M sulfuric acid needed to react with 45.0 g of aluminum is 166mL and % yield of the reaction is 39.46%.
How do we calculate moles?Moles of any substance will be calculated by using the below formula as:
n = W/M, where
W = given mass
M = molar mass
Given chemical reaction is :
2Al(s) + 3H₂SO₄(aq) → Al₂(SO₄)₃(aq) + 3H₂(g)
Moles of 45g of Al will be calculated as:
n = 45g / 27g/mol = 1.66 mole
From the stoichiometry of the reaction, it is clear that:
1.66 moles of Al = react with 3/2×1.66=2.49 moles of H₂SO₄
By using the formula of molarity we can calculate the volume of H₂SO₄ as:
M = n/V
V = (2.49) / (15) = 0.166L = 166mL
Again from the stoichiometry it is clear that:
1.66 moles of Al = produces 1/2×1.66= 0.83 moles of Al₂(SO₄)₃
Mass of 0.83 moles of Al₂(SO₄)₃ = (0.83mol)(341.96g/mol) = 283.82 g
Given actual yield of Al₂(SO₄)₃ = 112g
% yield will be calculated as:
Percent yield = (Actual yield/Theoretical yield) × 100
% yield = (112/283.82) × 100 = 39.46%
Hence required values are discussed above.
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