Answer:
The correct answer is 5021.25 kJ/mol octane
Explanation:
The heat absorbed by the calorimeter is given by:
heat absorbed = Ccal x ΔT
Given:
Ccal = 6.18 kJ/ºC (heat capacity of calorimeter)
ΔT= Final temperature - initial temperature = 41.5ºC-22.0ºC = 19.5ºC
We first calculate the heat absorbed:
heat absorbed = 6.18 kJ/ºC x 19.5ºC = 120.51 kJ
The change in internal energy (ΔE) is equal to the heat absorbed by the calorimeter. In order to determine ΔE in kJ/mol we have to divide the heat into the number of moles of octane (C₈H₁₈) burned in the calorimeter.
Molecular weight (C₈H₁₈) = (12 g/mol x 8) + (1 g/mol x 18) = 114 g/mol
Moles of C₈H₁₈= mass/molecular weight= (2.75 g)/(114 g/mol)= 0.024 moles
Finally, we calculate ΔE:
ΔE = heat absorbed/moles of octane = (120.51 kJ)/(0.024 mol octane) = 5021.25 kJ/mol octane
HELPSS!
Isopropyl alcohol has a density of 0.785g/ml at 25°C. How much is contained in a 150ml sample of this alcohol?
Answer:
The amount of isopropyl alcohol contained in 150 ml of the solution is 117.15 grams
Explanation:
The density of a substance is the mass per unit volume, therefore, we have;
The density of the isopropyl alcohol = 0.785 g/ml at 25°C
The density = mass/volume
Mass = Density × Volume
The mass of the 150 ml of isopropyl alcohol is therefore;
Mass = 0.785 g/ml × 150 ml = 117.15 g
The amount in grams contained in 150 ml of sample = 117.15 g.
Describe the crystallization process as applied in salt preparation
Explanation:
The principle used in the preparation of these salts is to dissolve
the cystine in an alcoholic alkali solution to which just sufficient
water to effect solution has been added, and, after filtering from
excess cystine, to precipitate the salt by addition of a suitable
indifferent solvent. While various solvents, such as acetone,
ether, or large amounts of alcohol caused precipitations, these were
either oily or amorphous. Only acetonitrile was found to possess
the power of initiating regular crystallization in the salt solutions.
While the solutions of the different salts require different amounts
of the solvent for complete precipitation, a partial substitution of
absolute ether for acetonitrile was found expedient in the case
of the most soluble of the salts, the K salt.
Answer:
It is simply a process of forming crystal.
Explanation: When salt is heated and dissolve in the liquid mainly water then its called saturated solution. When we further add salt and increase heat in order to dissolve it then it forcibly dissolve in liquid it's called supersaturated solution. After we slowly cool down the temperature then the salt we have put in supersaturated solution arises in the form of crystal. Hence its called crystalization.
An isotope of lead can be represented by the following symbol ²⁰⁷ 82 PB. From this symbol, it can be deduced that one atom of the isotope has: A) 82 neutrons B) 82 protons C) 125 protons D) 207 protons
Answer:
B) 82 protons
Explanation:
The number of protons for an element never change. 82 Is the atomic number for Pb which is how many protons it has. An isotope means it has more neutrons.
------------neutral particles in an atom
Answer:
neutrons :
Explanation:
Protons are positively charged, while electrons are negatively charged. Neutrons are electrically neutral, as the name suggests. The electric charge, noted Q , is a physical quantity.
For reaction: 2 C + O2 --> 2 CO2 If 5.50 g C was reacted with enough O2, what would be the volume (in liter) of the CO2 generated at STP? (0 C and 1 atm)
Answer:
10.2 L of CO₂
Explanation:
Our reaction is:
2C + O₂ → 2CO₂
We convert the mass of C, to moles:
5.50 g / 12g/mol = 0.458 moles
Ratio is 2:2, so if 2 moles of C can produce 2 moles of CO₂ then 0.458 moles of C would produce 0.458 moles of gas.
By the Ideal Gases Law, we know that 1 mol of gas is contained in 22.4L, so:
0.458 mol . 22.4L / 1mol = 10.2 L
If 50.0cm3of a saturated solution of KNO3at 40oC contained 5.05g of the salt. What is the solubility of the salt at 40oC? [KNO3=101].
Answer:
The solubility of KNO₃ at 40° C is 1 mol/dm³
Explanation:
The solubility of a substance is the number of moles of that substance (solute) contained in a unit volume of solvent at that particular temperature.
Now, Solubility = n/V where n = number of moles of KNO₃ and V = volume of saturated solution = 50.0 cm³ = 0.05 dm³
n = m/M where m = mass of KNO₃ = 5.05 g and M = molar mass of KNO₃ = 101 g/mol
n = 5.05 g/101 g/mol = 0.05 mol
Solubility = n/V
= 0.05 mol/0.05 dm³
= 1 mol/dm³
So, the solubility of KNO₃ at 40° C is 1 mol/dm³
distinguish between deliquescence and efflorescence.
Explanation:
Deliquescent substances are solids that absorb moisture from the atmosphere until they dissolve in the absorbed water and form solutions. Efflorescent: Efflorescent substances are solids that can undergo spontaneous loss of water from hydrated salts.
What is the solute in the mixture of muddy water
Answer:
A solute is a solid which dissolves in a solvent. Muddy water contains water and soil, soil does not dissolve in water
what does a metreologist study
Answer:
A meteorologist studies meteorology which is the study of the atmosphere in order to predict/forecast the weather.
Explanation:
I hope this helps.
Answer:
they study the atmosphere and atmospheric events of our weather
Explanation:
Which of the following would NOT be a conversion factor for mole to mole calculations for the following reaction: 2Al + 3Cl2 --> 2AlCl3
A: 3 mol Cl2 3 mol Al
B: 2 mol Al 3 mol Cl2
C: 2 mol AlCl3 2 mol Al
D: 3 mole Cl2 2 mol AlCl3
Answer: A. 3 mol [tex]Cl_2[/tex] 3 mol Al:
Explanation:
Te given balanced chemical equation is :
[tex]2Al+3Cl_2\rightarrow 2AlCl_3[/tex]
According to the stochiometry :
A: 3 mol [tex]Cl_2[/tex] 3 mol Al:
3 moles of chlorine reacts with 2 moles of aluminium
B. 2 mol [tex]Al[/tex] 3 mol [tex]Cl_2[/tex]:
2 moles of aluminium reacts with 3 moles of chlorine
C. 2 mol [tex]AlCl_3[/tex] 2 mol Al
2 mol of aluminium produces 2 mol of [tex]AlCl_3[/tex]
D. 3 mol [tex]Cl_2[/tex] 2 mol [tex]AlCl_3[/tex]
3 moles of chlorine produces with 2 moles of [tex]AlCl_3[/tex]
Thus the conversion factor not used for mole to mole calculations is 3 mol [tex]Cl_2[/tex] 3 mol Al:
Give one reason why water gas and producer gas are prepared together in the same furnace. Pls ansa its urgent
Answer:
because water gas has high heat content more than producer gas
Explanation:
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The reaction below was carried out in an acidic solution. Upper I minus, plus upper I upper O minus subscript 3 right arrow upper I subscript 2. Which statement is true about this equation?
Answer:
It has been balanced by using the half-reaction method.
Explanation:
I- and IO3- gives I2
We divide the reaction into two half-reactions
(2 I- >> I2 + 2e-) x5 ( oxidation : I goes from -1 to 0 )
2 IO3- + 12H+ + 10e- >> I2 + 6H2O ( reduction : I goes from +5 to 0 )
10 I- >> 5I2 + 10e-
2IO3- + 12H+ + 10e- >> I2 + 6H2O
-----------------------------------------------------
10 I- + 2IO3- + 12H+ >> 6I2 + 6H2O
To get the smallest numbers we divide by 2 :
5 I- + IO3- + 6H+ >> 3I2 + 3H2O
It has been balanced by using the half-reaction method. Hence, option B is correct.
What is a redox reaction?A chemical reaction that takes place between an oxidizing substance and a reducing substance.
We divide the reaction into two half-reactions
[tex](2 I^-[/tex] → [tex]I_2 + 2e^-)[/tex] x 5 ( oxidation : I goes from -1 to 0 )
[tex]2 IO^{3-} + 12H^+ + 10e^-[/tex] → [tex]I_2 + 6H_2O[/tex] ( reduction : I goes from +5 to 0 )
[tex]10 I^-[/tex] →[tex]5I_2 + 10e^-[/tex]
[tex]2IO^{3-} + 12H^+ + 10e^-[/tex] → [tex]I_2 + 6H_2O[/tex]
[tex]10 I^- + 2IO^{3-} + 12H^{+}[/tex]→ [tex]6I_2 + 6H_2O[/tex]
To get the smallest numbers we divide by 2 :
[tex]5 I^- + IO^{3-} + 6H^+[/tex] → [tex]3I_2 + 3H_2O[/tex]
Hence, option B is correct.
Learn more about the redox reaction here:
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A container initially holds 5.67 x 10^-2 mol of propane and has a volume of V1. The volume of the container was increased by adding an additional 2.95 x 10^-2 mol if propane to the container, so that the container has a final volume of 1.93 L. If the temperature and pressure are constant, what was the initial volume of the container?
Answer:
Initial volume of the container (V1) = 1.27 L (Approx)
Explanation:
Given:
Number of mol (n1) = 5.67 x 10⁻²
Number of mol (n2) = (5.67 +2.95) x 10⁻² = 8.62 x 10⁻²
New volume (V2) = 1.93 L
Find:
Initial volume of the container (V1)
Computation:
Using Avogadro's law
V1 / n1 = V2 / n2
V1 / 5.67 x 10⁻² = 1.93 / 8.62 x 10⁻²
V1 = 10.9431 / 8.62
Initial volume of the container (V1) = 1.2695
Initial volume of the container (V1) = 1.27 L (Approx)
Answer: 1.27 L
Explanation:
First, calculate the final number of moles of propane (n2) in the container.
n2 = n1 + nadded = 5.67 × 10^−2 mol + 2.95 × 10^−2 mol = 8.62 × 10^−2 mol
Rearrange Avogadro's law to solve for V1.
V1 = V2 × n1 / n2
Substitute the known values of n1, n2, and V2,
V1 = 1.93 L × 5.67 × 10^−2 mol / 8.62 × 10^−2 mol = 1.27 L
How many moles of ZnCl2 will be produced from 61.0 g of Zn, assuming HCl is excess?
Answer: 0.938 moles of [tex]ZnCl_2[/tex] will be produced.
Explanation:
To calculate the moles, we use the equation:
[tex]\text{Number of moles}=\frac{\text{Given mass}}{\text {Molar mass}}[/tex]
moles of zinc:
[tex]\text{Number of moles}=\frac{61.0g}{65g/mol}=0.938moles[/tex]
[tex]Zn+2HCl\rightarrow ZnCl_2+H_2[/tex]
As HCl is in excess , zinc is the limiting reagent and it limits the formation of product.
According to stoichiometry :
1 mole of Zn produce = 1 mole of [tex]ZnCl_2[/tex]
Thus moles of Zn produce = [tex]\frac{1}{1}\times 0.938=0.938[/tex] moles of [tex]ZnCl_2[/tex]
Thus 0.938 moles of [tex]ZnCl_2[/tex] will be produced.
how many sigma and pi bonds in propionic bond
What is meant by 1m length
Answer:
The metre is defined as the length of the path travelled by light in a vacuum in 1/299 792 458 of a second.
In an experiment, 125ml of H2 is collected over water at 27C and barometric pressure of 753 torr. the vapor pressure of water at 27C is 26.74 what is the partial pressure of H2?
Answer:
Partial pressure of H₂ = 0.9556 atm
Explanation:
Given:
Barometric pressure = 753 torr
Vapor pressure of water = 26.74 torr
FInd:
Partial pressure of H₂
Computation:
Partial pressure of H₂ = Barometric pressure - Vapor pressure of water
Partial pressure of H₂ = 733 - 26.74
Partial pressure of H₂ = 726.26 torr
1 atm = 760 torr
So,
Partial pressure of H₂ = 726.26/760
Partial pressure of H₂ = 0.9556 atm
How fast do sound waves travel under normal conditions? A. 110 feet each second B. 1100 miles per hour C. 1100 feet each second D. 1100 miles each second
Answer:
110 feet each second......
I think
Answer:
110 hope its right
Explanation:
Magnesium unites completely and vigorously with oxygen to form magnesium oxide, which contains 60% magnesium by weight. If 1.00 gram of magnesium is sealed in a glass tube with 1.00 gram of oxygen, what will be present in the tube after the reaction has taken place
Answer:
After the reaction, there will 0.60 g of magnesium oxide and 0.25 g of oxygen gas present in the tube
Explanation:
Equation of the reaction between magnesium and oxygen is given as follows:
2Mg(s) + O₂(g) ---> 2MgO(s)
From the equation of reaction, 2 moles of magnesium reacts with i mole of oxygen gas to produce 1 mole of magnesium oxide
molar mass of magnesium is 24.0 g; molar mass of oxygen gas = 32.0 g; molar mass of magnesium oxide = 40.0 g
Therefore 24 g of magnesium reacts with 32 g of oxygen gas
I.00 g of magnesium will react with (24.0 / 32.0) * 1.00 g of oxygen = 0.75 g of oxygen gas.
Therefore, magnesium is the limiting reagent. Once it is used up, the reaction will stop and the excess oxygen will be left in the tube together with the product, magnesium oxide.
mass of excess oxygen = 1.00 - 0.75 = 0.25 g
mass of magnesium oxide formed = (24.0 / 40.0 g) * 1 = 0.60 g
What is the electron configuration of chlorine (Cl)?
1s22s22p63s23p3
1s22s22p63s23p5
1s22s22p63s24s23p3
1s22s22p63s23p23d3
Answer:
b) 1s22s22p63s23p5
Explanation:
Answer:
b) 1s22s22p63s23p5
Explanation:
edge 2021
Which scenario would result in a decrease in population size, or a negative population growth? Use this formula: population growth = (birth rate + immigration) – (death rate + emigration) 0 individuals emigrate, 14 individuals die, 14 individuals are born, 14 individuals immigrate 40 individuals emigrate, 0 individuals die, 10 individuals are born, 28 individuals immigrate 12 individuals emigrate, 5 individuals die, 17 individuals are born, 0 individuals immigrate 19 individuals emigrate, 4 individuals die, 25 individuals are born, 0 individuals immigrate
Answer:
B) 40 individuals emigrate, 0 individuals die, 10 individuals are born, 28 individuals immigrate
Explanation:
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Answer:
0.333333 cal/g-°C
Explanation:
Energy = mass x specific heat capacity x temperature change.
(E = mcΔT)
Energy = 100.0 cal
specific heat capacity c= unknown
mass m = 4.0 g
temperature change ΔT = 100 - 25 =75°
100 = 4c(75)
c = 0.333333 cal/g-°C
What would be the charge on an ion whose neutral atom has an electron configuration of 2.8.7?
O A. +7
OBO
C. +1
Answer:
–1
Explanation:
The electronic configuration of the neutral atom is given below:
2 8 7
From the electronic configuration of the neutral atom, we can see that the atom has 7 electrons in it's outermost shell. This implies that the element needs 1 more electron to complete it's octet configuration.
Therefore the charge on the ion of the element will be –1 indicating that the atom has received 1 electron to complete it's octet configuration.
The temperature of a sample of liquid water changes from 50°C to 30°C. Which statement best explains the change
that must happen at the molecular level?
ОООО
The molecules move more quickly and their average kinetic energy increases.
The molecules move more slowly and their average kinetic energy decreases.
The molecules move more quickly and their average kinetic energy decreases.
The molecules move more slowly and their average kinetic energy increases.
Answer:
The molecules move more slowly and their average kinetic energy decreases
Explanation:
The increased temperature meant that the atoms in liquid had a greater average energy of motion so as the temperature decreases the reaction would be inverse.
The branch of science which deals with the chemicals bond is called chemistry.
The correct option is B.
The energy which is produced by the motion of the particles is called kinetic energy. Temperature increases the motion of the particles. So, the kinetic energy increases when the temperature rises.
According to the question, the temperature of the water decreases therefore the kinetic energy decreases.
Hence, the correct option is B that is the molecules move more slowly and their average kinetic energy decreases.
For more information, refer to the link:-
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When Niels Bohr refined the model of an atom,what new idea did he include?
Answer:
Niels Bohr, refined the model of an atom by proposing a quantized shell structure atomic model in order to describe how the electrons are able to maintain stable orbits around the nucleus
Based on the predictions of classical mechanics the electron motion of the Rutherford model was unstable as the electrons where expected to have lost some energy during motion and thus having to come rest in the nucleus
According to the modification by Neils Bohr in 1913, electrons move in shells or orbits of fixed energy and emission of electromagnetic radiation takes place only when electrons changes the orbit in which they move
Explanation:
An antacid tablet has a pH of about 9.5 which
means it is considered to be in the _____
range.
Acidic or basic
Answer:
Basic
Explanation:
The pH scale is a scale that tells us about the concentration of hydrogen ions in a solution.
Acids have many hydrogen ions. Acids have a pH of less than 7.
Bases have fewer hydrogen ions and more hydroxide ions. Bases have a pH of less than 14.
If the solution has a pH of exactly 7, then it is pure water. Water has the same concentration of hydrogen and hydroxide ions.
The antacid tablet has a pH of roughly 9.5 Since this is less than 14, but not equal to or less than 7, this must be an base. Therefore, it is considered to be in the basic range.
Answer:
9.5 is a base
Explanation:
A ph of less than 7 is an acid
7 is neutral
7 to 14 is a base
9.5 is a base
Which of the following may suggest a catalyst has been used in a reaction, given the energy diagram for the same reaction without a catalyst?
Which of the outer planets is MOST like Earth? How?
Answer:
venus
Explanation:
hope i helped
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-Zylynn
Answer: I would say that Saturn is most like Earth. Not only does it have moons, like Earth, but the atmosphere is also denser like Earth. It also has windstorms, granite they are much more intense than Earth’s, but they do indeed happen. Saturn also has hydrogen gas; this gas is here on Earth supporting life in our ocean. Therefore, there is a chance that the conditions on Saturn could provide the essentials for there to be life.
Q2.
For the reaction given, how many litres of carbon dioxide gas will be formed by the reaction of 400
litres of oxygen with sufficient pentene (CH..)? The reaction takes place at 125°C and 10.5 atm.
2 C5H10(1) + 15 O2(g) →10 CO2(g) + 10 H20 (8)
Answer:
266 liters Carbon iv oxide will be formed
Explanation:
The first thing we need to do here is to calculate the number of moles of oxygen reacted.
This can be calculated using the ideal gas equation;
Mathematically;
PV = nRT
From the question;
P = pressure = 10.5 atm
V = volume = 400 liters
n = number of moles = ?
T = temperature = 125 + 273 = 398K
R = molar gas constant = 0.0821 L•atm•K^-1•mol^-1
Substituting these values, we have ;
n = PV/RT
n = (10.25 * 400)/(398 * 0.0821) = 125 moles
From the question;
15 moles oxygen gave 10 moles CO2
125 moles oxygen will give x moles CO2
x = (125 * 10)/15 = 83 moles
Now, we want to know the volume of CO2, present in 83 moles using the given reaction conditions.
Mathematically;
PV = nRT
V = nRT/P
= (83 * 0.0821 * 398)/10.25 = 265.65 which is approximately 266 Liters
MARKING BRAINLIEST!! - Determine the molar mass [MM] of a gas if 2 L of the gas weights 0.500 g at 298 K and 2.00 atm.
Answer:
3.125g/mol
Explanation:
To find the molar mass of the gas, we need to initially find the number of moles (n) contained in the gas. To find the number of moles, we use the general gas law whose equation is:
PV=nRT
Where; P= Pressure
V= Volume occupied by gas
n= number of moles
R= general gas constant
(0.0821 L atm mol/K)
T= absolute temperature
According to the question; P= 2.0atm, V= 2.0L, n= ?, T= 298K
To find n, we make it the subject of the formula:
n= PV/RT
n= 2.0 × 2.0 / 0.0821 × 298
n= 4/ 24.4658
n= 0.16mol
If number of moles (n) of the gas is 0.16mol and it weighs 0.500g, its molar mass can be found using:
number of moles (n) = mass (g) / molar mass
Making MM subject of the formula;
molar mass = mass / number of moles
MM= 0.500/0.16
MM= 3.125
Hence, the molar mass of the gas is 3.125g/mol.