Answer:
90.2%
Explanation:
% yield = actual yield/ theoretical yield * 100%
% yield = (312/346)*100% = 90.2%
A 10.0 g sample of an unknown liquid is vaporized at 120.0°C and 5.0 atm. The volume of the vapour is found to be 568.0 mL. The liquid is determined to be made up of 84.2% carbon and 15.8% hydrogen. What is the molecular formula for the liquid?
Answer:
molecular formula of liquid = C₈H₁₈
Explanation:
First we determine the empirical formula of the liquid:
Number of moles of each element present in the liquid = % mass / molar mass
For Carbon, (molar mass = 12.01 g/mol) : 84.2/12.01 =7.011 moles
For Hydrogen (molar mass = 1.01 g/mol) : 15.8/1.01 = 15.643
Simplest mole ratio of the elements, C : H is given by:
C = 7.011/7.011 = 1.0
H = 15.643/7.011 = 2.23
Multiplying through with 5, C:H = 5:11
Therefore, empirical formula is C₅H₁₁
The molecular mass of the liquid is next determined:
Using PV = nRT to find the number of moles of the liquid present
P = 5.0 atm; V = 568.0 mL = 0.568 L; R = 0.082 L*atmmol⁻¹ K⁻¹; T = 273 + 120 = 393 K
n = PV/RT = (5*0.568)/0.082*393
n = 0.088 moles
Molar mass of liquid = mass/no of moles = 10.0 g/ 0.088 moles = 113.63 gmol⁻¹
Molecular formula = n(empirical formula)
Molar mass of empirical formula, C₅H₁₁ = 71 gmol⁻¹
n = molecular mass/empirical mass = 113.63/71 = 1.6
Therefore, molecular formula = 1.6*(C₅H₁₁) = C₈H₁₈
The molecular formula for pentyne is
a.c6h6
b.c5h8
c.c5h12
d.c6h14
Answer:
B
Explanation:
The molecular formula for pentyne is C5H8
This formula equation is unbalanced. Pb(NO3)2(aq) + Li2SO4(aq) Right arrow. PbSO4(s) + LiNO3(aq) Which coefficient should appear in front of LiNO3 in the balanced equation? 1 2 3 4
Answer:2
Explanation:
Answer:
2
Explanation:
1) How much energy would be required to melt 15.0 g of ice at 0°C?
= 334 J/g)
(AH fusion
Answer:
5010J
Explanation:
The following data were obtained from the question:
Mass (m) = 15g
Heat of fusion (ΔHf) = 334J/g
Heat required (Q) =..?
The heat energy required to melt the ice can be obtained as follow:
Q = m·ΔHf
Q = 15 x 334
Q = 5010J
Therefore, the heat energy required to melt the ice is 5010J.
How many significant figures does 5.750 have?
Answer:
4
Explanation:
65g of nitric acid are produced in a reaction. 2.5g of platinum are added to the reaction vessel at the start of the reaction to act as a catalyst. How much platinum will there be left in the vessel at the end of the reaction?
Answer:
2.5 g of platinum
Explanation:
Recall that a catalyst is a specie added to a reaction system to increase the rate of reaction. A catalyst does not participate in the chemical reaction hence it remains unchanged at the end of the chemical reaction. A catalyst merely provides an alternative reaction pathway by lowering the activation energy of the reaction system. Hence a catalysed reaction usually proceeds faster with less energy requirement than the uncatalysed reaction.
Since the catalyst does not participate in the reactions and remains unchanged at the end of the reaction, the mass of platinum will remain the same (2.5g). The mass can only change if a specie participates in the chemical reaction. Hence the answer.
2.5 g of platinum will there be left in the vessel at the end of the reaction
The following information should be considered:
Since the catalyst does not participate in the reactions and remains the same at the end of the reaction, the mass of platinum will remain the same (2.5g). The mass can only change in the case when a specie participates in the chemical reaction.learn more: https://brainly.com/question/2514933?referrer=searchResults
___and ___exert pressure on the walls of the vessel in which they are carried out
A) Solid, liquid and Gases
B) Gases and solids
C) Liquids and gases
D) Solid and gases
Answer:
C) Liquids and gases
Explanation:
The correct answer would be liquids and gases.
The molecules of liquids and gases move randomly when held in a container. The random movement causes a collision between the molecules of the liquids/gases and between the walls of the container, creating pressure in the process. This is unlike the molecules of solids that vibrate about fixed positions.
Hence, the correct option is C.
please answer in details. what class of carbon is coal
PLEASE HELP CHEM BABES I HAVE BEEN CRYING FOR A WHILE NOW
1. Calculate the mass of nitrogen dioxide (NO2) present in a 0.831 L container if the pressure is 100 kPa at a temperature of 27 oC. R = 8.31 kPa x L / mol x K. (K = oC + 273).
2. A 33.2 L tank contains 280 g of compressed helium. If the pressure inside the tank is 700.0 kPa, what is the temperature of the compressed gas? You must convert the mass of helium into moles using the molar mass of He. The conversion factor will be 1 mol / molar mass of helium. R = 8.31 kPa x L / mol x K
Answer: See below
Explanation:
1. To calculate the mass, you know you can convert by using molar mass. Since mass is in grams, we can use molar mass to convert moles to grams. This calls for the Ideal Gas Law.
Ideal Gas Law: PV=nRT
We manipulate the equation so that we are solving for moles, then convert moles to grams.
n=PV/RT
P= 100 kPa
V= 0.831 L
R= 8.31 kPa*L/mol*K
T= 27°C+273= 300 K
Now that we have our values listed, we can plug in to find moles.
[tex]n=\frac{(100kPa)(0.831L)}{(8.31kPa*l/molK)(300K)}[/tex]
[tex]n=0.033mol[/tex]
We use the molar mass of NO₂ to find grams.
[tex]0.033mol*\frac{46.005g}{1mol }=1.52 g[/tex]
The mass is 1.52 g.
2. To calculate the temperature, we need to use the Ideal Gas Law.
Ideal Gas Law: PV=nRT
We can manipulate the equation so that we are solving for temperature.
T=PV/nR
P= 700.0 kPa
V= 33.2 L
R= 8.31 kPa*L/mol*K
n= 70 mol
Now that we have our values, we can plug in and solve for temperature.
[tex]T=\frac{(700kPa)(33.2L)}{(70mol)(8.31 kPa*L/molK)}[/tex]
[tex]T=40K[/tex]
The temperature is 40 K.
Which of the following reactions shows that the formation of CO2 releases
393.5 kJ/mol?
A. C(s) + O2(g) → CO2(g) + 393.5 kJ
O B. C(s) + 20(g) + 393.5 kJ → CO2(9)
O C. C(s) + O(g) + CO2(g) + 393.5 kJ
D. C(s) + O2(g) + 393.5 kJ → CO2(g)
Answer:
A. C(s) + O2(g) → CO2(g) + 393.5 kJ
Explanation:
The formation of carbon IV oxide (CO2) is an exothermic process. n exothermic process is a chemical process in which heat is evolved. Speaking in lay man's terminology, heat is one of the 'products' of the reaction. This implies that heat is evolved by the process.
The formation of CO2 is always a combustion reaction where heat is evolved or released by the reaction system. Hence the reaction could be shown as;
C(s) + O2(g) → CO2(g) + 393.5 kJ
This implies that 393.5 kJ of energy is released in the reaction in the form of heat. Hence the answer given in the answer box.
Answer: C(s) + O2(g) → CO2(g) + 393.5 kJ
Why does an ultraviolet light cause paint to fade
Answer:
There are light absorbing color bodies called chromophores that are present in dyes. Ultraviolet rays are one of the causes of fading because they can break down chemical bonds and fade the color in objects.
the list which contains only metals is
Answer:
Hydrogen in its metallic state (usually considered a nonmetal)
Lithium.
Sodium.
Potassium.
Rubidium.
Cesium.
Francium.
Explanation:
Answer:
The list of elements that contains only metals is tin, copper and cesium.
Carbon and iodine aren't metals.
Helium isn't metal.
Neither iodine, carbon, nor argon are metals.
(Hope this helps) Sky
I need this fast plz, 50 points
By doing which action will you decrease the number of collisions and energy of reactant molecules?
A.) decreasing the temperature of the reactant mixture
B.) increasing the pressure of the reactant mixture
C.) decreasing the concentration of reactants
D.) adding a catalyst
Answer:
It is decreasing the temperature of the reactant mixture.
Explanation:
Just took the test
In order to decrease the number of collisions and energy of reactant molecules, the temperature of the reactant mixture would need to be decreased as well.
Temperature of reactantsThe temperature of reactants is proportional to the average kinetic energy of the molecules of the reactants.
Also, the higher the average kinetic energy of the reactant molecules, the higher their chances of colliding and reacting to form products.
Thus, in order to decrease their energy and collision frequency, the temperature of the reactant mixture needs to be decreased.
More on temperature and kinetic energy can be found here: https://brainly.com/question/2731193
Please look at the photo and identify what’s in it!
Answer:
Explanation:
A battery
Answer:
Ac motor is in this images
A 10.0 g sample of an unknown liquid is vaporized at 120.0°C and 5.0 atm. The volume of the vapour is found to be 568.0 mL. The liquid is determined to be made up of 84.2% carbon and 15.8% hydrogen. What is the molecular formula for the liquid?
Answer:
C8H16
Explanation:
First thing to do here is to calculate the molar mass of the compound
Mathematically;
molar mass = mass/number of moles
we can calculate the number of moles using the ideal gas equation
Mathematically;
PV = nRT
n = PV/RT
where p is the pressure at 5 atm
V is the volume at 568 ml = 568/1000 = 0.568 L
R is the molar gas constant which is 0.0821
T is the temperature which is 120+ 273 = 393k
Inserting these values into the equation, we have
n = (5 * 0.568)/(0.0821 * 393)
n = 0.088 moles
So the molar mass = 10/0.088
= 114 g/mol
Now let’s go to the percentages
C = 84.2/12 = 7.016666666666667
H = 15.8/1 = 15.8
divide by the smallest
C = 7.016666666666667/7.016666666666667 = 1
H = 15.8/7.016666666666667 = 2 approximately
The empirical formula is CH2
So for the molecular formula, we have;
(12 + 2)n = 114
14n = 114
n = 114/14 = approximately 8
So the molecular formula of the liquid will be (CH2)n = C8H16
In the lab, a student adds 4.5 g of sodium chloride (NaCl) to 100.0 g of water. Calculate the molality of the solution.
Answer:
0.77mol/Kg.
Explanation:
The following data were obtained from the question:
Mass of NaCl = 4.5g
Mass of water = 100g.
Molality =...?
Next, we shall determine the number of mole in 4.5g of NaCl. This can be obtained as follow:
Mass of NaCl = 4g.
Molar mass of NaCl = 23 + 35.5 = 58.5g/mol
Number of mole NaCl =..?
Mole = Mass /Molar Mass
Number of mole of NaCl = 4.5/58.5
Number of mole of NaCl = 0.077 mole.
Next, we shall convert 100g of water to kilograms. This is illustrated below:
1000g = 1kg
Therefore, 100g = 100/1000 = 0.1Kg.
Finally, we can determine the molality of the solution as follow:
Molality is simply defined as the mole of solute per unit kilogram of solvent (water). Mathematically, it is represented as:
Molarity = mole of solute / kg of solvent
Mole of solute, NaCl = 0.077 mole
Kg of solvent = 0.1kg
Molality = 0.077mol/0.1kg
Molality = 0.77mol/Kg
The molarity of the solution is 0.77mol/Kg.
Calculation of the molarity of the solution:
Since
Mass of NaCl = 4.5g
Mass of water = 100g.
Here,
Mass of NaCl = 4g.
Molar mass of NaCl = 23 + 35.5 = 58.5g/mol
Now
Mole = Mass /Molar Mass
= 4.5/58.5
= 0.077 mole.
Now
1000g = 1kg
So,
100g = 100/1000 = 0.1Kg.
Now
Molarity = mole of solute / kg of solvent
Mole of solute, NaCl = 0.077 mole
Kg of solvent = 0.1kg
So,
Molality = 0.077mol/0.1kg
= 0.77mol/Kg
Learn more about sodium here: https://brainly.com/question/14248836
PLZZZZZZZZ HELLLLLLLLLLLLLLLLLPPPPPP!!!!! soo stuckkkkk
What is the similarity between 0.6 M KI and 0.6 m KI ?
Answer:
Molarity and molality are both used to express the concentration of a solution. The amount of solute is both expressed in moles.
Explanation:
Please help me with those questions please
Answer:
I know the answer to 5, i think
Explanation:
No, if both parents were left-handed, they would not have to be left-handedHow would you separate pure dry cleaning solvent from waste dry cleaning solvent containing dirt that dissolves in the solvent from clothes
Answer:
fddff s
Explanation:
v c dggbgzfx
Which substance is a mixture? Table salt, gasoline, aluminum, or carbon dioxide.
Answer:
gasoline
Explanation:
what is the atomic number of silver
Answer:
47
Explanation:
Silver (Ag), chemical element, a white lustrous metal valued for its decorative beauty and electrical conductivity. Silver is located in Group 11 (Ib) and Period 5 of the periodic table
The atomic number of silver is 47.
That also means that silver has 47 electrons and 47 protons.
The atomic mass of silver is 108u.
107 - 47 = 60
Silver has 60 neutrons.
Explain what environmental bias means. What are the categories that
make up environmental bias? How does environmental bias relate to
chemistry?
Answer: Environmental bias can be defined as the idea that suggests a group of people being living in the environment which is harmful for them.
Explanation:
There are three categories that make up the environmental bias there are socio-cultural choice, occupational choice, and personal choice.
The environmental bias can be related to chemistry as chemical lab is an area prone to chemical (acid, alkali) and fire so produced in reactions thus prone to accidental hazards not safe for working of people. But people like to work in chemical lab due to their personal and occupational choice.
In a galvanic cell, anode is where oxudatuon takes place?
In a galvanic cell, the oxidation and reduction of metals occurs at the electrodes. There are two electrodes in a very cell, one in each half-cell. The cathode is where reduction takes place and oxidation takes place at the anode.
A 315-mL bag of potato chips is packaged at sea level (1.00 atm) where the temperature is 25oC. If this bag of chips is transported to Denver (where the pressure is 0.775 atm and the temperature is 18oC), what will the new volume of the bag be?
Answer:
THE NEW VOLUME AT A PRESSURE OF 0.775 atm AND TEMPERATURE OF 18 °C IS 0.397 L
Explanation:
Using the combined gas equation
P1V1/T1 = P2V2/ T2
P1 = 1 atm
VI = 315 mL = 315 / 1000 L = 0.315 L
T1 = 25°C 25 + 273 K = 298 K
P2 = 0.775 atm
T2 = 18 °C = 18 + 273 K = 291 K
V2 = Unknown
Substituting the values into the equation, we obtain:
V2 = P1V1 T2/ P2 T1
V2 = 1 * 0.315 * 291 / 0.775 * 298
V2 = 91.665 / 230.95
V2 = 0.3969 L
The new volume at the given change in conditions is 0.397 L
Give four differences between rusting and burning
Answer:
burning is a rapid process, rustig is a slow process. burning releases light during the process,rusting does not. burning can speed up with addition of more external conditions, rusting cannot be sped up greately by addition of external materials. burning results in release of large amts of heat, rusting very little amt of heat
Hope helped
plesse give a thank
and most brainlest
-Rust happens when something is unpolished and is old. Burning has been modified by heat.
-Burning is a chemical change. Rust is a physical change.
-Burning something cannot be fixed back to its natural form, while when something is rusted it can possibly be re-used and fixed.
-The texture of something burnt is usually fragile and brittle while rust makes (metal for example) gritty.
-Rust usually forms solely on metals while almost anything can be burned.
note: you asked for 4 answers but i gave you 5 in case you didnt like any of them. Hope this helps!
quick question plz . .....Which one of the following is acidic oxide?
A. K2O
B. CO2
C. MgO
D. Al2O3
Answer:
B
Explanation:
its an acidic oxide, it disolves in water to form carbonic acid which is an acid
This type of substance has a pH of 7. It will not change the color of litmus.
1. Acid
2. Base
3. Neutral
This question was just so some of y'all can get more points lol.
Match these people to the discoveries or work that they are known for. Galileo developed geocentric theory Aristotle developed heliocentric theory Celsius founded nursing profession Torricelli invented barometer Copernicus considered "Father of Modern Science" Vesalius developed law of universal gravitation Newton examined the inner workings of the human body Nightingale developed metric temperature scale
Answer:
Galileo: "Father of Modern Science."
Aristotle: Geocentric theory." (The planests revolves around the earth.)
Torricelli: Invented the barometer. (An instrument which measures pressure.)
Copernicus: Heliocentric theory. (Aka, the planets revolves around the sun.)
Vesalius: Examined the inner workings of the human body
Newton: Developed law of universal gravitation.
Nightingale: Founded nursing profession.
Celsius: Developed metric temperature scale
I hope this helps! Thanks:)
determine the mass of a copper (ii) trioxonitrate(v) that will be formed when 15g og copper is added to excess dilute trioxonitrate(v) acid
Explanation:
Copper(II) carbonate basic, CuCO3•Cu(OH)2(s), is the dull green colour that forms on copper roofs. Copper oxidises in the air to form an approximately equimolar mixture of CuCO3 and Cu(OH)2.The percentage of CuCO3 in the