How many times as fast does helium (He) effuse compared to oxygen?
Answer:
The rate of effusion of helium is always about twice that of oxygen.
Explanation:
Recall Graham's law of effusion:
[tex]\displaystyle \frac{r_1}{r_2} = \sqrt{\frac{\mathcal{M}_2}{\mathcal{M}_1}}[/tex]
Where r are the rates of effusion and M are the respective molecular weights.
Let r₁ be the effusion rate of helium and r₂ be the effusion rate of oxygen. Hence, M₁ = 8.00 g/mol and M₂ = 32.00 g/mol.
Substitute:
[tex]\displaystyle \begin{aligned}\frac{r_1}{r_2} & = \sqrt{\frac{(32.00\text{ g/mol})}{(8.00\text{ g/mol})}} \\ \\ & = \sqrt{4.00} \\ \\ & = 2.00 \end{aligned}[/tex]
Solving for r₁ yields:
[tex]\displaystyle \begin{aligned} \frac{r_1}{r_2} & = 2.00\\ \\ r_1 & = 2.00r_2\end{aligned}[/tex]
Hence, the rate of effusion of helium is always about twice that of oxygen. This is expected, as helium is smaller than oxygen.
The value of AH° for the reaction below is -1107 kJ:
2Ba(s) + O₂(g) → 2BaO(s)
How many kJ of heat are released when 5.75 g of Ba(s) reacts completely with oxygen to form BaO(s)?
Select one:
O a. 96.3
O b. 26.3
O c. 46.4
O d. 23.2
Oe. 193
Answer:
C
Explanation:
We can use heat stoichiometry. Thus, convert from grams of Ba to moles of Ba; and use the ΔH value to calculate the amount of heat released. Hence:
[tex]\displaystyle 5.75\text{ g Ba}\cdot \frac{1\text{ mol Ba}}{137.33\text{ g Ba}} \cdot \frac{1\text{ mol}_{rxn}}{2\text{ mol Ba}} \cdot \frac{-1107\text{ kJ}}{1\text{ mol}_{rxn}} =-46.4 \text{ kJ}[/tex]
Therefore, about 46.4 kJ of heat was released.
In conclusion, our answer is C.
Hydrochloric acid is usually purchased in a concentrated form that is 37.0% HCl by mass and has a density of 1.20 g/mL. How much concentrated solution would it take to prepare 3.00 L of 0.480 M HCl upon dilution with water?
The required volume of concentrated stock solution of hydrochloric acid is 102.71 mL.
What is the relation between the volume & density?Volume of any solution will be calculated by using the density as:
Volume = Mass/Density
Given that percent mass of HCl is 37%, so mass of the HCl = 37g
So that mass of solution = 100g
And density of solution = 1.2 g/mL
Volume of solution = 100/1.2 = 83.33 mL = 0.08333 L
Moles of HCl will be calculated as:
n = W/M, where
W = given mass = 37g
M = molar mass = 36.4g/mol
n = 37/36.4 = 1.014mol
Then the molarity of the stock solution will be calculated as:
M = n/V
M = 1.014 / 0.0833 = 12.17M
Now the required volume of stock solution will be calculated by using the following equation as:
M₁V₁ = M₂V₂, where
M₁ & V₁ is the molarity and volume of stock solution and M₂ & V₂ is the molarity and volume of dilute solution. On putting values in the above solution we get
12.17 × V₁ = 0.5 × 2500
12.17 × V₁ = 1250
V₁ = 102.71 mL
Hence required volume of stock solution is 102.71 mL.
To know more about molarity, visit the below link:
https://brainly.com/question/22283918
#SPJ1
7. In the process of assembling bicycles, you have 114 frames, 300 tires, 75 seats, 109 sets of pedals, and 84 sets of handlebars. Which is the limiting reactant in this process?
a. frames
c. seats
e. handlebars
b. tires
d. pedals
In the bicycle assembling process, the limiting reactant is seats since they will be used up first.
What is a limiting reactant?A limiting reactant is a reactant which is used up first in a reaction and on which product formation depends on.
In a given reaction, once the limiting reactant is used up, the reaction will stop.
For a bicycle to be assembled, 1 frame, 1 seat, 1 seat of handlebars, 1 seat of pedals and 2 tires are required.
In the process of assembling bicycles, there are 114 frames, 300 tires, 75 seats, 109 sets of pedals, and 84 sets of handlebars.
Therefore, the limiting reactant is seats since they will be used up first.
Learn more about limiting reactant at: https://brainly.com/question/14225536
#SPJ1
The specific heat of water is 1.0 calorie/ gram °C. The amount of heat energy needed to raise the temperature of 450 grams of water from 25 °C to 55 °C is: O 15 calories
Answer:
Explanation:
We can use the equation to find out
E = mc△T
E is the total energy (calories) needed, m for mass, c for specific heat capacity and △T for the temperature change.
Substitute the numbers given
E = 500 x 1 x 10
E =5000
Therefore the answer is 5000CalWe can use the equation to find out
E = mc△T
E is the total energy (calories) needed, m for mass, c for specific heat capacity and △T for the temperature change.
Substitute the numbers given
E = 500 x 1 x 10
E =5000
Therefore the answer is 5000Cal
define concentration and give examples.
Answer:
Concentration: The amount of a given substance within a set solution.
Explanation:
For example, the units for concentration include mol/[tex]dm^{3}[/tex] which means that if a substance has 3 mol/[tex]dm^{3}[/tex], it means 3 moles of that substance is in a 1 dm cubed of that solution. You could give examples of the concentration of acids like Hydrochloric Acid (HCl) and alkalis like Hydroxide (OH).
Joel reacted 0.9845 g of iron filings with an excess of copper sulphate solution. When the reaction was complete the solution had changed from blue to green and a copper deposit weighing 1.024 g had formed in the solution. In this reaction, metallic iron is converted into ferrous ion (Fe2+) and cupric ion (Cu2+) is converted into metallic copper.
a) Calculate the number of moles of iron used and the number of moles of copper
formed.
b) Calculate the theoretical mass of copper that was expected to be produced and
hence deter,mine the percentage yield of Joel’s experiment.
c) How many molecules of iron are present in 0.9845 g of iron fillings?
Fiona prepared a solution by dissolving 1.35 g of silver nitrate in a 250 mL volumetric flask and diluting it up to the volume.
d) Calculate the molarity of the silver nitrate solution.
e) What volume of this solution is required to prepare 100 mL of 0.01 M of silver nitrate solution?
From the stoichiometry of the reaction, the percentage yiled of the copper is 89.6%
What is reaction equation?The reaction equation here is given as; Fe(s) + CuSO4 (aq) ----->FeSO4(aq) + Cu(s)
Number of moles of Fe = 0.9845 g/56 g/mol = 0.018 moles. Since the reaction is 1:1, this is also the number of moles of Cu formed.
Theoretical yiled of Cu = 0.018 moles * 63.5 g/mol = 1.143 g
Percentage yiled = 1.024 g/1.143 g * 100/1 = 89.6%
If 1 mole of Fe contains 6.02 * 10^23 molecules
0.018 moles of Fe contains 0.018 moles * 6.02 * 10^23 molecules/1 mole = 1.1 * 10^22 molecules.
Number of moles of AgNO3 = 1.35 g/170 g/mol = 0.0079 moles
Molarity of the solution = 0.0079 moles/250 * 10^-3 L = 0.0032 M
Hence; 0.0032 M * V1 = 100 mL * 0.01 M
V1 = 312.5 mL
Learn more about stoichiometry: https://brainly.com/question/9743981
#SPJ1
Which statement best describes the relationship between ocean CO2 and pH?
Question 3 options:
When CO2 increases, pH increases and acidity decreases.
When CO2 increases, pH decreases and acidity increases.
When CO2 increases, pH decreases and acidity decreases.
There is no relationship between CO2 and pH
Answer:
The answer is When CO2 increases, pH decreases and acidity increases.
Explanation:
Excess carbon dioxide (CO2) in the atmosphere gets absorbed at the ocean surface of the ocean. This excess CO2 results in more hydrogen ions, which increases the acidity of the ocean.
What is the total number of electrons in the correct Lewis dot formula of the phosphate ion?
30
26
36
34
32
8. Choose the compound that is metallic.
P4010
NaCI
FE
Your answer is FE, or iron!
Which element is most similar to nitrogen: Carbon or Phosphorus?
How many moles of water are needed in order to produce 21.8 g of
calcium hydroxide?
CaC2 + 2H₂O -------> C₂H₂ + Ca(OH)2
The number of moles of water are needed in order to produce 21.8 g of
calcium hydroxide is 0.588 moles.
How do we calculate the moles from mass?Moles of any substance will be calculated as:
n = W/M, where
W = given mass
M = molar mass
Given chemical reaction is:
CaC₂ + 2H₂O → C₂H₂ + Ca(OH)₂
Moles of 21.8g of Ca(OH)₂ = 21.8g / 74.1g/mol = 0.294mol
From the stoichiometry of the reaction, it is clear that
1 mole of Ca(OH)₂ = needed 2 moles of water
0.294 mole of Ca(OH)₂ = needed 2×0.294=0.588 moles of water
Hence required moles of water is 0.588 moles.
To know more about moles, visit the below link:
https://brainly.com/question/1034638
#SPJ1
The normal boiling point of a liquid is 282 °C. At what temperature (in °C) would the vapor pressure be 0.500 atm? (∆Hvap = 28.5 kJ/mol)
For a normal boiling point of a liquid is 282 °C, the temperature is mathematically given as
T2=181.55°C\
What temperature (in °C) would the vapor pressure be 0.500 atm?Generally, the equation for the gas is mathematically given as
ln(p1/p2)=dHvap/R(1/T2-1/T1)
Therefore
ln(1/0.26)=23500/8.214(1/T2-1/555)
T2=181.55^C
In conclusion
T2=181.55°C
Read more about Temperature
https://brainly.com/question/13439286
Which is NOT a disadvantage of using electromagnetism?
A.) cause cancer
B.) damage medical equipment
C.) accurate viewing of soft tissue in the body
D.) heat up quickly
Answer:
Electromagnetism can cause cancer
So option A is incorrect
Electromagnetism can damage a medical instruments
It is also a disadvantage and this option is not correct
Now come to C it says that electromagnetic is used to veiw the soft tissue it is not a disadvantage but a advantage so C IS THE CORRECT ANSWER
Explanation:
PLEASE MARK ME BRAINLIEST IF MY ANSWER IS CORRECT PLEASE
what as the cause of wrld war 2?
Answer:
because peoples don't has so mu thinking power that time[tex]\bold{Heya!}[/tex]
Wowie- nice cat... plus, he or she is fluffy...
Have a great day!
#LearnWithBrainly
[tex]\underline{Answer :}[/tex]
XxVioletXx
A constant volume of oxygen is heated from 100oC to 185 oC. The initial pressure is 4.1 atm. What is the final pressure?
A constant volume of oxygen has a pressure of 4.1 atm at 100 °C and 5.0 atm at 185 °C according to Gay-Lussac's law.
What does Gay-Lussac's law state?At constant volume, the pressure of an ideal gas is proportional to its absolute temperature.
Step 1: Convert the temperatures to the absolute scale.We will do so by adding 273.15 to the Celsius temperature.
T₁: 100 °C + 273.15 = 373 K
T₂: 185 °C + 273.15 = 458 K
Step 2: Calculate the final pressure of the gas.We will apply Gay-Lussac's law.
P₁/T₁ = P₂/T₂
P₂ = P₁ × T₂/T₁
P₂ = 4.1 atm × 458 K/373 K = 5.0 atm
A constant volume of oxygen has a pressure of 4.1 atm at 100 °C and 5.0 atm at 185 °C according to Gay-Lussac's law.
Learn more about Gay-Lussac's law here:
https://brainly.com/question/24691513
#SPJ1
When magnesium is added to hydrochloric acid it reacts violently. If 87.0g of magnesium is used during this reaction how much magnesium chloride is produced?
Answer:
Magnesium hydroxide is a base. Hydrochloric acid, as the name suggests, is an acid.
So an acid and a base together will produce salt and water. In this case, the salt is magnesium chloride.
This process is known as neutralisation
1) Sodium hydroxide is deliquescent. A sample of 3.0 g was dissolved in 100 mL; 10 mL was titrated with 34.9 mL HCl 0.2 M. What is the percent of absorbed water in the sample?
From the calculation, the percentage of water in the sodium hydroxide sample is 7%.
What is neutralization?The term neutralization has to do with the reaction between an acid and a base to yiled salt and water.
Now we have to apply the titration formula;
CAVA/CBVB = NA/NB
CA = concentration of acid
CB = concentration of base
VA = volume of acid
VB = volume of base
NA = number of moles of acid
NB = number of moles of base
The reaction equation is; HCl + NaOH ----->NaCl + H2O
CAVANB = CBVBNA
CB = CAVANB /VBNA
CB = 34.9 * 0.2 M * 1/10 * 1
CB = 0.698 M
Number of moles = Conncentration * volume
= 0.698 M * 100/1000 L = 0.0698 moles
Mass = Number of moles * molar mass
Mass = 0.0698 moles * 40 g/mol = 2.79 g
percent of NaOH = 2.79 g/ 3g * 100/1 = 93%
Percent of water = 100- 93 = 7%
Learn more about neutralization: https://brainly.com/question/15395418
Calculate the volume of hydrogen gas at 38.0 °C and 763 torr that can be produced
by the reaction of 4.33 g of zinc with excess sulfuric acid.
formula= PV = nRT
moles of Zn = 4.33 g Zn x 1 mol Zn/65.4 g
= 0.0662 moles Zn
moles H2 = 0.0662 moles Zn x 1 mol H2/mol Zn
= 0.0662 mole H2 gas
V = nRT/P
T = 38 + 273
= 311K
763 torr/760
= 1.00 atm
V = (0.0662 mol)(0.0821 Latm/Kmol)(311K)/1.00 atm
V = 1.69 L
A container holds 6.4 moles of gas. Hydrogen gas makes up 25% of the total moles in the container. If the
total pressure is 1.24 atm. What is the partial pressure of hydrogen? Must show work! Use P^a/P^t = n^a/n^t
Answer:
i let alone need more time to figure this out and i will get you the awnser.
Explanation:
An atom becomes an ion when there are
Question options:
unequal numbers of protons and electrons
equal number of protons, neutrons, and electrons
a different number of neutrons than protons
equal numbers of protons and electrons
Answer:
Unequal number of protons and electrons
Explanation:
When an atom loses or gains electrons, this affects its charge, thus creating it an ion (a charged atom)!
(image attached) AP CHEM ACID BASE Is my answer correct? I will mark as brainliest if you answer me. I don't need an explanation if i'm right just explain if i'm wrong. Thanks
Answer:
Your answer is correct based on what I remember from AP Chemistry
Explanation:
Calculate the volume in liters of 50.0 grams of NO2 at STP.
According to the mole concept, the number of moles in 50 g of NO₂ is 1.086 as molar mass of NO₂ is 46 g and as per STP conditions volume is 24.32 L.
What is a mole?Mole is defined as the unit of amount of substance . It is the quantity measure of amount of substance of how many elementary particles are present in a given substance.
It is defined as exactly 6.022×10²³ elementary entities. The elementary entity can be a molecule, atom ion depending on the type of substance. Amount of elementary entities in a mole is called as Avogadro's number.
It is widely used in chemistry as a suitable way for expressing amounts of reactants and products.For the practical purposes, mass of one mole of compound in grams is approximately equal to mass of one molecule of compound measured in Daltons. Molar mass has units of gram per mole . In case of molecules, where molar mass in grams present in one mole of atoms is its atomic mass.
Initially the number of moles is calculated as, 50/46=1.086 moles . As 1 mole occupies 22.4 L at STP conditions,1.086 moles occupy 1.086×22.4=24.32 L.
Hence, the volume in liters of 50 g of NO₂ at STP is 24.32 L.
Learn more about moles,here:
https://brainly.com/question/20486415
#SPJ2
Another word for, The spinning of a planet on its axis
Answer:
A rotation
Explanation:
What is the standard enthalpy change for the reaction:
3NO2(g)+H2O(l)→2HNO3(aq)+NO(g)
Use standard enthalpies of formation in your textbook.
Select one:
a.
-66.2 kJ
b.
-138 kJ
c.
-116 kJ
d.
-201 kJ
Which type of cell is shown in the following image?
Answer:
A prokaryotic cell is shown in the image
Explanation:
Prokaryotic cells are the most basic types. Since they are basic, they don't have a nucleus. All eukaryotic cells have it but prokaryotic cells don't have it. A nucleus contains organelles such as a mitochondria which the diagram doesn't show as well. Thus a prokaryotic cell is shown in the image.
What is the phase of water at 1.0 atm and 50°C?
Water
(liquid)
Water vapor
(gas)
100
Temperature (°C)
Pressure (atm)
1-
0.5-
0.25-
0
Ice
(solid)
-10
OA. Liquid and gas
OB. Liquid
OC. Solid
D. Gas
0-
0.01
The given temperature of water is 50 degrees Celsius, hence, we can conclude that the phase of the given water is liquid phase.
What is phase of water?
Water can exist in three different phases, namely;
Liquid phase - usually between 0 to 100 degrees CelsiusSolid phase - below 0 degrees CelsiusVapor phase or gaseous phase - usually above 100 degrees CelsiusTherefore, if the given temperature of water is 50 degrees Celsius, hence, we can conclude that the phase of the given water is liquid phase.
Learn more about water phase here: https://brainly.com/question/1612862
#SPJ1
A 25.0 mL solution of Sr(OH)₂ is neutralized with 31.6 mL of 0.150 M HBr. What is the concentration of the original Sr(OH)₂ solution?
A 25.0 mL solution of Sr(OH)₂ is neutralized with 31.6 mL of 0.150 M HBr, then the concentration of the original Sr(OH)₂ solution is 0.189M.
How do we calculate the concentration?Concentration of the solution will be calculated by using the below chemical reaction as:
M₁V₁ = M₂V₂, where
M₁ & V₁ is the molarity and volume of HBr solution and M₂ & V₂ is the molarity and volume of original Sr(OH)₂ solution.
On putting values on above equation by taking from question, we get
M₂ = (0.15)(31.6) / (25) = 0.189 M
Hence required molarity of Sr(OH)₂ solution is 0.189M.
To know more about molarity, visit the below link:
https://brainly.com/question/24305514
#SPJ1
What inference can be drawn from the graph?
A+B=C+D
45
40
35
30
25
Concentration
20
15
10
5
0
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16
Time (seconds)
OA. The reaction between A and B is reactant favored.
OB. The amount of product is greater than the amount of reactant.
OC. The reaction uses all its reactants to form products.
OD. The reaction reaches equilibrium at 1.5 seconds
OE. The amount of reactants is highest at equilibrium.
Answer:
i think its C
Explanation:
The graph indicates that the reaction reaches equilibrium around 1.5 seconds. The graph shows how the concentrations of reactants and products change over time until they eventually become constant. So, the correct option is D.
What is an Equilibrium?Equilibrium is a state in a chemical process when forward and backward reactions occur at the same rate, meaning that the concentrations of reactants and products do not change with time. In other words, the forward reaction rate equals the reverse reaction rate.
In the example above, the graph indicates that the reaction reaches equilibrium in about 1.5 seconds. The graph shows how the concentrations of reactants and products change over time until they eventually become constant. This indicates that the reaction has reached equilibrium when obtained in approximately 1.5 seconds.
So, the correct option is D.
Learn more about Equilibrium, here:
https://brainly.com/question/30807709
#SPJ7
Use the drop-down menus to name these structures
F
FICH
H
Answer:
What Structures??
Explanation:
Can you please explain the question more