What is the volume of a flask that contains 0.730 moles of Nitrogen at a pressure of 698 mmHg and a temperature of 35.4°C?
Answer:
V = 20.1 L
Explanation:
Given data:
Volume of flask = ?
Number of moles of nitrogen gas = 0.730 mol
Pressure = 698 mmHg (698/760 = 0.92 atm)
Temperature = 35.4°C
Solution:
The given problem will be solve by using general gas equation,
PV = nRT
P= Pressure
V = volume
n = number of moles
R = general gas constant = 0.0821 atm.L/ mol.K
T = temperature in kelvin
Now we will convert the temperature.
35.4+273 = 308.4 K
by putting values,
0.92 atm× V = 0.730 mol ×0.0821 atm.L/ mol.K × 308.4 K
V = 18.48 atm.L / 0.92 atm
V = 20.1 L
Ten gram of hydrated calcium tetra oxo sulphate(vi) ( caso4 × H20 weighs 7.90g after heating and cooling. Calculate the empirical formula of the compound
Answer:
CaSO4. 2H2O
Explanation:
mass of hydrated salt = 10 g
mass of anhydrous salt = 7.90 g
molar mass of hydrated salt = 136 + 18x g/mol
molar mass of anhydrous salt = 136 g/mol
mass of hydrated salt/molar mass of hydrated salt = mass of anhydrous salt/molar mass of anhydrous salt
10.0/136 + 18x = 7.90/136
136 * 10 = 7.90 (136 + 18x)
1360 = 1074.4 + 142.2x
1360 - 1074.4 = 142.2x
285.6 = 142.2x
x = 285.6 / 142.2
x = 2
Hence the empirical formula of the compound is CaSO4. 2H2O
why is
helium number 2 (the second element)
and beryllium number 4 (the fourth
element) on the periodic table ?
Answer:
See note in Explanation
Explanation:
The modern periodic table of the elements is arranged in order of increasing atomic numbers which is also in terms of the number of protons in the nucleus. That is, for any element listed on the periodic table its atomic number equals the number of protons in the nucleus. Thus, the element with 2 protons in its nucleus would be element #2 (Helium), element #3 (Lithium) has 3 protons in its nucleus and element #4 (Beryllium) has an atomic number 4 and contains 4 protons in its nucleus.
Also, this arrangement of elements finds that elements below elements 2, 3 & 4, Neon #10; sodium #11 & magnesium #12 have similar chemical and physical properties as does elements #2, #3 & #4. Such gives rise to the 'Periodic Law' => the chemical and physical properties of the elements is a periodic function of their atomic number (or, number of protons in the nucleus).
(05 06 MC) The theoretical yields of Cl2 from certain starting amounts of MnO2 and HCl were calculated as 65.36 g and 68.08 g, respectively.
If the percentage yield of Cl2 is 70%, what is its actual yield?
42.25g
45.65g
46.33g
47.66g
Actual yield : 45.752 g ⇒no option
Further explanationGiven
The theoretical yields of Cl₂ : 65.35 g and 68.08 g
Required
The actual yield
Solution
Reaction
4 HCl (aq) + MnO₂ (s) → MnCl₂ (aq) + Cl₂ (g) + 2H₂O (l)
Because there are two theoretical yields, then we can choose the smallest one because the value is usually determined from the limiting reactant (in this reaction the limiting reactant is MnO₂)
So 65.36 g is The theoretical yields of Cl₂
Then the actual yield :
[tex]\tt \%yield=\dfrac{actual}{theoretical}\times 100\%\\\\actual=\%yield\times theoretical\\\\actual=70\%\times 65.36=45.752[/tex]
which of the following has the smallest radius? K+, K, Rb, Rb+
:
Option (c) is the correct answer.
Explanation:
It is known that when we move down a group then there is increase in size of atom. This is because there occurs increase in number of shells in the atom.
Also, when an atom loses electrons then it acquires a positive charge and size of the atom decreases. On the other hand, when an atom gain electrons then it acquires a negative charge and size of the atom increases.
Since, both Rb and K are same group elements and Rb has larger atomic size than K.
Hence, we can conclude that out of the given options K^{+}
+ has the smallest size.
Answer:
K+
Explanation:
Just took the quiz :)
Compare the modern model of an atom to the atomic model proposed by John Dalton in 1805
Answer:
See explanation
Explanation:
Dalton's atomic theory furnished us with a basis to discuss the theory of atoms. However, not all his ideas holds up under the scruitiny of morden science.
He postulated that atoms were 'indivisible' the discovery of subatomic particles indeed show that there are smaller particles than atoms.
His postulation that atoms can neither be created nor destroyed does not hold water today because atoms are being created in nuclear reactors.
He said that atoms of all elements are exactly alike. Today we know there are isotopes of elements which are not exactly alike.
We can see that the Dalton's atomic theory did not take cognisance of the important role of subatomic particles in studying the structure of the atom. Modern atomic theory tries to look at the importance of these particles in the understanding the structure of the atom.
How many atoms of aluminum (Al) are in 3.94 mol of aluminum
Answer:
26.9
Explanation:
that is my answer I try to it
The density of H2O2 is 1.407 g/mL, and the density of O2 is 1.428 g/L. How many liters of O2 can be made from 55 mL H2O2
Explanation:
mass H2O2 = 55 mL(1.407 g/mL) = 80.85 g
molar mass H2O2 = 2(1.01 g/mol) + 2(16.00 g/mol) = 34.02 g/mol
moles H2O2 = 80.85 g/34.02 g/mol = 2.377 moles H2O2
For each mole of H2O2 you obtain 0.5 mole of O2 (see the equation).
moles O2 = 2.377 moles H2O2 (1 mole O2)/(2 moles H2O2) = 1.188 moles O2
Now, you need the temperature. If you are at STP (273 K, and 1.00 atm) then 1 mole of an ideal gas at STP has a volume of 22.4 L. Without temperature you are not really able to continue. I will assume you are at STP.
Volume O2 = 1.188 moles O2(22.4 L/mole) = 0.0530 L of O2.
which is 53 mL.
Help pls true or false
1. Oxygen from the lungs moves into the blood by active transport.
2. Osmosis requires no ATP energy
3. Active transport over time results in equilibrium
4. Oxygen, glucose, and carbon dioxide are not permeable to the cell membrane
5. In a salty environment, cells will decrease in volume and shrivel
Answer:
1 oxygen from the lungs
Explanation:
maybe too help you breath better
The carbon atom has six total electrons in two energy levels. How many will be in each
level?
Answer:
5
Explanation:
Answer:
2 in the first and 4 in the second
Explanation:
in an atom the first energy level has only 2 spaces for electrons, as the number electrons goes up so does the amount of energy levels
if an unknown gas has one third the root mean squarevspeed of H2 at 300 K, what is the molar mass of the gas?
The molar mass of the gas : 18 x 10⁻³ kg/mol
Further explanationGiven
An unknown gas has one third the root mean square speed of H2 at 300 K
Required
the molar mass of the gas
Solution
Average velocities of gases can be expressed as root-mean-square (V rms)
[tex]\large {\boxed {\bold {v_ {rms} = \sqrt {\dfrac {3RT} {Mm}}}}[/tex]
T = temperature, Mm = molar mass of the gas particles , kg/mol
R = gas constant 8,314 J / mol K
v rms An unknown gas = 1/3 v rms H₂
v rms H₂ :
[tex]\tt v_{rms}=\sqrt{\dfrac{3\times 8.314\times 300}{2.10^{-3}} }\\\\v_{rms}=1934.22[/tex]
V rms of unknown gas =
[tex]\tt \dfrac{1}{3}\times 1934.22=644.74[/tex]
[tex]\tt 644.74^2=\dfrac{3\times 8.314\times 300}{M_{gas}}\\\\M_{gas}=18\times 10^{-3}~kg/mol[/tex]
hypothesize why carbohydrates are found in plant cell walls
Answer:
Plants can split starch into it's simpler glucose units for use as energy when needed. Cellulose is known as a structural carbohydrate because of the fibers formed by it's molecules. It is the major component of plant cell walls and comprises over half of the carbon found on planets.
Explanation:
I majored in Chemistry
Name the three stress forces that cause changes in Earths crust. Explain how each type of force affects rock.Identify the type of fault that each force produces. This is science i couldnt find a science thing
Answer:
Shear
Tension
Compression
Explanation:
The 3 stress forces are;
-shear
-tension
-compression
1) Shear is the stress force that pushes back a mass of rock in two opposite directions which in turn will produce strike - slip faults.
2) Tension is the stress force that pulls on the crust thereby stretching in a manner that it becomes thinner at its middle which in turn will produce normal faults.
3) Compression is the stress force that makes rocks squeeze until they fold or break and this will in turn produce reverse faults.
The atmospheric pressure is highest at...
Answer: Sea Level
Explanation: facts
Which of the following salts has a 3 to 2 ratio of cations to anions?
O Barium Nitride
O Barium sulfide
Barium chloride
O Barium oxide
Explanation:
kind of ion formed (anion or cation) and the size of the ionic charge. ... O-‐2 oxide. S-‐2 sulfide. N-‐3 nitride. P-‐3 phosphide. Table 3.1. Common, simple anions. It is critically important that you distinguish between ...
Ions and Ionic Compounds – Introductory Chemistry – 1st Canadian Edition - BC Open Textbooks
opentextbc.ca › chapter › ions-and-ionic-...
The formula Na 2Cl 2 also has balanced charges, but the convention is to use the lowest ratio of ions, which ... For the ionic compound between magnesium cations (Mg 2+) and oxide anions (O 2−), again we need only ...
[PDF] Tutorial 2 FORMULAS, PERCENTAGE COMPOSITION, AND THE MOLE FORMULAS: A chemical formula shows the elemental composition of a sub
www.eiu.edu › eiuchem › forms › t...
Ba2+ barium. HSO3. – hydrogen sulfite. MnO4. – permanganate. Al3+ aluminum. SO4. 2– sulfate. NO2. – nitrite. Sn2+ tin(II). HSO4. – hydrogen sulfate. NO3. – nitrate. Sn4+ tin(IV). S2O3. 2– thiosulfate. OH– hydroxide.
Symbols and Charges for Monoatomic Ions
www.edu.xunta.es › portal › Nomenclature
Cs+ cesium ion O2- oxide. Be2+ beryllium ion S2- sulfide. Mg2+ magnesium ion Se2- ... one K+ and one Cl¯ are required. The resulting formula is KCl. Example 3: Write the formula from the following name: barium
Barium chloride salts has a 3 to 2 ratio of cations to anions. thus option C is correct.
what are the properties of barium chloride ?Barium Chloride an inorganic salt which is composed up of barium cations (Ba2+) and chloride anions (Cl–), otherwise named as Barium Muriate or Barium dichloride.
It is a white solid , water-soluble, hygroscopic and gives a slight yellow-green color to a flame, extensively used in the industry mainly The sulfate is used in white paints where as Barium chloride is poisonous in nature.
It is soluble in water which dissociate into barium cations and chloride anions in its dissolved state, However, the solubility of this compound in water is temperature-dependent.
For more details barium chloride, visit
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4. What is the substance called that dissolves the other substance in a solution?
a. Soluto
b. Mixture
c. Solvent
d. Concentrator
Answer:
Solvent
Explanation:
When one substance dissolves into another, a solution is formed. A solution is a homogeneous mixture consisting of a solute dissolved into a solvent
A diver dives off a 32-meter high diving board into
the water below. If the diver pushes off with an initial
horizontal velocity of 1.2 m/s, how far from the base
of the board does she land?
Answer:
3.06 m
Explanation:
Time of fall be t .
h = ut + 1/2 g t² , h is height , u is initial vertical velocity = 0
h = 1/2 g t²
32 = .5 x 9.8 x t²
t = 2.55 s
During this period , diver will move in horizontal direction also .
Horizontal displacement during fall
= horizontal velocity x time
= 1.2 x 2.55
= 3.06 m
________ is the enthalpy change when 1 mole of a substance is formed from its elements under standard conditions.
A. ΔHθc
B. ΔHθn
C. ΔHθf
D. ΔHθa
The correct answer is C. ΔHθf
We define the standard enthalpy of formation as the enthalpy change when one mole of a substance is formed from its elements under standard conditions. The standard conditions are 1 atm pressure, 273 K temperature and 1 M concentration.
The standard enthalpy of formation is denoted using the symbol ΔHθf.
Hence, ΔHθf is the enthalpy change when 1 mole of a substance is formed from its elements under standard conditions.
https://brainly.com/question/3640529
The reaction AgNO3(aq) + NaCl(aq) → AgCl(s) + NaNO3(aq) is a_________
reaction. please help
Answer:
it's a precipitation reaction.
Explanation:
the solid produced is insoluble with water–making it a precipitate.
why is carbon dioxide a green house gas
Answer:
That's because the glass walls of the greenhouse trap the Sun's heat. The greenhouse effect works much the same way on Earth.
Explanation:
Gases in the atmosphere, such as carbon dioxide, trap heat just like the glass roof of a greenhouse. These heat-trapping gases are called greenhouse gases.
how many atoms of hydrogen are in 420g sample of water
_____has particles with the greatest average kinetic energy
a
Ice water
b
Hot water
c
Warm water
d
Room temperature water
Answer:
c warm water
Explanation:
Kinetic energy is related to temperature. The molecules in a glass of warm water have more kinetic energy (they move faster – see Racing Molecules) than the molecules in a glass of cold water. The temperature of a substance is the average* amount of kinetic energy its molecules have.
Answer:
hot water
Explanation:
Question 8 of 10
What will happen when a reactant is added to a system at equilibrium?
A. The system will remain at equilibrium.
B. Only the concentration of that reactant will change.
C. More reactants will form.
D. The equilibrium of the system will be upset.
SUBMIT
the equilibrium of the system will be upset
Explanation:
What is the mass of sodium (Na) in 50 grams of table salt (NaCl)? Show
your work.
All living organisms are composed of
OA. at least three cells.
ОВ.
one or more cells.
OC. at least 100 cells.
OD. only one cell.
Answer:
OB- one or more cells
Explanation:
hope this helps :)
types of hardness water
Answer:
A water repellent protein that divides into hard and soft types
what geologic process directly forms beaches on the shores of the bay?
The geologic process that directly forms beaches on the shores of the bay should be considered as the sediment deposition.
What is sediment deposition?The Deposition refer to the laying down of sediment that should be carried by wind, where the water should be flowing down or there is the sea or ice. Sediment could be transported just like the pebbles, sand ,and mud, or as salts mix in the water.
Therefore, The geologic process that directly forms beaches on the shores of the bay should be considered as the sediment deposition.
Learn more about geologic here: https://brainly.com/question/3101097
In the following image, atoms are represented by colored circles. Different colors represent different
types of atoms. If atoms are touching, they are bonded.
Which of the following boxes shows a mixture of elements and compounds?
A. D
B. C
C. B
D. A
Dr. Moore and his team have learned from GPS data that two continents with an ocean between them have been moving toward each other. Some students living on the coast of one of these continents don’t understand what is happening and they are worried that the continents will run into each other. How could Dr. Moore explain to them what is happening?
Answer:
Dr. Moore can explain that it is continental drift.
Explanation:
continental drift is the phenomenon due to which all the continents are moving towards each other, due to this continental drift stundents afraidthat some day these continents will collide leading to catastrophe.
But this is not gonna happen in a snap, this needs a lot of time, this will take hundreds of years and even more. So there is nothing to be afraid of till then humans will find some or the other way to manage this. Plus as I said this process is very slow so there are very less chances that this could lead us to any kind of chaos or anhilation.
(Btw, this isn't my work, it's just that someone already answered this same question, and they didn't answer yours so I thought I'd give it to you.)
2. How much energy must be removed from a 50.0 g sample of steam in order to get it to condense
into a liquid? (assume the steam is at 100 ℃)
Answer:
113 kJ or 113,000J
Explanation:
Since we are condensing it, a physical change in the state of matter is occurring. 113 kJ or 113,000J because of the following equation: Q = 2260 times 50. 2260 is the Heat of Vaporization constant.