A gas is brought to a final pressure of 6.8 atm. after increasing its temperature from 40 K to 280 K. Calculate the original pressure of the gas.
Answer:
0.97 atm.
Explanation:
From the question given above, the following data were obtained:
Final pressure (P2) = 6.8 atm
Initial temperature (T1) = 40 K
Final temperature (T2) = 280 K
Initial pressure (P1) =?
Thus, we can obtain the initial (original) pressure of the gas as follow:
P1/T1 = P2/T2
P1 /40 = 6.8/280
Cross multiply
P1 × 280 = 40 × 6.8
P1 × 280 = 272
Divide both side by 280
P1 = 272/280
P1 = 0.97 atm
Therefore, the original pressure of the gas is 0.97 atm.
Consider the equation:
4Al + 3O2 = 2Al2O3
Is this equation balanced? Why or why not?
The equation is balanced. There are 4 aluminium atoms and 6 oxygen atoms on each side.
4. Kendrick drags his bat out to play baseball. which statement best describes the science of what he did?
O Kendrick would use less energy if he dragged the bat faster.
Kendrick did not have to work to move the bat because he dragged it.
Kindrick gave the bat potential energy.
Kindrick gave the bat kinetic energy.
Explanation:
Kendrick gave the bat potential Energy
Which elements are considered metals? Non-metals? Metalloids?
The answer is in the photo.
Calculate the energies of the n=2 and n=3 states of the hydrogen atom in Joules per
atom
Answer:
See Explanation
Explanation:
Positional Energy for electron as function of principle energy level (n)
=> Eₙ = -A/n²; A = 2.18x10⁻¹⁸J
Positional Energy for electron in n=2 => E₂ = -2.18x10⁻¹⁸/(2)² = -5.45x10⁻¹⁹J
Positional Energy for electron in n=3 => E₃ = -2.18x10⁻¹⁸/(3)² = -2.42x10⁻¹⁹J
ΔE(n=3→2) = -5.45x10⁻¹⁹J - (-2.42x10⁻¹⁹J) = -3.03x10⁻¹⁹J
a wooden block with a mass of 2.0kg starts from at the top of an inclined plane and ends with a force of 25N at the bottom what was the rate of acceleration of the block
Answer:
Force F = 20N .
Mass m = 2.0 kg
Initial velocity u = 0
acceleration, a = 10m/s
2
t = 1 sec.
Now Refer to the attachment, See the free body diagram of the block.
Force works on the block:-
Weight, W = mg
W = 2 × 10
W = 20N (which is Downward)
Normal force N = mg cos37
N = 20 × 0.80
N = 16 N. (perpendicular & upward to the plane )
Here Applied Force, P = 20N (which is down along the plane)
Now For Final Speed, We know the formula:-
v = u + at
v = 0 + 10 × 1
v = 10 m/s
the Distance travelled s = ut + 0.5 at×t
s = 0 + 0.5 ×10×1×1
s = 5 m.
Now,
(a) So work done by the force of gravity in 1 sec. = F × d
⇒20 N × 5m
⇒100 J.
(b) Here the weight act as downward, so distance travelled in downward.
⇒5 × sin37
⇒5 × 0.6
⇒3 m.
so work done by gravity,
⇒20 N × 3 m
⇒60 J.
(c) Now, work done by all the forces
⇒change in Kinetic energy
⇒
2
1 m(v2
−u 2
)
⇒0.5×2.0×(10 2
−0 2 )
⇒ 100 J.
⇒W.D by frictional force
= work was done by all forces -( work was done by Normal force + work done by applied force + work done by gravity )
= 100 J - (100 + 60 +0 )
= 100 - 1
Hope this helps you≅
A sample of helium gas at 841 mmHg and 14.7°C is heated to 84.7°C at constant volume. Calculate its final pressure (in atm).
_________________ atm. Do NOT enter unit. Report your final answer with 3 SFs.
Answer: 1.38
Explanation:
Gay-Lussac's Law: This law states that pressure is directly proportional to the temperature of the gas at constant volume and number of moles.
[tex]P\propto T[/tex] (At constant volume and number of moles)
[tex]\frac{P_1}{T_1}=\frac{P_2}{T_2}[/tex]
where,
[tex]P_1[/tex] = initial pressure of gas = 841 mm Hg
[tex]P_2[/tex] = final pressure of gas = ?
[tex]T_1[/tex] = initial temperature of gas =[tex]14.7^0C=(14.7+273)K=287.7K[/tex]
[tex]T_2[/tex] = final temperature of gas = [tex]84.7^0C=(84.7+273)K=357.7K[/tex]
[tex]\frac{841}{287.7}=\frac{P_2}{357.7}[/tex]
[tex]P_2=1045.6mm Hg=1.38atm[/tex] ( 760 mm Hg = 1atm )
Thus the final pressure is 1.38
Can someone help me I only have 5 minutes left.
find the number of hydrogen atoms of an alkyl group with 2 carbon atoms if n=2
Answer:
5
Explanation:
An alkyl group is a functional group that contains only hydrogen and carbon atoms. It has the general formula: CnH2n+1.
Since n=2, plug it into the formula.
C2H2(2)+1
=
C₂H₅
Hope that helps.
Which three are advantages of asexual reproduction?
A:Offspring are more likely to survive environmental changes.
B:Some offspring are more likely to survive a disease.
C:Less energy is required to reproduce.
D:The population can increase from only one parent.
E:The population can increase quickly.
Answer:
sorry if I get this wrong I think it is C
Explanation:
1) How many moles are in 4.0x10^24 atoms?
Answer:
6.64 molesExplanation:
To find the number of moles in a substance given it's number of entities we use the formula
[tex]n = \frac{N}{L} \\[/tex]
where n is the number of moles
N is the number of entities
L is the Avogadro's constant which is
6.02 × 10²³ entities
From the question we have
[tex]n = \frac{4 \times {10}^{24} }{6.02 \times {10}^{23} } \\ = 6.644518...[/tex]
We have the final answer as
6.64 molesHope this helps you
Giselle is working with a chemical substance in a laboratory. She observes that when the chemical is heated, it gives off a gas. She assumes that the gas is oxygen but decides to test this assumption to verify it. Which type of scientific knowledge is Giselle’s assumption? A. fact B. hypothesis C. law D. observation E. theory
Answer:
The correct answer is B. Hypothesis
Explanation:
What are the rules for writing
names/formulas for ionic
compounds? Give examples
where you need to produce
the formula from the name
AND the name from the
formula. Make sure to
include examples of
transition metals and
polyatomic ions.
Becky places a strip of metal into a clear liquid and they react. A has given off . The liquid is most likely which kind of substance?
Answer:
The liquid is likely to be a base e.g Sodium hydroxide solution or Ammonia solution
The liquid is likely to be a Base .
Acid and baseThe terms acid and base describe chemical characteristics of many substances that we use daily. Acidic things taste sour. Basic or alkaline things taste soapy. Strong acids are corrosive and strong bases are caustic; both can cause severe skin damage that feels like a burn. However, mild acids and bases are common and relatively harmless to us.
2 H2O ⇌ 1 H3O+ + 1 OH-
Examples of bases are sodium hydroxide, calcium carbonate and potassium oxide. A base is a substance that can neutralize the acid by reacting with hydrogen ions. Most bases are minerals that react with acids to form water and salts.Basic substances react to aqueous solutions by accepting protons, giving away electrons, or releasing hydroxide ions. They neutralize acids by reacting with hydrogen ions to form salts and water. A base that dissolves in water is also known as an alkali.The scale has values ranging from zero (the most acidic) to 14 (the most basic). As you can see from the pH scale above, pure water has a pH value of 7. This value is considered neutral—neither acidic or basic.Learn more about base, refer
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Which defines the average inetic energy of a system's particles?
O density
O pressure
O temperature
O volume
At which point is crust neither created nor destroyed?
island chain
mid-ocean ridge
divergent boundary
transform boundary
Answer:
transform battery
Explanation:
Answer: D. Transform Boundary
Explanation: I did the test.
Which of the following statements is true about exothermic reactions?
Answer:
An Exothermic Reaction , gives off more heat, and a little energy to its surroundings.
this can helps us figure out that the answer is , C, More heat is given off into its products.
Explanation:
The molar solubility of CaSO4 in water is 0 .67 gram per liter of solution. Calculate the Ksp.
Answer:
Ksp = 2.4 * 10⁻⁵
Explanation:
The equation for the dissolution and dissociation of CaSO4 in water is given as: CaSO₄ ---> Ca²⁺ + SO₄²⁻
The expression for the Ksp of the dissociation equation above is:
Ksp = [Ca²⁺] [SO₄²⁻]
The molar ratio of the dissociated ions and the solute is 1 : 1, this means that every 1 mole of CaSO₄ that dissolves produces 1 mole of Ca²⁺ and SO₄²⁻ each
The molar solubility of a substance is the number of moles that dissolve per liter of solution.
molar solubility of CaSO₄ = number of moles /liter of solution
number of moles of CaSO₄ = mass/molar mass
molar mass of CaSO₄ = 136 g/mol
number of moles of CaSO₄ = 0.67/136 = 0.0049 moles
molar solubility of CaSO₄ = 0.0049 mol/ 1 L = 4.9 * 10⁻³ moles per liter
therefore, molar solubility of CaSO₄ = 4.9 * 10⁻³
Ksp = (4.9 * 10⁻³) (4.9 * 10⁻³)
Ksp = 2.4 * 10⁻⁵
Answer:
2.4 * 10^-5
Explanation:
Molar solubility of CaSO4 = 0 .67 g/L/136 g/mol = 4.9 * 10^-3 Mol/L
Given that;
CaSO4(s) -------> Ca^2+(aq) + SO4^2-(aq)
Hence, Ksp = [Ca^2+] [SO4^2-]
Where [Ca^2+] =[SO4^2-]=s
Ksp = s^2
since s = 4.9 * 10^-3 Mol/L
Ksp = (4.9 * 10^-3 Mol/L)^2
Ksp = 2.4 * 10^-5
in which type of bond are electron shared between atoms?
A. ionic
B.covalent
C.metallic
Would a highly conductive, malleable, and lustrous solid be a metal, nonmetal, or metalloid?
1s2 3s2 3p6 3s2 3p6 3d6 4s2 what is element
The element with the electron configuration, 1s2 3s2 3p6 3s2 3p6 3d6 4s2, will be iron.
Atomic number and electronic configurationsIn the electronic configuration of elements, the number of electrons possessed by the element is shared into the orbitals according to their energy levels.
The electrons are first shared in orbitals in the same energy level before pairing starts.
Also for neutral atoms, the number of electrons is equivalent to the number of protons. The number of protons in itself represents the atomic number of elements.
Thus, considering this electron configuration, 1s2 3s2 3p6 3s2 3p6 3d6 4s2; the total number of electrons in all the orbitals is 26. The element with the atomic number of 26 is iron.
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Which process is constructive?
A:Water wears away rocks in a river.
B:Wind removes sand from a beach.
C:volcano forms an island in the ocean.
D:An earthquake breaks apart a cliff on a mountain.
which of the following could be classified as producing a physical change?
How many
electrons does Oravetium contain
Which chemical equation below is not balanced?
- 3 MgSO4 + 2 Nag PO4 → Mgs (PO4),+3 Na, S04
- 2 NaOH + HNO, → NaNO, + 2 H,0
- CH12 O6 4 6O2 → 6 CO, + 6 H,0
- HBr AGNO, → HNO, + AgBr
pic if needed ;)
Answer:
B
Explanation:
The second one is not balanced correctly.
2 NaOH + 2HNO3 → 2NaNO3 + 2 H20
I didn't notice this before but it can be balanced without the twos.
NaOH + HNO3 → NaNO3 + H20
It was still wrong. It needed to have the twos removed, not 2 more added. Adding two more isn't wrong, but it should be balanced without 2s if at all possible.
Explain how atomic
radius, valence electrons
and effect nuclear charge
creates the trend for metal
reactivity.
Answer:A higher effective nuclear charge causes greater attractions to the electrons, pulling the electron cloud closer to the nucleus which results in a smaller atomic radius. Down a group, the number of energy levels (n) increases, so there is a greater distance between the nucleus and the outermost orbital.
Answer:
A higher effective nuclear charge causes greater attractions to the electrons, pulling the electron cloud closer to the nucleus which results in a smaller atomic radius. Down a group, the number of energy levels increases, so there is a greater distance between the nucleus and the outermost orbital.Explanation:
An ideal gas sample is confined to 3.0 L and kept at 27 °C. If the temperature is raised to 77 °C and the initial pressure was 1500 mmHg, what is the final pressure?
The gas is confined in 3.0 L container ( rigid container) ⇒ the volume remains constant when the temperature is increased from from 27oC to 77oC and therefore V1=V2 .
Hope it helps you please mark as brainlistIdeal gas law is valid only for ideal gas not for vanderwaal gas. Ideal gas is a hypothetical gas. Vanderwaal gas can behave as ideal gas at low pressure and high temperature. Therefore the final pressure is 1,750 mmHg.
What is ideal gas equation?Ideal gas equation is the mathematical expression that relates pressure volume and temperature.
Mathematically the relation between Pressure, volume and temperature can be given as
PV=nRT
where,
P = pressure of gas
V= volume of gas
n =number of moles of gas
T =temperature of gas
R = Gas constant = 0.0821 L.atm/K.mol
At constant volume, the above equation can be rearranged as
P₁/T₁ = P₂/T₂
Substituting all the given values in the above equation, we get
1500 ÷300= P₂÷350
P₂ =1,750 mmHg
Therefore the final pressure is 1,750 mmHg.
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How many atoms are in a sample containing 4.000 moles of carbon?
A)6.022 x 10
23
atoms
B)2.408 x 10
24
atoms
O
24
C)7.233 x 10 atoms
D)2.893 x 10
25
atoms
Answer:
c I think but that's only what i think
Mole measure the number of elementary entities of a given substance that are present in a given sample. Therefore, 24.088×10²³ atoms of carbon are in sample containing 4.000 moles of carbon. The correct option is option B.
What is mole?The SI unit of amount of substance in chemistry is mole. The mole is used to measure the quantity or amount of substance. We know one mole of any element contains 6.022×10²³ atoms which is also called Avogadro number.
Mathematically,
number of atoms/molecules/ formula units of carbon= number of moles of carbon × 6.022×10²³
number of moles of carbon= 4 moles
substituting all the given values in the above equation, we get
number of atoms/molecules/ formula units of carbon= 4 × 6.022×10²³
number of atoms/molecules/ formula units of carbon=2.4088×10²⁴ atoms of carbon
There are 2.4088×10²⁴ atoms of carbon
Therefore, 24.088×10²³ atoms of carbon are in sample containing 4.000 moles of carbon. The correct option is option B.
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what is the balanced equation for naphthalene and sulphur?
napthalene: C10H8 sulphur: S02
Explanation:
C10H8
what is a common use for electromagnets
Answer:
Electromagnets are widely used as components of other electrical devices, such as motors, generators, electromechanical solenoids, relays, loudspeakers, hard disks, MRI machines, scientific instruments, and magnetic separation equipment.
Explanation:
Hope this helps :)
(didn't get this from the internet)