A crystal of table salt (NaCl) is dissolved in water. Which of the following statements explains why the dissolved salt does not recrystallize as long as the temperature and the amount of water stay constant?
Na+ and Cl- ions lose their charges in the water.
Water molecules surround the Na+ and Cl- ions.
Na+ and Cl- ions leave the water through vaporization.
Water molecules chemically react with the Na+ and Cl- ions.
Your answer: -
Answer: B - Water molecules surround the Na+ and Cl- ions.
The change in entropy, ΔS∘rxn , is related to the the change in the number of moles of gas molecules, Δngas . Determine the change in the moles of gas for each of the reactions and decide if the entropy increases, decreases, or has little or no change. A. 2H2(g)+O2(g) ⟶ 2H2O(l) Δngas= mol The entropy, ΔS∘rxn , increases. decreases. has little or no change.
Explanation:
Entropy of a reaction ΔS∘rxn is the degree of disoderliness in a system. Gases generally have a higher degree of disorder compared to liquids. Hence for the reaction 2H2(g)+O2(g) ⟶ 2H2O(l), the entropy decreases sice the reactants are in the gaseous state and the products is in the liquid state of matter
How many milliliters of 0.200 M NH4OH are needed to react with 12.0 mL of 0.550 M FeCl3?
FeCl3 + 3NH4OH Fe(OH)3 + 3NH4Cl
Answer:
9.9 ml of 0.200M NH₄OH(aq)
Explanation:
3NH₄OH(Iaq) + FeCl₃(aq) => NH₄Cl(aq) + Fe(OH)₃(s)
?ml of 0.200M NH₄OH(aq) reacts completely with 12ml of 0.550M FeCl₃(aq)
1 x Molarity NH₄OH x Volume Am-OH Solution(L) = 2 x Molarity FeCl₃ x Volume FeCl₃ Solution
1(0.200M)(Vol Am-OH Soln) = 3(0.550M)(0.012L)
=> Vol Am-OH Soln = 3(0.550M)(0.012L)/1(0.200M) = 0.0099 Liter = 9.9 milliliters
The amount of [tex]0.200 M NH_{4} OH[/tex] required to react with [tex]12.0 ml[/tex] of [tex]0.550 M FeCl_{3}[/tex]would be [tex]9.9 ml.[/tex]
Given that,
Reaction:
[tex]3NH_{4} OH(Iaq) + FeCl_{3} (aq) => NH_{4} Cl(aq) + Fe(OH)_{3} (s)[/tex]
To find,
The amount of [tex]0.200 M NH_{4} OH[/tex]required to react with [tex]12.0 ml[/tex] of [tex]0.550 M FeCl_{3}[/tex] = ?
Procedure:
As we know,
[tex]1[/tex] × molarity of [tex]NH_{4}OH[/tex]× [tex]Volume (Am-OH) Solution(l)[/tex] [tex]= 2[/tex] × molarity of [tex]FeCl_{3}[/tex]× volume of solution [tex]FeCl_{3}[/tex]
By substituting the given values in this formula, we get
⇒ [tex]1(0.200M)[/tex][tex](Vol Am-OH Sol)= 3(0.550M)(0.012L)[/tex]
⇒ [tex]Vol Am-OH Soln = 3(0.550M)(0.012L)/1(0.200M)[/tex]
⇒ [tex]Vol Am-OH Solution = 0.099 liters[/tex]
[tex]= 0.099[/tex] × [tex]1000[/tex]
[tex]=[/tex] [tex]9.9 milliliters[/tex]
Thus, [tex]9.9 ml[/tex] is the correct answer.
Learn more about 'compounds' here:
brainly.com/question/13516179
A chemist must prepare of nitric acid solution with a pH of at . He will do this in three steps: Fill a volumetric flask about halfway with distilled water. Measure out a small volume of concentrated () stock nitric acid solution and add it to the flask. Fill the flask to the mark with distilled water. Calculate the volume of concentrated nitric acid that the chemist must measure out in the second step. Round your answer to significant digits.
Answer:
The volume of concentrated nitric acid is
4.3mL
Explanation
Check the attachment
4. A burning candle is an example of a chemical reaction taking place. What i
can be inferred about this reaction? Choose the correct answer."
A.Mass is not conserved.
B. The reaction absorbs energy. C.The reaction releases energy
D.There are reactants but no products,
Answer:
C
Explanation:
heat is energy
Indicate the changes (increases, decreases, does not change) in its volume when the pressure undergoes the following changes at constant temperature and amount of gas. Match the words in the left column to the appropriate blanks in the sentences on the right. Make certain each sentence is complete before submitting your answer. ResetHelp 1. The pressure increases to 6.0 atm. The volume The pressure increases to 6.0 a t m. The volume blank.. 2. The pressure drops to 0.40 atm. The volume The pressure drops to 0.40 a t m. The volume blank.. 3. The pressure remains at 2.0 atm. The volume The pressure remains at 2.0 a t m. The volume blank..
The question is missing information. Here is the complete question.
A gas at a pressure of 2.0 atm is in a closed container. Indicate the changes (if any) in its volume when the pressure undergoes the following changes at constant temperature and constant amount of gas. Match the words in the left with the column to the appropriate blanks in the sentences on the right. Make certain each sentence is complete before submitting your answer.
1. The pressure increases to 6.0 atm. The volume ________
2. The pressure drops to 0.40 atm. The volume _________
3. The pressure remains at 2.0 atm. The volume _________
Answer: 1. Decreases
2. Increases
3. Does not change
Explanation: According to the Ideal Gas Law, Pressure, Volume and Temperature of an ideal gas is related, as the following: PV = nRT.
In this case, since temperature (T) and amount of gas (n) are constant, the Boyle's Law can be used.
The law states that the volume of a given gas, under the conditios of temperature and amount of it are constant, is inversely proportional to the applied pressure: P₁.V₁ = P₂.V₂
For case 1.)Initial P (P₁) = 2
Initial V (V₁) = V
Final P (P₂) = 6
P₁.V₁ = P₂.V₂
2.V = 6.V₂
V₂ = 1/3V
When the pressure increases to 6 atm, volume decreases by 1/3.
For case 2.)P₁ = 2
V₁ = V
P₂ = 0.4
2.V = 0.4V₂
V₂ = 5V
When pressure drops to 0.4 atm, volume increases by 5.
For case 3.)Since there are no change in the pressure, the volume is the same from the beginning, so does not change.
.
5.0 mg of radioactive nobelium-253 was removed from the reactor to be
used in an experiment. It took 291 seconds (just under 5 minutes) to
get the sample from the reactor to the laboratory. How many milligrams
of nobelium-253 remained upon arrival to the laboratory? The half-life
of nobelium-253 is 97 seconds.
Answer:
Explanation:
Half life of Nobelium-253 is 97 seconds . That means after every 97 seconds half of the Nobelium amount will be disintegrated .
Time taken in bringing the sample to laboratory = 291 seconds
291 second = 291 / 97 half life
n = 3
N = [tex]N_0 (\frac{1}{2})^n[/tex]
N₀ is original mass , N is mass after n number of half life.
N = 5 mg x [tex](\frac{1}{2})^3[/tex]
= .625 mg
Only 0.625 mg of Nobelium-253 will be left .
Which of the following is not an indication of a chemical change?
A. Fracture Formation
B. Energy transfer
C. Precipitate formation.
D. Gas production
Answer:
C. precipitate formation.
Explanation:
options C is correct answer.
Answer:
C. precipitate formation.
Explanation:
The number of molecules in one mole of a substance The number of molecules in one mole of a substance depends on the molecular weight of the substance. depends on the temperature of the substance. depends on the atomic weight of the substance. is the same for all substances. depends on the density of the substance.
Answer: is the same for all substances.
Explanation:
The number of molecules in one mole of a substance is the same for all substances because
A mole (which is the quantity of a substance that has the same number (Avogadro's number, is 6.022 * 10^23) of particles as are found in 12.000 grams of carbon-12 of the substance) for any substance has the same number of atoms, molecules, or ions contained in any other substance.
1 mole = 6.022 x 10^23 atoms, molecules, or ions
_______ occurs when a body’s molecular wavelength sends vibrations to another body, resulting in the production of another sound wave
Answer:
Natural frequency
Explanation:
Answer:
Resonance
Explanation:
does the reaction Fe + CuNO3 occur
Answer:
yes
Explanation:
