Answer: 25.3g
Explanation:
The number of moles in chemistry is connected to the Mass and Molar mass of a compond through the following formular;
Moles = Mass (g) / Molar Mass (g/mol)
0.25 mol = Mass (g) / 101 g/mol
Make 'Mass' the subject of the formular;
Mass = 0.25 mol x 101 g/mol
= 25.25 approx 25.3g
The Ksp for Cu(OH)2 is 4.8 × 10-20. Determine the molar solubility of Cu(OH)2 in a buffer solution with a pH of 10.1.
A) 6.0 × 10-10
B) 7.6
C) 2.2 × 10-10
D) 3.8 × 10-16
E) 3.0 × 10-12
Answer:
E) 3.0x10⁻¹²
Explanation:
Ksp of Cu(OH)₂ is defined as:
Cu(OH)₂(s) ⇄ Cu²⁺(aq) + 2 OH⁻(aq)
Ksp = [Cu²⁺] [OH⁻]²
When pH is 10.1, [OH⁻] is:
pOH = 14 - pH
pOH = 3.9
pOH = -log [OH⁻]
[OH⁻] = 1.26x10⁻⁴M
Replacing in ksp formula:
4.8x10⁻²⁰= [Cu²⁺] [1.26x10⁻⁴]²
3.0x10⁻¹² = [Cu²⁺]
That means the maximum amount of Cu²⁺ that can be in solution is 3.0x10⁻¹²M, thus, molar solubility of Cu(OH)₂ is
E) 3.0x10⁻¹²
Considering only specific heat,
would be the most ideal for use in cookware.
Aluminum
Copper
Iron
Lead
Answer:
Considering only specific heat,
✔ lead
would be the most ideal for use in cookware.
However, compared to the other options, lead is too
✔ dangerous and heavy.
Considering everything,
✔ aluminum
or
✔ iron
, would make the best cookware and therefore may be the best choices overall.
What is the effect of adding more water to the following equilibrium reaction?
CO2 + H2O —> 2H2CO3
Answer:
The reaction will be driven forward (to the right), creating more 2H2CO3
Explanation:
Reactions maintain balance so if you add more to the left side of the equation, the right side of the equation will increase
As the amount of charge on two objects increases, the strength of the electrical force between the objects
O increases
O decreases.
O varies
O remains the same
Answer:
Increases, since higher the charge concentration higher the electrical force of attraction and repulsion
What is the name of the “thing” that has antigens on its surface? Where are antigens found on these “things”? Please Help
Answer: Red blood cells is the name of the thing that has antigens on its surface.
Explanation:
The antigens are the molecules which are capable of stimulating an immune response in the body. Based on specific antigen on the surface of RBCs there are separate blood types A, or B. The antigens when inserted into another host organism can activate the antibodies and generate the immune response which can kill the antigens.
The antigens are present on the membranes of the red blood cells.
Interpret Graphics Which magnetic pole is closest to the geographic North Pole?
Answer:
South Magnetic Pole
Write the balanced COMPLETE ionic equation for the reaction when KOH and Cu(NO₃)₂ are mixed in aqueous solution. If no reaction occurs, write only NR.
When KOH and Cu(NO3)2 are mixed in aqueous solution, no precipitation occurs as all ions remain solvated, hence the complete ionic equation shows no net change and is written as NR (no reaction).
Explanation:When KOH (potassium hydroxide) and Cu(NO3)2 (copper(II) nitrate) are mixed in aqueous solution, a double displacement reaction occurs. KOH is a strong base and fully dissociates into K+ and OH− ions in water. Cu(NO3)2 is a soluble salt and dissociates into Cu2+ and NO3− ions.
However, no precipitate is formed in this reaction since all the ions remain in solution. Therefore, the complete ionic equation is:
K+(aq) + OH−(aq) + Cu2+(aq) + 2NO3−(aq) → K+(aq) + 2NO3−(aq) + Cu2+(aq) + OH−(aq)
After canceling the spectator ions, we are left with NR (no reaction) since there is no net change in the species present in the solution.
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Explain the alignment of Earth, Sun and Moon during a lunar and solar eclipse.
Answer: A lunar eclipse occurs when the Moon passes directly behind the Earth into its umbra (shadow). This can occur only when the Sun, Earth, and Moon are aligned exactly with the Earth in the middle.
Explanation:
To solve this, we must know each and every concept related to solar eclipse. Therefore, the alignment of Earth, Sun and Moon during a lunar and solar eclipse is sun, earth and moon.
What is solar eclipse?Solar eclipse occurs when the Moon passes between Sun and earth, casting a shadow on the Earth's surface. This shadow is divided into two parts the umbra, a cone that receives no direct sunlight, as well as the penumbra, which receives light from just a portion of the Sun's disk.
A lunar eclipse happens when the Moon transmits behind and into the shadow of the Earth. This can happen only when the earth, sun, and Moon are perfectly aligned, with Earth in the center.
Therefore, the alignment of Earth, Sun and Moon during a lunar and solar eclipse is sun, earth and moon.
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How do the bones protect your organs?
Answer:
Yes
Explanation:
Bones sustain our bodies, and help shape our form. While very thin, the bones are large enough to bear all of our mass. Bones shield the organs of the body too. The skull supports the brain, and creates the face shape.
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Question: What would be a good acid-base pair from which to prepare a buffer solution whose pH is 10.3?
Answer:
Sry i am unable to see the attached picture but i hope this helps
Explanation:
There are a couple of ways to prepare a buffer solution of a specific pH. In the first method, prepare a solution with an acid and its conjugate base by dissolving the acid form of the buffer in about 60% of the volume of water required to obtain the final solution volume
Answer:10.5 a la cubica co 5 de la 8
Explanation:ok no es bromaaaaa
What time of day is it in location A?
A.
sunrise
B.
daytime
C.
nighttime
D.
sunset
Answer:
B
Explanation:
Sunrise would be nearest the line (where B is), nighttime would be where C is, and sunset isn’t shown on the picture at all.
According to the graph, which statement is true?
The atmosphere is composed of only four gases.
Argon and carbon dioxide are represented in equal proportions.
Nitrogen is the most abundant.
Oxygen is the most plentiful gas
How many forces act on each person? When they put there hands together or High five
Answer:
Left and right: two forces
Total: four forces
Explanation:
If it's just the forces that they are using it would be two the force of each person's hand on the other. However there is also gravity pulling down on their hand but they use another force to pull it up which you can call the normal force.
if this helped please hit the thanks button <3
Answer:
Left and right= two
So the total is four forces.
Sodium (Na) reacts with nitrogen gas (N2) to produce sodium nitride. If a student collects 2.5 moles of sodium nitride (NaN3) after the reaction has been completed, determine the number of moles of nitrogen that were initially present.
2Na + 3N2 -> 2NaN3
Your answer:
3.75 mole N2
1.2 mole N2
3.87 mole N2
Answer : The correct option is, 3.75 mole [tex]N_2[/tex]
Explanation : Given,
Moles of [tex]NaN_3[/tex] = 2.5 mol
The balanced chemical equation is:
[tex]2Na+3N_2\rightarrow 2NaN_3[/tex]
From the balanced reaction we conclude that
As, 2 moles of [tex]NaN_3[/tex] produce from 3 moles of [tex]N_2[/tex]
So, 2.5 moles of [tex]NaN_3[/tex] produce from [tex]\frac{3}{2}\times 2.5=3.75[/tex] moles of [tex]N_2[/tex]
Therefore, the moles of [tex]N_2[/tex] initially present was, 3.75 moles.
How were all living things classified
Answer:
Classification of Living Things. All living organisms are classified into groups based on very basic, shared characteristics.
Explanation:
Answer:
All living things are classified into kingdoms. Living organisms are classified based on similarities within their DNA, structure, reproduction, and appearance.
Explanation:
hope this helped
solution with concentration of 7 mol per L is also denoted as
Answer:7M
Explanation:
There are different methods to express the concentration of a solution. Molarity, mole fraction, normality, molality are some examples. Here 7 mol / L is also called 7 M.
What is molarity?The molarity of a solution is defined as the number of moles of the solute present per litre of the solution. The molarity of a solution is generally expressed in mol / L which is its SI unit. It can also be represented as M.
The equation that is used to calculate the molarity is:
Molarity = Number of moles of the solute / Volume of the solution in litres
If the mass of the solute (w₂) of molecular mass (M₂) present in VL (or dm³) of the solution, then the molarity is given by:
M = w₂ / M₂ × V
Here the solution 7 mol per L can also be designated as 7 M.
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What has 6 valence electrons and 16 protons and ends withthe letter "r"
Answer:
Sulphur
Explanation:
Sulphur(S) is the Sixteenth element of the periodic table and it has an electronic configuration of 2,8,6. This means it has six electrons in its outermost shell( valence electrons).
Sulphur has sixteen(16) protons which is equal to the atomic number which is also sixteen. Sulphur ends with the letter ‘r’. All the descriptions of the element are satisfied and it validates Sulphur.
Final answer:
Sulfur, with symbol 'S', is the element with 6 valence electrons and 16 protons, fitting the clue of ending with 'r'.
Explanation:
The element with 6 valence electrons and 16 protons is sulfur, which is represented by the symbol S on the periodic table. Sulfur is in group 16 of the periodic table, which means it has six electrons in its outermost shell. The ending 'r' in the question hints at sulfur's symbol 'S'. This is consistent with the periodic table where elements in group 16, like oxygen (O) and sulfur (S), indeed have six valence electrons. Sulfur is used in a variety of chemical compounds and has numerous applications in both industrial and biological processes.
For the reaction 2Fe + 3Cl2 → 2FeCl3 which of the following options gives the correct reactant:reactant ratio? Fe:Cl2 = 1:1 Fe:Cl2 = 2:3 Fe:Cl2 = 3:2 Fe:FeCl3 = 1:1
Answer: Fe:Cl2 = 2:3
Explanation:
Answer:
Fe:Cl2 = 2:3
Explanation:
What is the molarity of H2SO3 if 250 mL of the acid was used to neutralize 200 mL of 1.5 M solution of Mg(OH)2?
Answer: Molarity of [tex]H_2SO_3[/tex] is 1.2 M.
Explanation:
To calculate the volume of acid, we use the equation given by neutralization reaction:
[tex]n_1M_1V_1=n_2M_2V_2[/tex]
where,
[tex]n_1,M_1\text{ and }V_1[/tex] are the n-factor, molarity and volume of acid which is [tex]H_2SO_3[/tex]
[tex]n_2,M_2\text{ and }V_2[/tex] are the n-factor, molarity and volume of base which is [tex]Mg(OH)_2[/tex]
We are given:
[tex]n_1=2\\M_1=?\\V_1=250mL\\n_2=2\\M_2=1.5M\\V_2=200mL[/tex]
Putting values in above equation, we get:
[tex]2\times M_1\times 250=2\times 1.5\times 200\\\\M_1=1.2M[/tex]
Thus molarity of [tex]H_2SO_3[/tex] is 1.2 M if 250 mL of the acid was used to neutralize 200 mL of 1.5 M solution of [tex]Mg(OH)_2[/tex]
jermey has two plants. he waters both equally. he puts one plant outside. he puts another plant in a closet
which one is true about the plants?
A. the plant in closet will die.
B. plants only need soil to grow.
c. plants only need water to grow.
d.it does not matter where he puts the plant.
A molecule of pentane is made of 5 carbon atoms and 12 hydrogen atoms. A collection of pentane molecules has 3.01 x 1024 carbon atoms. How many hydrogen atoms are in
the collection?
A. 3.01 x 1024 x (12/5) hydrogen atoms
B. (3.01 X 1024 / 5) hydrogen atoms
C. 3.01 x 1024 x 12 hydrogen atoms
D. 3.01 x 1024 x (5/12) hydrogen atoms
Answer:
3.01 × 1024 × (12/5) hydrogen atoms
Explanation:
A 250mL sample of air at STP contains approximately 52.5mL of O2. What is the percentage of oxygen in the air
Answer: 21 percent
Explanation:
Percentage of oxygen in the air is 21%
Percentage based formula:Given that;
Volume of air sample = 250 ml
Volume of O2 in sample = 52.5 ml
Find:
Percentage of oxygen in the air
Computation:
Percentage of oxygen in the air = [Volume of O2 in sample / Volume of air sample] × 100
Percentage of oxygen in the air = [52.5 / 250] × 100
Percentage of oxygen in the air = 21%
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which statement correctly compares chemical reactions with nuclear reactions?
Answer:
B. In chemical reactions, small amounts of energy can be absorbed or released. In nuclear reactions, changes in energy are much larger.
Explanation:
I apologize if this answer is late or doesn't answer your original question, but I answered this question correctly on my quiz :)
I hope others will find this helpful! :D
Positive ions from a base and negative ions from an acid forma
Electrical energy can be transformed into other types of energy. We often experience this transformation of energy in our everyday
lives. In one example the intended energy transformation produces thermal energy. That is the
Answer:
D) the pot
Explanation:
cus it produces thermal energy
The number of total electrons of iron is:
a) 55.85
b)29.85
c)26
d)27.78
e) 56
which of the following is the most stable isotope?
a. carbon-14
b. uranium-235
c. francium-227
d.plutonium-238
Answer:a. Carbon
Explanation:
What is an inorganic chemical?
O
A. A chemical that makes up living things
O
B. A chemical that is not from living things
O
C. A chemical that does not take part in reactions
O
D. A chemical that contains carbon atoms
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What is green building?
Answer:
Green building is usually referred to as those structures and buildings that are constructed in such a way that it helps in eliminating the negative influences such as pollution, emission of harmful gases in the environment, and in return, positively influences the ecosystem, environment and the climate in any particular place.
Explanation:
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What is the pH of 0.000134 M solution of HCI?
Answer: The pH will be 3.87
Explanation:
pH or pOH is the measure of acidity or alkalinity of a solution.
pH is calculated by taking negative logarithm of hydrogen ion concentration.
[tex]pH=-\log [H^+][/tex]
[tex]HCl\rightarrow H^++Cl^{-}[/tex]
According to stoichiometry,
1 mole of [tex]HCl[/tex] gives 1 mole of [tex]H^+[/tex]
Thus [tex]0.000134[/tex] moles of [tex]HCl[/tex] gives =[tex]\frac{1}{1}\times 0.000134=0.0001342[/tex] moles of [tex]H^+[/tex]
Putting in the values:
[tex]pH=-\log[0.000134][/tex]
[tex]pH=3.87[/tex]
Thus the pH will be 3.87
Answer: The pH of 0.000134 M solution of HCl is 3.873.
Explanation:
When HCl dissociates in water then it will give hydrogen and chlorine ions. The reaction will be as follows.
[tex]HCl \rightarrow H^{+} + Cl^{-}[/tex]
This means that 1 mole of HCl is giving 1 mole of hydrogen ions on dissociation.
Hence, pH of the given solution will be calculated as follows.
pH = [tex]-log [H^{+}][/tex]
= [tex]-log (0.000134)[/tex]
= 3.873
Thus, we can conclude that the pH of 0.000134 M solution of HCl is 3.873.