determine the ph of a buffer that is 0.55 M HNO2 and 0.75 M KNO2. tha value of Ka for HNO2 is 6.8*10^-4
Answer:
pH = 3.3
Explanation:
Buffer solutions minimize changes in pH when quantities of acid or base are added into the mix. The typical buffer composition is a weak electrolyte (wk acid or weak base) plus the salt of the weak electrolyte. On addition of acid or base to the buffer solution, the solution chemistry functions to remove the acid or base by reacting with the components of the buffer to shift the equilibrium of the weak electrolyte left or right to remove the excess hydronium ions or hydroxide ions is a way that results in very little change in pH of the system. One should note that buffer solutions do not prevent changes in pH but minimize changes in pH. If enough acid or base is added the buffer chemistry can be destroyed.
In this problem, the weak electrolyte is HNO₂(aq) and the salt is KNO₂(aq). In equation, the buffer solution is 0.55M HNO₂ ⇄ H⁺ + 0.75M KNO₂⁻ . The potassium ion is a spectator ion and does not enter into determination of the pH of the solution. The object is to determine the hydronium ion concentration (H⁺) and apply to the expression pH = -log[H⁺].
Solution using the I.C.E. table:
HNO₂ ⇄ H⁺ + KNO₂⁻
C(i) 0.55M 0M 0.75M
ΔC -x +x +x
C(eq) 0.55M - x x 0.75M + x b/c [HNO₂] / Ka > 100, the x can be
dropped giving ...
≅0.55M x ≅0.75M
Ka = [H⁺][NO₂⁻]/[HNO₂] => [H⁺] = Ka · [HNO₂]/[NO₂⁻]
=> [H⁺] = 6.80x010⁻⁴(0.55) / (0.75) = 4.99 x 10⁻⁴M
pH = -log[H⁺] = -log(4.99 x 10⁻⁴) -(-3.3) = 3.3
Solution using the Henderson-Hasselbalch Equation:
pH = pKa + log[Base]/[Acid] = -log(Ka) + log[Base]/[Acid]
= -log(6.8 x 10⁻⁴) + log[(0.75M)/(0.55M)]
= -(-3.17) + 0.14 = 3.17 + 0.14 = 3.31 ≅ 3.3
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The melting and boiling point tests will MOST help them to infer the strength of intermolecular forces between ionic and covalent compounds?
Question 12 options:
True
False
Answer:
True po
Explanation:
Sana nakatutulong
#Carry on learning
Ionic compounds have higher melting and boiling point than covalent compounds, since ionic bonds are stronger than covalent bonds. Hence, we can compare the intermolecular forces using melting or boiling points.
What is boiling point?Boiling point of a substance is the temperature at which the substance changes from liquid state to gaseous state. Melting point is the temperature at which the substance changes from solid state to liquid state.
Both melting point and boiling point depends on the bond type, molecular weight, temperature and pressure. Stronger the bond , higher energy needed to weaken the intermolecular force between molecules to convert them to liquid state or vapour state.
Hence, the temperature that have to be applied to loosen the bonds to boil them or melt them increases as bond strength increases. Therefore, these physical quantities definitely helps to infer the strength of bonds.
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Which ions are isoelectronic with ar?.
Answer:
Isoelectronic means same electronic configuration as Ar. These are such as sulfide ion (S2− ), chloride ion (Cl− ) and phosphide ion (P3− ).
Explanation:
Any atom or ion with 18 electrons is isoelectronic with Ar. Some examples are:
Ca2+S2-Cl-What are isoelectronic?Isoelectronic atoms or ions refer to those that possess an identical number of electrons consequently sharing the same electron configuration. The term "isoelectronic" derives from the Greek words "isos " signifying "equal " and "elektron " denoting "electron".
It is worth noting that isoelectronic atoms or ions may exhibit varying atomic numbers and charges; nonetheless, their electron count remains constant.
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IF U HAAD THEE RIGHHT ANSWERRR PLZZZ
- Which of the following is NOT part of Dalton's atomic theory?
A) Atoms are the smallest, indivisible particles in nature.
B) Chemical reactions are simple rearrangements of atoms.
C) Atoms follow the law of multiple proportions.
D) Each atom of an element is identical to every other atom of that element. b
Answer:A
Explanation: I’m pretty sure
Which liquid will evaporate more rapidly? Explain your answer in terms of intermolecular forces
acer
An atom of sodium has 11 electrons. Make a sketch of a sodium atom, showing how many electrons it has at each energy level. Infer how reactive sodium atoms are.
SOMEONE PLEASE HELP ME OUT. :( I DONT GET IT !!!
Answer:
Sodium has 11 electrons. The first two fill the innermost energy level. The second energy level is also full, holding eight electrons and one electron remaining in the outer energy level. It is the number of outer electrons that give an element its chemical properties.
Explanation:
Sodium has 11 electrons. Therefore electronic configuration of sodium is (2,8,1).
What are electrons?
Electrons are the negatively charged particles of an atom. An atom contains a positive proton, a negative electron, and a neutral neutron. Electrons are negatively charged particles that rotate around the atom.
There are around 118 elements in the earth. Sodium is a important element. The atomic number of sodium is 11. The first shell contains 2 electrons, 2nd shell contains 8 electrons and 3rd shell will have 1 electron in sodium.
Sodium is a metal. It will loose that one electron and become cation. It become Na+.
Therefore, Sodium has 11 electrons. Therefore electronic configuration of sodium is (2,8,1).
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Which statement accurately compares these flashlights?
A. The smaller flashlight has more inertia than the larger flashlight,
so it takes less force to change the motion of the smaller
flashlight
B. The smaller flashlight has less inertia than the larger flashlight, so
it takes more force to change the motion of the smaller flashlight.
C. The smaller flashlight has less inertia than the larger flashlight, so
it takes less force to change the motion of the smaller flashlight.
D. The smaller flashlight has more inertia than the larger flashlight,
so it takes more force to change the motion of the smaller
flashlight
The small flashlight has less inertia and smaller force is required to move it.
According to Newton's first law of motion, an object will continue at rest or in its state of uniform motion unless it is acted upon by an external unbalanced force. This is also called the law of inertia.
The quantity of mass contained in a body is a measure of its inertia. The greater the mass of the body, the greater the inertia and the greater the force required to move the body.
The smaller flashlight has less inertia than the larger flashlight, so it takes less force to change the motion of the smaller flashlight.
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Where does the energy come from to break the bonds of water and carbon dioxide molecules?
Answer:
carbohydrates
Explanation:
or carbon dioxide
what is the periodic trend for electronegativity
Answer:
mark me brainlest
Explanation:
Electronegativity values generally increase from left to right across the periodic table. Electronegativities generally decrease from top to bottom of a group. The highest electronegativity value is for fluorine.
Answer:
"Electronegativity increases as you move from left to right across a period because the number of charges on the nucleus increases." (sstudy30 on Quizlet)
Explanation:
It explains itself haha!
Have a nice day!
I hope this is what you are looking for, but if not - comment! I will edit and update my answer accordingly. (ノ^∇^)
- Heather
Why is productivity greatest near the ocean’s surface
Answer:
Sunlight penetrates the top layers of the ocean, so photosynthesis occurs there.
Explanation:
how can you keep a cold drink cold without ice or a refrigerator
Answer:
snow and a cooler
Explanation:
so if its really cold out side put your drink out there.
How many cl- ions are there in 2. 50 kg of barium chooride.
Which list includes only bulk properties of matter?
-boiling point, kinetic energy, surface tension
-kinetic energy, the strength of electrical forces, vapour pressure
-boiling point, the strength of electrical forces, vapour pressure
-boiling point, surface tension, vapour pressure
Boiling point, surface tension and vapour pressure is the list that includes only bulk properties of matter.
Bulk matter refers to those materials that contains large numbers of atoms, molecules, or ions. Its can be present into all states of matter that may be solid, liquid or gas.
Boiling is a bulk process and occurs throughout the liquid as well as surface tension and vapour pressure is also bulk properties of matter so we can conclude that boiling point, surface tension and vapour pressure is the list that includes only bulk properties of matter.
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How do you think getting fewer of these molecules to her cells contributed to Elisa’s tiredness?
Answer:
Elisa is always tired because her cells arent producing enough sugars also know as glucose forher body. another way to write out glucose is to use its equation C6H12O6.
Explanation:
Students figure out: Elisa feels tired because her cells aren't getting the molecules they need from food and air, which are necessary for her cells to function, grow, and repair. ... Students figure out: Elisa's cells are getting enough oxygen and amino acids, but not enough glucose
why are baseballs harder to pick up tennis balls?
Explanation:
Because baseballs are made out of things that make it heavier then tennis balls, easier to play the sport. that's why they use a bat in baseball.
Analysis of a 1.7500-g sample of
Pepto-Bismol yields 346 mg of bismuth. What percent by
mass is bismuth subsalicylate in the sample? (Assume that
there are no other bismuth-containing compounds in
Pepto-Bismol.)
Answer:
19.8 %
Explanation:
Analysis of a 1.7500-g sample of
Pepto-Bismol yields 346 mg of bismuth. What percent by
mass is bismuth subsalicylate in the sample? (Assume that
there are no other bismuth-containing compounds in
Pepto-Bismol.)
346 mg = 0.346 gm
0.346 gm/1.75 gm =0.198 = 19.8 %
If anhydrous mgso4 is the desired product, what is the atom economy of this reaction?.
This problem is referring to an anhydrous salt that is derive from a hydrated Epson salt (magnesium sulfate hydrate) and the atom economy is required. However, not enough information is provided, yet we can use the attached file as a reference to provide a methodology of calculation.
To begin with, we need to calculate the [tex]x[/tex] which refers to the degree of hydration of the salt, so that we use the mass before and after heating the sample to figure out the grams and subsequently moles of water that are in there:
[tex]m_w=3.648g-1.782g=1.866g\\\\n_w=0.103molH_2O[/tex]
Next, since 1.782g corresponds to the anhydrous salt, we calculate the moles in such a amount:
[tex]1.782gMgSO_4*\frac{1molMgSO_4}{120.4gMgSO_4}=0.0148mol[/tex]
Then, we divide the moles of water by those of the anhydrous salt to calculte [tex]x[/tex]:
[tex]x=\frac{0.103mol}{0.0148mol} =6.96=7[/tex]
This means the formula of the hydrate is:
[tex]MgSO_4\ 7H_2O[/tex]
Finally, for the atom economy we just divide the molar mass of the anhydrous salt by that of the hydrate:
[tex]A.E=\frac{120.4g/mol}{246.47g/mol} *100\%\\\\A.E=48.8\%[/tex]
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https://brainly.com/question/20796771Which pair of objects is experiencing the greatest gravitational force?
2 kg
2 kg
A.
d = 5 m
2 kg
2 kg
B.
dolm
5 kg
skg
doim
3 kg
skg
OD
da 5 m
Answer:
c
Explanation:
How do mixtures differ from substances?
Answer:
In chemistry: a pure substance consists only of one element or one compound. a mixture consists of two or more different substances, not chemically joined together.
Hope this helps :)
TRUE or FALSE the term “anti-inflammatory” likely means “against inflammation”
Answer:
True
ANTI MEANS AGAINST
Explanation:
what is temperature?
Answer:
a measure of hotness or coldness expressed in terms of a scale like Fahrenheit or Celcius
What is the molar concentration of a solution prepared by dissolving 3.05 grams of sodium acetate in enough water to prepare 3.43 x 102 mL of the solution
Answer:
0.296 M
Explanation:
What is the molar concentration of a solution prepared by dissolving 3.05 grams of sodium acetate in enough water to prepare 3.43 x 102 mL of the solution
sodium acetate NaCH3COO has molar mas of
23 + 12 +24 + 1 +32 = 92 g/mol
3.05 g is 3.05 g/ 92 g/mol = 0.0328 moles
it is distributed over 102 mL = 0.102 L
its concentration is 0.0328/ 0.102 =0.296 M Mhttps://brainly.com/question/25586315?answering=true&answeringSource=feedPublic%2FhomePage%2F3#
Sort the following elements in order from least reactive to most reactive.
A - Sb
B - S
C - F
D - As
Sorting the chemical elements in order from least reactive to most reactive, we have:
1. Fluorine (F).
2. Arsenic (As).
3. Antimony (Sb).
4. Silicon (S).
Given the following chemical elements:
Antimony (Sb).Silicon (S).Fluorine (F).Arsenic (As).Reactivity can be defined as a chemical property which determines how readily a chemical element bonds with other chemical elements, in order to form a new chemical compound.
Generally, the ability of a chemical element to bond with other chemical elements is largely (highly) dependent on the number of valence electrons it has in the outermost shell of its atomic nucleus.
As a general rule, chemical elements that are having fewer number of valence electrons are the most reactive while those having higher valence electrons are least reactive.
Also, chemical reactivity decreases down a group on the periodic table.
Based on the periodic table, the valency for the given chemical elements are:
Antimony (Sb): 5 valence electrons.Silicon (S): 4 valence electrons.Fluorine (F): 7 valence electrons.Arsenic (As): 5 valence electrons.In conclusion, sorting the chemical elements in order from least reactive to most reactive, we have:
1. Fluorine (F).
2. Arsenic (As).
3. Antimony (Sb).
4. Silicon (S).
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What is the meaning of term Amino acid
Answer:
Amino acids are molecules that combine to form proteins.
Explanation:
Amino acids are molecules that combine to form proteins. Amino acids and proteins are the building blocks of life. When proteins are digested or broken down, amino acids are left. The human body uses amino acids to make proteins to help the body: ... Repair body tissue.
Hope this helps :)
what makes your pulse? Explain
How to find the partial pressure of a gas.
Answer:
The total pressure of a mixture of gases can be defined as the sum of the pressures of each individual gas: Ptotal=P1+P2+… +Pn. + P n . The partial pressure of an individual gas is equal to the total pressure multiplied by the mole fraction of that gas.
Using diving terms, partial pressure is calculated as: partial pressure = (total absolute pressure) × (volume fraction of gas component) For the component gas "i": pi = P × F.
Break down the following equations into two half equations(One for oxidation, one or reduction )
1. Cu + 2Ag+ ➡️Cu2+ +2Ag
2. Cl2 +2I ➡️2cl-+I2
Answer:
see explanation
Explanation:
Break down the following equations into two half equations(One for oxidation, one or reduction )
1. Cu + 2Ag+ ➡️Cu2+ +2Ag
2. Cl2 +2I- ➡️I2 + 2Cl-
in reaction "1", the copper is being oxidized from 0 to +2 by losing 2 electrons
Cu---->Cu2+ + 2e-in reaction "2
in reaction "1" the silver is being reduced by gaining those 2 e-.
2Ag1+ + 2e----------->2Ag
In reaction "2", the iodine is being oxidized by losing 2 e-
2I- -------------> I2 + 2e
In reaction "2" the chlorine is being reduced by gaining those 2 e
Cl2 + 2e------------> 2Cl-
To solve such this we must know the concept of redox reaction. Therefore, the half reaction for the given reactions can be written as
1. Cu + 2Ag⁺ [tex]\rightarrow[/tex]Cu²⁺ +2A
Cu [tex]\rightarrow[/tex]Cu²⁺ + 2e⁻
2Ag⁺ + 2e⁻[tex]\rightarrow[/tex]2Ag
2.Cl[tex]_2[/tex]+2I⁻ [tex]\rightarrow[/tex]I[tex]_2[/tex] + 2Cl⁻
2I⁻[tex]\rightarrow[/tex] I[tex]_2[/tex] + 2e⁻
Cl[tex]_2[/tex] + 2e⁻-----------> 2Cl⁻
What is chemical reaction?Chemical reaction is a process in which two or more than two molecules collide in right orientation and energy to form a new chemical compound. The mass of the overall reaction should be conserved. There are so many types of chemical reaction reaction like combination reaction, double displacement reaction.
Redox reaction is a chemical reaction where oxidation and reduction takes place simultaneously. Oxidation is loss of electrons and reduction is gain of electrons. The electron transfer from oxidant to reductant.
1. Cu + 2Ag⁺ [tex]\rightarrow[/tex]Cu²⁺ +2A
Cu [tex]\rightarrow[/tex]Cu²⁺ + 2e⁻
2Ag⁺ + 2e⁻[tex]\rightarrow[/tex]2Ag
2.Cl[tex]_2[/tex]+2I⁻ [tex]\rightarrow[/tex]I[tex]_2[/tex] + 2Cl⁻
2I⁻[tex]\rightarrow[/tex] I[tex]_2[/tex] + 2e⁻
Cl[tex]_2[/tex] + 2e⁻-----------> 2Cl⁻
Therefore, the half reaction for the given reactions can be written as above.
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Which best describes the role of a negative feedback loop?
0 The output is reduced so the body can maintain homeostasis.
0 The output builds so the body can maintain homeostasis.
0 Hormone levels in the blood increase to increase effects.
0 Hormone levels in the blood decrease to increase effects.
Pls Hurry!!!! ANYONE PLS HELP ME!! I AM DOING THE UNIT TEST AND I NEED THIS FAST!!! APAP PPL!! PLS!! WILL MARK BRAINLIEST!!!
Answer:
A
Explanation:
now I'm not sure, but considering negative feedback allows the systems to self stabilize that would be the best option.
PLEASE NOTE THAT THIS IS A EDUCATED GUESS.
What is the unabbreviated electron configuration for Neptunium?
Answer:
Please mark me as brainliest and also give me 5 start Thank you
Explanation:
The radioactive element neptunium (atomic number 93) has the electron configuration
1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p6 5s2 4d10 5p64f14 5d10 6s2 6p6 7s2 6d1 5f4
The noble gas form is
[Rn] 7s2 6d1 5f4
Using the information in the table, calculate the number of moles in a 7.89 kg sample of aspirin
(C9H8O4).
Write your answer using three significant figures.
Answer:
43.7mol
Explanation:
[tex]?mol = 7.86kg * \frac{1000g}{1kg} *\frac{1mol}{180g}[/tex]
Above is dimensional analysis method. Write what you are trying to find with the question mark and write your given info on the other side of the equal sign. Follow the units and pay attention to them cancelling out. You should have your answer unit by the end.
the 180g came from the table with masses times the chemical formula all added together. Below is exact formula.
hydrogen mass(hydrogen amount) + carbon mass(carbon amount) + oxygen mass(oxygen amount)
1g(8)+12g(9)+16g(4)=180g
180g is 1 mole of [tex]C_{9} H_{8} O_{4}[/tex]