Answer:
Physical models can represent objects or systems that are too small, too big, or too far away to study. They are way easier, cheaper, and safer to work with or use when compared to the real objects that they represent.
Explanation:
A buffer solution contains 0.0200 M acetic acid and 0.0200 M sodium acetate. What is the pH after 2.0 mmol of NaOH are added to 1.00 L of this buffer? pKa = 4.75 for acetic acid.
Answer:
The correct answer is 4.84
Explanation:
We use the Henderson Hasselbach's equation to calculate the pH of a buffer solution:
pH = pKa = log ( [conjugate base]/[weak acid])
In this case:
conjugate base: acetate ⇒ [conjugate base] = [acetate] = 0.0200 M
weak acid: acetic acid ⇒ [weak acid] = [acetic acid] = 0,0200 M
pH = pKa + log ([acetate]/[acetic acid])= pKa + log (0.0200 M/0.0200 M)
When a strong base- such as NaOH- is added, the acid reacts with OH⁻ to form the conjugate base. So, the conjugate base is increased while the acid is decreased. Thus, in 1 liter of solution we have:
acetate = (0,0200 mol/L x 1 L) + (2.0 mmol x 1 mol/1000 mmol) = 0.022 mol
acetic acid= (0,0200 mol/L x 1 L) - (2.0 mmol x 1 mol/1000 mmol) = 0.018 mol
Finally, we calculate the pH:
pH = 4.75 + log (0.022 mol /0.018 mol )= 4.84
Buffer has been the solution that resists the change in the pH of the solution with the addition of acid or base. The pH of buffer with NaOH has been 4.84.
What is pH?The pH has been the hydrogen ion concentration in the solution. The pH has been equivalent to pKa and can be given as:
[tex]\rm pka=log\dfrac{[base]}{[acid]}[/tex]
The base in the buffer has been the acetate, while acetic acid act as the acid.
The concentration of NaOH added to the solution has been given as:
[tex]\rm Molarity=\dfrac{moles}{volume}\\\\ NaOH=\dfrac{0.002\;mol}{1\;L}\\\\ NaOH=0.002\;M[/tex]
The addition of NaOH adds the concentration of base, and neutralization reduces the concentration of acid. Thus, the new pKa can be given as:
[tex]\rm pKa=log\dfrac{0.2+0.002}{0.2-0.002} \\pKa=log\dfrac{0.022}{0.018}[/tex]
The new pH of the solution has been the sum of the old and the new pKa value.
Thus, the pH of the new buffer has been given as:
[tex]\rm pH=4.75+log\dfrac{0.022}{0.018}\\ pH=4.84[/tex]
The pH of buffer with NaOH has been 4.84.
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Which statement best describes heating by conduction?
1. Sunlight travels through space without the aid of fluids or solids.
2. Air at the equator rises and sinks at the poles.
3. Air molecules touch the warm ground, heating them up.
4. Warm air rises and takes heat with it; eventually it cools and sinks.
(If you want brainliest please explain why the answer is that answer)
Answer:
It would be A. Air molecules touch the warm ground, Heating them up because conduction is when a source of energy touches something directly.
Answer:
3. Air molecules touch the warm ground, heating them up.
Explanation:
What electrically neutral atom has 30 neutrons and 25 electrons?
Answer:
Manganese (Mn)
Explanation:
We know it's manganese because we are told it is an electrically neutral atom. This means it has the same number of protons and electrons. If it has 25 electrons, it has 25 protons. Protons tell us the atomic number of the atom, which also tells us the name of the element. Manganese is element 25 on the periodic table.
Please help me it’s due today
Answer:
I think it is A. the two forces are equal, or balanced, neither the table nor the book moves up or down.
Explanation:
Tome, the other options don’t make no sense
Write two sentences explaining how the illustration and student observations support the cell theory?
Answer:
The classical cell theory was proposed by Theodor Schwann in 1839. There are three parts to this theory.
Explanation:
How many moles of CO are produced when 1.8 moles C reacts?
Express your answer using two significat figures.
5C(s) + 2SO2(g) => CS2(l) +4CO(g)
Answer:
1.44mole of CO
Explanation:
The reaction equation is given as:
5C + 2SO₂ → CS₂ + 4CO
We check to see if the expression is balanced and it is so;
Now;
Given;
1.8mole of C reacted; how many moles of CO are produced;
From the balanced reaction equation:
5 mole of C is expected to produce 4 mole of CO
1.8 mole of C will then produce [tex]\frac{4 x 1.8}{5}[/tex] = 1.44mole of CO
Which units can be used to describe the thermal
energy within a substance?
Answer: Btu, British Thermal Unit is used to express thermal energy when working in pounds and degrees Farenheit.
Calories are used when working in grams and degrees Centigrade or Kelvin (SI units)
A Joule is the British system unit used to measure heat transfer.
Explanation:
Select the best answer from the choices below. Light has many properties of waves, but sometimes it also behaves like:
Answer:
A photon
Explanation:
When electrons pass close to the standing wave of light, they hit the particles that are called photons
plz help ❤️
Explain how the pH of water has a synergistic relationship with other substances.
Provide an example.
Answer:
Explanation:
he pH of the water will determine the toxic effects, if any, of these substances.
Pure water is neutral with the pH of 7. But when water combines with other substance the pH varies as per the acidity of the combining substance.
What is pH?pH is the measure of acidity of a solution and mathematically it is the negative logarithm of hydrogen ion concentration. Acidic substance have a pH of less than 7 whereas, basic substance have higher pH value.
Water when combines with some acids, its acidity increases. For example acid rain resulting from the reaction of rain water with oxides of nitrogen and Sulphur forming nitric acid and sulphuric acid.
pH of water have a role in the toxic effects of components in water pH and alkalinity of water determines the coagulation of other substances in water.
Hence, the properties of other substance in water is pH dependent and might effect the alkalinity or acidity of water as well the properties of substances in water such as toxicity.
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22. Which of the following molecules or ions contain polar bonds?
If Phosphorus, P, gained 3 electrons, the net ion charge would be
+5
-5
+3
-3
Answer:
-3
Explanation:
Phosphorus becomes phosphide with a -3 charge
A solution of NaF is added dropwise to a solution that is 0.0173 M in Ba 2. When the concentration of F- exceeds___M BaF2 will precipiate. Neglect volume changes. For BaF2
Answer:
0.0099M = [F⁻]
Explanation:
For BaF2, Ksp = 1.7x10⁻⁶
When BaF₂ is in solution, the equilibrium between the solid and the dissociated ions occurs as follows:
BaF₂(s) ⇄ Ba²⁺(aq) + 2F⁻(aq)
Where Ksp = 1.7x10⁻⁶ is defined as:
1.7x10⁻⁶ = [Ba²⁺] [F⁻]²
Where [] are equilibrium concentrations of each ion in solution.
That means you will add F⁻ until its concentration exceeds:
1.7x10⁻⁶ = [0.0173] [F⁻]²
9.827x10⁻⁵ = [F⁻]²
0.0099M = [F⁻]When more F⁻ is added, BaF₂ begins its precipitation.
what ore is turned to finished aluminum
An example of a suspension is a ____
A)chemical b)heterogenous
c)homogenous d)salad
Answer:
b
Explanation:
suspension is the heterogenos solution
Which term best describes the materials that make up rocks?
sand left by erosion
compressed magma
a mixture of minerals
layers of lava
Answer:
is c a mixture of minerals
Explanation:
Why do some transition metals have multiple oxidation states?
Transition metals have multiple oxidation states because of their
sublevel.
Answer:
Transition metals can have multiple oxidation states because of their electrons. The transition metals have several electrons with similar energies, so one or all of them can be removed, depending the circumstances. This results in different oxidation states.
Answer:
The answers are "partially filled" and "d" on Plato
Explanation:
Name and write one polyatomic ion with its charge.
Answer:
Because these ions contain more than one atom, they are called polyatomic ions. Polyatomic ions have characteristic formulas, names, and charges that should be memorized. For example, NO3− is the nitrate ion; it has one nitrogen atom and three oxygen atoms and an overall 1− charge.
Polyatomic Ions.
Name Formula
sulfite ion SO32−
Explanation:
List what you are thankful for! (It's Thanksgiving! Answer if you bake! Or if you like cakes pies cookies and treats!!! )
Answer:
I do not bake but my mom is a professional baker.
Explanation:
A roof over my head and a warm home.
Plenty of drinkable water.
I don't have to go hungry.
I can enjoy the small and free pleasures of life.
Access to the internet.
My friends and family.
My health.
The kindness of people I have never met before.
Choose ALL the answers that apply.
Sound _____.
travels in transverse waves
requires a medium to travel through
travels most slowly through solids
speeds up when temperature is increased
is changed into electrical impulses by the cochlea
Answer:
Speeds up when temperature is increased and can travel through a solid
Explanation:
Select the correct answer. The perimeter of a rectangle is 42 inches. If the width of the rectangle is 6 inches, what is the length? A. 12 inches B. 15 inches C. 21 inches D. 40 inches
Answer:
15
I hope this helps
X-rays are often used in medical settings to create images of the body's internal structures such as bones. This is made possible by the
fact that X-rays are able to pass through the body's softer tissues without being absorbed.
Radio waves are also able to pass through the body's softer tissues without being absorbed. Why are radio waves not used to generate
medical images?
OA. The electrons in most atoms are not in high enough energy states to absorb the photons of radio waves.
OB. Radio waves tend to bend too much when they encounter solid materials to be used for generating accurate images,
OC
The frequency of most radio waves is too low to allow them to pass through bones or other solid materials.
OD.
Radio waves carry so little energy that they tend to pass through most atoms without an interaction taking place.
Answer:D
Explanation:I did it on study island.
Radio waves are not used to generate medical images because as per the electromagnetic spectrum ,the radio waves carry little energy that they pass through most atoms without interaction.
What is an electromagnetic spectrum?The electromagnetic spectrum consists of radiation which consists of waves made up of electromagnetic field which are capable of propogating through space and carry the radiant electromagnetic energy.
The radiation are composed of electromagnetic waves which are synchronized oscillations of electric and magnetic fields . They are created due to change which is periodic in electric as well as magnetic fields.
In vacuum ,all the electromagnetic waves travel at the same speed that is with the speed of air.The position of an electromagnetic wave in an electromagnetic spectrum is characterized by it's frequency or wavelength.They are emitted by electrically charged particles which undergo acceleration and subsequently interact with other charged particles.
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What is the mass of florine
Answer:
18.998403
is the mass
What is the charge on an atom after it gains two electrons during the formation of a bond?
One positive charge
Two positive charges
Two negative charges
One negative charge
Answer:
Two Negative Charges
Explanation:
C. Two negative charges
If an atom has an equal number of protons and electrons, its net charge is 0. If it gains an extra electron, it becomes negatively charged and is known as an anion. If it loses an electron, it becomes positively charged and is known as a cation.Given condition: An atom gains two electrons during the formation of a bond.
As we know gaining an electron results in a negative charge and here two electrons being gained.
Therefore, the charge on it after gaining two electrons will be two negative charges.
Thus, the correct option is option C.
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What is the hydroxide concentration of a solution with a poH of 2? Is this solution acidic, basic or neutral?
1.For Structure B the bond between carbon and sulfur is polar or non polar
2. Explain you’re answer
Answer:
polar
Explanation:
because carbon and sulfur have different electronegativities, the S=C bond is polar.
The entire molecule is nonpolar however because the dipoles (polar bonds) cancel out due to the geometry of the molecule (linear)
What will be the substitution product of (S)-2-chloro-3-methylbutane in polar aprotic conditions favoring SN2?
In the compound MgCl2, the subscript 2 indicates
The subscript 2 indicates number of Cl atoms
Further explanationThe molecular formula shows the number of atoms of a compound
whereas the empirical formula is the simplest comparison of the atoms making up the compound
MgCl₂ is an ionic compound composed of Mg and Cl atoms
Mg is in group 2 which has a +2 charge, while Cl is in the Halogen group which has a charge of -1
If the two are bonded, the 2 electrons released by Mg will be bound by 2 Cl atoms, each of which atoms of Cl need 1 more electron in order to obtain a stable electron configuration such as a noble gas
So the number 2 in the MgCl compound indicates the number of Cl atoms
Perform the arithmic shown AND round your answers to the correct number of significant digits.
56.5in + 95.3in + 15 in
(Fill in the blank)
Answer:
167in
Explanation:
Given arithmetic;
56.5in + 95.3in + 15in
To determine the correct significant digits, the sum cannot be more precise than the least precise value in the addition;
The least precise is 15in and it is in 2significant places;
56.5in
95.3in
+ 15 in
......................
166.8in
......................
The value is 167in
If you wanted to change the polarity of hydrogen bromide (HBr) by substituting the bromine with a different atom. Which atom would increase the polarity of the molecule?
Answer:
This question is incomplete as it lacks options, the options are:
A. chlorine (CI)
B. iodine (1)
C. sulfur (S)
D. hydrogen (H)
The answer is A. Chlorine
Explanation:
Polarity of a substance in chemistry is a function of electric charges in the atoms of the molecules involved. Polarity, however, can be increased or decreased in molecules depending on the charges of the atoms that form them.
Since polarity increases when an atom in the molecule has a high ability to pull electrons toward itself i.e. electronegativity, one atom that can be substituted for Bromine in the hydrogen bromide (HBr) molecule in order to increase its polarity is CHLORINE. This is because Chlorine (Cl) is more electronegative than Bromine atom, hence, will pull more electrons from hydrogen to make the HCl molecule more polar than HBr.
To increase the polarity of HBr, the bromine atom can be replaced with a hydrogen atom.
A polar molecule is one in which a dipole moment exists. There is a positive end and a negative end in a polar molecule. Conventionally, the direction of the dipole is from the positive end of the molecule towards the negative end of the molecule.
If we want to increase the polarity of the molecule then we must substitute the bromine atom with a more electronegative atom. In this case, chlorine is the best option.
Missing parts;
If you wanted to change the polarity of hydrogen bromide (HBr) by substituting the bromine by a different atom. Which atom would increase the polarity of the molecule?
A. chlorine (CI)
B. iodine (1)
C. sulfur (S)
D. hydrogen (H)
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what is the iupac name of CH3-CH2CH(CH3)CH2-COOH
Answer:
Butanoic acid.
Explanation: