Answer:
2.89x10⁻⁵M = [HPO₄²⁻]
Explanation:
The equilibrium of H3PO4 in water occurs H2PO4-:
H3PO4(aq) + H2O(l) ⇄ H3O⁺(aq) + H2PO4⁻(aq)
pKa = 2.16. And as pKa = -log Ka; Ka = 10^-2.16
Ka = 6.9183x10⁻³ = [H3O⁺] [H2PO4⁻] / [H3PO4]
As both [H3O⁺] and [H2PO4⁻] comes from the same equilibrium,
[H3O⁺]=[H2PO4⁻] :
[H3O⁺] = X
[H2PO4⁻] = X
[H3PO4] = 0.042 - X
Where X is reaction coordinate
Replacing:
6.9183x10⁻³ = [X] [X] / [0.042 - X]
6.9183x10⁻³ = X² / 0.042 - X
2.905686x10⁻⁴ - 6.9183x10⁻³X - X² = 0
Solving for X:
X = -0.02M. False solution. There is no negative concentration.
X = 0.014M. Right solution
[H2PO4⁻] = 0.014M
In the second equilibrium:
H2PO4⁻(aq) + H2O(l) ⇄ HPO4-(aq) + H3O+(aq)
Based on the same principles of the last equilibrium:
pKa2 = 7.21
Ka2 = 6.166x10⁻⁸ = [HPO4-] [H3O+] / [H2PO4⁻]
[HPO4-] = X
[H3O+] = X
[H2PO4⁻] = 0.014M - X
6.166x10⁻⁸ = X² / [0.014M - X]
8.3623x10⁻¹⁰ - 6.166x10⁻⁸X - X² = 0
Solving for X:
X = -0.0000289485. False solution.
X =
2.89x10⁻⁵M = [HPO₄²⁻]Consider an acid-base titration in which the base is dispensed from a burette into a flask containing an acid. If any drops of the base adhere to the inner walls of the flask, but do not actually mix with the solution, the calculated acid concentration would be
Answer:
Higher than the actual value
Explanation:
Titration is a volumetric process in which a known volume of solution is dispensed from a burette to react with a known volume of solution in a conical flask.
When acid-base titration is carried out in such a way that the base is in the burette and the acid is in the conical flask and drops of the base adhere to the inner walls of the flask, but do not actually mix with the solution, the calculated acid concentration would be higher than the actual value.
This is because;
From CA= CBVBnA/VAnB
When VB(volume of base) that reacted is lower than the actual volume recorded, then the calculated volume of CA(concentration of acid) is much higher than the actual value since drops of the base adhere to the inner walls of the flask.
a 150 j of energy is added to a system that does 50 j of work is done.by how m uch will tyhe internal energy of system be raised?
The internal energy of system is raised by 3 times
Which procedure could a student use to examine an intensive property of a rectangular block of wood
Find the mass.
Record the length. Measure the volume. Determine the density.
Answer:
density
Explanation:
The procedure that the student could use to examine an intensive property of a rectangular block of wood is to determine its density. Density is intensive because it is the ration between the mass and the volume.
Answer: find the mass option A
Explanation:
Consider the following chemical equilibrium: Now write an equation below that shows how to calculate from for this reaction at an absolute temperature . You can assume is comfortably above room temperature. If you include any common physical constants in your equation be sure you use their standard symbols, found in the ALEKS Calculator.
Answer:
Kp=Kc *(RT)+-3
Explanation:
The relation between Kp and Kc is given below:
Where,
Kp is the pressure equilibrium constant
Kc is the molar equilibrium constant
R is gas constant , R = 0.082057 L atm.mol⁻¹K⁻¹
T is the temperature in Kelvins
Δn = (No. of moles of gaseous products)-(No. of moles of gaseous reactants)
For the first equilibrium reaction:
Δn = (0)-(2+1) = -3
Thus, Kp is:
Kp=Kc *(RT)+-3
define the following terms atom
Methanol has the formula CH3OH. What is the predominant intermolecular force between methanol molecules?
ANSWER:
dispersion forces
dipole forces
ionic bonds
hydrogen bonds
Answer:
hydrogen bonds
Explanation:
similarly CH3OH also has a OH group and H hydrogen thus it will also form h-bonding.
Why do gases act more ideal at
lower pressures?
Answer:
Gases act more ideal at lower pressure beacuse the attractive forces between molecules will decrease or become less significant compared to the empty space between them.
Explanation:
Generally, a gas behaves more like an ideal gas at higher temperature and lower pressure as the potential energy due to intermolecular forces becomes less significant compared with the particles "kinetic energy" and the size of the molecules become less significant compared to the empty space between them.
Attractive forces between molecules, decrease the pressure of a reak gas, slowing the molecules and reducing collisions with the walls.The higher the value of a gas, the greater the attraction between molecules and the more easily the gas will compress.
HOPE IT HELPS MUCHanswered by: John Glenly Pillazo Mahusay
Draw the skeletal structure for: (E)-hept-5-en-2-one
Answer:
Draw the skeletal structure for: (E)-hept-5-en-2-one
Explanation:
The root word hept indicates that the given compound has seven carons in its longest chain.
-en- primary suffix indicates that the compound has one double bond in it.
2-one indicates that the compound has -C=O bond in the second carbon.
The prefix (E) indicates that the highest priority groups are on the opposite direction of the double bond.
The structure of the given molecule is:
Silver has two naturally occurring isotopes with the following isotopic masses: 10747Ag 10947Ag 106.90509 108.9047 The average atomic mass of silver is 107.8682 amu. The fractional abundance of the lighter of the two isotopes is ________.
Answer: The fractional abundance of lighter isotope is 0.518
Explanation:
Average atomic weight is the sum of the masses of the individual isotopes each multiplied by its fractional abundance. The equation used is:[tex]\text{Average atomic weight}=\sum_{i=1}^{n}\text{(Atomic mass of isotope)}_i\times \text{(Fractional abundance)}_i[/tex] ......(1)
Let the fractional abundance of Ag-107 isotope be 'x'
For Ag-107 isotope:Atomic mass = 106.90509 amu
Fractional abundance = x
For Ag-109 isotope:Atomic mass = 108.9047 amu
Fractional abundance = (1 - x)
Average atomic mass of silver = 107.8682 amu
Plugging values in equation 1:
[tex]107.8682=(106.90509 \times x) + (108.9047 \times (1-x))\\\\107.8682=106.90509x+108.9047-108.9047x\\\\1.99961x=1.0365\\\\x=0.518[/tex]
Fractional abundance of Ag-107 isotope (lighter) = x = 0.518
Hence, the fractional abundance of lighter isotope is 0.518
Self-esteem and loss of control are key
factors of our mental well being.
A-True
B-False
if salt and sand is mixed with distilled water, what will be the residue? and, what will be the filtrate?
Answer:
Filtration is a technique used as a remedy to separate mixes
Explanation:
If you have a sodium, then you will explore that salt dissolves but the sand is still the same.
If the salt in the resin water solution scanners, the sand remains the residue and passes through the filter paper.
All you have to do now is pleasant the salty water so that the water can evaporate, leaving the salt behind.
A sample of Br2(g) takes 12.0 min to effuse through a membrane. How long would it take the same number of moles of Ar(g) to effuse through the same membrane
Answer:
6 mins
Explanation:
The time taken for Ar to effuse can be obtained as follow:
Time for Br₂ (t₁) = 12 mins
Molar mass of Br₂ (M₁) = 2 × 80 = 160 g/mol
Molar mass of Ar (M₂) = 40 g/mol
Time for Ar (t₂) =?
t₂/t₁= √(M₂/M₁)
t₂ / 12 = √(40/160)
Cross multiply
t₂ = 12 × √(40/160)
t₂ = 12 × 0.5
t₂ = 6 mins
Therefore, it will take 6 mins for the same amount of Ar to effused out.
The energy levels of hydrogenlike one-electron ions of atomic number Z differ from those of hydrogen by a factor of Z^2. Predict the wavelength of the 2s--->1s transition in He+.
Answer:
[tex]\mathbf{\lambda \simeq 3.039 \times 10^{-8} \ m}[/tex]
Explanation:
For a hydrogen-like atom, the spectral line wavelength can be computed by using the formula:
[tex]\bar v = Z^2 R_H \Big(\dfrac{1}{n_f^2}-\dfrac{1}{n_i^2}\Big)[/tex]
where:
emitted radiation of the wavenumber [tex]\bar v[/tex] = ???
atomic no of helium Z = 2
Rydberg's constant [tex]R_H = 1.097*10^7 \ m^{-1}[/tex]
the initial energy of the principal quantum [tex]n_1[/tex] = 2
the initial energy of the principal quantum [tex]n_1[/tex] = 2
Now, the emitted radiation of the wavenumber can be computed as:
[tex]\bar v = (2)^2 (1.097*10^7 \ m^{-1} ) \Big(\dfrac{1}{1^2}-\dfrac{1}{2^2}\Big)[/tex]
[tex]\bar v = 3.291 \times 10^ 7/m[/tex]
Now, the wavelength for the transition can be computed by using the relation between the wavelength λ and the emitted radiation of the wavenumber [tex]\bar v[/tex], which is:
[tex]\bar v = \dfrac{1}{\lambda}[/tex]
[tex]\lambda = \dfrac{1}{\bar v}[/tex]
[tex]\lambda = \dfrac{1}{3.291 \times 10^{7}}\times \dfrac{m}{1}[/tex]
[tex]\mathbf{\lambda =3.03859 \times 10^{-8} \ m}[/tex]
[tex]\mathbf{\lambda \simeq 3.039 \times 10^{-8} \ m}[/tex]
What types of house are found in very cold regions
Answer:
the house found in a very cold are Igloos or the ice house
A calorimeter has been filled with 75 mL of water. The density of water at 25 °C is
0.998 g/mL. How many grams of water do you have at 25°C?
Answer:
isn't it 0.998
Explanation:
cause 0.998 is in the same grams / mole. I don't get
A calorimeter has been filled with 75 mL of water. The number of grams of water is 74.85 grams.
What is a calorimeter?A calorimeter is an instrument that is used to measure calorimetry. It is used to measure the heat of chemical reactions and physical and chemical changes.
Mass is the quantity of matter in a physical body. Volume is the space occupied by a three-dimensional object. Mass is the quantity of matter in a physical body. The product of the compound's molar mass and the substance's moles are defined as mass.
Given, that the volume of the water is 75 mL
The temperature of the water is 25 °C
The density of water is 0.998 g/mL
To calculate the mass, the volume is multiplied by density.
Mass = volume x density
putting the values in the formula
75 x 0.998 = 74.85 grams
Thus, the grams of water that have at 25°C is 74.85 grams.
To learn more about density, refer to the link:
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important of organic chemistry in our daily life
Answer:
Human life has become very simple by using organic chemicals. The importance of organic chemicals in the daily life and industrial area can be explained as follows. (i) Food Vitamins, proteins, sugar, flour, fats etc. ... (ii) Agriculture is an important place for organic chemical for the growth of agricultural production.
Green plants use light from the Sun to drive photosynthesis, a chemical reaction in which liquid water and carbon dioxide gas form aqueous glucose (CH1206) and oxygen (O2) gas. Calculate the moles of glucose produced by the reaction of 2.40 mol of carbon dioxide. Be sure your answer has a unit symbol, if necessary, and round it to 3 significant digits.
Answer:
.
Explanation:
Please help
Why are different products formed in the combustion of butane ?
Explain please thanks :)
An unknown compound's 2,4-DNP product melting range is between 144-146'C. It does not give a silver mirror on the Tollens test and is slow to react to the chromic acid test. What would this compound be
Answer:
An unknown compound's 2,4-DNP product melting range is between 144-146'C. It does not give a silver mirror on the Tollens test and is slow to react to the chromic acid test. What would this compound be
Explanation:
From the given data it is clear that the unknown compound gives positive test with 2,4-DNP reagent.
That means it has a carbonyl group.Either aldehyde or ketone.
It does not give a silver mirror on the Tollens test and is slow to react to the chromic acid test.
That means aldehyde is absent.
So, the other carbonyl group that is ketone is present in the given unknown compound.
she goes away change to negative form
She goes away.
Negative
She doesn't go away.
Pablo, whose mass is 60 kg, is moving along at a velocity of 8 m/s. How much kinetic energy does he have?
Answer:
1920 Joules
Explanation:
* means multiply
^ means exponent
kinetic energy is in Joules or J
kinetic energy = 1/2 * mass * (velocity)^2
kinetic energy = 1/2 * 60 * (8)^2
kinetic energy = 1/2 * 60 * (8*8)
kinetic energy = 1/2 * 60 * (64)
kinetic energy = 1920 Joules or 1920 J
Answer:
KE = 1920 J
General Formulas and Concepts:
Energy
Kinetic Energy Formula: [tex]\displaystyle KE = \frac{1}{2}mv^2[/tex]
m is mass (in kg)v is velocity (in m/s)Explanation:
Step 1: Define
[Given] m = 60 kg
[Given] v = 8 m/s
Step 2: Find KE
Substitute in variables [Kinetic Energy Formula]: [tex]\displaystyle KE = \frac{1}{2}(60 \ kg)(8 \ m/s)^2[/tex]Evaluate: [tex]\displaystyle KE = 1920 \ J[/tex]Topic: AP Physics 1 Algebra-Based
Unit: Energy
Nickel + oxygen = nickel oxide. What is the balanced redox reaction?
Answer:
This is an oxidation-reduction (redox) reaction:
2 Ni0 - 4 e- → 2 NiII
(oxidation)
2 O0 + 4 e- → 2 O-II
(reduction)
Ni is a reducing agent, O2 is an oxidizing agent.
Which probing question lies within the scope of physics?
O A.
Are fish in the open ocean
attracted by underwater sounds?
O B.
Does increasing the saltiness of
ocean water affect the speed
of sound in the water?
O C.
What effect does the release of industrial wastewater have on
the acidity of oceans?
D. What is the effect of rising sea temperatures on
ocean currents?
Answer:
answer number C is the correct answer for this
plz help ASAP on my final project I will give you20$
Answer:
hey friend
how can I help you
A sealed vessel initially contains 100 g of chlorine gas and 90 g of hydrogen gas. The two gases undergo reaction to form HCl. Which of the following statements is true?
a. 100 g HCl is produced
b. 190 g HCl is produced
c. less than 90 g HCl is produced
d. between 100 and 190 g of HCl is produced
Answer:
d.
Explanation:
H2 + Cl2 = 2HCL
From the equation 2g hydrogen combine with 71g of chlorine.
So 35.5 g Cl2 combines with 1g of H2
There are 100g of Cl2 so this will, by proportion, react with 100/35.5 g hydrogen.
This is 2.8 g hydrogen so the mass of HCl formed = 102.8 g.
The true statement is that d. between 100 and 190 g of HCl is produced.
How do find the mass of HCL?To find mass of HCL:
H2 + Cl2 = 2HCL
From the equation, 2g of hydrogen combines with 71g of chlorine.
So 35.5 g Cl2 combines with 1g of H2
There are 100g of Cl2 so this will, by proportion, react with 100/35.5 g of hydrogen.
This is 2.8 g hydrogen so the mass of HCl formed = 102.8 g.
Hydrogen chloride may be formed by the direct combination of chlorine (Cl2) gas and hydrogen (H2) gas.
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Calculate the number of ATOMS in 1.0 mole of O2. blank x 1024
Answer:
6.023*10^23........ .......
How many atoms in each elemental sample?
4.9 mol Cu
5.4•10^-3 Mol C
24.0 Mol Hg
0.160 mol Na
Answer:
2.9 × 10²⁴ atoms Cu; 3.3 × 10²¹ atoms C; 1.44 × 10²⁵ atoms Hg; 9.63 × 10²² atoms Na
Explanation:
To convert moles to atoms, we need a conversion factor: Avogadro's number. There are 6.02 × 10²³ atoms in 1 mole of atoms.
4.9 mol Cu × 6.02 × 10²³ atoms Cu/1 mol Cu = 2.9 × 10²⁴ atoms Cu
5.4 × 10⁻³ mol C × 6.02 × 10²³ atoms C/1 mol C = 3.3 × 10²¹ atoms C
24.0 mol Hg × 6.02 × 10²³ atoms Hg/1 mol Hg = 1.44 × 10²⁵ atoms Hg
0.160 mol Na × 6.02 × 10²³ atoms Na/1 mol Na = 9.63 × 10²² atoms Na
Classify each of the following as a strong acid or a weak acid and indicate how each should be written in aqueous solution. Classify ... In solution this acid should be written as: weak 1. hydrocyanic acid H3O CN- _______ 2. hydrobromic acid
Answer:
HCN, weak acid
H⁺, Br⁻, strong acid
Explanation:
Hydrocyanic acid is a weak acid, according to the following equation.
HCN(aq) ⇄ H⁺(aq) + CN⁻(aq)
Thus, it should be written in the undissociated form (HCN).
Hydrobromic acid is a strong acid, according to the following equation.
HBr(aq) ⇒ H⁺(aq) + Br⁻(aq)
Thus, it should be written in the ionic form (H⁺, Br⁻).
Which of the following was NOT explained by Dalton's atomic theory?
ANSWER:
A. the Law of Multiple Proportions
B. the difference between elements and compounds
C.?the difference between isotopes of an element
D. the Law of Conservation of Mass
Answer:
i think 1. law of muliple proportion
Explanation:
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what type of properties change ina physical change? Give an example to support your answer?
pls quick who will give the answer first will get the brainliest
Explanation:
We can observe some physical properties, such as density and color, without changing the physical state of the matter observed. Other physical properties, such as the melting temperature of iron or the freezing temperature of water, can only be observed as matter undergoes. A physical change physical change involves a change in physical properties. Examples of physical properties include melting, transition to a gas, change of strength, change of durability, changes to crystal form, textural change, shape, size, color, volume and density.hope it helps.stay safe healthy and happy.