Answer:
6.24
Explanation:
The following data were obtained from the question:
Concentration of HA, [HA] = 0.280 M,
Concentration of H+, [H+] = 4×10¯⁴ M
Concentration of A-, [A−] = 4×10¯⁴ M
pKa =.?
Next, we shall write the balanced equation for the reaction. This is given below:
HA <===> H+ + A-
Next, we shall determine the equilibrium constant Ka for the reaction. This can be obtained as follow:
Equilibrium constant for a reaction is simply the ratio of concentration of the product raised to their coefficient to the concentration of the reactant raised to their coefficient.
The equilibrium constant for the above equation is given below:
Ka = [H+] [A−] /[HA]
Concentration of HA, [HA] = 0.280 M,
Concentration of H+, [H+] = 4×10¯⁴ M
Concentration of A-, [A−] = 4×10¯⁴ M
Equilibrium constant (Ka) =
Ka = (4×10¯⁴ × 4×10¯⁴) / 0.280
Ka = 1.6×10¯⁷/ 0.280
Ka = 5.71×10¯⁷
Therefore, the equilibrium constant for the reaction is 5.71×10¯⁷
Finally, we shall determine the pka for the reaction as follow:
Equilibrium constant, Ka = 5.71×10¯⁷
pKa =?
pKa = – Log Ka
pKa = – Log 5.71×10¯⁷
pKa = 6.24
Therefore, the pka for the reaction is 6.24.
An experiment looking at structures smaller than a cell would most likely employ a
1) dissecting microscope
B) transmission electron microscope
3) scanning electron microscope
D) compound light microscope
Answer:
The correct answer is - b. transmission electron microscope.
Explanation:
A transmission electron magnifying instrument fires a light emission through an sample to create an amplified and magnified picture of a specimen.
The transmission electron magnifying instrument is utilized to see thin slices of specimen or specimen smaller than 100 nm through which electrons can pass and form a image of specimen. The TEM is comparable to from various perspectives to the ordinary light magnifying instrument.
Thus, the correct answer is - b. transmission electron microscope.
Explain why each molecule has a higher boiling point than the other in the pair 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. exhibits dispersion forces The main reason that NO, has a higher boiling point than CO, is that NO
exhibits hydrogen bonding
has a larger molar mass
exhibits dipole-dipole The main reason that NHa has a higher boiling point than CHs is that NH
The main reason that CS2 has a higher boiling point than CO2 is that CS forces exhibits ion-dipole forces
Answer:
The main reason that NO, has a higher boiling point than CO is that NO has a larger molar mass.
The main reason that NH3 has a higher boiling point than CH4 is that NH exhibits hydrogen bonding.
The main reason that CS2 has a higher boiling point than CO2 is that CS2 has a larger molar mass.
Explanation:
The larger the molecular mass, the greater the surface area of the molecule and the greater the magnitude of dispersion forces. Hence, among nonpolar molecules, increase in molecular mass leads to a higher boiling point due to stronger dispersion forces.
Though CO and NO possess dipole-dipole forces, NO has a greater molar mass than CO, hence it has a higher boiling point than CO.
NH3 exhibits intermolecular hydrogen bonding hence it has a much higher higher boiling point than CH4 irrespective of the fact that their molar masses are close in magnitude.
Answer:
The main reason that NO2 has a higher boiling point than CO2 is that NO2 exhibits dipole-dipole forces.
The main reason that CS2 has a higher boiling point than CO2 is that CS2 has a larger molar mass.
The main reason that NH3 has a higher boiling point than CH4 is that NH3 exhibits hydrogen bonding.
How many moles of CO2 are produced
if 6 moles of O2 are used?
C6H12O6 + 602 + 6CO2 + 6H2O
Answer:
6 moles
Explanation:
Forst of all arrange the equation, it isn't in the right order and I suppose the equation is of aerobic respiration:
That is :
C6H12O6 + 6O2 ---------> 6CO2 + 6H20 + 2830kJ (energy)
Then use the ratio which can be seen by the balancing:
02 : CO2
6: 6
The ratio clearly shows how much moles of CO2 are produced; 6 moles
The term mole concept is used here to determine the moles of carbon dioxide produced. The moles of CO₂ produced from the given reaction is 6.
What is a mole?One mole of a substance is defined as that quantity of it which contains as many entities as there are atoms exactly in 12 g of carbon - 12. The formula used to calculate the number of moles is:
Number of moles = Given mass / Molar mass
The balanced equation for the oxidation reaction of glucose is given as:
C₆H₁₂O₆ + 6O₂ → 6CO₂ + 6H₂O + E
In a balanced equation the number of atoms of reactants and products on both sides of the equation are equal. The number of 'C', 'H' and 'O' atoms on both sides of the equation are equal.
Here the number of moles of CO₂ produced from 6 moles of oxygen is 6.
To know more about mole concept, visit;
https://brainly.com/question/19730733
#SPJ7
Now balance the chemical reaction by providing the correct coefficients:
Answer: 2 Al + 3 Cl₂ → 2 AlCl₃
Explanation:
To balance equations, you want to have the same amount of each element. We know 2 Al + 3 Cl₂ → 2 AlCl₃ is the balanced equation because there are equal amounts of each element on both sides. There are 2 Al and 6 Cl.
Are the bonds that chlorine forms with sodium (to form NaCl) and with carbon (to form CCl4) the same in both compounds?
Answer:
Organic chemistry is very important to know the strength and forms of the compounds.
Explanation:
There are two extreme bonding that is ionic and covalent. There are some ionic bonds that contains the covalent bonding. Some of ionic bond are partially covalent and some covalent bond are ionic. Polar covalent have the extreme type of bonding.
Most of the carbon compound are bonded covalently. But these are partial ionic too. Polarity is defined as the measurement of the separation of the charges of the compounds at both the ends.
Ionic compounds allow synthesis in organic compound. Covalent bonds are differently important for carbon molecules bonding.
Thus the bonds that chlorine forms with sodium is different and when form with carbon then compounds will be different
What is heat transferred from movement of fluids in a circular motion called
Answer: it's known as heat transfer
Explanation: Heat always moves from a warmer substance to a cooler substance. For example, holding an ice cube will make your hand begin to feel cold in a few seconds. But is the coldness in the ice cube moving to your hand? No! Since cold is the absence of heat, it’s the heat in your hand that moves to the ice cube. This is one of the ways that heat is transferred.
According to the concept of thermal energy, heat transfer in a circular motion is called as convection.
What is thermal energy?
Thermal energy is defined as a type of energy which is contained within a system which is responsible for temperature rise.Heat is a type of thermal energy.It is concerned with the first law of thermodynamics.
Thermal energy arises from friction and drag.It includes the internal energy or enthalpy of a body of matter and radiation.It is related to internal energy and heat .It arises when a substance whose molecules or atoms are vibrating faster.
These vibrating molecules and atoms collide and as a result of which heat is generated in a substance , more the collision of particles , higher is the thermal energy.There are three types of thermal energy.
Learn more about thermal energy,here:
https://brainly.com/question/3022807
#SPJ6
An element has four naturally occurring isotopes with the masses and natural abundances given here. Isotope Mass (amu) Abundance (%) 1 89.90470 52.93 2 90.90565 11.54 3 91.90504 17.65 4 93.90632 17.88 Find the atomic mass of the element. Express your answer to four significant figures and include the appropriate units.
Following are the calculation to the atomic mass:
Given:
Please find the attached file.
To find:
atomic mass=?
Solution:
Following are the calculation to the atomic mass:
[tex]\to 89.90470\times (0.5293)+90.90565\times (0.1154)+91.90504\times (0.1765)+93.90632\times (0.1788)\\\\\to 47.58655771 +10.49051201 +16.22123956+16.790450016\\\\\to 91.0887593\approx 91.0887\ amu \\\\[/tex]
Therefore, the final answer is "91.0887".
Learn more:
brainly.com/question/5165064
Please Help with this!!!!!
Answer:
a) 4.69
Explanation:
v=mp
m=10.55
p=2.25
v=10.55/2.25=4.69
Which of the following compounds is neither an acid or a base? (select as many)
Answer:
Sodium nitrate and CH4
Explanation:
Acids have an "H" at the start and bases have a hydroxide (OH)
A square table has an area of 400 square feet. They want to cut the table into two equal rectangles. If they cut the table in half, vertically, what would be the dimensions of the rectangular table?
Answer:
b=200
l=100
Explanation:
so since it is a square all sides would be equal
when you cut the square vertically the dimensions will change
the bredth would be same that is 200
but the length would be half that is 100
What is the role of the greenhouse gases in the atmosphere?
Answer:
greenhouse effects are molecules that trap heat on earth atmosphere
Answer:
play an important role in Earth's climate.
Explanation:
Greenhouse gases are certain molecules in the air that have the ability to trap heat in the Earth's atmosphere. Some greenhouse gases, like carbon dioxide (CO2) and methane (CH4), occur naturally and play an important role in Earth's climate. If they didn't exist, the planet would be a much colder place.
Which of the following statements best explains the observation that hydrogen fluoride has the highest boiling point of all the hydrogen halides?a. The fluorine in HF is the smallest atom for all of the halogens. b. Fluorine is the most electronegative of the atoms. c. HF can participate in hydrogen bonding. d. HF is very reactive and can react and dissolve glass e. HF is a weak acid, and doesn
Answer:
c. HF can participate in hydrogen bonding.
Explanation:
The boiling points of substances often reflect the strength of the intermolecular forces operating among the molecules.
If it takes more energy to separate molecules of HF than of the rest of the hydrogen halides because HF molecules are held together by stronger intermolecular forces, then the boiling point of HF will be higher than that of all the hydrogen halides.
A particularly strong type of intermolecular attraction is called the hydrogen bond, which is a special type of dipole-dipole interaction between the hydrogen atom in a polar bond, such as N-H, O-H, or F-H, and an electronegative O, N, or F atom.
A silicon atom has an atomic number of 14. What information does the atomic number tell you? (Choose all possible answers)
Group of answer choices
Silicon atoms have 14 protons.
Silicon atoms will react with other atoms in order to gain stability.
Silicon atoms are stable in their elemental form
Silicon atoms have 14 electrons.
Answer:
Silicon atoms have 14 protons.
Silicon atoms will react with other atoms in order to gain stability.
Silicon atoms have 14 electrons.
Write a balanced equation for the neutralization of hydrochloric acid by barium hydroxide. Use the smallest possible integer coefficients.
Answer:
2HCl + Ba(OH)2 = BaCl2 + 2H2O
Explanation:
To solve such this we must know the concept of neutralization reactions. Therefore, the balanced equation for the neutralization of hydrochloric acid by barium hydroxide is 2HCl + Ba(OH)[tex]_2[/tex] [tex]\rightarrow[/tex] BaCl[tex]_2[/tex] + 2H[tex]_2[/tex]O.
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.
Neutralization is an acid-base reaction in which an acid reacts with just a base to produce salt and water. The pH of a neutralizing solution is determined by the acid strength and concentrations of the reactants. The balanced equation for neutralization of hydrochloric acid by barium hydroxide can be written as
2HCl + Ba(OH)[tex]_2[/tex] [tex]\rightarrow[/tex] BaCl[tex]_2[/tex] + 2H[tex]_2[/tex]O
Therefore, the balanced equation for the neutralization of hydrochloric acid by barium hydroxide is 2HCl + Ba(OH)[tex]_2[/tex] [tex]\rightarrow[/tex] BaCl[tex]_2[/tex] + 2H[tex]_2[/tex]O.
Learn more about the chemical reactions, here:
https://brainly.com/question/3461108
#SPJ5
What is potential energy? Give an example please.
Answer:
Potential energy can be defined as the energy in a body due to its position
In simple terms potential energy is the energy at rest
Explanation: Examples ;
A spring has more potential energy when it is compressed or stretched.A steel ball has more potential energy raised above the ground than it has after falling to Earth.
100 POINTS & BRAINLIEST !!!! PLEASE HELP
Answer:
independent: type of liquid
dependent: growth of plant
control: time
constant: time
constant: time
hypothesis: If I water the plant with water, it will grow the most because water is the liquid that sustains life on earth.
Explanation:
Given six molecules, identify the molecules with polar bonds and the molecules that are polar.CCl4, CH3Cl, H20, CO2, O2
Answer:
Non-polar compounds: [tex]CCl_4[/tex], [tex]O_2[/tex], [tex]CO_2[/tex]
Polar compounds: [tex]CH_3Cl[/tex], [tex]H_2O[/tex]
Explanation:
For this question, we must start with the Lewis structure for each molecule and then we can do their respective analysis:
-) [tex]CCl_4[/tex]
In this case, we have 4 equal atoms attached to the central atom. Therefore, we have the same magnitude of electronegativity. Chlorine atoms have different and opposite directions. Therefore due to the orientation the dipole moments cancel and the net dipole moment will be zero and the molecule will be non-polar.
-) [tex]O_2[/tex]
In this case, we have a linear structure in which the magnitude of the dipole moment is the same, but the direction is the opposite. Therefore the dipole moments are canceled and the molecule will be non-polar.
-) [tex]CO_2[/tex]
In this case, we also have a linear structure in which the magnitude of the dipole moment is the same, but the direction is the opposite. Therefore the dipole moments are canceled and the molecule will be non-polar.
-) [tex]CH_3Cl[/tex]
For this molecule, we have a different atom. The hydrogen atom, therefore the magnitude of one of the atoms attached to the central atom is different and the magnitude of the net dipole moment will be different from zero and the molecule will be polar.
-) [tex]H_2O[/tex]
For this molecule, due to the structure of the molecule, the dipole moments of oxygens will not have a totally opposite configuration. Therefore, the net dipole moment will be different from zero and the molecule will be polar.
See figure 1 to further explanations
I hope it helps!
Identify all of the predominant forms of energy produced when each process occurs. Some processes may produce only one form of energy, whereas others may produce more than one form of energy. An electric light bulb is turned on. A log is burned in a fireplace. Answer Bank mechanical thermal cheat) electrical radiant light) chemical A green plant grows. A bicycle is pedaled. A flashlight is turned on.
Answer:
Explanation:
An electric light bulb is turned on. Thermal heat , radiant light
A log is burned in a fireplace . Thermal heat , radiant light
A green plant grows Chemical
A bicycle is pedaled Mechanical ,
A flashlight is turned on. radiant light
An electrically neutral atom bears what trait?
A) It contains protons in its nucleus.
B) It contains the same number of protons and neutrons.
C) It contains the same number of electrons and protons.
D) It contains electrons in its electron shells.
C) It contains the same number of electrons and protons.
Which of these mixtures are heterogeneous? a. oil and water b. salt and water c. brass (an alloy of copper and zinc) d. granite
The mixture that has been heterogeneous has been oil and water. Thus, option A is correct.
The mixture has been defined as the combination of two or more substances. The mixture has been categorized as pure and heterogeneous mixture based on the solubility of the constituents.
Heterogeneous mixtureThe pure mixture has been defined as the one in which the constituent substances are completely soluble, and are not visible with the bare eyes.
The heterogeneous mixture has been defined as the combination in which the constituents elements are not completely soluble and are easily differentiated from each other by physical means.
The mixture of oil and water has been a heterogeneous mixture, as the two liquids are immiscible and can be separated based on density.The salt and water is a pure mixture, as the two are completely soluble, and they can not be distinguished easily in the solution.The brass is the pure mixture as they have properties different from the constituent elements and has been completely miscible form.The granite has been a compound of carbon. It has been the mixture of carbon atoms in the specified arrangement, thereby is a pure form.Thus, the mixture that has been heterogeneous has been oil and water. Thus, option A is correct.
Learn more about heterogeneous mixture, here:
https://brainly.com/question/24898889
One way the U.S. Environmental Protection Agency (EPA) tests for chloride contaminants in water is by titrating a sample of silver nitrate solution. Any chloride anions in solution will combine with the silver cations to produce bright white silver chloride precipitate. Suppose an EPA chemist tests a 250 mL sample of groundwater known to be contaminated with nickel(II) chloride, which would react with silver nitrate solution like this: NiCl2 (aq) + 2AgNO3 (aq) -> 2AgCl (s) + Ni(NO3)2 (aq) The chemist adds 74.0 mM silver nitrate solution to the sample until silver chloride stops forming. She then washes, dries, and weighs the precipitate. She finds she has collected 8.3 of silver chloride. Calculate the concentration of nickel(II) chloride contaminant in the original groundwater sample. Show your work!
Answer:
15.0g/L is the concentration of nickel(II) chloride contaminant in the original groundwater sample.
Explanation:
Based on the reaction:
NiCl2 (aq) + 2AgNO3 (aq) -> 2AgCl (s) + Ni(NO3)2 (aq)
Where 1 mole of NiCl₂ reacts producing 2 moles of AgCl.
To solve this problem, we need to convert mass of AgCl to moles to know the moles of NiCl₂ that reacts. With these moles and the volume of the sample (250mL = 0.250L), we can determine the molar concentration of the contaminant in the sample
Moles AgCl:
8.3g of AgCl were collected. In moles (Molar mass AgCl: 143.32g/mol):
8.3g AgCl * (1mol / 143.32g) = 0.05791 moles AgCl
Moles NiCl₂:
As 2 moles of AgCl are produced from 1 mole of NiCl₂. Moles of NiCl₂ are:
0.05791 moles AgCl * (1 mole NiCl₂ / 2 moles AgCl) = 0.02896 moles NiCl₂
Molar concentration:
0.02896 moles NiCl₂ / 0.250L =
0.1158M
In g/L (Molar mass NiCl₂: 129.6g/mol):
0.1158 mol / L * (129.6g / mol) =
15.0g/L is the concentration of nickel(II) chloride contaminant in the original groundwater sample.True or False? If a substance is mixed with another substance and then the result is a new odor, then is reaction is a physical reaction.
Answer:
True
Explanation:
In a chemical reaction, there's usually something to do with the composition of the substance. In a physical reaction, the effect could have something to do with appearance or smell.
Hope this helps!
What does ultraviolet light from the sun do with oxygen gas.
Answer:
Gases in Earth's atmosphere form a protective layer
Nitrogen, oxygen and ozone molecules in the upper atmosphere and stratosphere absorb ultraviolet light from the Sun, providing a shield that prevents this radiation from passing to the Earth's surface.
Explanation:
i got this from
...www.aeronomie.be
R spectroscopy can be used to identify which _____________________ are present in a compound.
Answer:
IR spectroscopy can be used to identify chemical structures are present in compounds.
Explanation:
Infrared spectroscopy is a technique in organic chemistry that can be use use to identify chemical structures present in compounds because it is base on the ability of different functional groups to adsorb infrared light.
This work by shinning the infrared lights into the organic compounds to be identified, some of the frequencies of the infrared lights are adsorbed by the compounds and its identify groups of atoms and molecules in the compound.
Glve the number of significant figures: 13,436.0 mm
Significant figures:
Answer: 6
Explanation: Because there is a decimal point, the zero after is included. The first 5 numbers are significant because they aren’t zero. Zeros are included if there is a decimal point (13.0, 160.0) or are in the middle of a number (16007, 101). They are not included if they are before a decimal (000.0081, 0.000021)-(there are only 2 sig figs in these: the actual numbers) or after a number without a decimal (15840000, 100)-(all the zeros in these numbers are not significant).
Please have your periodic table of elements. An atom has 8 protons and 9 neutrons what is the chemical symbol for this isotope? Question 9 options: Flourine F-17 Oxygen O-17
Answer:
A. is the answer i think
Explanation:
How can you use the number of electrons in an aluminum atom to determine how many protons and neutrons are in its nucleus?
Answer:
You use the number of electrons in an aluminum atom to determine how many protons are in its nucleus because the atomic number of aluminum, 13, tells you how many electrons and protons they are. Then you can the number of neutrons by subtract it's atomic number by its mass, 27, which will result in the number of neutrons, 14.
Explanation:
The atomic number of aluminum is 13 and mass number of aluminum is 27. This helps us to tell us how many protons, electrons and neutrons are there in its nucleus.
What is atomic number?The atomic number of a chemical element is defined as the charge number of an atomic nuclei.
The mass number of an atom tells us the number of protons and neutrons are there in an atoms.
The number of electron surrounding the nucleus is equal to number of protons present in the nucleus. Hence there is 13 electrons and 13 protons in the nucleus.
Now we can calculate number of neutrons present in the nucleus.
Mass number = number of protons + number of neutrons
Number of neutrons = mass number - number of protons
= 27 - 13 = 14
So number of neutrons is 14 , and number of protons is 13.
Thus, atomic number of aluminum is 13 and mass number of aluminum is 27. This helps us to tell us how many protons, electrons and neutrons are there in its nucleus.
To learn more about atomic number, refer to the below link:
https://brainly.com/question/16858932
#SPJ2
Magnesium exists in nature as three stable isotopes. Suppose you determine that 9.87 moles of natural magnesium are required if you wish to isolate 1.00 mole of pure Mg-25 (24.9858 amu). The most abundant isotope is Mg-24 with a mass of 23.9850 amu. Determine how many grams of the third isotope, Mg-26 (25.9826 amu), can be isolated from the 9.87 mole sample of natural magnesium.
Answer: 28.2 g of ²⁶Mg can be isolated from the 9.87 mole sample of natural magnesium
Explanation:
we know that natural abundance of ²⁶Mg is 11.01 %
therefore moles of ²⁶Mg isolated from 9.87 mole sample of natural magnesium will be :
( 11.01 x 9.87 mol) / 100 = 1.09 mol
so
mass of ²⁶Mg = mol x molar mass
⇒ 1.09 mol x 25.9826 g/mol
= 28.2 g
Therefore 28.2 g of ²⁶Mg can be isolated from the 9.87 mole sample of natural magnesium
Which of the following is a property of a mixture?
Answer:
A mixture has 2 or more substances that are physically combined
Explanation:
Examples:
-Dirt and water (Mud)
-Water and salt (Sea water)
-Smoke and fog (Smog)
can someone help me please ??!!
Answer:
0.617
Explanation:
The experimental value is the average of all the values recorded:
(2.65 + 2.73 + 2.77)/3 = 2.72
Then use the equation:
(2.72 - 2.7)/ 2.7 x 100 = 0.617