Answer:
a) 3.969
b) 3.489
Explanation:
a) Calculate the pk, value of the acid HA
PH of salt hydrolysis
P[tex]^{H}[/tex] = 1/2 ( pkw + pka + logC )
8.7 * 2 = 14 + log ( 0.27 ) + Pka
∴ Pka = 3.9686 ≈ 3.969
b) Calculate the PH of a solution containing 0.3 M HA and 0.1 M NaA
PH = Pka + log ( salt / acid )
= 3.9686 + log ( 0.1 / 0.3 )
= 3.9686 - 0.48 = 3.489
in pressure dunt
uwing
frost shattering
Answer:
i dont get it???????
Explanation:
: Calculate molar mass of the following compounds:
NaCl :
Ba(NO3)2:
K(MnO4):
Cl2:
CO2
Answer:
1. 58.5g/mol
2. 261g/mol
3. 158g/mol
4. 71g/mol
5. 44g/mol
Explanation:
The molar mass of a compound is the total mass of the sum of masses of all individual elements that make up the compound. First, we need to know the atomic masses of each element in a compound.
1. NaCl
Where; Na = 23, and Cl = 35.5
Molar mass of NaCl = 23 + 35.5
= 58.5g/mol
2. Ba(NO3)2:
Where; Ba = 137, N = 14, O = 16
Molar mass of Ba(NO3)2: 137 + {14 + 16(3)} 2
137 + (14 + 48)2
137 + (62)2
137 + 124
= 261g/mol
3. K(MnO4)
Where; K = 39, Mn = 55, O = 16
Molar mass of KMnO4 = 39 + 55 + 16(4)
= 94 + 64
= 158g/mol
4. Cl2
Where; Cl = 35.5
Molar mass of Cl2 = 35.5(2)
= 71g/mol
5. CO2
Where; C = 12, O = 16
Molar Mass of CO2 = 12 + 16(2)
= 12 + 32
= 44g/mol
Why is DNA called a double helix?
Answer:
the double helix of dna is, like its name, implies, in the shape of a helix which is essentially a three-dimensional spiral. the double comes from the fact that the helix is made of two long strands of dna that are intertwined—sort of like a twisted ladder.
Explanation:
hope this helps :)
have a nice day !!
The main reason that we have different types of energy on the electromagnetic spectrum is because they have different
Answer:
Explanation:
The main reason is because they have different energy in the photon and different wavelength.
In the electromagnetic radiations, radio waves have little energetic photons, micro wave have more that radio waves, the visible light, ultraviolet x Ray's, and gamma Ray's have more energetic photons. They have different wavelength. The shorter the wavelength, the higher the frequency. Wavelength decreases while frequencies increases.
What is 3 pointing to
Answer:
Electrons
Explanation:
Electrons is the outside of the nucleus
Turbo or supercharger
At higher altitudes would there be more or less
oxygen available to breathe?
a. Less oxygen is available at higher altitudes.
b. More oxygen is available at higher altitudes.
Answer: less oxygen available at higher altitudes
Explanation:
The higher in elevation you get, the lower the air pressure, allowing oxygen atoms to spread out farther, therefore making available oxygen less.
Which separation technique could be used to separate a mixture based on differnces in boiling point.
a. filtration
b. distillation
c. chromatography
Movement of the ___
creates the London dispersion forces.
Answer: electrons
Explanation: moving electrons cause momentarily charge
Distribution on molecule. This distribution induces similar distribution to
Adjacent molecule.
Calculate the amount of heat needed to heat a 100.0 g sample of distilled water from 25°C to 65°C
Does the variable increase(1) or decrease(1) under the described conditions?
1. What happens to pressure as volume
increases?
2. What happens to pressure as temperature decreases?
3. What happens to volume as temperature decreases?
4. What happens to volume as the number of moles increase?
Answer:
Explanation:
Decreasing the volume of a contained gas will increase its pressure, and increasing its volume will decrease its pressure. In fact, if the volume increases by a certain factor, the pressure decreases by the same factor, and vice versa. Volume-pressure data for an air sample at room temperature are graphed in Figure 5.
Because the volume has decreased, the particles will collide more frequently with the walls of the container. ... When the volume decreases, the pressure increases. This shows that the pressure of a gas is inversely proportional to its volume. This is shown by the following equation - which is often called Boyle's law.
The kinetic energy of the gas molecules increases, so collisions with the walls of the container are now more forceful than they were before. As a result, the pressure of the gas doubles. Decreasing the temperature would have the opposite effect, and the pressure of an enclosed gas would decrease.
For a fixed mass of gas at constant temperature, the volume is inversely proportional to the pressure. That means that, for example, if you double the pressure, you will halve the volume. If you increase the pressure 10 times, the volume will decrease 10 times.
Temperature, pressure, volume and the amount of a gas influence its pressure.
Gay Lussac's Law - states that the pressure of a given amount of gas held at constant volume is directly proportional to the Kelvin temperature. If you heat a gas you give the molecules more energy so they move faster. This means more impacts on the walls of the container and an increase in the pressure.
i really hope some of this helped i would put more but its a lot too type
Choose the correct name for NH3 according to the naming system being used. What is the IUPAC name for NH3? ammonia mononitrogen hydride mononitrogen trihydride nitrogen trihydride
Answer:
Nitrogen Trihydride
Explanation:
Ammonia is the common name of NH3. However, with this naming system, you should name it as a non-metal. Nitrogen trihydride.
Answer:
Nitrogen Trihydride
Explanation:
A plastic bag containing 2.2 L of gas at
1.0 atm pressure is cooled from 30°C to
0 °C. What will be the volume of the gas?
Answer: The volume of the gas is 1.98 L.
Explanation:
To calculate the final volume of the system, we use the equation given by Charles' Law. This law states that volume of the gas is directly proportional to the temperature of the gas at constant pressure.
Mathematically,
[tex]\frac{V_1}{T_1}=\frac{V_2}{T_2}[/tex]
where,
[tex]V_1\text{ and }T_1[/tex] are the initial volume and temperature of the gas.
[tex]V_2\text{ and }T_2[/tex] are the final volume and temperature of the gas.
We are given:
[tex]V_1=2.2L\\T_1=30^oC=(30+273)K=303K\\V_2=?\\T_2=0^0C=(0+273)K=273K[/tex]
Putting values in above equation, we get:
[tex]\frac{2.2}{303}=\frac{V_2}{273}\\\\V_2=1.98L[/tex]
Thus the volume of the gas is 1.98 L
Write a nuclear equation for each description below.
Stronitum-84 combines with an alpha particle, creating sodium-25 and a daughter nucleus. 4 pts
Answer:
Sr-84 + He-2 -> Na-25 + Pm-61
Explanation:
How many moles of Iron Fe, are in 0.054g of iron?
Answer:
9.643×10^-4 mole is your answer
Explanation:
56 g of iron =1 mole
0.054 g of iron =1×0.054/56=9.643×10^-4 mole
Can someone double check my work? (Ideal Gas Law Equation)
I am solving for the amount of moles in two gases.
For one, it was 4.75mL at 0.5C (273.65K) and 1.2atm.
n=(1.2*4.75)/(0.0821/273.65)=(5.7/22.456)=0.25361653 moles
For the other gas, it was 4.6mL at 0.5C and 1.2atm.
n=(1.2*4.6)/(0.0821/273.65)=(5.52/22.456)=0.24581403 moles
Please double check these for any errors in math or whatever. Thank you.
I did not see any errors, i may be wrong but what i can see is that it is correct
Which of the following statements is not true about the object moving with constant speed?
A. The object is not accelerating
B. The speed of the object is equal to zero
C. The distance travelled by the object increase uniformly
D. The speed of the object remains the same all throughout the travel.
Answer: B The speed of the object is equal to zero
Explanation:
are you doing work when u are cleaning your teeth
Answer: Yes you are.
Explanation:
A deep teeth cleaning can remove a buildup of plaque and tartar on your teeth, reducing gum inflammation and improving gum health. Plaque is a sticky film that forms on teeth. It contains bacteria and develops when food particles mix with saliva. You can remove plaque, which collects on teeth daily, by brushing your teeth.
Bob sees some water droplets on the outside surface of a glass of lemonade. What process of the water cycle explains this?
A. condensation
B. evaporation
C. precipitation
D. transpiration
Answer:
es la a porque ay está condensación por
Potassium manganate(VI), K2MnO4, can be made to react with water,
forming potassium permanganate, KMnO4, potassium hydroxide,
KOH, and hydrogen gas. This reaction is used in industry to produce
potassium permanganate, which is widely used in analytical chemistry.
Write the balanced equation for this reaction
Explain your observations in term of how tempurature affects paritcle motion and how liquid changes to a solid
Answer:
See explanation
Explanation:
Temperature is defined as a measure of the average kinetic energy of the molecules of a body.
When a substance is heated, the kinetic energy of its molecules increases as the temperature increases; hence the particles of the substance moves faster with increasing temperature.
When heat is withdrawn from a liquid, the temperature decreases and the average kinetic energy of the molecules decreases. The molecules become less energetic hence the liquid changes into solid
What do we call the phenomena when plants bend towards the light?
Photomorphogenesis
Auxin
Phototropism
Photosynthesis
What does a wave carry
A.Energy B.Matter C.Molecule D.Particle
Answer:
Energy
Explanation:
As waves move from one place to another, they carry energy. Generally, the medium itself doesn't move much as it is the disturbance that is being transmitted
Answer:
energy because a wave isnt like a physical thing so it isnt gonna have matter or particles or molecules its just a movement of energy like a sound wave has no matter so it doesnt have particles and stuff
Explanation:
i know i sound very scientific XD
Sodium is a compound
O True
or
O False
Answer:
i think false.
Explanation:
tell me if this is wrong
The core of earth is made of iron and nickel the outer core is so hot that it melts metal. The inner core is solid. What causes these diffrences
Answer:
The inner core is solid by intense pressure of all the layers above it.
Explanation:
The inner core is made up of heavy elements such as iron and nickel. It therefore possesses an unusually high pressure that makes the expanded inner core which arose from effects of high temperature to be nullified.
Thus, we can say that the inner core is solid by intense pressure of all the layers above it.
What is the mass of an atom with 8 protons, 8 electrons, and 8 neutrons?
Answer:An oxygen atom usually has 8 protons, 8 neutrons, and 8 electrons. Looking at the periodic table, oxygen has atomic number 8 and atomic weight 15.999.
Explanation:
The mass of the atom with 8 protons, 8 electrons, and 8 neutrons would be approximately 16 atomic mass units as the number of electrons has an almost negligible contribution to the mass of the atom.
What is atomic mass?It is the sum of the mass of all the protons as well as the neutrons that are present inside the nucleus.
Atomic mass = total number of protons present in the nucleus + total number of neutrons present in the nucleus of an atom,
As given in the problem we have to find the atomic mass of the atom with eight protons, eight electrons, and eight neutrons,
This given specified atom clearly represents the oxygen atom as it has eight electrons protons and neutrons each.
Thus, the atomic mass of the given atom would be 16.
Learn more about atomic mass from here, refer to the link;
brainly.com/question/11681718
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Use the drop-down menus to complete the sentences.
The gain of electrons is called _________
The loss of electrons is called _________
Answer:
1.Reduction
2.oxidation
Explanation:
Answer:
Reduction
Oxidation
Explanation:
Help ASAP I’ll mark you as brainlister
Answer:
2.51g Mg
Explanation:
The empty crucible had a mass of 35.84. With the magnesium added, it had a mass of 38.45. This means that you should subtract the mass of the empty crucible from the mass of the crucible with Mg to find how much was added.
38.35g - 35.84g = 25.1g
Which factor decreases the rate of solution?
an increase in the surface area of the solute
an increase in pressure
increased stirring
a decrease in temperature
Answer:
the correct answer is D) a decrease in decrease in temperature
have a good day! :)
Explanation:
The factor that decreases the rate of solution is a decrease in temperature. Details about rate of a solution can be found below.
What is a solution?A solution is a homogeneous mixture, which may be liquid, gas or solid, formed by dissolving one or more substances.
The rate at which a solution moves can be affected by the following:
The surface area of the soluteThe pressure appliedThe temperatureThis means that the factor that decreases the rate of solution is a decrease in temperature.
Learn more about temperature at: https://brainly.com/question/24106768
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3. Infer Do all elements have half-lives? Why or why not?
Answer:
Elements with short half lives exist because each element has stable isotopes, and the decay os isotopes create more isotopes as well.