Answer:
pOH = 11
Explanation:
The pH is an unit of concentration widely used in chemistry to find the quality of a solution.
To solve this question we must, as first, find the [H+] using the pH:
[H+] = 10^-pH
[H+] = 10^-3
Now, using kw:
kw = 1.0x10-14 = [H+] [OH-]
1.0x10-14 = [10^-3] [OH-]
[OH-] = 1.0x10-11
pOH = -log [OH-]
pOH = 11To determine the molar mass of an element, one must know the element's
a. number of isotopes.
b average atomic mass
c avogradro constant
d atomic number
Answer:
d
Explanation:
from you know the atomic number it should be easy to find
To determine the molar mass of an element, one must know the element's atomic number. Therefore, option D is correct.
What is the atomic number ?An element's atomic number (Z) is the number of protons in the nucleus of each atom of that element. This means that the number of protons is the feature that distinguishes each element from all others. Elements differ based on their atomic number.
Because the combined masses of protons and neutrons account for nearly all the mass of a given atom, the atomic mass of a single atom can be calculated by adding the total number of protons and neutrons of that particular isotope.
The atomic mass of any element on the periodic table can be used to calculate its molar mass.
Thus, option D is correct.
To learn more about an atomic number, follow the link;
https://brainly.com/question/16858932
#SPJ6
explain how lithium atom is positive charge
definition of spirilla
don't write incorrect answer
Answer:
a bacterium with a rigid spiral structure,found in stagnant water and something causing disease
Sam is visiting the desert. He is standing beside a cactus watching a
snake move across the sand. There is a lizard basking in the sun on a rock
nearby. Which of the following correctly identifies the biotic and abiotic
parts of the ecosystem?
Abiotic: Rock, Sand, Sun Biotic: Cactus, Lizard, Sam, Snake
Abiotic: Cactus, Rock, Sam Biotic: Lizard, Sand, Snake, Sun
Abiotic: Cactus, Rock, Sand, Sun Biotic: Lizard, Sam, Snake
Abiotic: Cactus, Lizard, Sam, Snake Biotic: Rock, Sand, Sun
Answer:
A
Explanation:
Rock sand sun arent living. cactus lizard sam and snake are living or biotic
An engine operates on a Carnot cycle that uses 1mole of an ideal gas as the
working substance and operates from a most compressed stage of 100 Nm and
327 K. It expands isothermally to a pressure of 90 Nm and then adiabatically to a
most expanded stage of 27 K. Calculate the AU, 9, and w for each step. Calculate
the net work done and the efficiency of the cycle [Cv,m for the gas) is 25 J/k/mol.
Answer:
Step 1;
q = w = -0.52571 kJ, ΔS = 0.876 J/K
Step 2
q = 0, w = ΔU = -7.5 kJ, ΔH = -5.00574 kJ
Explanation:
The given parameters are;
[tex]P_i[/tex] = 100 N·m
[tex]T_i[/tex] = 327 K
[tex]P_f[/tex] = 90 N·m
Step 1
For isothermal expansion, we have;
ΔU = ΔH = 0
w = n·R·T·ln([tex]P_f[/tex]/[tex]P_i[/tex]) = 1 × 8.314 × 600.15 × ln(90/100) = -525.71
w ≈ -0.52571 kJ
At state 1, q = w = -0.52571 kJ
ΔS = -n·R·ln([tex]P_f[/tex]/[tex]P_i[/tex]) = -1 × 8.314 × ln(90/100) ≈ 0.876
ΔS ≈ 0.876 J/K
Step 2
q = 0 for adiabatic process
ΔU = 25×(27 - 327) = -7,500
w = ΔU = -7.5 kJ
ΔH = ΔU + n·R·ΔT
ΔH = -7,500 + 8.3142 × 300 = -5,005.74
ΔH = ΔU = -5.00574 kJ
ALL THE THINGS YOU SAID ALL THE THINGS YOU SAID RUNING THROUGH MY HEAD RUNNING THROUGH MY HEAD HELPPPP
Answer:
Gamma rays and X-rays
Explanation:
All the things she said
All the things she said
Running through my head
Running through my head
Running through my head
All the things she said
All the things she said
Running through my head
Running through my head
All the things she said
This is not enough
This is not enough
HELP PLEASE
1. Locations where volcanoes form far from plate boundaries are called
A. islands
B. hot spots
C. divergent zones
How many Fluorine atoms are needed to accept the electrons of one Ca atom?
1
2
3
4
2 F atoms
Explanation:
A Ca atom has a valence number of +2, which means that when ionized, it will give up two electrons. In turn, a F atom has a valence number of -1, which means it can only accept 1 electron when ionized. So to accommodate the two electrons from Ca atom, we need 2 F atoms.
1. Hay un gas con 700 milímetros de Mercurio de presión en 922 ml de volumen a 20 grados Celsius. Calcula la temperatura final a 500 mm de mercurio con 451 ml.
2. un gas ocupa un gas ocupa 205 mililitros a 20 grados centígrados y 1,05 atm. Calcule el volumen final a 60 grados centígrados y 2,4 Atmósferas de presión.
3. tenemos 22 L de un gas a una temperatura de 220 K y una presión de 5 Atm, si se modifican la presión a 6.5 atm y la temperatura a 200 K, cuál será el volumen que obtenemos.
Answer:
püvinlbxyfsswgrxzvnnchcyv nkivtcdg
All of the following elements are metals EXCEPT?
A. Br B. Co C. Cu D. Zn
Answer:
Br
Explanation:
How many grams of water are produced when 12.50 mol oxygen reacts with hydrogen?
Answer: According to reaction below, when one mol of oxygen reacts with two mol of hydrogen, two mol of water is produced. Thus, when 2.5 mol of oxygen reacted with hydrogen, 2 * 2.5 mol = 5 mol of water is produced. The molar mass of water is 18 g/mol.
Explanation:
Not My WORK! I got this info from another site. BUT I HOPE IT HELPS :)
6 a 100 sample of Au - 198 Au 198 be? Decays to 3.125 g in 13.5 days, what would the half-life of au198 be?
Answer:
Half-life = 2.7 days
Explanation:
The radioactive decay of an isotope follows the equation:
Ln[A] = -kt + ln[A]₀
Where [A] could be taken as the amount of A after t time, k is decay constant, [A]₀ initial amount of A.
Replacing to solve k:
Ln[3.125g] = -k*13.5days + ln[100g]
-3.465736 = -k*13.5days
k = 0.2567days⁻¹
Half-life is:
half-life = ln2 / k
Half-life = 2.7 days
the molar mass of CCI2F2
Answer:
The molar mass and molecular weight of CCI2F2 is 315.8271.
Explanation:
How GM food are produced?
What is genetic modification (GM) of crops and how is it done? GM is a technology that involves inserting DNA into the genome of an organism. To produce a GM plant, new DNA is transferred into plant cells. Usually, the cells are then grown in tissue culture where they develop into plants.
Answer:
GM is a technology that involves inserting DNA into the genome of an organism. To produce a GM plant, new DNA is transferred into plant cells. Usually, the cells are then grown in tissue culture where they develop into plants. The seeds produced by these plants will inherit the new DNA.
What is the molarity of a solution containing 9.0 moles of solute in 462 mL of solution
Answer:
[tex]\boxed {\boxed {\sf 19 \ M}}[/tex]
Explanation:
Molarity is a measure of concentration in moles per liter, so the formula is:
[tex]molarity= \frac{moles \ of \ solute}{liters \ of \ solution}}[/tex]
This solution has 9.0 moles of solute and 462 milliliters of solution. We must convert milliliters to liters. Remember that 1 liter contains 1000 milliliters.
Create a ratio.
[tex]\frac{ 1 \ L}{ 1000 \ mL}[/tex]Multiply by the value we are converting: 462 milliliters
[tex]462 \ mL *\frac{ 1 \ L}{ 1000 \ mL}[/tex][tex]462 *\frac{ 1 \ L}{ 1000}[/tex][tex]0.462 \ L[/tex]
Now we know both values and we can solve for the molarity.
moles of solute= 9.0 moles liters of solution = 0.462 L[tex]molarity= \frac{9.0 \ mol}{ 0.462 \ L}[/tex]
Divide.
[tex]molarity= 19.4805195 \ mol/L[/tex]
The original measurements of moles and milliliters have 2 and 3 significant figures respectively. We have to round our answer to the least number of sig figs, which is 2 in this case.
For the number we found, that is the ones place. The 4 in the tenths place (19.4805195) tells us to leave the 9 in the ones place.
[tex]molarity= 19 \ mol/L[/tex]
1 mole per liter is equal to 1 molar or M, so our answer is equal to 19 M.
[tex]molarity \approx 19 \ M[/tex]
The molarity of the solution is approximately 19 M.
5. Pick the list with the correct order of elements according to their reactivity, with the most
reactive metal first to the least reactive metal last.
A. potassium, calcium, sodium, magnesium, aluminum
B. magnesium, calcium, sodium, potassium, aluminum
C. sodium, calcium, potassium, magnesium, aluminum
D. calcium, aluminum, sodium, potassium, magnesium
Answer: do you have the answer for this yet ?
Explanation:
I’m stuck on the same question as well.
H=1.01
What is the molality of a solution containing 75.3 grams of KCI
dissolved in 100.0 grams of water?
K= 39
Cl = 35.45
Answer:
Molality of solution=10.11 m
Explanation:
We are given that
Given mass of KCl(WB)=75.3 g
Given mass of water (WA)=100 g=100/1000=0.1 kg
1 kg=1000 g
Molar mass of H=1.01 g
Molar mass of K=39g
Molar mass of Cl=35.45 g
We have to find the molality of a solution.
Molar mass of KCl(MB)=39+35.45
Molar mass of KCl(MB) =74.45 g
Number of moles of solute (KCl)=[tex]\frac{given\;mass}{molar\;mass}=\frac{W_B}{M_B}[/tex]
Number of moles of solute (KCl)=[tex]\frac{75.3}{74.45}[/tex]
Number of moles of solute (KCl)=1.011 moles
Molality of solution
=[tex]\frac{number\;of\;moles\;of\;solute}{mass\;of\;solvent}[/tex]
Using the formula
Molality of solution=[tex]\frac{1.011}{0.1}[/tex]
Molality of solution=10.11 m
8.
(a) Tick (™) the box next to the correct statement about the mixture.
mixture of four elements
mixture of four compounds
mixture of two elements and two compounds
mixture of one element and three compounds
Answer:
mixture of four compounds
mixture of two elements and two compounds
Explanation:
it can be one of thosecan u tell me if its correct pls I'm studying this tooWhich of the following processes
release energy?
A. Water evaporating
B. Ice melting
C. steam condensing
D. wax melting
what is the best definition of energy?
A. The capacity to measure heat.
B. The capacity to measure mass
C. The capacity to exert strength
D. The capacity to do work
Answer:
D. the capacity to do work
Explanation:
the basic definition of energy is the ability to do work
a gas with a volume of 20.0l at a pressure of 275 kpa is allowed to expand to a volume of 35.0l. what is the pressure in the container if the temperature remains constant?
1. 2.54 kPa
2. 157 kPa
3. 481 kPa
pls help ;(
Answer:
[tex]\boxed {\boxed {\sf 2. \ 157 \ kPa}}[/tex]
Explanation:
Since temperature remains constant, the only variables that change are volume and pressure. Therefore, we are using Boyle's Law. This states that the pressure is inversely proportional to the volume. The formula is:
[tex]P_1V_1=P_2V_2[/tex]
We know the gas starts with a volume of 20.0 liters at a pressure of 275 kPa. We can substitute these values into the left side of the formula.
[tex]275 \ kPa *20.0 \ L=P_2V_2[/tex]
We know the gas expands to a volume of 35.0 Liters, but we do not know the pressure.
[tex]275 \ kPa *20.0 \ L=P_2* 35.0 \ L[/tex]
Since we are solving for the new pressure, we must isolate the variable P₂. It is being multiplied by 35.0 Liters and the inverse of multiplication is division. Divide both sides by 35.0 L.
[tex]\frac {275 \ kPa * 20.0 \ L}{ 35.0 \ L}= \frac{P_2*35.0 \ L}{35.0 \ L}[/tex]
[tex]\frac {275 \ kPa * 20.0 \ L}{ 35.0 \ L}=P_2[/tex]
The units of liters cancel.
[tex]\frac {275 \ kPa * 20.0 }{ 35.0 }=P_2[/tex]
[tex]\frac {5500}{35.0} \ kPa= P_2[/tex]
[tex]157.142857 \ kPa=P_2[/tex]
The original measurements of pressure and volume have 3 significant figures, so our answer must have the same. For the number we calculated, that is the ones place.
The 1 in the tenths place (157.142857) tells us to leave the 7 in the ones place.
[tex]157 \ kPa= P_2[/tex]
If the gas expanded to a volume of 35.0 liters while the temperature remained constant, the pressure in container was approximately 157 kilopascals.
21.) This substance consists of two or more nonmetal elements in a fixed ratio.
a.) element
b.) mixture
c.) molecule
d.) compound
Answer:
Molecule
Explanation:
when two or more than two non-metal elements are combined then it form Molecule.
Which layer of the earth is the thinnest and thickest?
Answer:
crust
Discuss with the whole class what the relative thicknesses of the layers are — that the inner core and outer core together form the thickest layer of the Earth and that the crust is by far the thinnest layer.
Explanation:
Discuss with the whole class what the relative thicknesses of the layers are — that the inner core and outer core together form the thickest layer of the Earth and that the crust is by far the thinnest layer.
Calculate the Molar Mass of Radon pentaiodide (Rnls)
857
349
1237
Explanation:
222.01758 g/mol
3.1Computed Properties
If a sample of a gas occupies 5.22 L at 235 oC, what will its volume be at 75 oC if the pressure remains the same?
Answer:
1618.2
Explanation:
235+75=310×75=1618.2
please mark all that apply!
Answer:
F G there you go the guy on top is right
Explanation:
F G
Lee and some other students working with Dr. Yung were conducting an experiment and ended up with some confusing results. In the experiment, each student combined sodium and hydrogen chloride, but, as shown in the table below, each student ended up with different results. Lee is trying to determine what happened.
In a few minutes, you will see a video of what happened when Lee combined two substances. Before you watch the video, see if you can predict why each student ended up with different results.
Student's name Starting substances Ending substances
Lee sodium and hydrogen chloride hydrogen and sodium chloride
Vera sodium and hydrogen chloride hydrogen, sodium chloride, and sodium
Domingo sodium and hydrogen chloride hydrogen, sodium chloride, and hydrogen chloride
Why do you think Vera and Domingo ended up with three substances after the chemical reaction while Lee only ended up with two?
Answer:
chung long
Explanation:
cause 3 plus 2 =9
Which of the following pH numbers are acidic? (Choose 2)
9
11
7
5
3
the pH numbers that are acidic above is 3 and 5
What does an increase in temperature do to the reaction rate?
Answer:
An increase in temperature typically increases the rate of reaction because an increase in temperature will raise the average kinetic energy of the reactant molecules. Therefore, a greater proportion of molecules will have the minimum energy necessary for an effective collision.Increasing the temperature increases reaction rates because of the disproportionately large increase in the number of high energy collisions. It is only these collisions (possessing at least the activation energy for the reaction) which result in a reaction.
Explanation:
Can you please give this answer a brainliest answer please
Calculate the current in amperes required to produce 18.0g of aluminium in 1.50hrs (al=27.og )
Answer:
35.7 A
Explanation:
Let's consider the reduction half-reaction of Al³⁺.
Al³⁺ + 3 e⁻ ⇒ Al
We will calculate the charge required to produce 18.0 g of Al using the following conversion factors.
1 mole of Al has a mass of 27.0 g1 mole of Al is formed upon the circulation of 3 moles of electrons1 mole of electrons has a charge of 96486 C (Faraday's constant)[tex]18.0gAl \times \frac{1molAl}{27.0gAl} \times \frac{3mole^{-} }{1molAl} \times \frac{96486C}{1mole^{-} } = 1.93 \times 10^{5} C[/tex]
1.93 × 10⁵ C circulate in 1.50 hours. The intensity is:
[tex]I = \frac{1.93 \times 10^{5} C}{1.50h} \times \frac{1h}{3600s} = 35.7 A[/tex]