Answer:
78.04g of 0.448 moles must be added
Explanation:
Using H-H equation we can find the pH of the buffer:
pH = pKa + log [A⁻] / [HA]
Where pH is the pH of the buffer = 7.2
pKa = 7.1
[A⁻] = [K₂HPO₄]
[HA] = [KH₂PO₄]
Replacing:
7.2 = 7.1 + log [K₂HPO₄] / [KH₂PO₄]
0.1 = log [K₂HPO₄] / [KH₂PO₄]
1.2589 = [K₂HPO₄] / [KH₂PO₄] (1)
And as the concentration of the buffer is:
1M = [K₂HPO₄] + [KH₂PO₄] (2)
Replacing (2) in (1):
1.2589 = 1M - [KH₂PO₄] / [KH₂PO₄]
1.2589 [KH₂PO₄] = 1M - [KH₂PO₄]
2.2589 [KH₂PO₄] = 1M
[KH₂PO₄] = 0.44M
And [K₂HPO₄] = 0.56M
In 800mL = 0.8L:
0.8L * (0.56mol / L) = 0.448 moles K₂HPO₄. The mass is -Molar mass K₂HPO₄: 174.2g/mol-:
0.448 moles * (174.2g / mol) =
78.04g of 0.448 moles must be addedPLEASE HURRY IM TIMED Atoms are made up of electrons, neutrons, and____?
protons
compounds
mixtures
water
Answer: protons
Explanation:
A. Protons I learned this in class
fill in the blank
______ is a way to describe matter with numbers and units.
Measurement is a way to describe matter with numbers and units.
Measurement is a fundamental process used to describe and quantify various aspects of matter. It involves assigning numerical values to physical quantities and expressing them using appropriate units of measurement.
In scientific and everyday contexts, measurements provide a standardized and consistent way to communicate information about the properties, dimensions, quantities, and characteristics of objects, substances, or phenomena. By using measurements, we can describe the size, length, mass, volume, temperature, time, and many other attributes of matter.
The process of measurement typically involves two components: a numerical value and a unit. The numerical value represents the magnitude or quantity being measured, while the unit provides the reference or scale by which that quantity is expressed. Units help provide meaning, context, and comparability to measurements.
Hence, measurement provides a quantitative and objective way to describe matter, allowing us to understand and interact with the physical world in a systematic and meaningful manner.
Learn more about matter here:
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#SPJ 4
Select the correct answer.
Which substance is most likely to form in a precipitation reaction?
A.
calcium nitrate
B.
copper(I) nitrate
C.
iron(I) chloride
D.
iron(II) sulfide
E.
potassium sulfate
Answer:
C.
Explanation:
Iron is most likely to form a precipitation reaction.
Which of the following is
NOT a part of the digestive
system?
A
Mouth
B Esophagus
C Intestines
D
Kidneys
1137 AM
o search
B
Answer:
Kidneys
Explanation:
I learned about it :)
Answer:
DkidneysExplanation:
I hope it helps
PLS HELPPPP OMG PLSPLSPLSPLSPLS
Answer:
D 44.8 L liters of hydrogen gas
When a comet enters the solar system, it curves toward the sun. Which statement describes why the sun does not move when a comet is nearby?
Answer:
Explanation:
When a comet enters the solar system it curves towards the Sun due to the Sun's gravitational pull. Every celestial object in the universe has a gravitational pull whose force is dependent on the object's mass. The larger the object is the more gravitational pull it will have. The Sun is the largest object in our Solar system and therefore has the most gravitational pull. This is why the comet curves toward the Sun, but the opposite does not happen because the comet's gravitational pull is not strong enough to pull the Sun.
How many moles of nitrogen are in 1 mole of Al(NO3)3?
O A. 4 moles of nitrogen
O B. 1 mole of nitrogen
C. 3 moles of nitrogen
O D. 7 moles of nitrogen
Answer:
c i think
Explanation:
I NEED HELP WIT QUESTION THREE
Answer: 2.00
Explanation:
2 rounded to the nearest hundredth is 2.00
your welcome :)
answers for all three:
1. 4.00
2. 16.04
3. 2.00
Is the following statement true or false:
Cellular respiration only occurs in animal cells.
Question 1 options:
True
False
Answer:
False
Explanation:
Humans and plans do it as well
Answer:
False
Explanation:
Cellular respiration takes place in the cells of all organisms. It occurs in autotrophs such as plants as well as heterotrophs such as animals.
Plants respond to different kinds of stimuli. A plant's roots searching for water are an
example of what kind of response?
A. thigmotropism
B. phototropism
C. hydrotropism
D. gravitropism
Answer:
Explanation:
Hydrotropism
!! brainliest answer !! please help it's due tonight :)
Answer:
3. D
28. also known as Freon 12
Explanation:
Which group in the food chain uses the energy of the sun to create its own food A consumers B predators C producers D prey
Answer:
C producers
Explanation:
All food chains start with energy from the sun. This energy is captured by plants. Thus the living part of a food chain always starts with plant life and ends with an animal. Plants are called producers because they are able to use light energy from the sun to produce food (sugar) from carbon dioxide and water.
In 2011, fires in Bastrop County, Texas were the most damaging wildfires in Texas history. The fire spread through the pine trees and scorched nearly 5,700 acres of Bastrop State Park. The majority of the Houston toad’s habitat was lost, and the Lost Pines Forest was greatly affected. As ecological succession began, which of these most likely appeared in the Bastrop forest area first?
A.Shrubs and trees
B. Newly developed topsoil
C.Weeds and grasses
D.Lichens on fallen trees
The most likely appeared in the Bastrop forest area first is to be considered as the C.Weeds and grasses.
What is ecology?It is the study that represents the relationships between a living organism that involved the human, and the physical environment.
It is at the individual, population, community, ecosystem, etc.
Hence, the option c is correct.
Learn more about an area here: https://brainly.com/question/14403188
Combustibles fosiles ¿Por qué son inflamables los gases naturales?¿Dónde están los gases naturales?¿Cómo podemos sacar el aceite?¿Dónde está el carbón?¿Es el combustible fósil una fuente no renovable? AYUDAA
Answer:
1) Los gases naturales son inflamables porque el natural contiene metano junto con una pequeña cantidad de otros gases orgánicos, lo que hace que una mezcla de entre 5 y 15% de concentración de gas natural con aire u oxígeno se queme por completo cuando se enciende.
2) El petróleo crudo, que son depósitos de hidrocarburos que se encuentran en depósitos naturales en las formaciones subterráneas de la Tierra, se obtiene perforando un pozo en el yacimiento de petróleo a través del cual se permite que una parte importante del petróleo fluya fuera del yacimiento bajo la presión del yacimiento para recibir procesamiento e instalaciones de almacenamiento en la superficie
3) El carbón se forma cuando se aplica compactación y calor a la turba que proviene de material vegetal muerto enterrado durante un período de varios millones de años.
4) Los combustibles fósiles se consideran una fuente de combustible no renovable porque la velocidad a la que se produce es más rápida que la velocidad a la que se forma.
Una fuente de energía renovable, como la energía eólica, es producida por la naturaleza tan rápido como se consume para generar energía.
Explanation:
What does the word photosynthesis mean?
PIC IS BELOW!
Calculate the pH if the pOH = 7.4
Round your answer to two decimal places.
i need points
Explanation:
What is the freezing point of solution that has 185.25 grams of Ca(OH)2 (formula mass = 74.1) dissolved in 2,500 grams of water at standard pressure?
Answer:
The freezing point depression ∆T = KF·m where KF is the molal freezing point depression constant and m is the molality of the solute. Rearrangement gives: mol solute = (m) x (kg solvent) where kg of solvent is the mass of the solvent (lauric acid) in the mixture. This gives the moles of the solute.
Explanation:
Does this help at all??
Give the number of protons, electrons and neutrons in one atom of Carbon.
Answer:
6 protons, 6 neutrons, and 6 electrons.
Explanation:
Electrotonic configuration of potassium 19K ion equal the Electrotonic configuration of
1) ⁸0
2) ¹¹Na
3) ¹⁸Ar
4) ¹⁷C1
3) What are the three types of sedimentary rocks?
Answer:
clastic, organic, and chemical
What is the ratio of the effusion rate of the helium to methane? (round to hundreds)
Answer:
2.00
Explanation:
From Graham's law; the rate of effusion is inversely proportional to the square root of the relative molecular mass.
Let the rate of effusion of Helium be R1
Let the rate of effusion of Methane be R2
Let the molecular mass of Helium be M1
Let the molecular mass of Methane be M2
Hence;
R1/R2 = √M2/M1
R1/R2 = √16.0294/4.0026
R1/R2 = 2.00
1. Which of the following
equalities is false?
A. 1 kilogram = 100 meters
B. 50 milliliters = 5 centiliters
C. 3 grams = 0.003 milligrams
D. 70 hectometers = 7,000 decimeters
the spectral classes of four stars are shown in comparison with a Hertzsprung-Russell diagram. Based on the information which star is most like the sun?
Answer: star 3
Explanation: i did the test
Answer: star 3
Explanation:I did the test
The period of time needed for a radioisotope to lose one-half of its activity is known as that isotopes
Explanation:
The radioactive scattering technique is called radioactive degradation. For each radioactive isotope, the natural radioactive cycle is special and is determined by a period of time termed a half-life. One half-life was its time needed to experience radioactivity for half of both the radioactive nuclei.
Can somebody sort these from non-metals to metals?
Sonorous, low melting point, high density, brittle, dull, malleable, basic oxide
What temperature kelvin would .97mol of gas be to occupy 26L at 751.2mmHg?
Answer: 322.56 Kelvin
Explanation:
Use the Ideal Gas Law
[tex]PV=nRT[/tex]
R is the gas constant
T is the temperature in Kelvins
P is the pressure in atmospheres
V is the volume in liters
n is the number of moles of gas
First, the mm of mercury need to be converted to atmospheres using the conversion factor 1atm = 760 torr.
[tex]751.2mmHg (torr) =0.988atm[/tex]
Now plug everything in
[tex](0.988)(26)=(0.97)(0.0821)T\\T=322.56K[/tex]
how many moles are in 5g of Na2CO3?
a) 0.047
b) 1
c) 2
d)21.2
Answer:
0.047
Explanation:
Data : 5g , Na2CO3
Formula:
Molecular mass of Na2Co3 = no.of atomic mass x no. of atom
moles = mass÷ molecular mass
molecular mass = 2(23)+1(12)+3(16)
=106amu
moles = 5÷106
= 0.047 Ans:
please answer fast! Which of the following statements are false?
A: In a chemical change, atoms are rearranged to make new compounds.
B: The same element is present before and after a chemical change.
C: A physical change does not produce an entirely new substance.
D: A chemical property can be observed without changing the identity of the substance.
I believe it is C.
Hope this helps!
if a piece of aluminum has a density of 2.7g/cm^3. the mass of 5.2g,what is the volume
Answer:
Gold has a density of 19.3 grams per cubic centimeter, that is, 19.3 g/cm3 or 19.3 g cm-3. Aluminium has a density of 2.7 grams per cubic centimeter, that is, 2.7 g/cm3 or 2.7 g cm-3.
Explanation:
Answer:2.7 g cm-3.
Explanation:Gold has a density of 19.3 grams per cubic centimeter, that is, 19.3 g/cm3 or 19.3 g cm-3. Aluminium has a density of 2.7 grams per cubic centimeter, that is, 2.7 g/cm3 or 2.7 g cm-3.
What is specific heat?
Specific heat is the amount, like the other brainly answer said, of heat per unit mass required.