Answer:
pH = -log[H⁺] = -log(4.75 x 10⁻⁷) = -(- 6.32 ) = 6.32
Explanation:
Given 4.3 x 10⁻⁷M H₂CO₃ (Ka1 = 4.2 x 10⁻⁷ & Ka2 = 4.8 x 10⁻¹¹)
Note: The Ka2 value for the 2nd ionization step is so small (Ka2 = 4.8 x 10⁻¹¹) It will be assumed all of the hydronium ions (H⁺) come from the 1st ionization step.
1st Ionization step
H₂CO₃ ⇄ H⁺ + HCO₃⁻
C(initial) 4.3 x 10⁻⁷ 0 0
ΔC -x +x +x
C(final) 4.3 x 10⁻⁷ - x x x
Note: the 'x' value in this analysis can not be dropped as the Conc/Ka value is less than 10². In this case he C/Ka ratio* (4.3E-7/4.2E-7 ≈ 1) is far below 10².
So, one sets up the equilibrium equation to be quadric and the x-value can be determined.
Ka1 = [H⁺][HSO⁻]/[H₂SO₃] = (x)(x)/(4.3 x 10⁻ - x) = x²/(4.3 x 10⁻⁷ - x) = 4.2 x 10⁻⁷
=> x² = 4.2 x 10⁻⁷(4.3 x 10⁻⁷ - x)
=> x² + 4.2 x 10⁻⁷x - 1.8 x 10⁻¹³ = 0
a = 1, b = 4.2 x 10⁻⁷, c = - 1.8 x 10⁻¹³
x = b² ± SqrRt(b² - 4(1)(-1.8 x 10⁻¹³ / 2(1) = 4.75 x 10⁻⁷
x = [H⁺] = 4.75 x 10⁻⁷
pH = -log[H⁺] = -log(4.75 x 10⁻⁷) = -(- 6.4 ) = 6.4
______________________
* The Concentration/Ka-value is the simplification test for quadratic equations used in Equilibrium studies. If the C/Ka > 100 then one can simplify the C(final) by dropping the 'x' if used in this type analysis. However, if the C/Ka value is < 100 then the x-value must be retained and the solution is determined using the quadratic equation formula.
for ax² + bx + c = 0
x = b² ± SqrRt(b² - 4ac) / 2a
10. A balloon is blown up to a volume of 18 L at a pressure of 1.0 atm and
298 K. What would the pressure inside the balloon be when its volume
becomes 4.0 L and its temperature is 239 K?*
Answer:
3.6 atm
Explanation:
10. A balloon is blown up to a volume of 18 L at a pressure of 1.0 atm and
298 K. What would the pressure inside the balloon be when its volume
becomes 4.0 L and its temperature is 239 K?*
PV/T = P'V'/T'
(18 X 1)/298 =(P' X 4)/239
so
P' = (18 X 239)/(298 X 4)= 3.6 atm
P'=(18 X 239)/(298 x 4) =
Elements in the same period have the same…
Answer:
Elements in the same period have the same (number of electron shells)
1.A sample has a mass of 15 g and a volume of 3 mL. Calculate the density.
Answer:
5 g/mLExplanation:
The density of a substance can be found by using the formula
[tex]density = \frac{mass}{volume} \\[/tex]
From the question
mass = 15 g
volume = 3 mL
We have
[tex]density = \frac{15}{3} = 5 \\ [/tex]
We have the final answer as
5 g/mLHope this helps you.
ENT
Which of the following is one of Mendel's laws?
Law of Independent Assortment
ouTube
Law of DNA contains genes
Law of Segregation of Genes
Answer:
law of independent assortment
In which state of matter are electrons stripped from the nucleus
Plasma is one of the four common states of matter. A plasma is an electrically charged gas. In a plasma, some electrons have been stripped away from their atoms.
Explanation:
Plasma is one of the states of matter that are electrons stripped from the nucleus
. Which situation will result in lower average kinetic energy? a) 100 people go swimming into a NYC public pool b) 100 people go swimming at Coney Island beach
Answer:
I think it would be the beach because all the waves and such but in a pool with more people there is a tight space so they cant move around as much and as freely. But this could be a trickster question but I would choose the beach.
Hope this is right :)
(1) __________ are separated without any chemical reactions. There are many
different kinds of mixtures. Different mixtures are separated in (2)__________ ways.
Physical (3)__________ separates the components of varying sizes using a
spoon or any scooping material or by picking. The use of (4)__________ can be done
to separate the metallic materials from nonmetallic materials. (5)__________ is the
separation of an insoluble solid from a liquid mixture using a semipermeable
membrane like filter paper.
In decantation, the large particles of insoluble solid are separated from the
(6)__________ mixture. (7)__________ separates the soluble solid from the liquid
component of the solution by evaporating the liquid substance.
choices
magnet
mixtures
filtration
different
manipulation
evaporation
liquid
Answer:
1. Mixtures
2. Different
3. Manipulations
4. Magnet
5. Filtration
6. Liquid
7. Evaporation
12. What is the mass of 5.00 moles of F^2 O^3?
Answer:
798.5 grams
Explanation:
a helium laser emits light with a wavelength of 633nm. what is the frequency of light
Answer:
14 ft 7 inches
step-by-step explanation:
since each model inch corresponds to 25 real inches, 7 model inches will correspond to
7×25" = 175"
at 12" per foot, that is 14 feet, 7 inches.
Explanation:
Chemistry
How does the difference in size of particles affect the rate of diffusion?
Explanation:
Heavier particles will move more slowly and so will have a slower rate of diffusion. Smaller particles on the other hand will diffuse faster because they can move faster.
Explanation:
smaller particles diffuse faster
larger particles diffuse slower
I'll pay someone to do my chemistry work.
Answer:
yo te puedo ayudar
tu solo di cuando donde
Explanation:
na+F2-> naF a chemical reaction. the synthesis of sodium fluoride noF is shown above all chemical reactions involve a change to an atoms number of protons neutrons electrons
Answer: Electrons
Explanation:
A chemical reaction usually only affects elctrons. A chemical reaction usually results in the electrons being transferred or shared. When sodium and fluorine react to produce sodium fluoride, a sodium electron is transferred to the fluorine to produce ionic bonds. This ionic bond exists between the sodium cation and fluoride (fluorine) anion.
this is the new one I will mark brainlist NO LINKS OR I WILL REPORT YOU
Answer:
ok what is new. ........,,,,,
Nitrogen makes up ________ of our atmosphere??? will mark Brainliest
1
16. What biological concept was Mendel studying when he crossed pea plants many times
over many generations?
A dominant and recessive traits
B. imbalance in ecosystems
C. predator-prey relationships
D. male and female genetic difference
Answer:
Explanation:
A: Since the Pea plant matured very quickly he was able to identify how the dominant and recessive genes worked.
which factor increases as the efficiency of a machine increases
Answer:
Because all machines lose input work to friction, one way to improve the efficiency of a machine is by reducing friction. Oil is used to reduce friction between the moving parts of car engines. The use of oil makes engines more efficient. Another machine that loses input work is a bicycle.
Explanation:
Hope this helps.
The factor which increases as the efficiency of a machine increases is: work output.
Efficiency can be defined as a ratio of work (energy) output to work (energy) input.
Mathematically, the efficiency of a machine is given by the formula:
[tex]Efficiency = \frac{W_O}{W_I} \times 100[/tex]
Where:
Wo is the work output.Wi is the work input.Work can be defined as the amount of energy required to move an object from one point to another.
Hence, the work done by a machine is the product of the perpendicular force acting on the machine and the distance it covers or travels.
Ideally, the work output of a machine is highly dependent on its efficiency and as such, it is a factor which increases as the efficiency of a machine increases
Read more: https://brainly.com/question/22599382
All matter is made up of atoms and molecules that are what?
A block of material has a density of 1.29 g/cm. what is the volume of 190 g in cubic
centimeters?
No units required
Answer:
147.28 cm³
Explanation:
Density = m/V
1.29 g = 190 g/cm3/V
V = 190 g/cm³ : 1.29 g
V = 147.28 cm³
Why can some mixtures not be classified as solutions?
A. Not all mixtures have solutes
B. Not all mixtures are heterogeneous
C. Mixtures are made of only one substance
D. Not all mixtures are homogenous
Answer:
not all mixture have solutes
what does it mean to say that density is a characteristic property of a pure substance
Density is the degree of the heaviness of a particular substance.
Density can also be defined as the unit mass of a substance per the substance's volume.Density is said to be the characteristic property of a pure substance because the density of a pure substance is constant and fixed
Pure substances are substances that are homogenous in nature, which means they are uniform and are made up of only one component.Density is said to be the characteristic property of a pure substance because the density of a pure substance is constant and fixed but its mass and volume can vary.To learn more, visit the link below:
https://brainly.com/question/11208248
why should you not change the subscripts in chemical formulas when balancing chemical equations?
Answer:because the chemical formula is vital to the equation it tells you what creates the chemical and whats in it you can change the exponents but not the formula itself
Explanation:
best answer will be tagged brainliest.... no spamming pliz
[tex]\huge \mathcal \fcolorbox{cyan}{black}{ \blue{AnSweR}}[/tex]
A. Chloride ions (CI)
[tex] \large{ \green{ \bold{ \underline{ \underline{ \overline{ \overline{ \pink{hope \: this \: helps \: you \: \: ✌}}}}}}}}
[/tex]
What gas is dissolved into soft drinks such as soda which causes them to bubble when opened? A. Carbon dioxide B. Ethylene C. Hydrogen D. Argon
Answer: A, Carbon Dioxide
Explanation:
A. Soda water, like other carbonated beverages, contains carbon dioxide that has dissolved under pressure. When the pressure is released by opening the soda container, the liquid cannot hold as much carbon dioxide, so the excess bubbles out of the solution.
Answer:
A. carbon dioxide
Explanation:
the answer is A
when an atom become a negative ion, where do the extra electrons come from?
Answer:
Valence Shell
Explanation:
Some atoms have nearly eight electrons in their valence shell and can gain additional valence electrons until they have an octet. When these atoms gain electrons, they acquire a negative charge because they now possess more electrons than protons.
Mass of a single 35Cl atom
What does this picture represent?
А. 0
Hot Plate
B.
Graduated cylinder
С.
Goggles
D.
Electronic Balance
the answer is d electronic balance
Part E
In which state of matter are the particles the most spread out?
Gas has the most spread out particles.
why is beryllium-8 different from beryllium-9 in terms of the nuclear particles?
Answer:
Beryllium-8 (8Be, Be-8) is a radionuclide with 4 neutrons and 4 protons. It is an unbound resonance and nominally an isotope of beryllium. It decays into two alpha particles with a half-life on the order of 10−16 seconds; this has important ramifications in stellar nucleosynthesis as it creates a bottleneck in the creation of heavier chemical elements. The properties of 8Be have also led to speculation on the fine tuning of the Universe, and theoretical investigations on cosmological evolution had 8Be been stable.
Explanation:
helppppppppppppppppp
Answer:
sana all may brainnnnnnnnnnnnn
new substances are formed in a chemical reaction as a result of
Answer:
New substances formed when breaking of bonds take place and new bonds get formed which results in formation of new products. That breaking of bond is a chemical change because in such a process composition of substance gets changed and forms a new substance.