Answer:
pKa = 3.97
Explanation:
Let's state the equations:
NaA → A⁻ + Na⁺
A⁻ + H₂O ⇄ OH⁻ + HA Kb
We don't have the concentration of [OH⁻] but we do know pH, so we can determine, pOH and after that, [OH⁻].
14 - pH = pOH → 14 - 8.70 = 5.30
10^-pOH = [OH⁻] → 10⁻⁵'³⁰ = 5.01×10⁻⁶ M
Initially we can know, the moles of base, we had.
20 mL . 0.27M = 5.4 mmoles. So now, let's make the expression for Kb.
Kb = [OH⁻] . HA / [A⁻]
As the [OH⁻] is so low, we can assume, there where no loses and the salt is well concentrated. So:
Kb = (5.01×10⁻⁶)² / 0.27 → 9.29×10⁻¹¹
Kw = Ka . Kb, then Ka = Kw/ Kb
Ka = 1×10⁻¹⁴ /9.29×10⁻¹¹ = 1.08×10⁻⁴
pKa = - log Ka → - log 1.08×10⁻⁴ = 3.97
name two examples which are not considered as matter
Answer:
Light and Sound can be considered as non-matter.
Explanation:
Various forms of Energy like Heat, Sound, Light can be considered as non-matter
What are the chemical reactions involved in CO2 emission?
Oleic acid's melting point is 14°C and it's boiling point is 360°С. What phase is this substance
at room temperature 25°C?*
A. Solid
B. Liquid
C. Gas
D. Impossible to tell
what is the advantage of rusting
Answer:
Provide more strength
Explanation:
Rust is metal that has been oxidised . Oxides are usually more fragile and porous than their crystals metal equivalents. Some oxides, such as Aluminum oxide, are useful because they have a thin, strong shell that protects the metal from further corrosion.
C + O2 + CO2
What type of reaction occurs when carbon dioxide is formed from carbon and oxygen?
Answer:
combustion reaction.Explanation:
It is a combination reaction as carbon combines with oxygen to form carbon dioxide. It is a combustion reaction as carbon is burnt in the presence of oxygen.
Mariah wants to determine how much energy is needed to change 500 g of liquid water at 100°C to steam at 100°C. What information will BEST help her make this
calculation?
Two tons of water is pumped into a tank 15 ft. High in 5 minutes. Determine the power output of the pump. (Note: One ton is equal to 2,000 lb. And remember to convert the minutes to seconds.)
Answer:
200 lb•ft/s
Explanation:
From the question given above, the following data were obtained:
Force (F) = 2 tons
Time (t) = 5 mins
Height (h) = 15 ft
Power (P) =?
Next, we shall convert 2 tons to pound. This can be obtained as follow:
1 ton = 2000 lb
Therefore,
2 tons = 2 × 2000
2 tons = 4000 lb
Next, we shall convert 5 mins to seconds. This can be obtained as follow:
1 min = 60 s
Therefore,
5 mins = 5 × 60
5 mins = 300 s
Finally, we shall determine the power of the pump. This can be obtained as follow:
Force (F) = 4000 lb
Time (t) = 300 s
Height (h) = 15 ft
Power (P) =?
P = F × h / t
P = 4000 × 15 / 300
P = 60000 / 300
P = 200 lb•ft/s
Thus, the power of the pump is 200 lb•ft/s
Answer:
It's 200 ft-lb/sec
Explanation:
I did it before!
Which of the following would not produce a sound?
some pls help me
Answer:
D
Explanation:
sound waves can not be carried in space
Answer:D
Because space us silent
Calculate the molarity of a sugar solution if 4 liters of the solution contains 12 moles of sugar.
Answer:
3M
Explanation:
Molarity is one of the measures of the molar concentration of a solution, which can be calculated by using the formula below:
Molarity = number of moles ÷ volume
From the information given in this question, 4 liters of a solution contains 12 moles of sugar. This means that n = 12mol and V = 4L
Molarity = n/V
Molarity = 12/4
Molarity = 3
Hence, the molarity of the sugar solution is 3mol/L or 3M
Venus Fly trap is a great example of which type of tropism?
a
Thigmotropism
b
Gravitropism
c
Phototropism
d
Hydrotropism
A sample of hydrogen changes its pressure from 756 torr to 499 torr while the temperature remains constant. After the pressure is reduced, the volume of the gas is 789 mL. What was the original volume?
P1 = 756 torr
P2 = 499 torr
V2 = 789 mL
V1 = ?
applying Boyle's Law
P1 * V1 = P2 * V2
756 torr * V1 = 499 torr * 789 mL
V1 = 499 torr * 789 mL / 756 torr
V1 = 520.78 mL
Which shows substances placed in order from strongest to weakest attractive forces at room temperature?
es )
A)
1. Br (s) 2. Br (9) 3 Br (1)
B)
1. Br (s) 2. Br (1) 3 Br (9)
1. Br (9) 2. Br (1) 3 Br (s)
D)
1. Br (aq) 2. Br (1) 3 Br (9)
Dhusical Dror
Explanation:
es la b es ciertos que es el resultado
Help please if link will report
Before a child takes a bath, his mother mixes bubbles into bath water. Physical or Chemical Change?
Answer:
so i think correct answer is chemmical
3)
:NEN:
How many nonbonding electrons are on each nitrogen atom?
A)
0
B)
2
c)
4
D)
6
4)
-))
Answer:
your answer is C
Explanation:
The electron-dot structure of NH3 places one set of nonbonding electrons in the valence shell of the nitrogen atom. that means there are three bonded atoms and one single pair for a coordination number of four surrounding the nitrogen, the same occurs in water to. along with the Lewis dot structure for ammonia, NH3. the non bonding atoms are basically like hydrogen atoms the try to refuse to bond and they can't be fused unless the right conditions are met.
what happens to the electrons in an ionic bond and a covalent bond?
Answer:
In ionic bonding, atoms transfer electrons to each other. Ionic bonds require at least one electron donor and one electron acceptor. In contrast, atoms with the same electronegativity share electrons in covalent bonds, because neither atom preferentially attracts or repels the shared electrons.
Answer:
In ionic bonding,
atoms transfer
electrons to each
other. Ionic bonds
require at least one electron
donor and one electron
acceptor. In contrast, atoms
with the same electronegativity
share electrons in covalent
bonds, because neither atom
preferentially attracts or repels
the shared electrons.
is the distilled water/acidic/basic/netural?
Distilled Water Has A Neutral pH, Which Means It Is Neither Acidic Nor Basic. Therefore, It's Neutral.
Help please!!!!!!!!!!!!!!!!!!!!!!!!
Which type of a reaction is best represented by the equation - AB + CD → AD + BC?
Answer:
AB + CD → AD + BC
Explanation:
This is a double displacement reaction. It is also known as precipitation reaction.
What is needed for our cells to get energy from our food?
Answer:
cellular respiration is needed for our cells to get energy from our food.
Explanation:
Through the process of cellular respiration, the energy in food is converted into energy that can be used by the body's cells. During cellular respiration, glucose and oxygen are converted into carbon dioxide and water, and the energy is transferred to ATP.
Gold can be pounded out to make a foil only a few atoms thick because of
A. Metallic Bonds
B. Ionic Bonds
C. Valence Bonds
D. Covalent Bonds
Answer:
A. Metallic Bonds
Explanation:
Metallic bonding is a type of chemical bonding that arises from the electrostatic attractive force between conduction electrons and positively charged metal ions.
Which property of sulphuric acid makes it suitable to use as a catalyst for the preparation of esters?
When converting from grams to the must be used as a conversion factor
What number is pointing to the area where magma is less dense due to
heat?
Answer:
I think it's 2
Explanation:
The magma gets so hot, it floats up before cooling and sinking again
1. This balanced equation represents a chemical reaction.
2C4H10+ 1302
8CO2 + 10H2O
What type of chemical reaction is represented by the equation?
A. Double replacement
B. Combustion
C. Single replacement
D. Synthesis (combination)
Answer:
combustion is the answer
A solution's hydrogen ion concentration is 1 x 10-5M.
What is the pH?
Answer:
pH=5
Explanation:
-log(1 x 10-5)=5
The chemical symbols of hydrogen, calcium and chlorine are:
H, C, Cl
H, C, Cn
H, Ca, Cl
Hn, Cal, Cl
Answer:
H, Ca, Cl is the answer dude
Answer:
hydrogen is H
calcium is Ca and chlorine is Cl
. Chalk is made of CaCO 3 . How many molecules are in 5 grams of chalk?
Answer:
20.02 grams of chalk.
Explanation:
formation of ionic bond is affected by
Answer:
Ionization energy, electronegativity, and lattice energy are the factors that influence the formation of ionic bonds of elements.
6.
Ammonia (NH3) acts as a weak base in aqueous solution. What is the acid that reacts with this base
when ammonia is dissolved in water?
(A) NHA
(B) H2O
(C) Oxygen, which is always dissolved in water
(D) None of the above, there are no acids in pure water
Answer:
90% of people marry there 7th grade love. since u have read this, u will be told good news tonight. if u don't pass this on eight comments your worst week starts now this isn't fake. apparently if u copy and paste this on ten comments in the next ten minutes you will have the best day of your life tomorrow. you will either get kissed or asked out in the next 53 minutes someone will say i love you.!Explanation:
Ammonia acts as a weak base in aqueous solution. Water is the acid that reacts with this base when ammonia is dissolved in water.
What is a base?According to the Arrhenius concept, base is defined as a substance which yields hydroxyl ions on dissociation.These ions react with the hydrogen ions of acids to produce salt in an acid-base reaction.
Bases have a pH higher than seven as they yield hydroxyl ions on dissociation.They are soapy in touch and have a bitter taste.According to the Lowry-Bronsted concept, base is defined as a substance which accepts protons .Base react violently with acids to produce salts .Aqueous solutions of bases can be used to conduct electricity .They can also be used as indicators in acid-base titrations.
They are used in the manufacture of soaps,paper, bleaching powder.Calcium hydroxide ,a base is used to clean sulfur dioxide gas while magnesium hydroxide can be used as an antacid to cure acidity.
Learn more about base,here:
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