Answer:
0.0562 moles
Explanation:
Based on the H-H equation, for the HF buffer:
pH = pKa + log [F⁻] / [HF]
Where pH is the pH of the buffer = 3.630
pKa is pKa of HF buffer: 3.17
And [] could be taken as the moles of each reactant
3.630 = 3.17 + log [F⁻] / [HF]
0.46 = log [F⁻] / [HF]
2.884 = [F⁻] / [HF] (1)
The initial moles of HF are:
0.250L * (0.303mol / L) = 0.07575 moles
The HF reacts with NaOH as follows:
HF + NaOH → NaF + H₂O
That means the moles of HF will be the initial moles of HF - Moles NaOH
And moles NaF = F⁻ = Moles of NaOH added
That means:
0.07575 moles = [F⁻] +[HF] (2)
Replacing (2) in (1):
2.884 = [F⁻] / 0.07575 moles - [F⁻]
0.218 - 2.884[F⁻] = [F⁻]
0.218 = 3.884[F⁻]
[F⁻] = 0.0562 moles
That means the moles of NaOH that must be added are:
0.0562 molesOday, you will observe drops of liquid water and compare them to drops of liquid isopropanol, noting whether either liquid evaporates. Given that the energy transferred in from the air will be the same for both liquids, make a prediction about whether both drops or only one drop will evaporate within five minutes. Explain your prediction below.
Answer:
Liquid isopropanol.
Explanation:
Liquid isopropanol will evaporate earlier than water because the boiling point of isopropanol is less than water. That liquid which have high boiling point require more heat energy for change into vapor state as compared to those liquids that has low boiling point. The isopropanol has boiling point i.e. 82.5 °C while on the other hand, water has boiling point i.e. 100 °C so we can say that isopropanol will evaporate first.
The liquid that will be the first to evaporate within 5 minutes is; Liquid Isopropanol
We have the 2 liquids as;
Liquid Isopropanol
Liquid water
Now, since we are dealing with the one that will evaporate within five minutes, we need to know their boiling points.
From online research;
Boiling point of liquid isopropanol is 82.5°C
Boiling point of liquid water is 100°C
Now, we are told that the same energy is transferred for both liquids. However, boiling point of the liquid with the lower boiling point will be achieved first and as a result will evaporate first since the next stage after boiling point is evaporation of steam.
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Can someone help me? It needs to have a diagram that has arrows.
Answer: The enthalpy change for formation of butane is -125 kJ/mol
Explanation:
The balanced chemical reaction is,
[tex]C_4H_{10}(g)+\frac{13}{2}O_2(g)\rightarrow 4CO_2(g)+5H_2O(l)[/tex]
The expression for enthalpy change is,
[tex]\Delta H=[n\times H_f{products}]-[n\times H_f{reactants}][/tex]
Putting the values we get :
[tex]\Delta H=[4\times H_f_{CO_2}+5\times H_f_{H_2O}]-[1\times H_f_{C_4H_{10}}+\frac{13}{2}\times H_f_{O_2}][/tex]
[tex]-2877=[(4\times -393)+(5\times -286)]-[1\times H_f_{C_4H_{10}}+\frac{13}{2}\times 0][/tex]
[tex]H_f_{C_4H_{10}=-125kJ/mol[/tex]
Thus enthalpy change for formation of butane is -125 kJ/mol
Explain why it is necessary to use a mixture, alumina and cryolite, rather than just
alumina
Explanation:
The mixture of cryolite and aluminium oxide has a lower melting point than pure aluminium oxide. This means a lower amount of energy is required to establish effective conditions for electrolysis and thus makes it more cost effective.
12) Balance the following chemical equation:
Zn +
H3PO4
Zn3(PO4)2 +
H2
Answer:
Sorry I am not very good at chemistry.
Explanation:
Does axons have insulation
Answer: Yes they do;
Explanation:
Axons, the long projections of neural cells that make up our peripheral nervous system's nerves, are comparable to power wires in that they have dense electrical insulation and can easily transmit impulses from the body and signals from the brain to a toe, for example.
What is the correct illustration of the bonding that occurs in H2O?
Answer:
covalent is the bonding that occurs in H2O
Explanation:
DONT SKIP OR ELSE what solids, liquids, and gases does the human body produce
farting pooping peeing :3
Balance this chemical equation. A coefficient of "1" is understood. Choose option "blank" for the correct answer if the coefficient is "1."
Choose... H 2 O 2 → Choose... H 2 O + Choose... O 2
Suppose a fox population exists in an ecosystem. Some of the foxes maintain a heavy coat year-round, while others shed their heavy coat in the summer. Summers in this ecosystem
are becoming steadily hotter because of global warming. Which members of the species will most likely be able to adapt to the changing temperatures?
subject science
Answer:
The fox who shed their heavy coat in the summer.
Explanation:
If a fox has the ability to shed its coat in the summer, it will have no difficulties adapting to new temperatures even during winter. However, the heavy-coated one will.
What might be a possible outcome if you left a soda in a glass bottle in the freezer for a very long time?
A.
The gases in the soda will increase in volume as the soda transitions from liquid to solid. This will cause the bottle to explode.
B.
The gases in the soda will decrease in volume as the soda transitions from liquid to solid. This will cause the bottle to implode or collapse.
C.
H2O will decrease in volume when transitioning from a liquid to solid state. This will cause the bottle to implode or collapse.
D.
H2O will increase in volume when transitioning from a liquid to solid state. This will cause the bottle to explode.
A the soda will increase in volume
Which solution will conduct electric current a sugar solution or a salt solution
Which of the following is a pure substance?
Chlorine B. salt solution C. bronze D. salad dressing
What is the boiling point of pure water?
About 1000 C B. exactly 1000 C C. it varies D. slightly above 1000 C
Which is an example of a chemical change?
Water evaporating B. butter melting C. match burning D. powder being made
Which of these indicate a chemical change?
Color change B. temperature change C. gas-forming D. all of the above
Which of these is an impure substance?
Tap water B. gold C. carbon dioxide D. boron
Answer:
1. B
2. 100 C
3. C
4. D
5. D
Explanation:
What is the temperature range for our planet? Why is this important?
Answer:
are temperature range for are planet is -129 ⁰F (-18⁰C) that's the minimum.
+136⁰F (+58⁰C) this is the maximum surface temperature
Explanation:
"the planet is not too close or too far away from the sun, earth's atmosphere also plays a vital role is regulating the temperature by providing a blanket of gases that not only protects us from excessive heating and harmful radiation from the sun, but also traps heat rising from earth's interior core, keeping us warm"- Space.com
A pine tree seed was produced by self-pollination. How many parents does this seed have?
A. one
B. two
The pine tree that produced the seed would be the only parent of a pine seed that was formed through self-pollination. So, the correct option is A.
What is Self-pollination?In the process of self-pollination, pollen from one flower or plant fertilizes the egg cells of another flower or plant. For self-fertilization to occur, both male and female reproductive components must be present within the same flower or plant.
The pollen from the male flower component, the anther, is carried to the female component, the stigma, during self-pollination either by the wind or by pollinators like bees, butterflies, or birds.
A pine tree that produces seeds will be the sole parent of pine seeds that form through self-pollination. Self-pollination occurs when pollen from the same pine tree fertilizes the pine tree's own egg cells, producing seeds with the genetic makeup of only one individual.
Therefore, the correct option is A.
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#SPJ2
if the velocity of an object is doubled, its kinetic energy is multiplied by
What creates a bond dipole and how can you tell if a bond dipole exists?
Answer:
A dipole exists when there are areas of asymmetrical positive and negative charges in a molecule. Dipole moments increase with ionic bond character and decrease with covalent bond character.
what is the smallest halogen atom
Answer:
Hey mate...
Explanation:
This is ur answer.....
This is because fluorine atoms are the smallest of the halogens—the atoms are bonded close together, which leads to repulsion between free electrons in the two fluorine atoms.
Hope it helps you,
mark me as the brainliest....
Follow me! :)
DO 25 through 37 WRITE IF ITS TRUE OR FALSE FOR EACH ONE. ILL MARK YOU AS BRAINLIEST IF YOU COMPLETE IT AND ALSO SEND ME YOUR CASHAPP NAME SO I SEND YOU $25.
Write the chemical equation for water
Answer:
H2O
Explanation:
Q
1 At which electrode does reduction always take place?
2 Give the half-equation for the reaction at the anode, during
the electrolysis of these molten compounds:
a potassium chloride b calcium oxide
3 Give the two half-equations for the electrolysis of:
a a concentrated solution of hydrochloric acid, HCl
b a dilute solution of sodium nitrate, NaNO3
c a dilute solution of copper(II) chloride, CuCl2
I am trying to figure out what blood type the father of my son could have since my son and I are both type A. Also, my brother is type o and my mom is A.
Answer:
It could probably be O.
Explanation:
Just like eye or hair color, our blood type is inherited from our parents. Each biological parent donates one of two ABO genes to their child. The A and B genes are dominant and the O gene is recessive. For example, if an O gene is paired with an A gene, the blood type will be A.
I need help finding the volume, can't tell if i'm over thinking or if i'm wrong ;(
64.26,162.30,98.04,0.0983 if you cant read my handwriting
Answer:
98.04 ml
Explanation:
density of water is 1g/ml
since volume =mass/density
=98.04/1
= 98.04
which type of window is double glazed window
Answer:
Hope this helps and have a good day!
Explanation:
Double glazed is a fancy term for a window that has two panes of glass. There are also triple glazed windows (three panes). The multiple panes of glass in a single window frame helps with insulation.
What is the molarity of 3 mole of hydrochloride acid in 3 L of water ?
Answer:
1
Explanation:
Formula of molarity is
[tex]M=\frac{n}{v}[/tex]
M= molarity
n= no of moles
v= volume in liters (if mL then you have to convert it to L)
Which sets of elements have similar chemical and physical properties?
1. Mg and Ra 2. Al and P 3. Be and Ba 4. Na and Cl
1 & 2 ,
2 & 3
1 & 3
2 & 4
Answer:
1 & 3
Explanation:
Elements have similar chemical and physical properties if and only if they belong to the same group of elements in the periodic table.
A group of elements in the periodic table is a family of elements, the elements in the in the same group have the same number of valence electrons in their outermost shell, share similar chemical reactivity (with slight variation within the group) and similar physical properties (with slight variation within the group).
Magnesium, radium, beryllium and barium all belong to group 2 hence they have similar chemical and physical properties.
Convert the following temperature units (Hint: K = °C +273)
A) 50°C = __________ K
B) 288 K = __________°C
Answer: a- 323 b- 15
Explanation:
Name the 6 kinetic factors
moles are in 4.3 * 10^22 molecules of H3PO4
Answer:
The answer is 0.073
Explanation:
Final step: 0.73 x 10^-1
help..................
Answer:
Volcanic eruption
Explanation:
a crater is this bowl shaped hole in the ground, and it is caused by a meteorite or volcanic activity
HELP
What is the total pressure of a wet gas mixture at 60°C, containing water vapor, nitrogen, and helium. The partial pressures are
Pnitrogen - 53.0 kPa and Phelium = 25.5 kPa.
Answer:
98.4 kPa
Explanation:
Step 1: Given and required data
Partial pressure of water vapor at 60°C (pH₂O): 19.9 kPa (this info is tabulated)Partial pressure of nitrogen (pN₂): 53.0 kPaPartial pressure of helium (pHe): 25.5 kPaStep 2: Calculate the total pressure of the gaseous mixture
The total pressure of the gaseous mixture (P) os equal to the sum of the partial pressures of the gases that form it.
P = pH₂O + pN₂ + pHe
P = 19.9 kPa + 53.0 kPa + 25.5 kPa = 98.4 kPa
The total pressure of the wet gas mixture is 98.4 KPa
Dalton's law of partial pressureThis law states that at constant temperature, the total pressure of a mixture of gases is equal to the sum of the partial pressure exerted by each gas. Mathematically, it is expressed as
Total pressure = partial pressure of A + partial pressure of B
How to determine the total pressure Partial pressure of water vapor at 60°C (pH₂O) = 19.9 KPa Partial pressure of nitrogen (pN₂) = 53.0 KPa Partial pressure of helium (pHe) = 25.5 KPa Total pressure (P) =?P = pH₂O + pN₂ + pHe
P = 19.9 + 53 + 25.5
P = 98.4 KPa
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