Answer:
pH = 14 - pOH = 14 - 6.907 = 7.903
=> [H₃O⁺] = 10^-pH = 10^-7.903 = 1.25 x 10⁻⁸M
Explanation:
Occurs when the membrane surrounds a large substance and engulfs it.
) Active Transport
O Diffusion
O Endocytosis
Exocytosis
How many moles of water will be produced from the combustion of 0.27 moles of CH3OH?
Answer:
0.54 mole of H2O.
Explanation:
We'll begin by writing the balanced equation for the reaction. This is illustrated below:
2CH3OH + 3O2 —> 2CO2 + 4H2O
From the balanced equation above,
2 moles of CH3OH reacted to produce 4 moles of water.
Finally, we shall determine the number of mole of water (H2O) produced by the reaction of 0.27 moles of CH3OH. This can be obtained as follow:
From the balanced equation above,
2 moles of CH3OH reacted to produce 4 moles of water.
Therefore, 0.27 moles of CH3OH will react to produce = (0.27 × 4)/2 = 0.54 mole of H2O.
Thus, 0.54 mole of H2O is produced from the reaction.
A candle made of certain wax blend burns at a rate of 44.2 mg/min. What is the value of this burn rate if expressed in grams/hour
Answer:
2.652 g/h.
Explanation:
Burn rate (in mg/min) = 44.2 mg/min
Burn rate (in m/h) =?
We'll begin by converting 44.2 mg/min to g/min. This can be obtained as follow:
1 mg/min = 0.001 g/min
Therefore,
44.2 mg/min = 44.2 mg/min × 0.001 g/min / 1 mg/min
44.2 mg/min = 0.0442 g/min
Finally, we shall convert 0.0442 g/min to g/h. This can be obtained as follow:
1 g/min = 60 g/h
Therefore,
0.0442 g/min = 0.0442 g/min × 60 g/h / 1 g/min
0.0442 g/min = 2.652 g/h
Therefore, 44.2 mg/min is equivalent to 2.652 g/h.
Thus, the burn rate (in m/h) is 2.652 g/h.
A buffer is prepared by adding 24.6 mL of 0.65 M to 49.6 mL of 0.28 M. What is the pH of the final solution?
The given question is incomplete, the complete question is:
A buffer is prepared by adding 24.6 mL of 0.65 M NaF to 49.6 mL of 0.28 M HF. What is the pH of the final solution?
Answer:
The correct answer is 3.23.
Explanation:
The calculations of pH in a buffer solution is determined with the help of Henderson-Hasselbalch equation, that is,
pH = pKa + log[conjugate base]/[acid]
= pKa + log[A⁻][HA]
Here Ka is the equilibrium constant.
Based on the given information, the volume and concentration of NaF is 24.6 ml and 0.65 M. Now the millimoles of NaF can be determined by using the formula,
millimoles = Molarity × Volume
= (0.65 M) (24.6 ml) (1 mmol/ml/1M)
= 16 mmol
Thus, the millimoles of NaF or F⁻ is 16 mmol.
On the other hand, the volume and concentration given of HF is 49.6 ml and 0.28 M. Now the millimoles of HF will be,
Millimoles = 0.28 M × 49.6 ml (1mmol/ml/1M)
Millimoles = 13.9 mmol
Thus, the millimoles of HF is 13.9 mmol.
The value of Ka for strong acid is 6.8 × 10⁻⁴.
Now the pH of the buffer solution can be determined by using the above mentioned Henderson-Hasselbalch equation,
pH = pKa + log[F⁻]/[HF]
= -logKa + log[16 mmol]/[13.9 mmol]
= -log(6.8 × 10⁻⁴) + 0.06
= 3.17 + 0.06
= 3.23.
Hence, the pH of the solution is 3.23.
A student mixes 50.0 mL of 1.00 M Ba(OH)2 with 83.5 mL of 0.475 M H2SO4. Calculate the mass of BaSO4 formed.
Answer:
9.26g of BaSO₄ are formed
Explanation:
The reaction of Ba(OH)₂ with H₂SO₄ is:
Ba(OH)₂ + H₂SO₄ → BaSO₄ + 2H₂O.
To solve this question we need to determine the moles of each reactant in order to find the limitng reactant. With the moles of limiting reactant we can find the theoretical moles of BaSO₄ produced and its mass, as follows:
Moles Ba(OH)₂:
50.0mL = 0.050L * (1.00mol / L) = 0.0500moles
Moles H₂SO₄:
83.5mL = 0.0835L * (0.475mol / L) = 0.0397moles
That means limiting reactant is H₂SO₄.
Based on the reaction, 1 mole of H₂SO₄ produce 1 mole of BaSO₄. The theoretical moles of BaSO₄ produced are 0.0397 moles.
The mass is (Molar mass BaSO₄: 233.38g/mol):
0.0397 moles BaSO₄ * (233.38g / mol) =
9.26g of BaSO₄ are formedQuestion 8 (3 points) What is the formula for Silver (III) sulfide? O Ag2(SO4)3 O Ag3(SO4)2 Ag3S2 Ag2S3
The formula of Silver (III) Sulfide is Ag2S3.
Hope this helps. Please mark brainliest!
What change would you expect on the rate of the SN2 reaction of 1-iodo-2-methylbutane with cyanide ion if the nucleophile concentration is halved and the alkyl halide concentration is doubled?
a. divided by 4
b. halved
c. no effect
d. increased 2x
e. increased 3x
f. increased 6x
g. increased 9x
Answer:
no effect
Explanation:
In an SN2 reaction, the mechanism is bi-molecular and first order in both the alkyl halide and the nucleophile.
Hence the rate of reaction is;
Rate = k [1-iodo-2-methylbutane] [cyanide ion]
Given that it is a bimolecular reaction, if we double the concentration of 1-iodo-2-methylbutane and the concentration of the cyanide ion is halved, the rate of reaction remains the same.
Compare the properties of solid , liquid , and gas?
Based on the information in the table, which of the following arranges the bonds in order of decreasing
polarity?
Choose 1 answer:
H-S > Sn-Te > Si-F
Sn-Te > H-S > Si-F
Si-F>H-S > Sn-Te
Si-F > Sn-Te > H-S
Answer:
what grade so i can help
Explanation:
Answer:
I believe it’s Sn-Te > H-S > Si-F
Explanation:
Which sentence from “Broken Chain” contains the most descriptive language? “He asked his mother if he could have braces, like Frankie Molina, her godson, but he asked at the wrong time.” “He went to the back yard, where he unlocked his bike, sat on it with the kickstand down, and pressed on his teeth.” “Sunday morning, Ernie and Alfonso stayed away from each other, though over breakfast they fought over the last tortilla.” “At four he decided to get it over with and started walking to Sandra’s house, trudging slowly, as if he were waist-deep in water.”
Answer:
" At four he decided to get it over with and started walking to Sandra's house, trudging slowly, as if he were waist-deep in water. "
Explanation:
The sentence "At four he decided to get it over with and started walking to Sandra's house, trudging slowly, as if he were waist-deep in water" is the most descriptive language.
What is descriptive language?Descriptive language is a technique that are used in speaking and writing which involves a detailed description of a place or a person.
It's intended to create a vivid and specific picture in the reader's mind to give them a better feel for the story
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A 12.0% sucrose solution by mass has a density of 1.05 gem, what mass of sucrose is present in a 32.0-mL sample of this solution?
A) 0.126g
B) 3.66g
C) 4.03g
D) 3.84g
E) 280 g
Answer:
Option C. 4.03 g
Explanation:
Firstly we analyse data.
12 % by mass, is a sort of concentration. It indicates that in 100 g of SOLUTION, we have 12 g of SOLUTE.
Density is the data that indicates grams of solution in volume of solution.
We need to determine, the volume of solution for the concentration
Density = mass / volume
1.05 g/mL = 100 g / volume
Volume = 100 g / 1.05 g/mL → 95.24 mL
Therefore our 12 g of solute are contained in 95.24 mL
Let's finish this by a rule of three.
95.24 mL contain 12 g of sucrose
Our sample of 32 mL may contain ( 32 . 12) / 95.24 = 4.03 g
What are the roles of chlorophll, light, carbon dioxide, and water in the production of food and oxygen for a plant? (15 points to answer)
Explanation:
Chlorophyll make food the plant can use from carbon dioxide, water, nutrients, and energy from sunlight. This process is called photosynthesis. During the process of photosynthesis, plants release oxygen into the air. People and animals need oxygen to breathe.
hope it helps!
S this true or false most energy we use comes from fossil fuels
Answer:
True. Hope this helps. :)
Please respond guys I’ll give brainliest and 100 points
Compare and contrast the reactions of lithium and cesium when they are added to water. At least 5 sentences
Answer:Both lithium and cesium are classified as alkali metals because they both have just one electron in their outermost shell.
The electronic configuration of both atoms are:
Lithium = 2, 1
Cesium = 2, 8, 18, 18, 8, 1
Explanation:
What is magnetism?
O a property of all rocks
O a property of all metals
O the force of attraction or
repulsion of magnetic materials
O a force that depends on mass and distance
Explanation:
I think it's the third one but I'm not sure
Answer:
The Answer for this is C
How many joules are required to melt 250 grams of water
Answer:
i not sure but i searched it up and it said Q=104525J
Explanation:
From top to bottom within a group of the periodic table, first ionization energy tends to *
A. increase.
B. decrease.
C. remain approximately the same.
D. change in an irregular way.
Answer:
B. decrease.
Explanation:
Because size of atom increases so it is easy to remove electron
based on the table below, what is the density of material A?
Middle school science help please. ill give brainliest
Answer:
It converts The liquid into a gas at the same temperature.
Explanation:
Answer:
it converts the liquid into gas at the same temperature
Explanation:
when heat is added to a liquid at boiling temperature it converts the liquid into gas at that same boiling temperature
please give brainliest
Which of the following is a pure substance?
pizza
pizza
salt (NaCl)
salt (NaCl)
air
air
sweet tea
sweet tea
Answer:
salt (NaCl)
Explanation:
Pure substance is defined as the substance that consist of a single type of material and does not contain contaminants. A pure substance has uniform composition throughout the process.
sodium chloride (NaCl) also known as table salt is a pure substance because it has a uniform and definite composition that is 1:1 ratio of sodium and chloride ions.
Hence, the correct answer is "salt (NaCl)".
A student in chemistry class mixes two clear solutions together. Which of the following is the best evidence that a chemical reaction has occurred?
Question 5 options:
The solutions are soluble when mixed together.
The volume of the liquids increased.
A Yellow precipitate is formed when mixed together.
One liquid is insoluble in the other liquid.
Answer:
a yellow precipitate is formed when mixed together
A student in chemistry class mixes two clear solutions together. Then, a Yellow precipitate is formed when mixed together.
What is the solution ?A particular kind of homogenous combination made up of two or more components is known as a solution. A solute is a material that has been dissolved in a solvent, which is the other substance in the combination.
In a combination called a solution, every component is well combined. Solutions can contain solids, liquids, and gases and are regarded as homogenous mixes. A solute plus a solvent makeup a solution. Any material that dissolves in a solvent is referred to as a solute.
Solid, liquid, and gaseous solutions can be classified as solutions based on the physical states of the solvent and solute. Both the solute and the solvent are in the solid state in solid solutions.
Thus, option C is correct.
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Carbonic acid (H2CO3) is a polyprotic acid. Write balanced chemical equations for the sequence of reactions that carbonic acid can undergo when it's dissolved in water.
Answer:
H₂CO₃(aq) ⇄ H⁺(aq) + HCO₃⁻(aq)
HCO₃⁻(aq) ⇄ H⁺(aq) + CO₃²⁻(aq)
Explanation:
Carbonic acid (H₂CO₃) has 2 acidic protons. When is dissolved in water, it loses the protons (H⁺) in two sequential steps:
- First, it loses 1 proton to form the hydrogen carbonate ion (HCO₃⁻)
H₂CO₃(aq) ⇄ H⁺(aq) + HCO₃⁻(aq)
- Then, the acid carbonate anion loses its proton to form carbonate ion (CO₃²⁻):
HCO₃⁻(aq) ⇄ H⁺(aq) + CO₃²⁻(aq)
Suppose you are titrating an acid of unknown concentration with a standardized base. At the beginning of the titration, you read the base titrant volume as 2.04 mL. After running the titration and reaching the endpoint, you read the base titrant volume as 20.95 mL.
1. What volume, in mL, of base was required for the titration?
2.Calculate the mass percent of a vinegar solution with a total mass of 96.92 g that contains 2.28 g of acetic acid.
Answer:
1) 18.91 mL
2) 2.35 %
Explanation:
1. The volume of base that was required is equal to the difference between the reading at the end of the titration and the reading at the beginning:
V = 20.95 mL - 2.04 mL = 18.91 mL2. The mass percent can be written as:
Mass Percent = Mass solute / Total mass * 100%For this problem:
Mass solute = 2.28 gTotal mass = 96.92 gWe input the data and calculate the mass percent:
% mass = 2.28/96.92 * 100% = 2.35 %Use calc to determine whether it is possible to remove 99.99% Cu2 by converting it to Cu(s) in a solution mixture containing 0.12 Cu2 and 0.12 MSn2 suppose it is at room temperature.
Answer:
it is possible to remove 99.99% Cu2 by converting it to Cu(s)
Explanation:
So, from the question/problem above we are given the following ionic or REDOX equations of reactions;
Cu2+ + 2e- <--------------------------------------------------------------> Cu (s) Eo= 0.339 V
Sn2+ + 2e- <---------------------------------------------------------------> Sn (s) Eo= -0.141 V
In order to convert 99.99% Cu2 into Cu(s), the equation of reaction given below is needed:
Cu²⁺ + Sn ----------------------------------------------------------------------------> Cu + Sn²⁺.
Therefore, E°[overall] = 0.339 - [-0.141] = 0.48 V.
Therefore, the change in Gibbs' free energy, ΔG° = - nFE°. Where E° = O.48V, n= 2 and F = 96500 C.
Thus, ΔG° = - 92640.
This is less than zero[0]. Therefore, it is possible to remove 99.99% Cu2 by converting it to Cu(s) because the reaction is a spontaneous reaction.
C4H10 is an example of a (n) a. Molecular formula b. Structural formula c. Atomic formula d. Geometric formula
Answer:
molecular formula
Explanation:
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A balloon contains a mixture of 2 gases, X and Y. If the pressure in the balloon is 1.50 atm and there are 3 moles of X and 7 moles of Y present, what is the partial pressure of each gas?
Answer:
Partial Pressure of X = 0.45 atm
Partial Pressure of Y = 1.05 atm
Explanation:
Mixture of gas = Gas X + Gas Y
Total number of moles = 3 + 7 = 10 moles
Total pressure = 1.50 atm
The relationship between partial pressure, total pressure and number of moles is given as;
Partial pressure of gas X / Total pressure = Number of moles of gas X / Total number of moles
Partial Pressure of gas X / 1.50 = 3 / 10
Partial Pressure of gas X = 1.5 * 3 / 10 = 0.45 atm
The total pressure of a mixture is a sum total of the individual pressures, hence;
Pressure of mixture = Partial Pressure of X + Partial pressure of Y
1.5 = 0.45 + Partial pressure of Y
Partial Pressure of Y = 1.5 - 0.45 = 1.05 atm
How many atoms of carbon are present in the products?
6CO2+6H2O=C6H12O6+6O2
Answer:
2.41 * 10^24 atoms of carbon present in the products.
Explanation:
First, we need to find the moles of carbon in the products in order to find the number of atoms.
We see that in the chemical formula, carbon belongs to the compound known as glucose. To get the amount of moles of carbon, we need to divide my the amount of carbon within glucose (in grams) from the total amu ( or grams) of glucose to get the moles.
C6 = 72.066.
C6H12O6 = 180.156
72.066/180.156 = 0.4000199827 moles of Carbon within the Glucose compound
Now we will convert to atoms/molecules by multiplying the moles by avogadro's number..
0.4000199827 moles C * 6.022*[tex]10^{23}[/tex] = 2.408920336 *[tex]10^{24}[/tex] atoms of Carbon present in the products
*Note --> this can be estimated to 2.41 * [tex]10^{24}[/tex] atoms of Carbon
A solution has a pH of 11.75. Calculate the [H:0*] of the solution
The [H₃0⁺] of the solution : 1.778 x 10⁻¹² M
Further explanationpH is the degree of acidity of a solution that depends on the concentration of H⁺ ions. The greater the value the more acidic the solution and the smaller the pH.
pH = - log [H⁺]
So that the two quantities between pH and [H⁺] are inversely proportional because they are associated with negative values.
A solution whose value is different by n has a difference in the concentration of H⁺ ion of 10ⁿ.
pH of solution = 11.75
the [H₃0⁺] of the solution :
[tex]\tt pH=-log[H_3O^+]\\\\11.75=-log[H_3O^+]\\\\(H_3O^+]=10^{-11.75}=1.778\times 10^{-12}[/tex]
30 Points!
Which of the following tasks falls under the responsibility of a forensic scientist?
Cleaning the crime scene after evidence has been collected
Making the final determination as to if a suspect is, in fact, guilty of the crime
Signing search warrants
Training officers in how to collect evidence
Which is an example of a compound? * He3 or H2O or C
Answer:
H2O
Explanation:
There is more than one element