Answer:
It sounds fine, but it may be a bit too long. It's difficult to shorten things like this, but getting more straight to the point would give it that "catchy" feel.
Explanation:
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.
How much excess reactant remains from the reaction of 8.3g of sodium and 4.5g of chlorine?
a. 8.2g Na
b. 5.4g Na
c. 5.4g Cl2
d. 8.2g Cl2
Answer:
5.4 g Na
Explanation:
Calculate the mass of sodium chloride from both reactants. The lesser value is the amount is the theoretical yield. Subtract the mass of the calculated mass of sodium chloride from the mass of the reactants.
VERY EASY QUESTION
Does a theory help prove an experience or an experience help prove a theory?
Answer:both
Explanation:
It depends on where your looking at it from
Answer:
an expierience help prove a theory.
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:
Chemistry problem. please help
Answer:
solid X contains only ionic bond, and solid Y contains only covalent bonds.
Explanation:
solid X contains only ionic bond, and solid Y contains only covalent bonds. Because ionic compounds they have high melting point compared to covalent compounds, ionic compound they are generally insoluble in non polar solvent such as toluene but soluble in polar solvent such as water, ionic compound they conduct electricity.
Why do the carbon anodes need to be replaced regularly in the electrolysis of Al2O3 into aluminum metal?
A) They get oxidized into carbon monoxide and carbon dioxide by the oxygen molecules generated on the electrode.
B) The intense heat for the reaction breaks them apart.
C) They become saturated with aluminum metal.
D) They get oxidized by air in the intense heat of the reaction.
Answer:
A) They get oxidized into carbon monoxide and carbon dioxide by the oxygen molecules generated on the electrode.
Explanation:
In the electrolysis of Aluminium, the oxygen reacts with the carbon anodes forming carbon dioxide. That is, the anodes are oxidized. To ensure that the reaction completes, the anode must gradually be replaced as the reaction proceeds. The correct option is hence;
A) They get oxidized into carbon monoxide and carbon dioxide by the oxygen molecules generated on the electrode.
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
What is the tissue that allows for flexibility of bones?
Answer:
Bone Marrow, or Cartilage
Mrs. Rushing fills a balloon with hydrogen gas to demonstrate its ability to burn. Which combination could she use to produce the hydrogen she needs? NaOH and oil Zn and KOH H2SO4 and CaCO3 Mg and HCl
Answer:
Mg and HCI
Explanation:
The combination that she uses to produce hydrogen gas is:
d. Mg and HCl(Magnesium and Hydrochloric acid)
Production of hydrogen gas:When magnesium reacts with Hydrochloric acid, It leads to the formation of Magnesium chloride as a salt, and hydrogen gas is liberated.
[tex]Mg+2HCl--- > MgCl_2+H_2[/tex]
When a metal reacts with an acid, it leads to the liberation of hydrogen gas and the production of their respective salt.
Thus, option d is correct.
Find more information about Hydrogen gas here:
brainly.com/question/25597694
I need help ASAP pls
Answer:
1.40.078 u
2.26.981539 u
3.207.2 u
4.56
5.53.9396147 u
6.1.00784 u
Explanation: your welcome
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!
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:
A compound of a transition metal and iodine is 56.7% metal by mass.How many grams of the metal can be obtained from 630 g of this compound?
Answer:
357 g of the transition metal are present in 630 grams of the compound of the transition metal and iodine
Explanation:
In any sample of the compound, the percentage by mass of the transition metal is 56.7%. This means that for a 100 g sample of the compound, 56.7 g is the metal while the remaining mass, 43.3 g is iodine.
Given mass of sample compound = 630 g
Calculating the mass of iodine present involves multiplying the percentage by mass composition of the metal by the mass of the given sample;
56.7 % = 56.7/100 = 0.567
Mass of transition metal = 0.567 * 630 = 357.21 g
Therefore, the mass of the transition metal present in 630 g of the compound is approximately 357 g
1. These values were obtained as the mass of products from the same reaction: 8.83 g;
8.84 g; 8.82 g. The known mass of products from that reaction is 8.60 g. The values
are:
accurate
precise
both precise and accurate
neither precise nor accurate
0
Answer:
precise
Explanation:
precise because they are almost the same measurement over and over ( remember in significant digits the last number is considered to be an estimate on measurements). The known value, 8.60 g, is pretty far from the measurements taken so it cant be accurate.
The values obtained in the measurement of the mass of products from the same reaction are precise but not accurate.
Recall that:
Precision refers to the closeness of repeated measurements made on the same variableAccuracy refers to the proximity of a measurement to its true, predetermined value.In this case, one can see that the repeated measurements of the mass of the products were close to each other with a range of 0.02 g.
The average of the measurement can be calculated such that:
8.83 + 8.84 + 8.82/3 = 8.83 g
The predetermined mass of products from the reaction is 8.60 g. The difference from the average measurement can be calculated as:
8.60 - 8.83 = 0.23
The difference between the measurement and true value is significant. thus, the result is not accurate.
More on precision and accuracy can be found here: https://brainly.com/question/18974348
Which of the following bonds are most polar?
The concentration of KBr in a solution prepared by dissolving 2.21g of KBr in 897 g of water is __________ m.
A) 2.46.
B) 0.0167.
C) 2.07 x 10-5.
D) 0.0186.
E) 0.0207.
Answer:
E) 0.0207
Explanation:
The molal concentration, m, is defined as the ratio between moles of solute (In this case, KBr) per kg of solvent (water):
Moles KBr -Molar mass: 119g/mol-
2.21g KBr * (1mol / 119g) = 0.01857moles
Mass solvent:
897g * (1kg / 1000g) = 0.897kg
Molal concentration:
0.01857 moles / 0.897kg =
0.0207m
Right solution is:
E) 0.0207.Occurs when the membrane surrounds a large substance and engulfs it.
) Active Transport
O Diffusion
O Endocytosis
Exocytosis
If a substance has a half-life of 14.9 s, and there are initially 100.0 g of the substance, how many grams will remain after precisely five minutes?
Answer:
[A] = 8.69x10⁻⁵g
Explanation:
Kinetics law of a radioactive atom, A, is:
Ln[A] = -kt + ln[A]₀
Where [A] could be taken as mass of A after time t (In seconds),
k is rate constant = ln2 / Half-Life
[A]₀ is intial mass of A
k = ln2 / 14.9s = 0.04652s⁻¹
Time in seconds:
5min * (60s / 1min) = 300s
Replacing each value:
ln[A] = -0.04652s⁻¹*300s + ln[100.0g]
ln[A] = -9.35
[A] = 8.69x10⁻⁵gbased on the table below, what is the density of material A?
Which statement correctly describe the nucleus of the atom
Protons,neutrons,electrons
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
Volume and mass examples
Answer: Example: A bowling ball and a basketball are about the same volume as each other, but the bowling ball has much more mass
Explanation: Mass and volume are two units used to measure objects. Mass is the amount of matter an object contains, while volume is how much space it takes up.
A lidded glass container is filled with a colored gas. After a period of time, it is observed that the gas is uniformly spread throughout the box and that the movement has slowed considerably. Next, a warm iron plate is carefully placed under the box. Why is there resumed movement of the gas in the container?
A) The warm iron plate absorbed energy from the gas particles, making them move faster.
B) The warm iron plate vibrated due to the energy it had, disturbing the gas in the process.
C) Heat from the warm iron plate transferred energy to the gas particles, making them move faster.
D) The warm iron plate heated the insulated box causing it to vibrate, disturbing the gas in the process.
Answer:
It's not A, it's likely not C? I'm guessing B or D.
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.
how many s orbitals are there for silver?
5 electron orbits
I hope this helps
Question 3 of 25
What is another name for Group 14?
Answer:
4A
Explanation:
on the periodic table
I need help on my homework I don’t know this answer
Answer:
I believe the answer would be
b.) valence electrons, all thw electrons that surround the nucleus of an atom
Explanation:
You're welcome
How many atoms of oxygen are present in the reactants
6CO2+6H2O=C6H12O6+6O2
Answer:
3.6132 * 10^24 atoms/molecules of 02
Explanation:
When we look at the balanced chemical equation, we can see that there are 6 moles of O2.
In order to convert from moles to formula units (atoms and molecules),
you need to multiply by avogadro's number.
6 moles * [tex]6.022*10^{23}[/tex]/1 mol = 3.6132 * 10^24 atoms/molecules of 02
Question 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!
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 %