Answer:
1. 1.80x10⁻⁵ (w/w %).
2. 1.80x10⁻⁴ parts per thousand
3. 0.18 parts per million
Explanation:
The solution contains 45.1μg / 250mL.
1. Weight percent (100 times mass in grams of solute per gram of solution, as there are 250mL of water = 250g):
45.1x10⁻⁶g / 250g * 100 =
1.80x10⁻⁵ (w/w %)2. Parts per thousand (mg of solute per g of solution).
45.1μg * (1x10⁻³mg / 1μg) = 0.0451mg.
0.0451mg / 250g =
1.80x10⁻⁴ parts per thousand3. Parts per million (μg of solute per g of solution):
45.1μg / 250g =
0.18 parts per millionIf Nurse Antonio adds that 7 grams of NaCI to water to make 1 liter of solution, what is the molar concentration of the solution? Use dimensional analysis and show how you completed the unit conversion.
Given :
Nurse Antonio adds that 7 grams of NaCI to water to make 1 liter of solution.
To Find :
The molar concentration of the solution .
Solution :
Molecular mass of NaCl , [tex]m=58.44\ g/mol[/tex] .
Now , number of moles is given by :
[tex]n=\dfrac{\text{Given weight}}{\text{Molecular Mass}}\\\\n=\dfrac{7}{58.44}\ mole\\\\n=0.12\ moles[/tex]
Molarity is given by :
[tex]M=\dfrac{\text{Number of moles}}{\text{Volume ( in Liters)}}\\\\M=\dfrac{0.12}{1}\ M\\\\M=0.12\ M[/tex]
Hence , this is the required solution .
Which acid and its conjugate base would be the best buffer at pH=7.5?
Answer:
HEPES.
Explanation:
Hello,
In this case, considering the given options, and the pH requirement of 7.5, considering the Henderson-Hasselbach equation:
[tex]pH=pKa+log(\frac{[base]}{[acid]})[/tex]
The best buffer is that having the closest pKa to the required pH, thus, for the given Ka, we obtain:
[tex]pKa_{MES}=-log(Ka_{MES})=-log(7.9x10^{-7})=6.10\\\\pKa_{HEPES}=-log(Ka_{HEPES})=-log(3.2x10^{-8})=7.49\\\\pKa_{Formic \ acid}=-log(Ka_{Formic \ acid})=-log(1.8x10^{-4})=3.74\\\\pKa_{Acetic\ acid}=-log(Ka_{Acetic\ acid})=-log(1.8x10^{-5})=4.74\\\\pKa_{Tris}=-log(Ka_{Tris})=-log(6.3x10^{-9})=8.2[/tex]
Therefore, the best buffer is the HEPES since its pKa is almost the required pH.
Regards-
Air should be classified as:
Element
Compound
Homogeneous mixture
Heterogeneous mixture
Answer:
element
Explanation:
it is use full for you thanks
What is the mass of 12.83 mL of acetic acid (98% wt/wt)?
Answer:
The mass of the acetic acid is 13.5 g
Explanation:
Given;
weight percent of the acetic acid (ratio of solute to total solution), w/w = 98 %
volume of acetic acid, v = 12.83 mL
density of acetic acid, ρ = 1.05 g/mL
density is given by;
density = mass / volume
mass = density x volume
mass of the acetic acid in 12.83 mL = 1.05 g/mL x 12.83 mL
mass of the acetic acid in 12.83 mL = 13.5 g
Therefore, the mass of the acetic acid is 13.5 g
7. Why is the d-block one energy level behind the s-block? Also, why would the f-block be so far behind?
Answer:
7. Why is the d-block one energy level behind the s-block? Also, why would the f-block be so far behind?
me to
Explanation:
What is the percent by mass of glucose in a solution made by dissolving 163 g glucose in 755 g water? Do you need to know the formula of glucose to do that calculation?
Explain
Answer:
Explanation:
%mass of glucose =( mass of gucose /mass of solution )x100%
= 163 / (755+ 163 )
= 17.76 %
Draw the structure of 4-methyl-5-oxohexanal.
Answer:
Explanation:
The structural formula provides more information which is often used to represent a particular organic substance. A structural formula indicates how the atoms are arranged within the molecule of a substance. From the information, the structure of 4-methyl-5-oxohexanal is represented by using a stick formula where the methyl group falls into position 4 and oxygen group falls into position 5 on the hexanal compound.
The structure is provided in the image attached below for better understanding.
Using a ruler, you measure the length of a rectangle to be 12.75 cm and the width to be 3.64 cm. Calculate the area of this rectangle
Answer:
46.41 cm
Explanation:
Area is length times width. Multiply 12.75 by 3.64 to get your answer. Don't forget to label it as cm!
Which statement below regarding evaporation is not correct?A. When a liquid is first placed in a closed container, the evaporation rate is higher than it is in an open container under the same conditions. B. When a liquid is first placed in a closed container, the evaporation rate is higher than the condensation rate. C. When the rates of evaporation and condensation are equal, the system has reached dynamic equilibrium. D. Vapor pressure refers to the pressure of a gas at a given temperature in equilibrium with its liquid phase. E. Stronger intermolecular forces within the liquid typically result in a lower vapor pressure under a given set of conditions.
Answer:
A. When a liquid is first placed in a closed container, the evaporation rate is higher than it is in an open container under the same conditions.
Explanation:
Evaporation refers to the process by which a liquid changes to gas or vapor. It usually occurs at the surface of a liquid.
Factors that affects evaporation include; nature of the liquid, surface area of liquid exposed, temperature and wind.
Considering the options given:
A. When a liquid is first placed in a closed container, the evaporation rate is higher than it is in an open container under the same conditions. = False
This is false because, the more the surface of the liquid exposed, the higher the rate of evaporation.
B. When a liquid is first placed in a closed container, the evaporation rate is higher than the condensation rate. = True
This is true because when a liquid is first placed in a container, the equilibrium position favors evaporation initially than condensation as saturation of the space above the liquid with vapor has not been achieved.
C. When the rates of evaporation and condensation are equal, the system has reached dynamic equilibrium.= True
Dynamic equilibrium is achieved when the rate of forward and backward reaction, in this case, evaporation and condensation are equal.
D. Vapor pressure refers to the pressure of a gas at a given temperature in equilibrium with its liquid phase. = True
E. Stronger intermolecular forces within the liquid typically result in a lower vapor pressure under a given set of conditions. = True
Strong intermolecular forces between the molecules of the liquid causes the liquid to remain in the liquid state rather than turning to vapor, thereby lowering vapor pressure
What are the derived SI units?
Calculate the density of the following objects:
a. A box with a mass of 1500 grams that occupies 7600 mL of space.
Please help! will mark you as brainliesy
Answer:
Density =M/V
1500/7600
5.0666666667=Ans...
Which is a representation of a compound that gives the number of atoms and types of atoms in that compound?
Why should an experiment be replicated
an experiment should be replicated for one: it my give more reason to people who did not do it them selves two: during the experiment one variable could have been wrong like a gust of wind or a draft that's why you should conduct the experiment 3 to 4 times then get the medium or the average of your results giving you a more accurate answer.
Which of the following features describe your graph? Check all that apply. appropriate title of graph showing the effect of changing temperature on the volume of a gas appropriate axes titles time on the x-axis as the independent variable temperature on the y-axis as the dependent variable data sets are all at equal intervals on each axis range on both axes cover data points in such a way that there is not too much extra space on the graph
Answer:
you'll be fine if you mark all or one, it's really up to you
Explanation:
did it on edgenuity
All of the statements describe hydrogen bonds EXCEPT: a. Hydrogen bonds account for the anomalously high boiling point of water. b. In liquid water, the average water molecule forms hydrogen bonds with two to three other water molecules. c. Individual hydrogen bonds are much weaker than covalent bonds. d. Individual hydrogen bonds in liquid water exist for many seconds and sometimes for minutes. e. The strength of a hydrogen bond depends on the linearity of the atoms involved in the bond.
Answer:
The correct option is e
Explanation:
Hydrogen bond is an intermolecular interaction/bonding that are formed between an electronegative atom (such as nitrogen, oxygen and fluorine) and a hydrogen atom. They are weak intermolecular bonds compared to covalent bonds but account for the high boiling point of water because of the strong hydrogen bond presence between the water molecules. Water molecules form hydrogen bonds between each other; since an oxygen atom (in a water molecule) has two lone pairs on it's outermost shell, it forms an hydrogen bond with two hydrogen atoms of other water molecule. Due to the fluidity of liquid water molecules, hydrogen bonds keep getting broken (although recreated/formed almost immediately), hence, individual hydrogen bonds in liquid water does not exist for long.
In the explanation above, it was stated that the strength of the hydrogen bond in water is the reason for it's high boiling point. The atoms in a water molecule are bent NOT linear hence the strength of hydrogen bond does not depend on the linearity of the atoms involved in the bond.
A good experimental design should always:
Answer:
A good experimental design should always: include more than one independent variable. have predictable outcomes. be repeatable.
Explanation:
Hope this helps :D
How many moles are there in 45.0 g of SF6?
Answer:
0.31 mole
Explanation:
The following data were obtained from the question:
Mass of SF6 = 45.0 g
Number of mole of SF6 =..?
Next, we shall determine the molar mass of SF6.
This can be obtained as follow:
Molar mass of SF6 = 32 + (19×6)
Molar mass of SF6 = 32 + 114
Molar mass of SF6 = 146 g/mol
Finally, we shall determine the number of mole in 45 g of SF6 as follow:
Molar mass of SF6 = 146 g/mol
Mass of SF6 = 45.0 g
Number of mole of SF6 =..?
Number of mole = mass /Molar mass
Number of mole of SF6 = 45 /146
Number of mole of SF6 = 0.31 mol
Therefore, 0.31 mol is present in 45 g of SF6.
Why do Christians call Jesus "the Christ”? Christ comes from the Greek word for Messiah. Christ comes from the Greek word for salvation. Christ comes from the Latin word for Nazareth. Christ comes from the Latin word for Resurrection.
Answer:
it is A
Explanation:
Its on edge
Christians call Jesus "the Christ” because of the meaning behind the word. The term “Christ” comes from the Greek word “Christos” which means “the anointed one” or “the messiah”.
What is the reason for giving this title to Jesus ?This title was given to Jesus because of the many prophecies in the Old Testament that foretold of a coming messiah who would save the people of Israel from their enemies and bring peace and justice to the world.
The term “Christ” is also associated with the Latin word “Nazareth”, which is the town where Jesus was born. This further reinforces the idea of Jesus as the messiah, as it was prophesied that the messiah would be born in Bethlehem, which is a town near Nazareth.
Finally, the term “Christ” is also associated with the Latin word “resurrection”. This is because Jesus was believed to have been resurrected from the dead, which was seen as proof of his divine power and the fulfillment of the prophecies about the messiah. This further emphasizes the idea of Jesus as the messiah and savior of the world.
In conclusion, Christians call Jesus “the Christ” because of the meaning behind the word and because of the many prophecies in the Old Testament that foretold of a coming messiah who would save the people of Israel from their enemies and bring peace and justice to the world. The term is also associated with the Latin words “Nazareth” and “resurrection”, which further emphasize the idea of Jesus as the messiah and savior of the world.
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Which of the following is equivalent to 251 torr?
A. 0.330 atm.
B. 1900 atm.
C. 29.4 psi.
D. All of these choices.
Answer:
Option A. 0.330 atm.
Explanation:
To know the correct answer, we simply do the following:
1. Conversion of 251 torr to atm
760 torr = 1 atm
Therefore,
251 torr = 251 torr / 760 torr × 1 atm
251 torr = 0.330 atm
2. Conversion of 251 torr to psi
1 torr = 0.0193 psi
Therefore,
250 torr = 250 torr / 1 torr × 0.0193 psi
250 torr = 4.825 psi
From the above illustrations, 251 torr is equivalent to both 0.330 atm and 4.825 psi. Therefore, only option A is correct.
At elevated temperatures, methylisonitrile (CH3NC) converts to acetonitrile (CH3CN): CH3NC(g) --> CH3CN(g) At the start of the experiment, there are 0.200 mol of reactant (CH3NC) and 0 mol of product (CH3CN) in the reaction vessel. After 25 min of reaction, 0.108 mol of reactant (CH3NC) remain. The average rate of decomposition of methyl isonitrile, CH3NC, in this 25 min period is __________ mol/min. A. 3.7 x 10-3 B. 0.092 C. 2.3 D. 4.3 x 10-3 E. 0.54
Answer:
A. 3.7 x 10⁻³
Explanation:
In the beginning of the reaction there are 0.200 moles of reactant. After 25 minutes, remain 0.108 moles. That means the moles that wer descomposed are:
0.200 moles - 0.108 moles = 0.092 moles of reactant were descomposed.
That descomposition occurs in 25 minutes. The average rate of descomposition in moles / minute are:
0.092 moles Methyl isonitrile / 25 minutes = 3.7x10⁻³ mol/min.
Right option is:
A. 3.7 x 10⁻³Which of the following is an example of a quantitative observation? a. The piece of metal is longer than the piece of wood. b. Solution 1 is much darker than solution 2. c. The liquid in beaker A is blue. d. The temperature of the liquid is 60°C. e. At least two of the above (A-D) are quantitative observations.
Answer: d. The temperature of the liquid is 60°C.
Explanation:
A quantitative observation is an observation of measure of variables sing in the study or experiment . Variables can be length, weight, temperature , volume etc which can be measured.
From all the given options only option d. is describing a measure ( 60°C).
Hence, an example of a quantitative observation: "The temperature of the liquid is 60°C."
So correct option is d.
Which of the following may happen to astronauts when they return to Earth from space? (1 point)
They may feel dizzy because the flow of blood to and from the heart to the brain is affected in space.
They may feel dizzy because the heart pumps more blood per beat on Earth than in space.
Their heart rate may slow down because there is more blood to circulate around the body.
Their heart rate may slow down because there is less blood to circulate around the body.
Answer:
i believe its They may feel dizzy because the heart pumps more blood per beat on Earth than in space.
Explanation:
Answer:
They may feel dizzy because the flow of blood to and from the heart to the brain is affected in space.
Explanation:
How much Ca(NO3)2 should be weighed out to have 0.650 mol?A) 66.4 g.B) 97.68.C) 107 g.D) 133 g.E) 165 g.
Answer:
C) 107 g
Explanation:
Step 1: Calculate the molar mass of Ca(NO₃)₂
We can calculate the molar mass of Ca(NO₃)₂ by adding the masses of its elements.
M = 1 × Ca + 2 × N + 2 × 3 × O
M = 1 × 40.08 g/mol + 2 × 14.01 g/mol + 6 × 16.00 g/mol
M = 164.10 g/mol
Step 2: Calculate the mass corresponding to 0.650 moles of Ca(NO₃)₂
We multiply the number of moles by the molar mass.
0.650 mol × 164.10 g/mol = 107 g
Classify each reactant and product in this reaction as an acid or base according to the Brønsted theory.
HF + H2O = F + H30+
Answer Bank
HF
H30+
F-
H2O
Answer:
Reaction: [tex]\rm HF + H_2O \rightleftharpoons F^{-} + H_3O^{+}[/tex].
[tex]\rm HF[/tex]: Bronsted-Lowry Acid.[tex]\rm H_3O^{+}[/tex]: Bronsted-Lowry conjugate Acid of [tex]\rm F^{-}[/tex]: Bronsted-Lowry conjugate Base of [tex]\rm HF[/tex].[tex]\rm H_2O[/tex]: Bronsted-Lowry Base.Explanation:
In the Bronsted-Lowry acid-base theory, the acid in a reaction is the species that loses a proton, [tex]\rm H^{+}[/tex]. The resultant species would be the conjugate base of that acid.
On the other hand, the Bronsted-Lowry base in a reaction is the species that accepts a proton [tex]\rm H^{+}[/tex]. The resultant species would be the conjugate acid of that base.
Identify the conjugate acid-base pairs in this reaction. Note that the two species in each pair are related by the gain or loss of a single proton. Therefore, their formula should look similar to each other.
For this reaction, [tex]\rm HF[/tex] and [tex]\rm F^{-}[/tex], as well as [tex]\rm H_2O[/tex] and [tex]\rm H_3O^{+}[/tex] form two similar-looking reactant-product pairs:
The reactant [tex]\rm HF[/tex] loses one proton to form the product [tex]\rm F^{-}[/tex]. Therefore, [tex]\rm HF\![/tex] would be the Bronsted-Lowry acid, while [tex]\rm F^{-}\![/tex] would be its conjugate base.The reactant [tex]\rm H_2O[/tex] gains one proton to form the product [tex]\rm H_3O^{+}[/tex]. Therefore, [tex]\rm H_2O\![/tex] would be the Bronsted-Lowry base, while [tex]\rm H_3O^{+}\![/tex] would be the conjugate acid.
Which term, speed or velocity, gives you more information about an object's motion? Why?
Answer:
Velocity
Explanation:
Both speed and velocity give speed information but only velocity gives information about the direction. So Velocity is more information. :)
In the firs reaction of glycolysis, glucose is converted to _________. The phosphate comes from __________.
A __________ is an enzyme that transfers the terminal phosphate of _________ to a substrate. The product of this reaction is then ______________ to fructose-6-phosphate.
Fructose-6-phosphate is then phosphorylated by a second __________ reaction, giving ___________.
Answer:
EMP Pathway - Embden Meyerhof Parnas Pathway
Answer:
glucose 6-phosphate; ATP
kinase; ATP; isomerized
kinase; fructose 1,6-bisphosphate
Explanation:
For the following reaction, 2.45 grams of methane (CH4) are allowed to react with 27.7 grams of carbon tetrachloride . methane (CH4)(g) + carbon tetrachloride(g) dichloromethane (CH2Cl2)(g) What is the maximum mass of dichloromethane (CH2Cl2) that can be formed? grams What is the FORMULA for the limiting reagent? What mass of the excess reagent remains after the reaction is complete? grams
Answer:
The limiting reactant is CH₄
26.0g of CH₂Cl₂ is the maximum amount that can be formed
4.15g CCl₄ will remain
Explanation:
The reaction of methane, CH₄, with carbon tetrachloride, CCl₄ is:
CH₄ + CCl₄ → 2CH₂Cl₂
To find the maximum mass of dichloromethane that can be determined we need to find moles of methane and carbon tetrachloride:
Moles CH₄:
2.45g * (1mol / 16.04g) = 0.153 moles
Moles CCl₄:
27.7g * (1mol / 153.82g) = 0.180 moles
That means just 0.153 moles of CCl₄ will react until CH₄ is over.
The limiting reactant is CH₄
Assuming the whole 0.153 moles will react, the moles of CH₂Cl₂ will be:
0.153 moles CH₄ * (2 moles CH₂Cl₂ / 1 mole CH₄) = 0.306 moles of CH₂Cl₂
The mass is (Molar mass dichloromethane: 84.93g/mol):
0.306 moles of CH₂Cl₂ * (84.93g / mol) = 26.0g of CH₂Cl₂
The moles of CCl₄ that remain are:
0.180 moles - 0.153 moles = 0.027 moles
In grams:
0.027 moles * (153.82g / mol) = 4.15g CCl₄
What tool do you use to measure mass?
Answer: Balance
Explanation: Mass is the amount of matter contained in a body.
Imagine you are going to eat your lunch soon. How did that stuff you eat originally get transformed into food by the plants or animals in the first place?
What is the [A-]/[HA] ratio when the weak acid is in a solution two pH units above its pKa?a. 5:1b. 10:1c. 100:1d. 1:10e. 1:2
Answer:
c. 100:1.
Explanation:
Hello,
In this case, considering the Henderson-Hasselbach equation:
[tex]pH=pKa+log(\frac{[A^-]}{[HA]} )[/tex]
And the pH two units above the pKa:
[tex]pH=pKa+2[/tex]
We obtain the required ratio as follows:
[tex]pKa+2-pKa=log(\frac{[A^-]}{[HA]} )\\\\\frac{[A^-]}{[HA]} =10^2=100[/tex]
Which is also a c. 100:1 ratio containing 100 parts of base per 1 part of acid.
Regards.
According to Henderson - Hawelbach equation:
[tex]\to pH = pka + \log (\frac{A^{-}}{HA})...........(a)[/tex]
According to question pH two unit above pka:
[tex]\to pH = pka + 2[/tex]
Put value of PH is equation (a)
[tex]\to pKa+2=pKa+ \log (\frac{A^{-}}{HA})\\\\\to 2= \log (\frac{A^{-}}{HA})\\\\\to (\frac{A^{-}}{HA})= 10^2\\\\\to (\frac{A^{-}}{HA})= 100\\\\[/tex]
So, the ratio is [tex][100 : 1][/tex]
Therefore, 100: 1 Ratio containing 100 part of base per 1 part of acid.
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