Answer: 0.885 M
Explanation: 19.4 grams of NaCl is (19.4g/58.55 g/mole) = 0.332 moles of NaCl. 375ml is 0.375 liters. Molar is moles per liter: (0.332 moles NaCl/0.375 liters) = 0.885 M
A cylinder fitted with a movable piston and filled with a gas has a volume of 188.5mL at 26.7 °C when the applied pressure is 755.2 torr. The temperature of the oil bath surrounding the cylinder was increased to 165.2 °C, and the load on the piston was changed. Careful measurement now gave a value of 210.5mL for the volume. What was the final pressure in the system, in torr? Select one:
O a. 715.5 tor O b. 576.9 torr Oc. 988 6 torr O d. 1233 torr 462.6 tor
Answer:
C
Explanation:
To find the new pressure, we will use this formula: P₁V₁/T₁ = P₂V₂/T₂
P₁ = Original pressure (755.2)
V₁ = Original volume (188.5)
T₁ = Original temperature in kelvins (26.7 + 273.15 = 299.85)
P₂ = Final Volume (?)
V₂ = Final volume (210.5)
T₂ = Final temperature in kelvins (165.2 + 273.15 = 438.35)
Here is our equation
(755.2)(188.5)/(299.85) = (210.5)P₂/(438.35)
Hopefully, you have a calculator handy because this equation will end up looking like this:
474.75471 = (0.48021)P₂
Divide both sides by the coefficient
474.75471/0.48021 = (0.48021)P₂/0.48021
P₂ = 988.64
A pycnometer is a glass apparatus used for accurately determining the density of a liquid. When dry and empty, a certain pycnometer had a mass of 27.056 g. When filled with distilled water at 25.0°C, it weighed 36.773 g. When filled with chloroform (a liquid once used as an anesthetic before its toxic properties were known), the apparatus weighed 41.451 g. At 25.0°C, the density of water is 0.99704 g/mL
Complete Question
A pycnometer is a glass apparatus used for accurately determining the density of a liquid. When dry and empty, a certain pycnometer had a mass of 27.056 g. When filled with distilled water at 25.0°C, it weighed 36.773 g. When filled with chloroform (a liquid once used as an anesthetic before its toxic properties were known), the apparatus weighed 41.451 g. At 25.0°C, the density of water is 0.99704 g/mL
-What is the volume of the pycnometer (mL)
We have that the volume of the pycnometer in mL is
[tex]V=9.111mL[/tex]
From the Question we are told that
Pycnometer mass of [tex]m_p=27.056 g.[/tex]
Temperature [tex]T=25 \textdegree[/tex]
Pycnometer filled with distilled water [tex]m_{pf}= 36.773 g[/tex]
Apparatus weighed [tex]w=41.451 g[/tex]
Density of water [tex]\rho= 0.99704 g/mL[/tex]
Generally the equation for Density is mathematically given as
[tex]\rho=\frac{mass}{Volume}[/tex]
Since pycnometer is filled with water its volume can be defined by the volume of water in it
Therefore
Mass of water Pycnometer filled with distilled water-Pycnometer mass
[tex]M_w=36.773 -27.056\\\\M_w=9.084g[/tex]
Hence
[tex]V=\frac{9.084g}{0.99704 }[/tex]
[tex]V=9.111mL[/tex]
in conclusion
The volume of the Pycnometer in mL is
[tex]V=9.111mL[/tex]
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Arrange the following aqueous solutions in order of increasing boiling points.
0.050 m Mg(NO 3) 2; 0.100 m ethanol; 0.090 m NaCl
a. Mg(NO3) < NaCl < ethanol
b. ethanol < Mg(NO3)2 < NaCl
c. ethanol < NaCl < Mg(NO3)2
d. NaCl < ethanol < Mg(NO3)2
e. Mg(NO3)2 < ethanol < NaCl
Answer:
The correct choice is option b. ethanol < Mg(NO3)2 < NaCl
Explanation:
Ethanol = 0.100 m
Mg(NO3)2 = 0.15 m
NaCl = 0.18 m
The molar concentration of NaCl is the highest, which is why its boiling point will be the highest, too.
Classify these compounds as acid, base, salt, or other. Drag the appropriate items to their respective bins.
HCOOH, CH3OH, NaOH, HNO3, NaBr, NH3, CO2, KCl
HCOOH is an acid, KCL is a Salt, NaOH is a base.
Acids Bases and SaltsAn acid is defined as a substance which when dissolved in water produces hydronium ion (H3O+), neutralizes bases, tastes sour and turns blue litmus red.
Acids incldes:
HCOOH-weak acidHNO3-Strong acidA Base is a substance which in its aqueous solution produces hydroxyl ions (OH–), neutralizes acids , tastes bitter and turns red litmus blue
Bases incldes:
NaOHNH3A Salt is an ionic compound produced from the neutralization reaction of acids and bases. it is neutral substance and has no effect on litmus.
NaBrKCLThe folloing can be classifed as other or in aqueous solution as :
CO2-acidic oxide, Bronsted lewis acid CH3OH -Bronsted-Lowry acidLearn more on acids base and salts here:https://brainly.com/question/2927542
Answer
Choice A
Answer
Choice B
Answer
Choice C
Question
A scientist hypothesizes that a new medication can reduce
the chances of catching a cold Which of these would most
likely be the dependent variable in a study involving this
medication?
//
The participants
who do not receive
the medication
Color PURPLE
The number of
participants who
catch a cold
Color YELLOW
The age of the
participants
Color GRAY
Tt remains the
T+ is purposely
It is used for
Answer:
what is the question????
Hehe someone help I have put down heat but I think there is another
Answer:
chemical potential enery
Mark brainliest
13. Find the total number of atoms present in the following molecules. a. 5 H₂O b. Zn Cl₂
Answer:
A= 15 atoms B= 3
Explanation:
5 x 2 + 5 x 1
3 + 2 x 1
An unknown compound has the following chemical formula: where stands for a whole number. Measurements also show that a certain sample of the unknown compound contains of magnesium and of chlorine. Write the complete chemical formula for the unknown compound.
Answer: This is only a guess: The "following chemical formula: " doesn't appear on my screen. But since you mentioned Mg and Cl, I would guess MgCl2
Explanation: Mr loses 2 electrons while each Cl gains one each: Two chlorines for every 1 magnesium.
which picture shows the particles in a compound?
picture I and II
picture I
picture III and IV
picture II
hi <3
compound are 2(or more) elements combined together
thus your answer will be picture I
hope this helps <3
Which term best describes the important pieces of information that scientists gather and record during an experiment?
conclusions
data
research
supplies
Answer:
conclusions i think i am not confirmed
Answer:
b-data
Explanation:
right on the unit test review on edge
brainliest???
Solid calcium oxide and gaseous water are produced by the decomposition of solid calcium oxide hydroxide. Write a balanced chemical equation for this reaction.
[tex]\boxed{\sf {Ca(OH)_2(s)\atop Calcium\:Hydroxide}\longrightarrow {CaO(s)\atop Calcium\;oxide}+{H_2O(g)\atop water}}[/tex]
On reactant side
Hydrogen= 2atomsOxygen=2atomsCalcium=1atomOn product side
Hydrogen=Oxygen=2atomsCalcium=1atom.hence balanced.
An unknown element is a mixture of isotopes ¹²⁹X and ¹³²X. The average atomic mass of X is 131.01 amu. What is the percent abundance of ¹³²X?
Answer: 67%
Explanation: The weighted averages of the two isotopes must add to 131.01. Let Y be the percentage of isotope 129. Then (1-Y) will be the percentage of isotope 132. The weighted average of each is:
129: 129Y
132: 132(1-Y)
Their sum is equal to 131.01
129Y + 132(1-Y) = 131.01
Y = 0.33, or 33%
(1-Y) = 0.67, or 67%
Check: 129*(0.33) = 42.57
132*(0.67) = 88.44
Sum = 131.01 It checks OK The 132 isotopes is 67% of the sample.
Considering the definition of atomic mass, isotopes and atomic mass of an element, the percent abundance of ¹³²X is 67%.
Definition of atomic massFirst of all, the atomic mass (A) is obtained by adding the number of protons and neutrons in a given nucleus of a chemical element.
Definition of isotopeThe same chemical element can be made up of different atoms, that is, their atomic numbers are the same, but the number of neutrons is different. These atoms are called isotopes of the element.
Definition of atomic massOn the other hand, the atomic mass of an element is the weighted average mass of its natural isotopes. In other words, the atomic masses of chemical elements are usually calculated as the weighted average of the masses of the different isotopes of each element, taking into account the relative abundance of each of them.
Percent abundance of ¹³²XIn this case, you know:
An isotope has an atomic mass of 132 amu and a percent natural abundance of y.An isotope has an atomic mass of 129 amu and a percent natural abundance of 1-y. The average atomic mass of X is 131.01 amuThen, the average mass of X can be calculated as:
132 amu×y + 129 amu×( 1-y)= 131.01 amu
Solving, you can find the percent abundance of ¹³²X:
132 amu×y + 129 amu×1 - 129 amu×y= 131.01 amu
132 amu×y + 129 amu - 129 amu×y= 131.01 amu
132 amu×y - 129 amu×y= 131.01 amu - 129 amu
3 amu×y= 2.01 amu
y= 2.01 amu÷ 3 amu
y= 0.67= 67%
Finally, the percent abundance of ¹³²X is 67%.
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What is the Molality of a solution prepared by dissolving 84.7 g of KMnO4 (potassium permanganate, an oxidizing agent) in 165 g of water?
a) 0.513 m
b) 11.3 m
c) 0.308 m
d) 3.25 m
e) 0.958 m
1. Distinguish between a mixture and a pure substance.
Answer:
1)Mixture is the combination of substance
2)There are two types of mixture such as heterogeneous mixture and homogeneous mixture
3)foreg=Salt solution ,sedimentation
Pure substance
1)Pure substances are also called elements
2)They are made up of small atoms
3)for eg= oxygen,Venadium ,Iron,Oxygen
89. The element bromine at room temperature is a liquid with a
density of 3.12 g/mL. Calculate the mass of 125 mL of bro-
mine. What volume does 85.0 g of bromine occupy?
The mass of 125 mL of bromine and the volume occupied by 85 g of bromine are:
1. The mass of bromine is 390 g. 2. The volume of bromine is 27.24 mL.Density is simply defined as the mass of an object per unit volume of the object. It can be expressed mathematically as
[tex]Density = \frac{mass}{volume }[/tex]
1. Determination of the mass of bromineDensity = 3.12 g/mL
Volume = 125 mL
Mass =?[tex]Density = \frac{mass}{volume} \\\\3.12 = \frac{mass}{125}[/tex]
Cross multiply
Mass = 3.12 × 125
Mass = 390 gTherefore, the mass of bromine is 390 g
2. Determination of the volume of bromineDensity = 3.12 g/mL
Mass = 85 g
Volume =?[tex]Density = \frac{mass}{volume } \\\\3.12 = \frac{85}{volume }[/tex]
Cross multiply
3.12 × Volume = 85
Divide both side by 3.12
[tex]Volume = \frac{85}{3.12}\\\\[/tex]
Volume = 27.24 mLTherefore, the Volume of bromine is 27.24 mL
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Using the ruler, what is the value of A considering significant
figures?
Answer:
13.7 cm
Explanation:
If the number is between two whole numbers then that means it is going to be a decimal, how to determine the decimal is by how many ticks/lines are between it, so if you count from 13 cm and count each line as 1 you get to the number 7 and since that number is between the whole number it becomes 13.7
20,000 $ give a way but answer this first
Plz
12.Write the basis of naming of the following elements. 1.Neptunium,2.Mendelevium,
Answer:juhygjdkeExplanation:
Mendelevium is named for Dmitri Mendeleev who produced one of the first periodic tables.
Abelson first found neptunium in 1940 after uranium had been bombarded by neutrons from the cyclotron at Berkeley, California. ... The element was named after the planet Neptune, which is the first planet beyond Uranus.
Answer in explanation
Explanation:
neptunium was named after the discovery of the planet neptune in september 23 1846
mendelevium was named as dimitri mendeleev
This picture shows students working in a
chemistry laboratory. What could they do to make
their lab safer?
Label the test tubes and plastic cups.
Move the fire extinguisher closer to their
table.
Wear chemical protective gloves.
Reduce the clutter on the table.
Stand at the table instead of sitting. Tie long hair back.
DONE
Answer:
yes it is true they apply necessary safety measures
Answer: Label the test tubes, wear chemical protective gloves, tie long hair back
Explanation:
Just got it wrong
? Is a scientist who is studying cancer with the
goal of finding an effective treatment doing
pure research or applied research?
A scientist who is studying cancer with the goal of finding an effective treatment is doing applied research.
Applied research refers to scientific investigations that are conducted with the specific purpose of solving practical problems or improving existing technologies. In the case of cancer research, the scientist is aiming to find a treatment that can be directly applied to patients in order to combat the disease.
In contrast, pure research, also known as basic or fundamental research, is conducted to gain a deeper understanding of a particular phenomenon without any immediate practical application in mind. Pure research aims to expand scientific knowledge and explore new theories or concepts. While pure research may indirectly contribute to the development of applied research, its primary goal is to advance our understanding of the natural world.
In summary, a scientist studying cancer with the goal of finding an effective treatment is engaged in applied research, as they are conducting research with the intention of solving a specific problem and developing practical solutions for the benefit of cancer patients.
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A student performs an experiment to determine the molar mass of magnesium oxide. The student repeats the experiment five times and collects the following data: 40.220gmol, 40.654gmol, 40.314gmol, 40.165gmol, and 40.554gmol. What is the relative standard deviation (RSD) for this set of data?
The relative standard deviation for the set of data obtained by the student is 0.470%
The formula for calculating the relative standard deviation is given below as:
Relative standard deviation (RSD) = (S * 100)/x
where S stands for the standard deviation and x is the mean of the data set.
The following are the steps to calculate to determine the relative standard deviation using the given formula:
Step 1: Calculate the mean of the numbers in the data set.
mean, x = sum of numbers / number of numbers
(40.220 + 40.654 + 40.314 + 40.165 + 40.554)/5
mean = 40.381 g/mol
Step 2: Subtract the mean from each number in the data to determine the deviation for each number and then square the deviations.
(40.220 - 40.381)² = 0.0259
(40.654 - 40.381)² = 0.0745
(40.314 - 40.381)² = 0.00449
(40.165 - 40.381)² = 0.0466
(40.554 -40.381)² = 0.0299
Step 3: Sum the squared deviations.
0.0259 + 0.0745 + 0.00449 + 0.0466 + 0.0299 = 0.181
Step 4: Determine the variance by dividing the sum of the squared deviations by the total number of values.
Variance = 0.181/5 = 0.0362
Step 6: Determine the standard deviation of the data by taking square root of the variance.
Standard deviation, S = √0.0362 = 0.190
Step 7: Determine the relative standard deviation by inserting the values in the formula, (RSD) = (S * 100)/x
RSD = (0.190 * 100)/40.381
RSD = 0.470%
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13. Find the total number of atoms present in the following molecules.
a. 5 H₂O
b. Zn Cl₂
Answer:
zxcdfzdg
Explanation:
zszghzd
6. How many meters are in 0.00253 kilometers?
Answer:
2.53 kilometers
A popular car has a gas tank that holds a maximum of 14.5 gallons of fuel. What is
the size of the tank in liters ?
Answer:
54.883, so rougly about 54.9 liters.
Explanation:
To convert gallons to liters, multiply the amount of gallons by 3.785.
14.5 * 3.785 = 54.883
Taking into account the change of units, the size of the tank is 54.88 liters.
In first place, the rule of three is a tool used to quickly solve problems involving a proportional relationship between two variables.
The rule of three is a way of solving problems of proportionality between three known values and an unknown value, establishing a relationship of proportionality between all of them.
If the relationship between the magnitudes is direct, that is, when one magnitude increases, so does the other (or when one magnitude decreases, so does the other), the direct rule of three should be applied.
The rule of three is applied as follows, with A, B and C being known values and D being an unknown value: if A maintains a certain relationship with B, and it is known that C and D have the same relationship, it is possible to calculate the unknown value D using the following expression:
[tex]D=\frac{CxB}{A}[/tex]
In this case, the rule of three can be applied as follows: if 1 gallon is equal to 3.785 liters, 14.5 gallons are equal to how many liters?
[tex]D=\frac{14.5 gallonsx3.785 liters}{1 gallon}[/tex]
Solving:
D= 54.88 liters
In summary, the size of the tank is 54.88 liters.
Learn more with this example:
https://brainly.com/question/17839792?referrer=searchResultshttps://brainly.com/question/14586541?referrer=searchResultsWhich of the following are considered elements:
Answer:
considered as element
Helium He
Which one of the following is NOT the unit of wave number:
m-1
cm-1
mm-1
cm
Answer:
e
Explanation:
cm is not the unit of wave number out of the following.
What is a wave number?Definition: Total number of wave cycles present in a unit distance is termed a wave number.
Wave number is always a reciprocal of the unit of distance.Wave number is denoted by the letter 'k'.The formula for wave number is 2π/λ where λ is the wavelength. Since wave number is always reciprocal, cm is not the unit for a wave number. The higher the wave number, the higher the frequency and energy.To learn more about wave number, refer to:
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As discussed during the lecture, the enzyme HIV-1 reverse transcriptae (HIV-RT) plays a significant role for the HIV virus and is an important drug target. Assume a concentration [E] of 2.00 µM (i.e. 2.00 x 10-6 mol/l) for HIV-RT. Two potential drug molecules, D1 and D2, were identified, which form stable complexes with the HIV-RT.
The dissociation constant of the complex ED1 formed by HIV-RT and the drug D1 is 1.00 nM (i.e. 1.00 x 10-9 mol/l). The dissociation constant of the complex ED2 formed by HIV-RT and the drug D2 is 100 nM (i.e. 1.00 x 10-7 mol/l).
1. Compute the total concentration of [D1]tot that is needed to bind 90% of the HIV-RT at the given concentration [E]tot. Provide your answer as a numerical expression with 3 significant figures in the unit mol/l. You do NOT have to consider competition betwwen the drugs D1 and D2! They are administered separately.
2. Compute the total concentration of [D2]tot that is needed to bind 90% of the HIV-RT at the given concentration [E]tot. Provide your answer as a numerical expression with 3 significant figures in the unit mol/l.You do NOT have to consider competition betwwen the drugs D1 and D2! They are administered separately.
Answer:
C)[D]/[ED] = 5.20
D)[D]/[ED] = 5.20
E)[D']_T = 1.495* 10 ^-7 M
F)[D'] / [ED'] = 0.0579
Explanation:
E = 250 nM =2.5* 10 ^-7 mol/L , T=298.15 K
Dissociation constant of K_D = 1.3 μM (1.3 *10 ^-6 M)
E + D ⇄ ED → K_a = [ED] / [D][E] (association constant)
ED ⇄ E + D → K_D = [E][D] / [ED] (dissociation constant)
C)
[E] =2.5*10^-7 mol/L
K_D = 1.3* 10^-6 M
K_D = [E][D] / [ED] → [D]/[ED] = K_D / [E]
= [D]/[ED] = 1.3* 10 ^-6 / 2.5 *10^-7
= 13/25 * 10
=130/25 = 5.20
[D]/[ED] = 5.20
D)
ΔG =RTln Kd
ΔG_2 for E and D = 1.987 * 298.15 * ln 1.3*10^-6
ΔG_2 592.454 * [ln 1.3 +ln 10^-6]
ΔG_1 = 592.424 [0.2623 - 13.8155]
ΔG_2 = -592.424 * 13.553
ΔG_1 = -8184.633 cal/ mol
ΔG_1 = -8184.633 * 4.18 J/mol = -34244.508 J?mol
ΔG_1 = -34.245 KL/mol
so, ΔG_2 = ΔG_1 - 10.5 KJ/mol
ΔG_2 = -34.245 - 10.5
ΔG_2 = -44.745KJ / mol
ΔG_2 =RT ln K_D
-44.745 *10^3
=8.314 *298.15 lnK_D
lnK_D' = - 44745 / 2478.81 g
ln K_D' = -18.051
K_D' = -18.051
K_D' = e^-18.051
[D]/[ED] = 5.20
E)
[E] = 2.5* 10 ^-7 mol/ L = a
K_D' = [E][D] / [ED'] E +D' → ED'
K_D' = a/2(x-(a/2) / (a/2)
KD' = x - a/2
=2.447 *10^-8 = (2.5/2) * 10^-7
x=2.447 * 10^-8 + 1.25 * 10^-7
x = 2.447 *10^-8 + 1.25 * 10 ^-7
x= 10^-7 [1.25 + 0.2447]
x = 1.4947 * 10^-7
[D']_T = 1.495* 10 ^-7 M
F)
K_D' = [E][D'] / [ED']
[D'] / [ED'] = KD' / [E]
[D'] / [ED'] = 1.447 *10^-8 / 2.5* 10^-7
[D'] / [ED'] = 0.5788 * 10^-1
[D'] / [ED'] = 0.0579
Explanation:
...
If the sum of the last
number and the middle
number of three consecutive
integersis is 71, then the
Least (smallest) number
mumber must be
Answer:
number must be 0000.999
What is an atomic number
Answer:
the number of protons is called the atomic number
hope it helps you buddy
Answer: number of protons in an atom
Explanation:
how many grams are in one mole of CH3CO2H ?
Answer: 60.2g
Explanation:
One mole acetic acid weighs 60.2g
What is true of an element that is oxidized?
It increased in electronegativity.
It decreased in electronegativity.
It gained electrons.
It lost electrons.
Answer:
When an element is oxidized, it loses electrons
Answer:
The last option is the correct answer.
Explanation:
When an element is oxidized, it loses electrons. But when an element is reduced, it gains electrons. This is the basis of redox reactions.
However, an oxidizing agent oxidizes something else, and gets reduced, therefore gaining electrons. Meanwhile, a reducing agent reduces something else, and gets oxidized in the process, losing its own electrons.
