This question is describing an spectrophotometry experiment in which the concentration of copper(II) ions has to be determined when 2.50 g of a copper-rich penny is reacted with 50.0 mL of nitric acid. In addition, the absorbance of a sample of the solution turned out to be 0.12 at 635 nm, so that the concentration was estimated as 12.8 g/L.
First of all, we must recall the Beer's law that can be written as follows:
[tex]A=ebC[/tex]
Whereas A is the absorbance of the sample, e the molar absorptivity, b the cuvette's path and C the concentration. However, this problem is not providing sufficient information to calculate the required concentration, however, similar absorbance experiments have graphed (absorbance vs concentration) calibration curves exhibiting trendlines as the one shown below:
[tex]y=0.009647x-0.003655[/tex]
Thus, since y stands for the absorbance and x for the concentration but in g/L not M (mol/L) for those experiments, we can set y equal to 0.12 so we solve for x as the concentration of the copper(II) ions in the sample:
[tex]y=0.009647x-0.003655\\\\x=\frac{0.12+0.003655}{0.009647}\\\\x=12.8g/L[/tex]
Nevertheless, it would be great if you come up with your own trendline, having clear the units for the absorbance vs concentration graph and thus double check your results because the data was not enough for the time being.
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(Beer's law and trendlines) https://brainly.com/question/5093710(Spectrophotometry) https://brainly.com/question/14467788Make a atomic model of carbon-12 in mine craft
(If it's good I'll give a lot of points)
Here is the atomic model in the picture.
Please help due tomorrow
Giving Brainlesst
Answer:
Down arrow:
-a car comes to a stop when a traffic light turns red
Up arrow:
-race car accelerates when a race begins
Circle:
-car driving 45 mile per hour down straight road
Explanation:
and i think the car going around a bend would be an up arrow
Why must labs that use mercury thermometers calculate Kelvin ?
Answer:
because those are the only thermometers that are truly accurate for kelvins
Explanation:
The Kelvin temperature in thermometers is used by scientists because it provides a temperature where zero indicates the complete absence of thermal energy.
What is the Kelvin scale?All thermometers have a scale on them that we use to find the temperature, known as a temperature scale. Kelvin proposed that the temperature interval from the ice point to the steam point be defined as 100° containing earlier centigrade scales.
Lord Kelvin had given an absolute temperature scale based on the Carnot cycle. The zero point is 273.15 on Kelvin’s scale below that of the Celsius scale.
On the kelvin scale, Each division is called a Kelvin (K) and is equal to a degree on the Celsius scale. On the Celsius scale, zero degrees is the freezing point of water while on the Kelvin scale the zero point is at absolute zero temperature.
Therefore, 0 K is equal to - 273.15°C, and 0°C is equal to 273.15 kelvins. A mathematical expression that gives the relation between the Celsius and Kelvin scales:
Temperature (K) = Temperature (°C) + 273
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Which molecule does not obey the Octate rule of valence electrons .
BeCl2
FeCl2
CuCl2
ZnCl2
Explanation:
Which molecule does not obey the Octate rule of valence electrons .
BeCl2
FeCl2
CuCl2
ZnCl2
→BeCl2
Explaination:
BeCl2 violates the octet rule because the boron should be in a suitable valence state such that it binds to 3 chlorines. However, in this molecule boron is associated with six electrons.
Answer:
BeCl2
Explanation:
hope Its useful for you
[tex] \\ \\ [/tex]
kk
What is the required mass to prepare a 0.5M potassium chloride solution using 250mL of water
how many molecules are in 18 grams of water
Answer:
6.023×10^23
Explanation:
Molecular mass= 2 (H)+1 (O) =2*1+1*16=2+16= 18 gm per 1gm molecule of water
The stage in which the hair begins to destroy itself as it disconnects from the
papilla is called?
Heart, 5 stars, and Brainiest if right! Answer needed ASAP PLEASE!What type of forces do not change the motion of an object?
A. Acceleration forces
B. Balanced forces
C. Inertia forces
D. Unbalanced forces
Answer:
unbalanced force
Explanation:
pls mark me brainliest
Answer:
B. balanced forces
Explanation:
the motion of an object will not change if the forces pushing or pulling the object are balanced
Which of the following statements are true about energy and bonds?
Check all that apply.
A. The formation of bonds does not absorb or release energy.
B. When bonds are formed, energy is released.
C. Energy is absorbed to break bonds.
D. Breaking bonds does not absorb or release energy.
Answer:
A. Energy is necessary for bond formation.
C. Breaking bonds takes energy.
D. When bonds are formed, energy is released.
Energy is always required for bond formation because when a chemical reaction occurs, either molecular bonds are broken or other bonds are formed to make different molecules. Energy is released during bond formation and is an exothermic process because bond formation represents a stable configuration and the energy lost is released as heat energy that makes it more stable. Breaking bonds takes energy and is an endothermic reaction because energy is absorbed to break bonds.
Hope that helps. x
a solid substance a is soluble in water to the extent of 10 mg/ml of water at 25oc and 100 mg/ml of water at 100oc. you have a sample that contains 100 mg of a and 25 mg of an impurity b. a and b have the same solubility behavior. if one 10ml portion of water was used for the recrystallization, what was the % recovery of a
Answer:
join the provisonal IRA and help free and unite ireland
Explanation:
fight aganst the english oppressors and free ireland
erinn go braugh
Why was the war in Peru difficult?
Answer:
in contrast, peru and Bolivia entered the war hindered by numerous domestic fractures and by an economic and insititutional backwardness that nearly prevented the two countries from fighting the war at all
The ion of aluminum is
Al+
Al2-
Al2+
Al3+
Al3-
Answer:
A13+
Explanation:
I took a test that had this question.
a
What did you discuss in your response? Check all that
apply.
Sample Response: Using a historical perspective helps
the reader understand that Nnaemeka's decision to marry
Nene goes against long-standing traditions. He marries
for love instead of taking part in an arranged marriage.
He also marries outside of his tribe. As a result of his
choice, his father shuns him. A feminist perspective
reveals the marriage also goes against patriarchal values
in this society. Women are expected to be homemakers.
However, Nene is a teacher and does not fit the
expectation. Both perspectives help the reader
understand opposition to the marriage. However, one
approach focuses on tradition, while the other focuses on
the treatment of women in their culture.
cultural values
feminist perspective
historical perspective
similarities between the two perspectives
differences between the two perspectives
One approach focuses on tradition, while the other focuses on the treatment of women in their culture the response is cultural value. Hence option A is correct.
What are traditions?Traditions are defined as a notion or practice that has been passed down within a community or society and has unique importance or symbolic value that dates back in time. Traditions are notions and convictions that are passed down from generation to generation.
Cultural value are defined as the fundamental values and concepts that underpin a community's existence and provide a foundation for its protection and reliance on peaceful coexistence. Cultural values are the fundamental notions of right and wrong held by a culture.
Thus, one approach focuses on tradition, while the other focuses on the treatment of women in their culture the response is cultural value. Hence option A is correct.
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Answer: only culture value
Explanation: just answered it
napthalene combustion can be used to calibrate the heat capacity of a bomb calorimeter The heat of combustion of naphthalene is -40.1kj/g. When .8210g of naphthalene was burned in a calorimeter containing 1,000g of water, a temperature rise of 4.21C was observed. What is the heat capacity?
A bomb calorimeter with a heat capacity of 3.63 kJ/°C experiences a temperature rise of 4.21 °C when .8210 g of naphthalene is burned.
The combustion of naphthalene is used to calibrate the heat capacity of a bomb calorimeter.
What is a bomb calorimeter?It is a device used to measure the change in the internal energy of a reaction.
To determine the heat capacity of the calorimeter (C), we need to follow a series of steps.
Step 1: Calculate the heat released by the combustion.The heat of combustion of naphthalene is -40.1kJ/g and .8210g were burned.
Qcomb = -40.1kJ/g × .8210g = -32.9 kJ
Step 2: Determine the heat absorbed by the bomb calorimeter.According to the law of conservation of energy, the sum of the heat released by the combustion and the heat absorbed by the bomb calorimeter is zero.
Qcomb + Qbomb = 0
Qbomb = -Qcomb = 32.9 kJ
Step 3: Calculate the heat capacity of the bomb calorimeter.32.9 kJ were absorbed, part by the calorimeter itself and part by the 1,000 g (m) of water, whose specific heat capacity (c) is 4.18 J/g°C.
A temperature rise (ΔT) of 4.21 °C is observed. We can determine the heat capacity of the bomb calorimeter (C) using the following expression.
Qbomb = Qcal + Qwater
32.9 kJ = C × ΔT + c × m × ΔT
32.9 kJ = C × 4.21 °C + (4.18 × 10⁻³ kJ/g.°C) × 1,000 g × 4.21 °C
C = 3.63 kJ/°C
A bomb calorimeter with a heat capacity of 3.63 kJ/°C experiences a temperature rise of 4.21 °C when .8210 g of naphthalene is burned.
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2). How are simple carbohydrates, like glucose, used to build starches?
Carbohydrates which include sugars and starches are the primary energy sources produced in plants and used by heterotrophic organisms.
Carbohydrates are composed of a basic chemical formula that typically contains a ratio of one Carbon atom for every two Hydrogen atoms and one Oxygen atom C1H2O1. Basically one carbon atom for every one water molecule Carbon + Water = Carbohydrate.
Monosaccharides or Single Carbon Chain Sugars include Glucose C6H12O6
Disaccharides or Double Carbon Chain Sugars include Sucrose C12H22O11
Combining monosaccharides and disaccharides create Polysaccharides which are complex sugars called starches.
- 5. Venus is like Earth because A. They both have oceans, air, and plant life. B. They both have people living on them. C. They are about the same size and have about the same amount of gravity.
Answer:
C
Explanation:
Answer:
c
Explanation:
Venus and Earth are often called twins because they are similar in size, mass, density, composition and gravity. Venus is actually only a little bit smaller than our home planet, with a mass about 80% of Earth's.
Convert 12.044×10²² molecules of sulphur dioxide into moles
Answer:
➜ Properties of liquids and gases. Liquids have a fixed volume but no fixed shape. Gases have no fixed volume and no fixed shape. Gases expand to fill the space available. They can also be compressed into a very small space.
Explanation:
12.044 × 10 ²³molecules of sulphur dioxide are 0.2 mole.
When vectors are added or subtracted, the net force is called the _____.
will give brainliest to whoever gets it right
Answer:
resultant
Explanation:
What is the mass of a 2.5 mole sample of MgO2
what is the element found in all living matter.
Answer:
There are four elements that are found in all living animals, that are:
Oxygen (O)
Carbon (C)
Hydrogen (H)
Nitrogen (N).
It takes 120 mL of 0.15 M of carbonic acid (H2CO3) to neutralize 300 mL of sodium hydroxide (NaOH) for the following balanced chemical reaction:
2NaOH + H2CO3 → N2CO3 + 2NaOH
The concentration of the sodium hydroxide _____.
0.03 M
0.24 M
0.12 M
0.06 M
3. Carbon dioxide gas lowers the amount of oxygen that enters the blood? True or false
Answer:
true
Explanation:
because carbon dioxide is dencer than oxygen therefore it displaces it
In each of the combinations, predict the more electronegative element based on its position on the
periodic table. Then look up the actual electronegativities. Circle the reaction pair that should
actually caust a reaction.
More
Combination Combination electronegative
A
B
element based on
position on table
Ba + Fe2-
Ba?- + Fe
Actual
Actual
electronegativity electronegativity
of element of element
a)
Ba =
Fe=
b)
)
Sn + Hg
Sn- + Hg
Sn =
Hg =
c)
)
Na + Mg2+
Na + Mg
Na=
Mg =
=
Zn + CO2-
Zn?- + Co
Zn =
Co=
c)
)
Na + Mg2+
Na + Mg
Na=
Mg =
=
Zn + CO2-
Zn?- + Co
Zn =
Co=
A block has 73 kg is being pushed and accelerated at rate of 10 m/s. what force is being applied to the block?
730 N
7.3 N
7300 N
730 Kg
Answer:
730 N
Explanation:
force =mass ×acceleration
force= 73kg×10m/s
F=730N
A quantity of 1.922 g of methanol (CH3OH) was burned in a constant-volume bomb calorimeter. Consequently, the temperature of the water rose by 4.20 Ce … lsius. If the heat capacity of the bomb plus water was 10.4 kJ/degree Celsius, calculate the molar heat of combustion of methanol
The formula for calculating the amount of energy or heat released is:
ΔH = C ΔT
where ΔH is heat of combustion, C is heat capacity, while ΔT is change in temperature
ΔH = 8.69 kJ / °C * (5.14°C)
ΔH = 44.67 kJ
Then we calculate the moles of CH3OH which has molar mass of 32.04 g/mol:
moles = 1.922 / 32.04 = 0.05999 mol
SO the molar heat of combustion is:
ΔHm = 44.67 kJ / 0.0599875 mol
ΔHm = 744.60 kJ / mol
pa help thank yoeee <3333
Answer:
1.c
2.c
3.a
4.b
5.a
i think that's the answer
Which of the following statements is true about CO?
а
The carbon and oxygen share electrons.
b
Carbon is the cation and oxygen is the anion.
с
It is the element cobalt.
d
Its name is monocarbon monoxide.
e
none of these
Answer:
it is the element cobalt with atomic number 27
How are the sensory clues from watching a fire different from the sensory clues from watching a firefly?
Answer:
sensory experience of a chemical reaction called combustion. In a way, fire is like the leaves changing color in fall, the smell of fruit as it ripens, or a firefly's blinking light. All of these are sensory clues that a chemical reaction is taking place
Explanation:
Sensory encounter with the combustion chemical process. Fire can be compared to the fall foliage's shifting hues, the aroma of ripe fruit, or the blinking light of fireflies. These are all sensory indicators that a chemical reaction is occurring.
What is combustion?Combustion is defined as a chemical interaction between different compounds, usually involving oxygen, that produces heat and light in the form of flames. Hydrocarbons and oxygen are the only reactants in a combustion reaction. The fuel is a hydrocarbon, and oxygen is required for burning.
It stimulates several of our senses at once, producing the vivid experience we anticipate from a tangible object. By using fuel, heat, and oxygen during combustion, that sensory experience is produced.
Thus, sensory encounter with the combustion chemical process. Fire can be compared to the fall foliage's shifting hues, the aroma of ripe fruit, or the blinking light of fireflies. These are all sensory indicators that a chemical reaction is occurring.
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find the molar mass of 8.54 x 10²⁴ g A₂O₃
Very Very sorry
What do the colors red, green, and blue have to do with light?
Answer:
The three specific cone cells in our eyes work together, allowing us to translate these three colors of light into millions of different colors. ... When green and blue light are combined, they make cyan. Red and green light make yellow. And when all three primary colors of light are combined, we see white light.
Explanation: