Answer: The answer is B) 1.00 M CaCl2
Explanation: I just did it on usatestprep and it said it was correct .
In order to prepare a sample for absorbance readings, a vitamin tablet containing 25 mg of iron was dissolved in 6M HCl, quantitatively transferred into a 100 mL volumetric flask and diluted to the 100 mL mark with DI water. Then 20 mL and 17 mL of this solution were pipetted into separate 100 mL volumetric flasks and each of these was brought up to 100 mL volume by diluting with DI water to the mark.
Required:
Calculate concentration of iron in mg/L in each of these flasks
Answer:
C₂ = 50 mg/L
C₃ = 42.5 mg/L
Explanation:
To do this, we just need to use the following expression:
C₁V₁ = C₂V₂ (1)
Where:
C₁: Original concentration of the Iron solution (mg/L)
V₁: aliquot of the iron solution (mL or L)
C₂: Concentration of the iron after beind dilluted (mg/L)
V₂: Volume of the flask that's being used.
Using the above expression, we just solve for C₂:
C₂ = C₁V₁ / V₂ (2)
We have the required volumes, but we do not have the concentration of the iron solution (C₁). To determine this, we use the initial flask of 100 mL and the mass of the iron:
C₁ = 25 mg / 0.1 L = 250 mg/L
With this value, we can replace in (2) to get the concentration on each flask.
Flask 1:
We have an aliquot of 20 mL, and it was dilluted to 100 mL, the concentration would be:
C₂ = 250 mg/L * (20/100)
C₂ = 50 mg/LFlask 2:
We have an aliquot of 17 mL dilluted to 100 mL so:
C₃ = 250 * (17/100)
C₃ = 42.5 mg/LHope this helps
The concentration of iron in mg/L in each of the two flasks is 50 mg/l and 42.5 mg/L respectively.
The initial concentration of iron in the sample is obtained as follows:
A vitamin tablet containing 25 mg of iron is dissolved in 6M HCl and then made up to 100 mL in a 100 mL volumetric flask with DI water.
Concentration of iron in the solution = 25 mg/ 100 mL
Converting to mg/L; 1 L = 1000 mL, then 100 mL = 1000 * 1 L/ 1000 mL = 0.1 L
Concentration of iron in the solution in mg/L = 25 mg / 0.1 L = 250 mg/L
Then 20 mL and 17 mL of this solution were pipetted into separate 100 mL volumetric flasks and each of these was brought up to 100 mL volume by diluting with DI water to the mark.
Using the dilution formula C₁V₁ = C₂V₂ to determine the concentration of iron in each of these flasks:
C₁ = initial concentration; V₁ = initial volume
C₂ = final concentration; V₂ = final volume
Flask 1:
C₁ = 250 mg/L, V₁ = 20 mL, C₂ = ?, V₂ = 100 mL
C₂ = C₁V₁ / V₂
C₂ = 250 * 20 / 100
C₂ = 50 mg/L
Flask 2:
C₁ = 250 mg/L, V₁ = 17 mL, C₂ = ?, V₂ = 100 mL
C₂ = C₁V₁ / V₂
C₂ = 250 * 17 / 100
C₂ = 42.5 mg/L
Therefore, the concentration of iron in mg/L in each of the two flasks is 50 mg/l and 42.5 mg/L respectively.
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Please someone help me!
I need this done ASAP *URGENT*
I Need this done before Thursday or Friday because Friday is my last day of school so please finish this today!
Best answer gets BRAINLIEST
PLEASE HURRY AND ANSWER ALL QUESTIONS CORRECTLY
NO LINKS OR ANSWER REPORTED
What’s the difference worksheet
Atoms,molecules,elements and compounds
PLEASE PLEASE PLEASE PLEASE PLEASEEEEEEE ANSWER THIS I only have TWO days of school left! And I need this done quickly
sorry needed the points
If 467.08 grams of Oz are reacted, how many grams of C6H5CH3 will also be reacted?
In order to react with 467.08 grams of O2, 4034.95 g of toluene (C6H5CH3) is required.
What are some uses for toluene?Toluene is a white liquid hydrocarbon found in petroleum and coal tar that is employed like a solvent and in the synthesis of organic compounds. Toluene is a naturally occurring substance found in crude oil and is used for oil refining as well as the production of glues, lacquers, paints, and explosives. Toluene can be discovered in household products like paint, paintbrush cleaner, nail polish, glue, inks, and stain removers.
For the balanced equation
2C6H5CH3 + 3O2 → 7CO2 + 4H2O
We required three steps
1.) Convert mass of O2 to mol of O2
mole = mass / molar mass
2.) Find mole of C6H5CH3 by multiply mol O2 by the mol ratio between O2 and C6H5CH3 in balanced equation.
3.) Find mass C6H5CH3 by multiply mol C6H5CH3 by its molar mass (92.14 g/mol)
= 467.08 gm /15.999 gm × 3/ 2 ×92.14 gm
= 4034.95 gm. of C6H5CH3
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20. A compound's empirical formula is C5H5O If the molecular mass of the compound is
162.2g, what is the molecular formula? NO LINKS PLEASE:)!
Answer:
Just use a text book.. So that you get the concept
Hence, [tex]C_{20}H_{20}O_4[/tex] is the molecular formula of a compound's empirical formula is [tex]C_5H_5O[/tex].
What is an empirical formula?The empirical formula is the chemical formula of a compound that gives the proportions (ratios) of the elements present in the compound but not the actual numbers or arrangement of atoms.
Divide the molar mass of the compound by the empirical formula mass. The result should be a whole number or very close to a whole number. Multiply all the subscripts in the empirical formula by the whole number
The molar mass of the empirical formula compound [tex]C_5H_5O[/tex] is 46.06844 g/mol.
The molecular mass of the compound is 162.2g given.
162.2g ÷ 46.06844
3.520848546 =4
[tex]C_{20}H_{20}O_4[/tex] is the molecular formula.
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the maximum allowed concentrations of chloride in municipal drinking water supply in 250 ppm cl. when the supply of water exceeds this limit it often has a distinctive salty taste. what is the concentration in molarity?
The allowed concentration of Cl in water is 250 ppm. Then the equivalent concentration in molarity is 0.007 molar.
What is molarity ?Molarity is a common term used to express the concentration of a solution. It is the ratio of the number of moles of solute to the volume of solution in liters. Molarity is a temperature dependent measurement.
Parts per million is another term of concentration have the formula as written below:
ppm = ws/W × 10⁶
Where, ws is the weight of solute and W be the weight of solution in grams.
1 molar = 35500 ppm
therefore, 250 ppm = 250 ppm × 1M /35500 ppm = 0.007 M.
Hence, the molarity of the salt solution will with the maximum allowed concentration will be 0.007 M.
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Which fuels are non-renewable
Answer:
fossil fuels
Explanation:
Well I had some topics on this stuff last quarter in science and from what I can remember it should be fossil fuels I think that fossil fuels are technically renewable but they are considered non-renewable since they are either in small supplies, are hard to obtain or take a long time to form.
What is the molecular weight of (NH4)2SO4
The molecular weight of [tex](NH_4)_2SO_4[/tex] would be 132 g/mol.
Calculation of molecular weightsThe molecular weight, otherwise known as the molar mass of substances is the sum of the molar weights of individual atoms that make up the substance.
[tex](NH_4)_2SO_4[/tex] is made up of 2 atoms of N, 8 atoms of H, 1 atom of S, and 4 atoms of O.
Molar weight of N is 14 g/molMolar weight of H is 1 g/molMolar weight of S is 32 g/molMolar weight of O is 16 g/molThus, the molecular weight of [tex](NH_4)_2SO_4[/tex] = (14x2) + (1x8) + 32 + (16x4)
= 132 g/mol
In other words, the molecular weight of [tex](NH_4)_2SO_4[/tex] is 132 g/mol.
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Which of the following is an oxidation-reduction reaction?
A) HBr(aq) + NaOH(aq) → NaBr(aq) + H2O(l)
B) NaI(aq) + AgNO3(aq) → AgI(s) + NaNO3(aq)
C) Pb(C2H3O2)2(aq) + 2 LiBr(aq) → PbBr2(s) + 2 LiC2H3O2(aq)
D) Ba(s) + 2 HCl(aq) → BaCl2(aq) + H2(g)
E) All of the above are oxidation-reduction reactions.
Answer:
D) Ba(s) + 2 HCl(aq) → BaCl2(aq) + H2(g)
Explanation:
In a redox reaction, One atom is gaining electrons (Reduction) whereas other is loosing electrons (Oxidation). In the reactions:
A) HBr(aq) + NaOH(aq) → NaBr(aq) + H2O(l)
As sodium is always +1 and Br always -1, this is not a redox reaction.
B) NaI(aq) + AgNO3(aq) → AgI(s) + NaNO3(aq)
Sodium is always +1 and nitrate ion is -1. This is not a redox reaction
C) Pb(C2H3O2)2(aq) + 2 LiBr(aq) → PbBr2(s) + 2 LiC2H3O2(aq)
Acetate ion, C2H3O2 is -1 as Br is -1, lithium is +1 and Pb +2, This is not a redox reactoin
D) Ba(s) + 2 HCl(aq) → BaCl2(aq) + H2(g)Barium is 0 as Ba(s) but +1 as BaCl2. Is oxidizing
Hydrogen is +1 as HCl but 0 as H2. Is reducting.
This reaction is an oxidation-reduction reaction
I need help with this question...
The half-life of Po-218 is three minutes. How much of a 2.0 gram sample remains after 15 minutes? Suppose you wanted to buy some of this isotope, and it required half an hour for it reach you. How much should you order if you need to use 0.10 gram of this material?
(2)(½^(15/3)) = 0.0625 (5 half-lives) 102.4 grams order
What is the half-life of an isotope?A radionuclide's half-life is the amount of time it takes for half of its radioactive atoms to decay. A good rule of thumb is that you will have less radiation than 1% of the original amount after seven half-lives.Knowing an element's alpha, beta, or gamma decay can help someone properly protect their body from excessive radiation. Within one half-life, the amount of radioactive nuclei present at any particular time will be reduced to half.Each radioisotope has a set half-life that can be anywhere between a few milliseconds (for example, 215At at 0.1 milliseconds) and billions of years (e.g.,238U at 4.468 billion years). Both stable and radioactive isotopes can exist for an element.The period of time needed for something to go from 50% to 50%To learn more about half-life of an isotope refers to:
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How is the rock in the deep mantle similar to the rock in the parts of the mantle nearest to the surface? How are they different?
They are distinct Similarity: Compared to crustal rocks, mantle rocks have higher concentrations of magnesium and iron. The deep mantle's rocks are under extreme pressure and heat.
A mantle is what?Earth's interior is made up primarily of the mantle, which is solid. Between the thin crust at the surface of the planet and its dense, extremely hot core is the mantle. A staggering 84% of the volume of the Earth is made up of the mantle, which is around 2,900 kilometers 1,802 miles thick.
The mantle layer is how thick?The thickest layer on Earth measures just under 3,000 kilometers 1,865 miles. The beginning is only 18.6 miles 30 kilometers below the surface. It is thick, heated, and semi-solid like caramel candy, mostly made of iron, magnesium, and silicon. It circulates, much like the layer beneath it.
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8KCIO3 +1C12H22011
- >12CO2 + 11H20 + 8KCI
If you want the gummy bear to be the limiting reactant
for the reaction above, what is the minimum
amount of potassium chlorate that must be used to react completely with one gummy bear?
note: gummy bears are many made up of sucrose (1.1 g of sucrose in this equation)
3.2 g KClO3
Explanation:
1.1 g C12H22O11 × (1 mol C12H22O11/342.3 g C12H22O11)
= 0.0032 mol C12H22O11
0.0032 mol C12H22O11 × (8 mol KClO3/1 mol C12H22O11)
= 0.026 mol KClO3
Therefore, the minimum amount of KClO3 needed is
0.026 mol KClO3 × (122.55 g KClO3/1 mol KClO3)
= 3.2 g KClO3
How many moles of gas are present if P=1atm, V=1L, T=1K?
it depends on the chemical's molar mass
O.12
8.314
01
The number of moles of the ideal gas is 0.12 moles. Option A
What is the number of moles?In the context of the problem that we have here, we are looking at the ideal gas equation. When we look at the idea gas equation, we can tell that we would have the pressure of the gas, the volume of the gas as well as the temperature of the gas in view as is the case that we have here.
Thus, the idea that we are asked to pass across in the question is that we should be able to find out the number of moles that we have in the compound that have the variables that have been listed here.
Pressure (P) = 1 atm
Volume (V) = 1 L
Temperature (T) = 1 K
Number of moles (n) = ?
Using;
PV = nRT
n = PV/RT
n = 1 * 1/0.082 * 1
n = 0.12 moles
The moles of the gas is 0.12 moles.
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Balance the following chemical equation:
Br2+
Nal-
NaBr
+
Answer:
2 NaI (aq) + Br2 (aq) → 2 NaBr (aq) + I2 (s)
This is an oxidation-reduction (redox) reaction:
2 Br0 + 2 e- → 2 Br-I
(reduction)
2 I-I - 2 e- → 2 I0
(oxidation)
Pls help due tommorow
Answer:
.
Explanation:
a. 2, 2
b. 2, 2
c. 2, 3, 2
d. 1, 5, 3, 4
Just make sure there is an equal amount of each ELEMENT on each side of the reaction. Starting with, O, H, C, then other elements is a good method too
What do the observations for changes to volume and pressure show you about the
relationship between the volume and pressure of a gas? Explain using the data! Does
this demonstration support Boyle's Law or not?
(Hint: pressure is not being measured in this video, but think what would happen to a
balloon if it was squeezed or compressed. Would it get larger or smaller?)
Answer: The given demonstration does not support Boyle's Law.
Explanation:
According to Boyle's law, at constant temperature the pressure of an ideal gas is inversely proportional to the volume of gas.
[tex]P \propto \frac{1}{V}[/tex]
Therefore, an increase in volume of gas will lead to a decrease in pressure and vice-versa.
Now, according to the given data of volumes there is occurring an increase on moving from final volume 1 to final volume 3. This means that pressure is decreasing.
As a result, if a balloon was squeezed or compressed then it would get smaller. But in the given demonstration pressure is not given.
Thus, we can conclude that the given demonstration does not support Boyle's Law.
HELP ME PLS
type an actual answer insted of saying I will help you
Answer:
develops,blossoms are synonyms
How many grams are in 4.2 × 10²² atoms of iron?
Answer:0.226 gram
Explanation:you can get the answer in two steps calculate 3.40 . 10^22 atoms =
Answer:
4.2 × 10²² ÷ 6.022× 10²³
4.2 × 10²² equals 0.069 moles (approx)
weight of 1 mole of iron = 56g
therefore, 0.069 moles = 56 × 0.069 = 3.9 g
Sorry for lazy work.. :P
I NEED HELP MY QUESTION IS "which of the following is a structural adaptation used to help animals move"
A: lungs
B: fur
C: wings
D: gills
Answer:
wings
Explanation:
this is an example of movement because it allows birds to fly in the air
how do i balance the first chemical reaction above?? plz plz help
Answer:
2K +F₂→ 2KF
Explanation:
When we balance an equation, we are trying to ensure that the number of atoms of each element is the same on both sides of the arrow.
On the left side of the arrow, there is 1 K atom and 2 F atoms. On the right, there is 1 K and 1 F atom.
Since the number of K atoms is currently balanced, balance the number of F atoms.
K +F₂→ 2KF
Now, that the number of F atoms is balanced on both sides, check if the number of K atoms are balanced.
Left
K atoms: 1
F atoms: 2
Right
K atoms: 2
F atoms: 2
The number of K atoms is not balanced.
2K +F₂→ 2KF
Left
K atoms: 2
F atoms: 2
Right
K atoms: 2
F atoms: 2
The equation is now balanced.
Nitrogen is important for _____. plant growth weather and temperature animals to breathe photosynthesis
Answer:
building amino acids in proteins
Explanation:
Plz help ASAP
What is the molarity of a 0.6 L solution that contains 50.0 grams of sodium hydroxide(NaOH)?
A) 2.1 M
B) 2.9 M
C) 3.3 M
Answer: A 2.1
Explanation:
34.1 g sodium nitrate is dissolved in water to
make 816 g of solution.
What is the percent sodium nitrate in the
solution?
1. 4.36117%
2. 4.17892%
3. 100%
4. 0.0117892%
Answer:
2.4.17892
Explanation:
34.1/816×100=4.17892
Pls help I need a good grade
Answer:
Option 2
Explanation:
70.8 g of CO is exposed 20.4 g of Hy and a reaction takes place.
CO + 2H2 - CH3OH
1. How many grams of methyl hydroxide (CH3OH) is produced?
2. What is the limiting reactant?
3. How much of the excess reactant is left unused?
literally what does any of this mean
Answer:
1. 80.9 g of CH₃OH
2. CO
3. 5.14moles
Explanation:
The reaction is:
CO + 2H₂ → CH₃OH
First place, we determine the moles of each reactant.
70.8 g . 1mol/ 28g = 2.53 moles of CO
20.4 g . 1mol / 2g = 10.2 moles of H₂
There is too much hydrogen, so the limiting reactant might be the carbon monoxide.
2 moles of H₂ react to 1 mol of CO
Then, 10.2 moles of H₂ may react to (10.2 . 1) /2 = 5.1 moles
We don't have enough CO, so it's ok that CO is the limiting. (We have 2.53 moles, we need 5.1 moles)
In the other hand, hydrogen is the excess reactant.
1 mol of CO react to 2 moles of hydrogen
2.53 moles may react to (2.53 . 2) /1 =5.06 moles
We have 10.2 moles, and we need 5.06 moles. Then (10.2 - 5.06) = 5.14 moles remains after the reaction goes complete.
Now that we know the limiting reactant, we can determine the grams of produced methanol. Ratio is 1:1
1 mol of CO produces 1 mol of CH₃OH
2.53 moles of CO must produce 2.53 moles of CH₃OH
We convert moles to mass: 2.53 mol . 32 g/mol = 80.9 g
What is the mass of phosphorus in a 63 kg person?
The mass of phosphorus in a 63 kg person would be 0.63 kg or 630 grams.
Percentage of phosphorus in humansAccording to several research findings, the percentage of phosphorus in the human body is about 1%. This means that the weight of an average human is about 1% phosphorus.
Using the above information, the mass of phosphorus in a 63 kg person can be estimated as follows:
1/100 x 63 = 0.63 kg
Since 1 kg = 1000 grams
Thus, 0.63 kg = 0.63 x 1000
= 630 grams
In other words, the mass of phosphorus in a 63 kg person would be 0.63 kg or 630 grams.
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5. Given the following unbalanced equation: N20(g) + O2(g) → NO2(g)
Answer:
2 N2O(g) + 3 O2(g) --> 4 NO2(g)
Explanation:
this is the chemical reaction balanced, if that was ur question.
The Law of Conservation of Matter states that in a closed system, matter cannot be created or destroyed. This means that atoms can NOT just appear or disappear. The mass will not change in a closed system.
This, however, is NOT what we observed. We observed that the mass of the substance in our measuring tray increased after burning.
Why do you think this happened? Where did the extra mass come from?
REMEMBER: Energy (light, heat, motion, etc.) is not made of atoms so has no mass.
RESOURCE: Access your online textbook through CLEVER, click to get the blue ribbon across the top of the page and go to the Table of Contents. Scroll down to Lesson 9 Conservation of Matter and select "Extending Your Knowledge: Mass and Matter"
Answer:
The Law of Conservation of Matter states that in a chemical reaction, matter is not created or destroyed. However, it is possible for the mass of a substance to change during a chemical reaction, as you observed.
When a substance burns, it reacts with oxygen in the air to form new compounds. For example, when wood burns, it reacts with oxygen to form water and carbon dioxide. The mass of the wood plus the mass of the oxygen is equal to the mass of the water and carbon dioxide produced.
In this case, the extra mass that you observed came from the oxygen that reacted with the wood. Oxygen has mass, and when it reacts with the wood, the mass of the resulting compounds is greater than the mass of the starting materials.
It's important to note that energy is not a form of matter, and therefore has no mass. However, energy can be converted into matter and vice versa, according to the famous equation E=mc^2, where E is energy, m is mass, and c is the speed of light. This equation demonstrates that mass and energy are fundamentally connected and can be converted into each other under certain conditions.
Explanation:
explain how dna which is 6 feet long, can be stored in the nucleus of a tiny human cell.
Answer:
Packed inside the nucleus of every human cell are nearly 6 feet of DNA, which is divided into 46 individual molecules, one for each chromosome and each about 1.5 inches long. Packing all this material into a microscopic cell nucleus is an extraordinary feat of packaging.
Explanation:
Packed inside the nucleus of every human cell are nearly 6 feet of DNA, which is divided into 46 individual molecules, one for each chromosome and each about 1.5 inches long. Packing all this material into a microscopic cell nucleus is an extraordinary feat of packaging. For DNA to function, it can't be crammed into the nucleus like a ball of string. Instead, it is combined with proteins and organized into a precise, compact structure, a dense string-like fiber called chromatin.
(hope this helps can i plz have brainlist :D hehe)
Select the correct answer
What is the noble gas configuration for silicon?
OA [Ne] 3s^2 3p^1
OB. [Ar] 4s^1
OC [Kr]5s^1
OD. [Ne] 3s^2 3p^2
Answer:
D
Explanation:
Silicon, element number 14 is the fourth element in the third period in the periodic table. Its electronic configuration is 1s^2 2s^2 2p^6 3s^2 3p^2.
The elemental symbol of the previous noble gas preceding the atom is replaced by the arrangement of the remaining electrons to form a noble gas configuration of an atom.
So for Silicon, we substitute [Ne] 1s^2 2s^2 2p^6 and the noble gas configuration can now be [Ne] 3s^2 3p^2.