Answer:
n=V/Vm
n=1/22.4
n=0.044 moles He
m=n×M
m=0.044×4
m=0.178 g False
difference between vegetative and reproductive part
Answer:
The vegetative parts includes the roots, stems,leaves and the reproductive parts include flowers. ... The vegetative parts can reproduce new plants by the process of vegetative propagation but the reproductive parts cannot produce new plants directly instead they produce precursor of new plants that are seeds or fruits.
Quinine in a 1.664-g antimalarial tablet was dissolved in sufficient 0.10 M to give 500 mL of solution. A 15.00-mL aliquot was then diluted to 100.0 mL with the acid. The fluorescence intensity for the diluted sample at 347.5 nm provided a reading of 327 on an arbitrary scale. A standard 100 ppm quinine solution registered 180 when measured under conditions identical to those for the diluted sample. Calculate the mass of quinine in milligrams in the tablet.
Answer:
605.6mg of quinine
Explanation:
Based on Lambert-Beer's law, the intensity of an optical measurement is directely proportional to its concentration.
Unknown concentration gives a reading of 327
100 ppm gives 180 of intensity
The concentration of the diluted quinine tablet is:
327 * (100ppm / 180) = 181.67 ppm. The final dilution
The concentration of the first diluted solution is:
181.67 ppm * (100.0mL / 15mL) = 1211ppm
ppm could be defined as mass of solute (In this case of quinine) in mg per liter of solution. That is:
1211mg / L
As the tablet was diluted to 500mL = 0.5L, the mass of the quinine is:
0.5L * (1211mg / L) =
605.6mg of quininePlease help with this one
Answer:
15g
Explanation:
hope this helped
What is the molar mass of AlCl3
Answer:
133.34 g/moles
Explanation:
but to make life easy it could be 133.4 g/ moles as well
the color of an object that absorbs all colors except red
Answer:
The color black absorbs most colors, while white reflects most colors.
Given a volume of 47.8 mL of gas at STP, _______________ moles of O2 exist
Due today please answer! Can we better understand plastics by using Periodic Table?
Answer is in a photo. I can only upload it to a file hosting service. link below!
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Answer:
I think not
Explanation:
Plastics can be understand through the knowledge of its types and structure than periodic table.
What is the molarity (M) of a solution that has 0.50 moles of solute dissolved in 1.0
liter of solution?
Answer:
it is 0.50=0.5 M
Explanation:
Molarity definition is measure the concentration of solution.
and the rule is
molarity(M)= moles of solute/volume of solution in liters
Ex: 2.1 M MgCl2= 2.1 mole MgCl2/ L MgCl2 solution
5. What physical property of foam makes it a good choice to
use in life vests?
A. Foam has a relative density less than water.
B. Foam is a good thermal insulator.
C Foam is non-magnetic.
D. Foam is soluble in water.
Water pollution has severely impacted animals and plants in New York's Hudson
When 3.52 g of bismuth oxide (molar mass - 465.96 g/ml) reacts with excess carbon to form 2.91 g of bismuth metal (molar mass-208.98) according to the equation:
Bi2O3(s) + 3C(s) = 2 Bi(s) + 3 CO(g)
24
What is the percent yield of the reaction?
(Answer to 1 decimal place)
25
A hot metal plate at 150°C has been placed in air at room temperature. Which event would most likely take place
over the next few minutes?
Molecules in both the metal and the surrounding air will start moving at lower speeds.
Molecules in both the metal and the surrounding air will start moving at higher speeds.
The air molecules that are surrounding the metal will slow down, and the molecules in the metal will speed up.
The air molecules that are surrounding the metal will speed up, and the molecules in the metal will slow down.
Answer:
molecules will speed up
Explanation:
PLEASE HELP WILL MARK BRAINLEST!!!
Answer:
C. i don't kow
Explanation:
is pyramidal molecular geometry?
A. N2
B. H2O
C. NH3
D. CCL4
Answer:
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Is pyramidal molecular geometry?[tex]\color{Blue}\huge\boxed{Answer} [/tex]
B.H2OHelp please I’ll mark as brainiliest
Answer:
B B
W BW BW
W BW BW
Explanation:
Hope this helps
3 attempts left
Check my work
Enter your answer in the provided box.
The pressure inside a 1.0 L balloon at 25°C was 750 mm Hg. What is the pressure (in mmHg) inside the
balloon when it is cooled to -65°C and expands to 3.3 L in volume?
mm Hg
Answer:
shhsss×<×>×××<××××
Explanation:
4×738×8<#329×
The combustion of coal, a fossil fuel, to produce electrical energy produces a by-product, sulfur dioxide, which is emitted into the atmosphere. Sulfur dioxide will mix with the components in the atmosphere to produce _____.
Forest Fires
Global warming
Acid Rain
Algae growing in ponds and lakes
What does the esophagus connect?
the intestine to the colon
the intestine to the mouth
The stomach to the intestine
the mouth to the stomach
Answer: it think it would be last one. the mouth to the stomach is the answer.
Explanation:
Answer:
The correct answer is D! The esophagus connects the mouth to the stomach.
Explanation:
The mouth is connected to the esophagus, which in turn is connected to the throat. The throat, in turn, connects the mouth to the stomach.
I had this on a science test and I got it right :D
I hope this helps! ;)
2. Water is an excellent solvent. With water being a polar
molecule, it can be an especially strong solvent for other
polar molecules. Give an example of how water acting as a
solvent is important for living organisms.
NO LINKS PLZ HELP
Answer:
Water acts as a solvent of carbon dioxide excreted from tissues, in blood and helps in regulating pH (because it forms carbonic acid that lowers pH when it tends to get higher). Blood pH should be maintained at about 7.4. One major reason is that the structure of protein is dependent ton pH because pH determines its ionization hence also affecting the charges and interaction between side groups of amino acids. A change in pH may, therefore, denature proteins and negatively affect cellular functions.
Explanation:
To get more on how water acts as a universal solvent check out brainly.com/question/7007192
An unknown compound was found to be soluble in concentrated sulfuric acid; however, the 2,4-DNP, chromic acid, and potassium permanganate gave negative results. The only positive result detected was the ferrous hydroxide test. What is the most likely functional group present in such compound
Explanation:
2,4-DNP is negative: aldehyde and ketone absent
Chromic acid is negative: alcohol absent.
KMnO4 test negative: alkene absent
The only positive result is for Fe(OH)2.
Nitro group-containing compounds react with ferrous hydroxide to give amine and ferric hydroxide red ppt. Hence given compound contains the nitro group (-NO2).
A 0.530 M Ca(OH)2 solution was prepared by dissolving 36.0 grams of Ca(OH)2 in enough water. What is the total volume of the solution thus formed? (4 points)
Answer:
0.917 L
Explanation:
Step 1: Given data
Molar concentration of the solution (M): 0.530 M (0.530 mol/L)Mass of Ca(OH)₂ (solute): 36.0 gStep 2: Calculate the moles corresponding to 36.0 g of Ca(OH)₂
The molar mass of Ca(OH)₂ is 74.09 g/mol.
36.0 g × 1 mol/74.09 g = 0.486 mol
Step 3: Calculate the volume of the solution
Molarity is equal to the moles of solute divided by the liters of solution.
M = moles of solute / liters of solution
liters of solution = moles of solute / M
liters of solution = 0.486 mol / (0.530 mol/L) = 0.917 L
Answer:
0.917 liters
Hope this helps! :D
Explanation:
5.
(08.02 MC)
A 0.530 M Ca(OH)2 solution was prepared by dissolving 36.0 grams of Ca(OH)2 in enough water. What is the total volume of the solution thus formed? (4 points)
Which of the following molecules has a bent shape?
O A. CO2
O B. H20
O C. BeCl2
O D. NH3
Which of the following galaxies do not have a regular structure?
A. Elliptical and barred spiral galaxies
B. Irregular and elliptical galaxies
C. Spiral galaxies
D. Irregular galaxies
Answer: D
Explanation: Irregular galaxies
Answer:
Your answer is D
Explanation:
Irregular galaxies do not have a regular structure.
Which type of formula shows an element symbol for each atom and a line for each bond between atoms?
structural
molecular
empirical
ionic
Answer: structural
Explanation:
When metals and non metals combine in fixed proportion then a chemical compound is formed. Structural formula shows an element symbol for each atom and a line for each bond between atoms. The correct option is option A.
What is chemical formula?Chemical formula is a formula where cation and anion combine to form a molecule in fixed proportion. Metals combine in form of cation and non metals combine in form of anion.
Cation is the species that give electron and attain positive charge while anion is a species which gain electron and attains negative charge so when anion and cation combine in fixed ration the the overall charge of the molecule is zero that is molecule is neutral.
Out of given structural is a 3D representation of any chemical formula, in which symbol of each element is shown .Along with symbol line for each bond between atoms is also shown.
Therefore, the correct option is option A.
To learn more about Chemical formula, here:
https://brainly.com/question/28522480
#SPJ2
How many moles of water are produced from the reaction of 0.224 mol oxygen according to this equation? 2H2 + O2 -> 2H2O
Answer:
0.448 mols
Explanation:
Use balanced equation:
2H2 + O2 -> 2H2O
For every one mole of oxygen, there are two moles of water
hence the molar ratio 1:2
So if there are 0.224 mols of oxygen
Water = 0.224×2
Which is 0.448 mols of H20
Today, there are ____ GMO crops currently produced in the US.
A. 120
B. 10
C. 55
D. 1000
Answer: I think that is 55
Explanation: I hope I help
Obsidian _____.
is formed from sand and quartz
cools very quickly
has large mineral crystals
cools very slowly
Answer:
Cools Very Quickly
Explanation:
This is the right answer!
can someone help me???
Answer:
Waning Crescent
Explanation:
Hope iT Help
Brainliest please
a 55g block of metal has a specific heat of 0.45 J/g°C. What will be the temperature change of this metal if 450 J of heat energy are added
Answer:
18.18C
Explanation: Write whats below to show your work :D
m=55
C=0.45
Q=450zj
ch.temp=?
Q=mct
450 = (55)(.45)T
450 = 24.75
/24.75 = /24.75 (cancels out)
18.18 is the answer
Hope this helps! did it with my teacher.
What is happening to the electrons between several atoms of Copper?
A.nothing happens to the electrons
B.the electrons become delocalized and form a "sea"
C.they are shared between two atoms
D.the electrons are transferred from one atom to another
Answer:
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B.the electrons become delocalized and form a "sea"