Answer:
Heat absorbed = mS△T
51 = ( 8.2/1000)Kg ×S (11.5)
51×1000= 8.2 (11.5)S
S = 51000/94.3
S = 540.8 J/kg K
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 quinineWater pollution has severely impacted animals and plants in New York's Hudson
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
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.
Please help with this one
Answer:
15g
Explanation:
hope this helped
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
Help please I’ll mark as brainiliest
Answer:
B B
W BW BW
W BW BW
Explanation:
Hope this helps
Given a volume of 47.8 mL of gas at STP, _______________ moles of O2 exist
Trojans are _____.
a. asteroids which fall to the Earth
b. long-period comets
c. planets with ring systems
d. asteroids affected by Jupiter's gravity
Answer:
d. asteroids affected by Jupiter's gravity
Explanation:
A Trojan horse or Trojan is a type of malware that is often disguised as legitimate software. Trojans can be employed by cyber-thieves and hackers trying to gain access to users' systems. Users are typically tricked by some form of social engineering into loading and executing Trojans on their systems.
Answer:
D
Explanation:
D is the correct answer, they are planets that are close to the center star
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).
Like in a cat's eye, the human pupil changes shape in response to changes in
the environment. What is the most likely function of this structure?
A. To allow humans to read
B. To allow humans to see clearly in different levels of light
C. To allow humans to see shades in color
D. To allow humans to see at varying distances
Answer:
B.
Our pupils contract and expand depending on the amount of light at any given time in order to avoid being blinded and to see better in the darkness.
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
is pyramidal molecular geometry?
A. N2
B. H2O
C. NH3
D. CCL4
Answer:
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B.H2O
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.
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.