Answer:
133.34 g/moles
Explanation:
but to make life easy it could be 133.4 g/ moles as well
how can a scientist make a solution using salt and water?
Answer:
by boiling water and add the salt
Explanation:
because salt dissolves better if mixed with hot water which makes the process faster and effective
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 quinineAn 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).
Which of these actions is an example of erosion caused by gravity?
A.
Constant freezing and thawing water forming a hole in an asphalt road
B.
Pieces of rock breaking off and falling from a mountain top
C.
Chemicals in the air dissolve minerals in a marble statue
D.
Plant roots widening cracks in a large granite rock
Answer:
The answer is a
Explanation:because yes
Answer: The answer is B.
Explanation: The rocks falling off is caused by gravity. Other options don't include effects of gravity; Therefore, B is correct.
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
the sum of two number is 50,and their difference is 30.find the sum
Answer:
40 and 10
Explanation:
40 plus 10 is 50 40 minus 10 is 30
Answer:
40 and 10
Explanation: