2.0 L
The key to any dilution calculation is the dilution factor
The dilution factor essentially tells you how concentrated the stock solution was compared with the diluted solution.
In your case, the dilution must take you from a concentrated hydrochloric acid solution of 18.5 M to a diluted solution of 1.5 M, so the dilution factor must be equal to
DF=18.5M1.5M=12.333
So, in order to decrease the concentration of the stock solution by a factor of 12.333, you must increase its volume by a factor of 12.333by adding water.
The volume of the stock solution needed for this dilution will be
DF=VdilutedVstock⇒Vstock=VdilutedDF
Plug in your values to find
Vstock=25.0 L12.333=2.0 L−−−−−
The answer is rounded to two sig figs, the number of significant figures you have for the concentration od the diluted solution.
So, to make 25.0 L of 1.5 M hydrochloric acid solution, take 2.0 L of 18.5 M hydrochloric acid solution and dilute it to a final volume of 25.0 L.
IMPORTANT NOTE! Do not forget that you must always add concentrated acid to water and not the other way around!
In this case, you're working with very concentrated hydrochloric acid, so it would be best to keep the stock solution and the water needed for the dilution in an ice bath before the dilution.
Also, it would be best to perform the dilution in several steps using smaller doses of stock solution. Don't forget to stir as you're adding the acid!
So, to dilute your solution, take several steps to add the concentrated acid solution to enough water to ensure that the final is as close to 25.0 L as possible. If you're still a couple of milliliters short of the target volume, finish the dilution by adding water.
Always remember
Water to concentrated acid →.NO!
Concentrated acid to water →.YES!
Humans! They inhale and Exhale Oxygen and Carbon Dioxide.
Answer:
i took the test but failed and just got that question right so b
Explanation:
Before the periodic table, there were a bunch of symbols, number, letters etc (In all kinds of languages) that represented the elements. Scientists around the world saw that a chart of the elements needed to be universally accepted and finalized. A guy named Mendeleev presented this idea to the scientific community. Mendeleev was also the first to order elements according to atomic number rather than atomic weight. The modern day periodic table was not published by him, it was developed with the help of the entire scientific community. Honestly, there isn't a specific way to tell you how the periodic table was constructed, scientists developed thousands of tables that represented the elements. And just to let you know, the modern day periodic table is constantly going through changes as we discover more and more about elements, atoms, molecules etc. so in the near future it wouldn't be surprising if we saw something completely different than what we see today.
A. When two chemicals mix their temperature rise: <span>Exothermic
b. </span>A solid burns brightly and releases heat, light and sound: <span>Exothermic
c. </span>When two chemicals are mixed their temperature drops: <span>Endothermic
d. </span>Two chemicals will only react if you heat them continually: <span>Endothermic
e. </span>Plants take in light energy for photosynthesis: <span>Endothermic
I hope this helps :)</span>
