Answer:
126.5g
Explanation:
n=<u>m</u><u> </u>
M
where n is moles
m is mass of substance
M is molar mass
molar mass of sodium is 23g/mol
m=nM
m=5.5(23)
m=126.5
Answer:
890 has 2 significant figures
By Gay Lussacs law you can find the pressure. First both temperatures of Celsius must change to Kelvin by adding 273. Temperature one will be 308K and temperature 2 will be 258K
With this info, you can now find the pressure with Lussacs law
P1 = P2
— —
T1 T2
Pressure 1 is given which is 32 psi so just plug it all in and find P2
32 = x
—— ——
308 258
308x = 8256 (Cross multiply)
X = 26.8 (divide both sides by 308)
Answer is 26.8 PSI
This makes sense because as temperature increases pressure increases, as well as when temperature decreases, pressure decreases. Since it’s a colder day the pressure will be lower.
Answer:
17,890 J
Explanation:
The amount of heat released by a gaseous substance when it condenses is given by the formula
where
n is the number of moles of the substance
is the latent heat of vaporization
The formula can be applied if the substance is at its vaporization temperature.
In this problem, we have:
n = 0.440 mol is the number of moles of steam
is the latent heat of vaporization of water
And the steam is already at 100C, so we can apply the formula:
Answer:
- <em>He realized that some elements had not been discovered.</em>
Explanation:
Some scientists that tried to arrange the list of elements known before Mendeleev include Antoine Lavoisier, Johann Döbereiner, Alexandre Béguyer de Chancourtois, John Newlands, and Julius Lothar Meyer.
<em>Dimitri Mendeleev</em> was so succesful that he is recognized as the most important in such work.
Mendeleev by writing the properties of the elements on cards elaborated by him, and "playing" trying to order them, realized that, some properties regularly (periodically) repeated.
The elements were sorted in increasing atomic weight (which is not the actual order in the periodic table), but when an element did not meet the pattern discovered, he moved it to a position were its properties fitted.
The amazing creativity of Mendeleev led him to leave blanks for what he thought were places that should be occupied by elements yet undiscovered. More amazing is that he was able to predict the properties of some of those elements.
When years after some of the elements were discovered, the genius of Mendeleev was proven because the "new" elements had the properties predicted by him.
