They are the same because the definition of a mole is 6.022 x 10^23 molecules or atoms based on whether it is a molecule or element. so there are 6.022 x 10^23 atoms of argon in one mole of argon and 6.022 x 10^23 molecules of ammonia in one mole of ammonia
Answer:
0.42 g
Explanation:
<u>We have: </u>
pH = 12.10 (25 °C)
V = 800.0 mL = 0.800 L
To find the mass of sodium hydroxide (NaOH) we can use the pH:
![pOH = -log ([OH^{-}])](https://tex.z-dn.net/?f=%20pOH%20%3D%20-log%20%28%5BOH%5E%7B-%7D%5D%29%20)
![[OH]^{-} = 10^{-pOH} = 10^{-1.90} = 0.013 M](https://tex.z-dn.net/?f=%5BOH%5D%5E%7B-%7D%20%3D%2010%5E%7B-pOH%7D%20%3D%2010%5E%7B-1.90%7D%20%3D%200.013%20M)
Now, we can find the number of moles (η) of OH:
![\eta = ([OH]^{-})*V = 0.013 mol/L * 0.800 L = 1.04 \cdot 10^{-2} moles](https://tex.z-dn.net/?f=%5Ceta%20%3D%20%28%5BOH%5D%5E%7B-%7D%29%2AV%20%3D%200.013%20mol%2FL%20%2A%200.800%20L%20%3D%201.04%20%5Ccdot%2010%5E%7B-2%7D%20moles)
Since we have 1 mol of OH in 1 mol of NaOH, the number of moles of NaOH is equal to 1.04x10⁻² moles.
Finally, with the number of moles we can find the mass of NaOH:
<em>Where M is the molar mass of NaOH = 39.9 g/mol </em>
Therefore, the mass of sodium hydroxide that the chemist must weigh out in the second step is 0.42 g.
I hope it helps you!
Answer:
well if you ever do neeed help im here
Explanation:
Gilbert N. Lewis (1875-1946) was an American physical chemist.
His work with heavy water and resources were adapted by Ernest Lawrence in the development of the cyclotron.
SCIENTIFIC CONTRIBUTIONS
Lewis made many contributions to science. He was nominated for the Nobel Prize 41 times, though he was never awarded the prize.
He discovered covalent bonds and electron pairs. He worked with isotope separation, and became the first person to purify a sample of heavy water. The heavy water was later used as projectiles in Lawrence’s 27-inch cyclotron.
He also made contributions in ideas on relativity and acid-base reactions and coined the term “photon” as the smallest unit of light.
Answer:
a lack of genetic variety
first one is the correct one
