Answer:
[H₃O⁺] = 1.4 × 10⁻⁹ M.
Explanation:
NH₄Cl is a salt that dissolves well in water. The 2.5 M NH₄Cl will give an initial NH₄⁺ concentration of 2.5 M.
NH₃ is a weak base. It combines with water to produce NH₄⁺ and OH⁻. The opposite process can also take place. NH₄⁺ combines with OH⁻ to produce NH₃ and H₂O. The final H₃O⁺ concentration can be found from the OH⁻ concentration. What will be the final OH⁻ concentration?
Let the increase in OH⁻ concentration be x. The initial OH⁻ concentration at room temperature is 10⁻⁷ M.
Construct a RICE table for the equilibrium between NH₃ and NH₄⁺:
.
The 
value for ammonia is small. The value of x will be so small that at equilibrium, 
and 
.
![\displaystyle \text{K}_b = \frac{[{\text{NH}_4}^{+}]\cdot [{\text{OH}}^{-}]}{[\text{NH}_3]} \approx \frac{2.5\;(x + 1.0\times 10^{-7})}{1.0}](https://tex.z-dn.net/?f=%5Cdisplaystyle%20%5Ctext%7BK%7D_b%20%3D%20%5Cfrac%7B%5B%7B%5Ctext%7BNH%7D_4%7D%5E%7B%2B%7D%5D%5Ccdot%20%5B%7B%5Ctext%7BOH%7D%7D%5E%7B-%7D%5D%7D%7B%5B%5Ctext%7BNH%7D_3%5D%7D%20%5Capprox%20%5Cfrac%7B2.5%5C%3B%28x%20%2B%201.0%5Ctimes%2010%5E%7B-7%7D%29%7D%7B1.0%7D)
.
.
![\displaystyle [\text{OH}^{-}] = x+1.0\times 10^{-7} = 1.8\times 10^{-5} /\left(\frac{2.5}{1.0}\right) = 7.2\times 10^{-6}\;\text{mol}\cdot\text{L}^{-}](https://tex.z-dn.net/?f=%5Cdisplaystyle%20%5B%5Ctext%7BOH%7D%5E%7B-%7D%5D%20%3D%20x%2B1.0%5Ctimes%2010%5E%7B-7%7D%20%3D%201.8%5Ctimes%2010%5E%7B-5%7D%20%2F%5Cleft%28%5Cfrac%7B2.5%7D%7B1.0%7D%5Cright%29%20%3D%207.2%5Ctimes%2010%5E%7B-6%7D%5C%3B%5Ctext%7Bmol%7D%5Ccdot%5Ctext%7BL%7D%5E%7B-%7D)
.
Again, 
at room temperature.
![\displaystyle [\text{H}_3\text{O}^{+}] = \frac{\text{K}_w}{[\text{OH}^{-}]}=\frac{1.0\times 10^{-14}}{7.2\times 10^{-6}} = 1.4\times 10^{-9} \;\text{mol}\cdot\text{L}^{-1}](https://tex.z-dn.net/?f=%5Cdisplaystyle%20%5B%5Ctext%7BH%7D_3%5Ctext%7BO%7D%5E%7B%2B%7D%5D%20%3D%20%5Cfrac%7B%5Ctext%7BK%7D_w%7D%7B%5B%5Ctext%7BOH%7D%5E%7B-%7D%5D%7D%3D%5Cfrac%7B1.0%5Ctimes%2010%5E%7B-14%7D%7D%7B7.2%5Ctimes%2010%5E%7B-6%7D%7D%20%3D%201.4%5Ctimes%2010%5E%7B-9%7D%20%5C%3B%5Ctext%7Bmol%7D%5Ccdot%5Ctext%7BL%7D%5E%7B-1%7D)
Answer:
1.38×10^25 molecules
Explanation:
Applying n= (no. of molcules)/NA
23 = N/6.02×10^23
= 1.38×10^25 molecules
Answer:
Hiya there!
Explanation:
Both fission and fusion are nuclear reactions that produce energy, but the applications are not the same. Fission is the splitting of a heavy, unstable nucleus into two lighter nuclei, and fusion is the process where two light nuclei combine together releasing vast amounts of energy.
For example, uranium can fission to yield strontium and krypton. Fusion joins atomic nuclei together. The element formed has more neutrons or more protons than that of the starting material. For example, hydrogen and hydrogen can fuse to form helium.
<em><u>Hope this helped!</u></em> :D
Credit sourced from "nuclear.duke-energy.com, thoughtco.com"
Protons in science is positive
