Answer:
The mole fraction of NaOH in an aqueous solution that contain 22.9% NaOH by mass=0.882
Explanation:
We are given that
Aqueous solution that contains 22.9% NaOH by mass means
22.9 g NaOH in 100 g solution.
Mass of NaOH(WB)=22.9 g
Mass of water =100-22.9=77.1
Na=23
O=16
H=1.01
Molar mass of NaOH(MB)=23+16+1.01=40.01
Number of moles =![\frac{Given\;mass}{Molar\;mass}](https://tex.z-dn.net/?f=%5Cfrac%7BGiven%5C%3Bmass%7D%7BMolar%5C%3Bmass%7D)
Using the formula
Number of moles of NaOH![(n_B)=\frac{W_B}{M_B}=\frac{22.9}{40.01}](https://tex.z-dn.net/?f=%28n_B%29%3D%5Cfrac%7BW_B%7D%7BM_B%7D%3D%5Cfrac%7B22.9%7D%7B40.01%7D)
![n_B=0.572moles](https://tex.z-dn.net/?f=n_B%3D0.572moles)
Molar mass of water=16+2(1.01)=18.02g
Number of moles of water![(n_A)=\frac{77.1}{18.02}](https://tex.z-dn.net/?f=%28n_A%29%3D%5Cfrac%7B77.1%7D%7B18.02%7D)
![n_A=4.279 moles](https://tex.z-dn.net/?f=n_A%3D4.279%20moles)
Now, mole fraction of NaOH
=![\frac{n_B}{n_B+n_A}](https://tex.z-dn.net/?f=%5Cfrac%7Bn_B%7D%7Bn_B%2Bn_A%7D)
![=\frac{4.279}{0.572+4.279}](https://tex.z-dn.net/?f=%3D%5Cfrac%7B4.279%7D%7B0.572%2B4.279%7D)
=0.882
Hence, the mole fraction of NaOH in an aqueous solution that contain 22.9% NaOH by mass=0.882
Using p1v1/t1=p2v2/t2
p1=50
p2=225
v1=400ml
v2=?
t1=-20=253k
t2=60=333k
50x400/253=225xv2/333
7.9=0.7xv2
v2=7.9/0.7
v2=11.3ml
Answer:
The atomic number on the Periodic Table identifies the number of protons in any atom of that element. Copper, atomic number 29, has 29 protons. Finding the atomic number of an element reveals the number of protons.
To find the number of neutrons in the atom, subtract the atomic number from the atomic mass.
I would say is because of the Boron from O?
We know that when calculating percent yield, we use the equation:
![Percent yield=\frac{Actual yield (A)}{Theoretical yield (T)}](https://tex.z-dn.net/?f=%20Percent%20yield%3D%5Cfrac%7BActual%20yield%20%28A%29%7D%7BTheoretical%20yield%20%28T%29%7D%20%20)
Since the quantities that we are given in the question are equal, we can just directly divide them to find percent yield:
![Percentyield=\frac{480kg}{550kg} =0.8727*100=87.27](https://tex.z-dn.net/?f=%20Percentyield%3D%5Cfrac%7B480kg%7D%7B550kg%7D%20%3D0.8727%2A100%3D87.27%20)
So now we know that the percent yield of the synthesis is 87.27%.