The diameters of the spheres are 72.5 meters square
Answer:
1. pH = 1.23.
2. ![H_2C_2O_4(aq) +OH^-(aq)\rightarrow HC_2O_4^-(aq)+H_2O(l)](https://tex.z-dn.net/?f=H_2C_2O_4%28aq%29%20%2BOH%5E-%28aq%29%5Crightarrow%20HC_2O_4%5E-%28aq%29%2BH_2O%28l%29)
Explanation:
Hello!
1. In this case, for the ionization of H2C2O4, we can write:
![H_2C_2O_4\rightleftharpoons HC_2O_4^-+H^+](https://tex.z-dn.net/?f=H_2C_2O_4%5Crightleftharpoons%20HC_2O_4%5E-%2BH%5E%2B)
It means, that if it is forming a buffer solution with its conjugate base in the form of KHC2O4, we can compute the pH based on the Henderson-Hasselbach equation:
![pH=pKa+log(\frac{[base]}{[acid]} )](https://tex.z-dn.net/?f=pH%3DpKa%2Blog%28%5Cfrac%7B%5Bbase%5D%7D%7B%5Bacid%5D%7D%20%29)
Whereas the pKa is:
![pKa=-log(Ka)=-log(5.90x10^{-2})=1.23](https://tex.z-dn.net/?f=pKa%3D-log%28Ka%29%3D-log%285.90x10%5E%7B-2%7D%29%3D1.23)
The concentration of the base is 0.347 M and the concentration of the acid is 0.347 M as well, as seen on the statement; thus, the pH is:
![pH=1.23+log(\frac{0.347M}{0.347M} )\\\\pH=1.23+0\\\\pH=1.23](https://tex.z-dn.net/?f=pH%3D1.23%2Blog%28%5Cfrac%7B0.347M%7D%7B0.347M%7D%20%29%5C%5C%5C%5CpH%3D1.23%2B0%5C%5C%5C%5CpH%3D1.23)
2. Now, since the addition of KOH directly consumes 0.070 moles of acid, we can compute the remaining moles as follows:
![n_{acid}=0.347mol/L*1.00L=0.347mol\\\\n_{acid}^{remaining}=0.347mol-0.070mol=0.277mol](https://tex.z-dn.net/?f=n_%7Bacid%7D%3D0.347mol%2FL%2A1.00L%3D0.347mol%5C%5C%5C%5Cn_%7Bacid%7D%5E%7Bremaining%7D%3D0.347mol-0.070mol%3D0.277mol)
It means that the acid remains in excess yet more base is yielded due to the effect of the OH ions provided by the KOH; therefore, the undergone chemical reaction is:
![H_2C_2O_4(aq) +OH^-(aq)\rightarrow HC_2O_4^-(aq)+H_2O(l)](https://tex.z-dn.net/?f=H_2C_2O_4%28aq%29%20%2BOH%5E-%28aq%29%5Crightarrow%20HC_2O_4%5E-%28aq%29%2BH_2O%28l%29)
Which is also shown in net ionic notation.
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Answer:
Percent yield: 78.2%
Explanation:
Based on the reaction:
4Al + 3O₂ → 2Al₂O₃
<em>4 moles of Al produce 2 moles of Al₂O₃</em>
<em />
To find percent yield we need to find theoretical yield (Assuming a yield of 100%) and using:
(Actual yield (6.8g) / Theoretical yield) × 100
Moles of 4.6g of Al (Molar mass: 26.98g/mol) are:
4.6g Al × (1mol / 26.98g) = 0.1705 moles of Al.
As 4 moles of Al produce 2 moles of Al₂O₃, theoretical moles of Al₂O₃ obtained from 0.1705 moles of Al are:
0.17505 moles Al × (2 moles Al₂O₃ / 4 moles Al) = <em>0.0852 moles of Al₂O₃</em>,
In grams (Molar mass Al₂O₃ = 101.96g/mol):
0.0852 moles of Al₂O₃ × (101.96g / mol) =
<h3>8.7g of Al₂O₃ can be produced (Theoretical yield)</h3>
Thus, Percent yield is:
(6.8g / 8.7g) × 100 =
<h3>
78.2% </h3>
☛ <u>299,792,458</u> meters per second.
Answer:
The answers are in the explanation.
Explanation:
The energy required to convert 10g of ice at -10°C to water vapor at 120°C is obtained per stages as follows:
Increasing temperature of ice from -10°C - 0°C:
Q = S*ΔT*m
Q is energy, S specific heat of ice = 2.06J/g°C, ΔT is change in temperature = 0°C - -10°C = 10°C and m is mass of ice = 10g
Q = 2.06J/g°C*10°C*10g
Q = 206J
Change from solid to liquid:
The heat of fusion of water is 333.55J/g. That means 1g of ice requires 333.55J to be converted in liquid. 10g requires:
Q = 333.55J/g*10g
Q = 3335.5J
Increasing temperature of liquid water from 0°C - 100°C:
Q = S*ΔT*m
Q is energy, S specific heat of ice = 4.18J/g°C, ΔT is change in temperature = 100°C - 0°C = 100°C and m is mass of water = 10g
Q = 4.18J/g°C*100°C*10g
Q = 4180J
Change from liquid to gas:
The heat of vaporization of water is 2260J/g. That means 1g of liquid water requires 2260J to be converted in gas. 10g requires:
Q = 2260J/g*10g
Q = 22600J
Increasing temperature of gas water from 100°C - 120°C:
Q = S*ΔT*m
Q is energy, S specific heat of gaseous water = 1.87J/g°C, ΔT is change in temperature = 20°C and m is mass of water = 10g
Q = 1.87J/g°C*20°C*10g
Q = 374J
Total Energy:
206J + 3335.5 J + 4180J + 22600J + 374J =
30695.5J =
30.7kJ