When the concentration is expressed in molality, it is expressed in moles of solute per kilogram of solvent. Since we are given the mass of the solvent, which is water, we can compute for the moles of solute NaNO3.
0.5 m = x mol NaNO3/0.5 kg water
x = 0.25 mol NaNO3
Since the molar mass of NaNO3 is 85 g/mol, the mass is
0.25 mol * 85 g/mol = 21.25 grams NaNO3 needed
Answer:
pH = 2.059
Explanation:
At the Cathode:
The reduction reaction is:

At the anode:
At oxidation reaction is:

The overall equation for the reaction is:

The overall cell potential is:



Using the formula for the Nernst equation:

where;
E = 0.66
(Zn^2+)=0.22 M
Then
![0.66 =0.76- ( \dfrac{0.0591}{2})log \bigg ( \dfrac{[Zn^{2+} ] PH_2}{[H^+]^2} \bigg )](https://tex.z-dn.net/?f=0.66%20%3D0.76-%20%28%20%5Cdfrac%7B0.0591%7D%7B2%7D%29log%20%5Cbigg%20%28%20%5Cdfrac%7B%5BZn%5E%7B2%2B%7D%20%5D%20PH_2%7D%7B%5BH%5E%2B%5D%5E2%7D%20%5Cbigg%20%29)
![0.66 =0.76- 0.02955 * log \bigg ( \dfrac{0.22*0.87}{[H^+]^2} \bigg )](https://tex.z-dn.net/?f=0.66%20%3D0.76-%200.02955%20%2A%20log%20%5Cbigg%20%28%20%5Cdfrac%7B0.22%2A0.87%7D%7B%5BH%5E%2B%5D%5E2%7D%20%5Cbigg%20%29)
3.4 = log ( 0.1914) - 2 log [H⁺]
3.4 = -0.7180 - 2 log [H⁺]
3.4 + 0.7180 = - 2 log [H⁺]
4.118 = - 2 log [H⁺]
pH = log [H⁺] = 4.118/2
pH = 2.059
C. 10 amu i am 100 sure that it is 10 amu
Answer:
C
Explanation:
C. Nucleophilic attack and carbocation rearrangement to form the most stable carbocation before the substitution reaction