Answer
a) A solution with a hydronium molarity of 0.00045 is acidic. True
Doing the calculus of pH
![pH= -Log [H^{+}] = -Log (0.00045)](https://tex.z-dn.net/?f=pH%3D%20-Log%20%5BH%5E%7B%2B%7D%5D%20%3D%20-Log%20%280.00045%29)
b) pH is a way to express the hydronium concentration over a wide range. True
pH means –Log[H+] and this value is used to express a wide range of hydronium concentration sometimes obtaining pH minor than zero.
c) Percent K and Fe are determined by doing ion exchange then a pH titration. False
Usually, Fe is determined by redox titration with potassium permanganate due to it’s more accurate. On the other hand, K is determined usually by volumetric process which includes precipitation like potassium picrate precipitate
d) About 0.2M HCl is the reagent used for the pH titrations. False.
In order to do pH titration, it is possible to use a wide range of HCl concentrations and other acids as reagent if the analyte is a basic compound. Otherwise, if the analyte is an acid compound you should use a basic compound as reagent.
e) A Lewis base is specie that can donate a proton to an acid. False
A Lewis base is an electron pair donor.
Dalton's Law of Partial Pressures, commonly applied to ideal gases, explains that the partial pressures of individual, non-reacting gases are equal to the total pressure exerted by the gas mixture. The given gas mixture composed of 90% argon and 10% carbon dioxide has the following partial pressures: 3.6 atm for argon and 0.4 atm for carbon dioxide (answer).
Here we have to calculate the heat required to raise the temperature of water from 85.0 ⁰F to 50.4 ⁰F.
10.857 kJ heat will be needed to raise the temperature from 50.4 ⁰F to 85.0 ⁰F
The amount of heat required to raise the temperature can be obtained from the equation H = m×s×(t₂-t₁).
Where H = Heat, s =specific gravity = 4.184 J/g.⁰C, m = mass = 135.0 g, t₁ (initial temperature) = 50.4 ⁰F or 10.222 ⁰C and t₂ (final temperature) = 85.0⁰F or 29.444 ⁰C.
On plugging the values we get:
H = 135.0 g × 4.184 J/g.⁰C×(29.444 - 10.222) ⁰C
Or, H = 10857.354 J or 10.857 kJ.
Thus 10857.354 J or 10.857 kJ heat will be needed to raise the temperature.