Answer:
5.7
Explanation:
(C₂H₅)₃NHCl dissociates according to the following equation.
(C₂H₅)₃NHCl ⇒ (C₂H₅)₃NH⁺ + Cl⁻
The molar ratio of (C₂H₅)₃NHCl to (C₂H₅)₃NH⁺ is 1:1. Then, the concentration of (C₂H₅)₃NH⁺ is Ca = 0.166 M.
(C₂H₅)₃NH⁺ is the conjugate acid of (C₂H₅)₃N. Given the Kb of (C₂H₅)₃N, we can calculate Ka for (C₂H₅)₃NH⁺ using the following expression.
Ka × Kb = Kw
Ka = Kw / Kb
Ka = 1.0 × 10⁻¹⁴ / 5.2 × 10⁻⁴
Ka = 1.9 × 10⁻¹¹
(C₂H₅)₃NH⁺ dissociates according to the following equation.
(C₂H₅)₃NH⁺ ⇄ (C₂H₅)₃N + H⁺
We can calculate [H⁺] using the following expression.
[H⁺] = √(Ca × Ka) = √(0.166 × 1.9 × 10⁻¹¹) = 1.8 × 10⁻⁶
The pH is:
pH = -log [H⁺] = -log 1.8 × 10⁻⁶ = 5.7
Answer:

Explanation:
Hello!
In this case, when two substances at different temperature are put in contact and an equilibrium temperature is attained, we can evidence that the heat lost by the hot substance (metal) is gained by the cold substance (water) and we can write:

Which can be also written as:

Thus, since we need the specific heat of the metal, we solve for it as shown below:

Best regards.
CH3CH2OH + 3O2 = 2CO2 + 3H2O
Basically you do trial and error on both sides so they can be equal
Answer:
1
Explanation:
There is only one calcium atom because the subscript 3 applies only to the oxygen. Outside of the parentheses, the subscript 2 only applies to the chlorate ion. Therefore, there is only one calcium atom because there are no coefficients and subscripts. (Also drawing it out will help)