Answer:
OUTCOME VARIABLE: Attraction to negatively charged balloon
Explanation:
In an experiment, two major variables must be included viz: the independent variable and the dependent variable. The independent variable also referred to as the test variable is the variable that is being changed in the experiment while the dependent or outcome variable is the variable that responds to the changes made to the independent variable. The outcome variable is the variable that is measured in an experiment.
In this experiment involving Marianne wanting to know which objects will be attracted to a negatively charged balloon. The type of objects are the independent variable while the ATTRACTION is the outcome or dependent variable as it is dependent on the type of object used.
The acid in a battery is an electrolyte.
Answer:
Determine the pH of the solution half-way to the end-point on the pH titration curve for acetic acid.
Explanation:
The equation for the ionization of acetic acid is
HA + H₂O ⇌ H₃O⁺ + A⁻
For points between the starting and equivalence points, the pH is given by the Henderson-Hasselbalch equation:
![\text{pH} = \text{pK}_{\text{a}} + \log\dfrac{[\text{A}^{-}]}{\text{[HA]}}](https://tex.z-dn.net/?f=%5Ctext%7BpH%7D%20%3D%20%5Ctext%7BpK%7D_%7B%5Ctext%7Ba%7D%7D%20%2B%20%5Clog%5Cdfrac%7B%5B%5Ctext%7BA%7D%5E%7B-%7D%5D%7D%7B%5Ctext%7B%5BHA%5D%7D%7D)
At the half-way point, half of the HA has been converted to A⁻, so [HA] = [A⁻]. Then,
The pKₐ is the pH at the half-way point in the titration.
