Answer:
The given statement is false.
Explanation:
- A common method of experimentation that is used to collect data on hypotheses of end up causing-effect is a contrast between two groups.
- One community, the experimental group, is receiving medication for having any result. Some other group becomes left exposed, the control group, whether creating a different treatment.
Measure the brightness of a star through two filters and compare the ratio of red to blue light.
Explanation:
Anions and cations have different atomic sizes than the neutral atoms.
When the bromine atom becomes an anion, it ______ in size.
Anions involves gaining extra electrons. This basically leads to increased repulsion between the electrons and thereby increasing the size. Anions are always larger than the neutral atoms.
This means the answer is A. Increase
When the strontium atom becomes a cation, it ______ in size.
Cations involves losing valence electrons. This basically leads to a decrease in electron shells and electron repulsion thereby reducing the size. Cations are always larger than the neutral atoms.
This means the answer is B. Decrease
That would be an endothermic reaction! :)
We are given the molar concentration of an aqueous solution of weak acid and the pH ofthe solution, and we are asked to determine the value of Ka for the acid.
The first step in solving any equilibrium problem is to write the equation for the equilibriumreaction. The ionization of benzoic acid can be written as seen in the attached image (1).
The equilibrium-constant expression is the equation number (2)
From the measured pH, we can calculate pH as seen in equation (3)
To determine the concentrations of the species involved in the equilibrium, we imagine that thesolution is initially 0.10 M in HCOOH molecules. We then consider the ionization of the acidinto H+ and HCOO-. For each HCOOH molecule that ionizes, one H+ ion and one HCOO- ionare produced in solution. Because the pH measurement indicates that [H+] = 1x 10^-4 M atequilibrium, we can construct the following table as seen in the equation number (4)
To find the value of Ka, please see equation (5):
We can now insert the equilibrium concentrations into the expression for Ka as seen in equation (6)
Therefore, 2.58x10^-4 M is the concentration of benzoic acid to have a pH of 4.0