Answer:
pH = 4.25
Explanation:
A solution composed of a weak acid and its conjugate base is a <em>buffer solution</em>. To calculate the pH of a buffer solution we use the Henderson-Hasselbach equation:
pH = pKa + log ([conjugate base]/[weak acid]
In this case, we have the following data:
[conjugate base] = [sodium benzoate] = 0.230 M
[weak acid] = [benzoic acid] = 0.205 M
The pKa of benzoic acid is 4.2. So, we introduce the data in the equation:
pH = 4.2 + log (0.230 M/0.205 M) = 4.2 + 0.050 = 4.25
Answer:
False
Explanation:
It is wrong to claim that when the attraction between particles overcomes their motion, the particles will clump together to boil.
During boiling particles do no clump together, they tend to move apart more rapidly.
- Boiling occurs when the vapor pressure overcomes the ambient atmospheric pressure.
- The hotter part of the boiler close the heat source moves rapidly away because they have become less dense.
- The colder and denser part sinks and this interaction sets up a convection cell.
Answer:
A. It formed by barium(Ba+2) ion and sulfate ( SO42- )
B. It is formed by calcium ion (Ca+2) and two fluoride ions (2F-)
C. It is formed by magnesium ion (Mg+2) and nitride ion (N3-)
D. It is formed by two potassium ions (2 K+) and oxide ion(O2-)
