Energy is required to melt a solid because the cohesive bonds between the molecules in the solid must be broken apart so that the molecules can move around at comparable kinetic energies
Answer:
=> moles = Given mass/molar mass
=> 0.787 = Given mass/(39 + 12 + 14)
=> 0.787 = Given mass/65
=> mass = 0.787 × 65
=> <u>mass = 51.155 g</u>
Answer:
- <u>Yes,</u> <em>all titrations of a strong base with a strong acid have the same pH at the equivalence point.</em>
This <u>pH is 7.</u>
Explanation:
<em>Strong acids</em> and <em>strong bases</em> ionize completely in aqueous solutions. The ionization of strong acids produce hydronium ions, H₃O⁺, and the ionization of strong bases produce hydroxide ions, OH⁻.
Since the ionization of strong acids and bases progress until completion, there is not reverse reaction.
The definition of pH is pH = - log [H₃O⁺]. Acids have low pH (below 7, and greater than 0) and bases have high pH (above 7 and less than 14). Neutral solutions have pH = 7.
Acid-base titrations are a method to determine the concentration of an acid from the known concentration of a base, or the concentraion of a base from the known concentration of an acid.
The<em> equivalence point</em> of the titration is the point at which the the number of moles of hydronium ions and hydroxide ions are equal.
Then, at that point, the hydronium and hydroxide ions will be in the stoichiometric proportion to form a neutral solution, i.e. the pH of the solution wiill be 7.
Answer:
B. It is important that people are not harmed for the sake of science.
Explanation:
Ethical principles stress the need to do good and cause no harm.A researcher is therefore required to;
- obtain an informed consent from the participants
- minimize or eliminate risk of harm to participants
- protect the anonymity and confidentiality of participants
- Apply no deceptive techniques
- allow the right to withdraw from the study by a participant
Probably telophase because for the difference in the nuclear membrane
