Chemistry Tasks Scholarship Essay Example | Topics and Well Written Essays - 1000 words

Chemistry Tasks - Scholarship Essay Example 6. A conjugate acid base pair are the compounds formed by the removal or addition of a proton from the original compound. In the question, only H3O+ and OH- are not a conjugate acid base pair as there is a difference of 2 protons. 9. The aqueous solution of a salt would be acidic if the salt consists of the conjugate base of a strong acid and conjugate acid of a weak base. Therefore the aqueous solution of NH4F would result in a acidic solution. 12. The aqueous solution of a salt would be basic if the salt consists of the conjugate base of a weak acid and conjugate acid of a strong base. Therefore the aqueous solution of NaCH3CO2 would result in a basic solution as NaOH is a strong base and CH3COOH is a weak acid. 13. Arrhenius base is the substance that when added to water increases the concentration of OH- ions present in the solution. NH3 when added to water does not increase the concentration of OH- ions therefore it is not an Arrhenius base. 14. Arrhenius acid is the substance that when added to water increases the concentration of H+ ions present in the solution. Addition of FeCl3 to water would not increase the concentration of H+ ions in the solution, so it is not a Arrhenius acid. From this it is clear that the reaction moves in the forward direction, which means that HNO2 gets converted to NO2- and CH3COO- gets converted to CH3COOH. Therefore it is clear that CH3COOH is a weaker acid compared to HNO2. So for this reaction CH3COOH is the weakest acid. 17. We know that pH = -log[H+] therefore if the pH increases by 1. The H+ concentration would decrease exponentially by a factor of 10. 18. Molecular weight of Ba(OH)2 is 171.34 g/mole. Therefore the moles of Ba(OH)2 added would be (5/171.34) = 0.029 moles. Each mole of Ba(OH)2 would dissociate to give 2 moles of OH- ions. So, we have