Channel: Wayne Breslyn

Category: Education

Tags: hcl + naoh neutralizingneutralization reactionhcl vs naohstrong acid and strong base neutralizationreaction of hcl and naoh

Description: Using pH paper we'll add a strong acid (HCl) and a strong base (NaOH) and watch the color changes as they meet and neutralize each other. We first at distilled water, which is a pH of 7. Not much happens to the color of the pH paper, it may turn slightly greener. Next we add Hydrochloric acid at a concentration of 1M. This corresponds to a pH of zero. This produces a red color on the paper. We then add Sodium hydroxide (1M) on the opposite side. This has a pH of 14 and produces the dark blue color on the paper. When they meet they neutralize each other and result in a pH of 7. That is the yellow line between the two colors. The chemical equation is: HCl (aq) + NaOH (aq) → NaCl (aq) + H2O (l) In the reactants we have the strong acid (HCl) and strong base (NaOH). they react and neutralize to produce salt (NaCl) and water (H2O). The salt water solution has a pH of 7. That is the yellow line between the red and blue. After a while most of the HCl and NaOH have reacted and the paper is yellow again. There was likely a bit more NaOH than HCl so we have some green still in the right hand corner of the pH paper.