{[ promptMessage ]}

Bookmark it

{[ promptMessage ]}


Vinegar_Analysis - Experiment 4 Vinegar Analysis...

Info iconThis preview shows pages 1–2. Sign up to view the full content.

View Full Document Right Arrow Icon
Experiment 4: Vinegar Analysis Introduction: Many common substances contain acids and bases. For example, the fluid in our stomach contains hydrochloric acid; CaO, a base, can be found in cement. According to Arrhenius definitions , acids are substances that produce H + ions in aqueous solution. Bases are substances that produce OH ions in aqueous solution. Other definitions of acids and bases will be discussed in CHEM C106/C126. If acids or bases ionize completely, they are called strong acids and strong bases. Common strong acids include HCl, HBr, HI, H 2 SO 4 , HNO 3 , and HClO 4 . Common strong bases are hydroxides of IA group and larger member of IIA, such as NaOH, KOH, Ca(OH) 2 , Ba(OH) 2 . If the acids or bases ionize incompletely, they are called weak acids and weak bases. Acetic acid (CH 3 COOH), an active ingredient in vinegar, is a common weak acid. Ammonia, used as fertilizers in early days, is an example of weak base. When an acid and a base are mixed, the H + ( aq ) from the acid – whether it is weak or strong – combine with the OH ( aq ) from the base to form H 2 O( l ). This reaction is called acid-base reaction, or neutralization reaction. Acid-base reaction generally produces water and an ionic compound. For example: HCl( aq ) + NaOH( aq ) NaCl( aq ) + H 2 O( l ) Acid-base titration is an analytical method to determine the concentration of an unknown acid or base accurately. For example, we can use a NaOH solution of known concentration to titrate an HCl solution of unknown concentration. Ideally, equivalent amount of NaOH will be used to neutralize all HCl in solution. This is called equivalent point . However, equivalent point is impossible to reach. Instead, indicators are used to
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
Image of page 2
This is the end of the preview. Sign up to access the rest of the document.

{[ snackBarMessage ]}