Answer to Question #328615 in General Chemistry for lilly

Question

you are asked to identify two clear, colourless beakers full of solution as acidic or basic. State what you would expect to see if beaker A was an acid and beaker B was a base for each of the following properties:

BEAKER A vs BEAKER B

- Conductivity

- pH

- Bromothymol blue

- Reaction with zinc

- Taste

Answer 1

Strongly acidic [or strongly basic] solution will have high conductivity. Since the pH is a measure of the concentration of the Hydrogen [and the Hydroxyl] ions, for an acidic solutin, the lower the pH [i.e. the higher the H⁺ concentration,] the greater the conductivity will be.

pH of acidic solution < 7 and pH of basic solution > 7.

Bromthymol Blue is a dye used as an indicator in determining pH. Bromthymol blue is a weak acid. It can be in acid or base form, depending on the pH of the solution. This reagent is yellow in acidic solutions, blue in basic solutions and green in neutral solution.

Most metals do not react with bases but zinc metal does because it is amphoteric. That is, it reacts with acids as well as bases. When sodium hydroxide solution is heated with zinc, then sodium zincate and hydrogen gas are formed.

Acids taste sour while bases taste bitter.