Question

a) a strong base
b) a weak acid
c) a strong acid
d) a weak base
→9. a solution has a ph of 4. to neutralize it you should add:
a) an acid
b) a base
c) water
d) salt
10.indicators are substances that have specific colors in specific ph of a
solution. in an acidic solution litmus red becomes:
a) white
b) blue
c) remains red

Explanation:

Question 9:

A pH of 4 means the solution is acidic. Neutralization requires reacting an acid with a base to form a neutral solution (pH 7).

Question 10:

Litmus is an acid-base indicator. Red litmus does not change color in acidic conditions; it turns blue only in basic solutions.

Answer:

1. b) a base
2. c) remains red