Please help me with the answers?

How does litmus paper indicate an acid?

Which of the following statements about acidic water is true? a. acid has no effect on the h, o molecules. b. the solution contains a larger number of oh ions than h, o ions. c. the solution contains a larger number of h, o ions than qh ions. d. the solution contains an equal number of h, o ions and oh ions. none of the above e.

How much would the freezing point of water decrease if 4 mol of sugar were added to 1 kg of water(k=1.86 c/mol/kg for water and i=1 for sugar