25 cm 3 of sulphuric acid of concentration 0.2 mol dm^ -3 are needed to exactly neutralize 40 cm 3 of sodium hydroxide solution. What is the concentration of the
sodium hydroxide solution in mol dm ^-3 .

The equation below shows the reaction of zinc with hydrochloric acid (hcl). zn (s) + 2 hcl (aq) —> zncl2 (aq) + h2 (g) what will happen if the concentration of hcl is decreased? a. more zncl2 will be produced. b. the reaction rate will slow down. c. the hydrochloric acid will become more acidic. d. the reaction will produce water instead of hydrogen gas.