A student carried out a titration to find the exact volume of hydrochloric acid that would neutralise 25.0 cm3 of sodium hydroxide solution. NaOH + HCl → NaCl + H2O
In a different experiment 25.0 cm3 of 0.50 mol dm-3 sodium hydroxide solution reacted with 21.65 cm3 of hydrochloric acid.
Calculate the concentration of the hydrochloric acid.
Give your answer to 2 s. f.

you need to give more information

it is a good conductor

explanation:

2h2o2--> 2h2o + o2

this reaction is of the spontaneous decomposition of hydrogen peroxide down into water and oxygen.

add 2 molecules of hydrogen peroxide and 2 molecules of water. since oxygen is naturally diatomic, the total number of atoms of each element is now the same on both sides of the equation so it is balanced.

this may not be entirely correct but let me know.