When a chemist titrates a standard solution of 168.61 ml of hydrochloric acid (hcl) with 0.104 m sodium hydroxide (naoh) , she finds that it requires 259.4 ml of the base to reach the endpoint of the titration. what is the molarity of the acid solution ?

Modern pennies are composed of zinc coated with copper. a student determines the mass of a penny to be 2.482 g and then makes several scratches in the copper coaling (to expose the underlying zinc). the student puts the scratched penny in hydrochloric acid, where the following reaction occurs between the zinc and the hcl (the copper remains undissolved): zn(s) + 2 hcl(aq) → h2(g) + zncl(aq)the student collects the hydrogen produced over water at 25 °c. the collected gas occupies a volume of 0.899 l at a total pressure of 79 j mmhg. calculate the percent zinc (by mass) in the penny. (assume that all the zn in the penny dissolves.)

How many grams of sodium chloride are in 250ml of a 2.5m naci solution

Twenty-seven milliliters of an acid with an unknown concentration are titrated with a base that has a concentration of 0.55 m. the indicator changed color when 12.5 milliliters of base were added. what is the concentration of the unknown acid?