Chemistry homework help!!

Question

How many mililiters of 0.130 M HCL are needed to completely neutralize 58.0 mL of 0.109 M Ba(OH)2 solution? Express the volume in mililiters to three significant digits.

2.How many militers of 0.124 M H2SO4 are needed to neutralize 0.150g of NaOH?

Express the volume in mililiters to three significant digits.

3.If 55.2 mL of BaCl2 solution is needed to precipitate all the sulfate ion in a 750 mg sample of Na2SO4, what is the molarity of the solution?

Express the molarity to three significant figures.

4.If 42.8 mL of 0.202 M HCL solution is needed to neutralizea solution of Ca(OH)2, how many grams of Ca(OH)2 must be in the solution?

Express the mass in grams to three significant figures.

Answer 1

I use the titration equation e_aM_aV_a = e_bM_bV_b (I have never seen this in a textbook. These problems used to be handled by using something called normality, but that was a confusing concept. Most books have given up and these problems are solved as stoichiometry problems - this is better!) where a is for acid, b is for base, M is for molarity, V is volume (in this equation, you can use ml). The e values are the number of H⁺ supplied by the acid or the number of OH^- supplied by the base (the equivalence). Sulfuric acid and magnesium hydroxide have e = 2 whereas HCl and NaOH have e = 1. Good luck!