Is someone could please help me answer 6-12 on this I will greatly appreciate it, please and thank you

An aqueous solution of calcium hydroxide is standardized by titration with a 0.120 m solution of hydrobromic acid. if 16.5 ml of base are required to neutralize 27.5 ml of the acid, what is the molarity of the calcium hydroxide solution?

The following reaction shows sodium carbonate reacting with calcium hydroxide. na2co3 + ca(oh)2 → naoh + caco3 how many grams of naoh are produced from 20.0 grams of na2co3? (molar mass of na = 22.989 g/mol, c = 12.01 g/mol, o = 15.999 g/mol, ca = 40.078 g/mol, h = 1.008 g/mol) 12.2 grams 15.1 grams 24.4 grams 30.2 grams

According to the vsepr theory what is the shape of a molecule that has a central atom valence three other items with no lone pairs of electrons