# chemistry 1 question?

1) What is the (H3O) in a solution that contains 1.5 g HNO3 in .50 L of solution

2) What is the PH of 1.0g of Ca(OH)2 in water to make 875mL

3) How many mL of .215M NaOH are needed to neutralize 2.5mL of .825M H2SO4?

I'm not even sure how to get started on these..any help would be appreciated.

Relevance
• Anonymous

Since all the acids involved are categorized as strong they full dissociate making calculations fairly simple.

1. (Mass of HNO3 / Molar mass of HNO3)/ Volume = H3O concentration

2. (Mass of Ca(OH)2 / Molar mass of Ca(OH)2 Volume = Ca(OH)2 concentration. pKa + pKb = 14. Thus pKb = 14 - pKa. Then -log(Ca(OH)2 concentration)+14 = pH

3. When the solution is neutralized #mols of NaOH = # of mols H2SO4 using this piece of information just do basic stoich.

• Anonymous

1. Use the atomic weight of HNO3 to calculate the molarity of the solution. The hydronium ion concentration can then be determined by arithmetic.

2. Do this the same way as above, except that you want the OH- concentration instead of H+. Subtract the Briggs log of this from 14.

3. This one is just a simple proportion; you don't even have to worry about molecular weights.

• ?
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