I was absent for this info and im stuck.

A)calculate the pH in an acid-base titration when 10.00mL o 1.000 m NaOH is added to 50.00 mL of 1.000m HNO2. Ka=6.0x10^-4

B) How many grams of NaC2H3O2 must be added to 500mL o 0.200m HAc to produce a buffer with pH=5? 1.8 x 10^-5 =Ka Hac

Look in your text book you lazy bum

I apologize if you feel that way, but I'm here to help you understand how to solve these problems step by step. So, let's break down each problem and explain the necessary steps to find the answers.

A) To calculate the pH in an acid-base titration, you need to determine the concentration of the resulting solution after the NaOH is added to HNO2. Here's how you can solve it:

Step 1: Calculate the moles of NaOH:
Moles of NaOH = Molarity of NaOH x Volume of NaOH
Moles of NaOH = 1.000 M NaOH x 0.01000 L NaOH

Step 2: Calculate the moles of HNO2:
Moles of HNO2 = Molarity of HNO2 x Volume of HNO2
Moles of HNO2 = 1.000 M HNO2 x 0.05000 L HNO2

Step 3: Determine which reactant is the limiting reagent:
Since the stoichiometric ratio between NaOH and HNO2 is 1:1, the limiting reagent is the one with fewer moles.

Step 4: Calculate the remaining moles of the limiting reagent:
Moles of limiting reagent = Moles of initial limiting reagent - Moles of added limiting reagent

Step 5: Calculate the concentration of the resulting solution:
Volume of resulting solution = Volume of HNO2 + Volume of NaOH
Concentration of resulting solution = Moles of limiting reagent / Volume of resulting solution

Step 6: Calculate the pOH of the resulting solution:
pOH = -log10([OH-])
[OH-] = Concentration of resulting solution
pOH = -log10(Concentration of resulting solution)

Step 7: Calculate the pH of the resulting solution:
pH = 14 - pOH

B) To find the grams of NaC2H3O2 needed to produce a buffer with pH 5, you need to set up an equilibrium expression using the Ka value for HAc. Here's how you can solve it:

Step 1: Write the balanced equation for the dissociation of HAc:
HAc ⇌ H+ + Ac-

Step 2: Write the expression for the Ka of HAc:
Ka = [H+][Ac-] / [HAc]

Step 3: Rearrange the equation to solve for [Ac-]:
[Ac-] = (Ka × [HAc]) / [H+]

Step 4: Convert the pH value to [H+] concentration using the equation:
[H+] = 10^(-pH)

Step 5: Substitute the values into the equation:
[Ac-] = (Ka × [HAc]) / [H+]
[Ac-] = (1.8 × 10^(-5) × 0.200 M) / (10^(-5))

Step 6: Calculate the moles of NaC2H3O2:
Moles of NaC2H3O2 = [Ac-] × Volume of solution

Step 7: Convert moles to grams of NaC2H3O2 using its molar mass.

I hope these step-by-step explanations help you understand the process of solving these problems. If you have any further questions, feel free to ask!