## Chemistry and Chemical Reactivity (9th Edition)

a)Average volume: $(20.15+21.30+20.40+20.35)/4=20.55\ mL$ Number of moles of NaOH: $20.55\ mL\times 0.1760\ M=3.617\ mmol$ Number of moles of sulfuric acid: $1.808\ mmol$ Concentration: $1.808\ mmol/10.00\ mL=0.181\ M$ Concentration before dilution: $0.181\ M\times 500.\ mL\div 5.00\ mL=18.08\ M$ b) Mass: $18.08\ M\times 98.07\ g/mol=1.773\ kg$ Mass percentage: $1.773/1.84\times100\%=96.38$