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To measure calcium in a breakfast cereal, 0.6796 grams of crushed cereal were reacted for 1 hour in warm 1MHNO3. The reaction mixture was filtered and the filtrate transferred to a 100mL volumetric flask and diluted to the mark with 1MHNO3. A series of eight standards were prepared by transferring 5.00mL aliquots of this solution to 50mL volumetric flasks to which increasing volumes of a 20.0ppm stock solution of Ca2+ were added, diluting to the final volume with deionized water. The samples were then analyzed by flame atomic absorption. Use the data and graph below to find the percent by mass calcium in the cereal. Regression equation: y=0.0705x+0.1581