The average atomic weight of copper, which has two naturally occurring isotopes, is 63.5. one of the isotopes has an atomic weight of 62.9 amu and constitutes 69.1% of the copper isotopes. the other isotope has an abundance of 30.9%. the atomic weight (amu) of the second isotope is amu.

Gusing the milligrams of ascorbic acid you entered above, the ratio of total sample volume to aliquot volume, and the total milligrams of the vitamin c tablet that you dissolved, calculate the mass of ascorbic acid in the vitamin c tablet for each trial. do this by scaling up to find the amount (mg) of ascorbic acid in your 250 ml flask. enter your calculated mass of ascorbic acid in the vitamin c tablet, for each trial. be sure to enter your calculated mass in the corresponding order that you entered your milligrams of ascorbic acid. the milligrams of ascorbic acid you entered for entry #1 previously should correspond to the mass of ascorbic acid that you enter for entry #1 here.