HOW MANY GRAM-EQUIVALENT ARE CONTAINED IN 1.8909 G OF CHEMICALLY PURE OXALIC ACID

Answer 1

Oxalic acid is H2C2O4.
1 gram equivalent is molar mass/2 = 90/2 = 45 but I've used rounded numbers. You can look up the atomic mass of each element and get a more exact answer than 45.
Then 1.8909 g/45 = ? (use your better value of 45 here).