[填空题]
Ascorbic acid $(C_6H_8O_6)$,or vitamin C, is a water-soluble vitamin that is essential for our immune system.
1.Calculate the number of moles in 2.50g of ascorbic acid. mol
2.Calculate the mass of 1.28 moles of ascorbic acid. g
3.Calculate the number of molecules in 50.0 g of ascorbic acid. $\times10^{23}$
4.Determine the number of moles of carbon in 225 mg of ascorbic acid. mol C
