Answer: 0.887 g of 
should be added to excess HCl(aq).
Explanation:
According to ideal gas equation:
P = pressure of gas = 805 torr = 1.06 atm (760torr=1atm)
V = Volume of gas = 235 ml = 0.235 L
n = number of moles = ?
R = gas constant =
T =temperature =
According to stoichiometry:
1 mole of chlorine is produced by = 1 mole of
Thus 0.0102 moles of chlorine is produced by = 
moles of
Mass of =
0.887 g of should be added to excess HCl(aq).
Hence, it is less preferrable to choose an isotope to enter your body, which will emit radioactivity for a long time, so we tend to choose isotopes, the radioactivity of which ceases quickly, so that the least possible amount of damage is caused to the cells
Molarity is expressed as
the number of moles of solute per volume of the solution. The mass of oxalic acid dihydrate needed for the solution is calculated as follows:
Amount in moles: (0.357 mol H2C2O4•2H2O / L) (.250 L ) = 0.0893 mol H2C2O4•2H2O
Amount in mass : 0.0893 mol H2C2O4•2H2O (126.08 g / mol ) = 11.2589 g H2C2O4•2H2O
Hope this answers the question. Have a nice day.
