Question

How much MnO2(s) should be added to excess HCl(aq) to obtain 315 mL of Cl2(g) at 25 °C and 725 Torr?

Answer 1

you first need to convert the values of the information you've been given into appropriate measurements. i.e) mL to L , *C to K (25+273), and Torr into atm (Torr is equal to mmHg, 760mmHg is equal to 1.0atm), and then use the ideal gas equation and solve for n (no. of moles) you can chose to leave it in moles or convert to grams depending on what the question asks for.

ideal gas equation: PV = nRT (R=0.0821)