Calcium metal and water produce hydrogen gas if the volume of gas collected overwater is 95.0 ML at 20°C and 758 mmHg?

hydrogen-gas
volume-of-gas

#1

calcium metal and water produce hydrogen gas if the volume of gas collected overwater is 95.0 ML at 20°C and 758 mmHg what is the volume of dry gas at stp conditions?

Answer:

Pressure x Volume = Number of moles x ideal gas constant x Temperature
( atm) (Liters) (mol) (Lxatm/molxK) (K)
Convert:
758mmHg x 1 atm /760mmHg=0.997atm
95mL x 1L /(10^-3) = 0.095 L
20Celsius +273=293K
Rearrange equation:
(PV)/(RT)=n =(0.997 atm x 0.095 L)/(0.0821(Lxatm/molxK) x293K)
number of moles =.004 moles