posted by Yuli
A student generates H2(g) over water using the reaction between zinc and hydrochloric acid
Zn(s)+ 2HCl(aq)---> ZnCl2(aq)+ H2(g)
Mass of vial and zinc 15.5082
mass of vial 15.3972
mass of zinc 0.111
final burette reading 45.30mL
barometric pressure: Patm 100.6kPa
temperature of trapped gas 24.3C
vapour pressure of water at 24.3 C: PH2O 3.004kPa
diff in solution lvls inside and outside burette 162mm H2O
calculate the equivalent pressure of the column of water representing the difference between the solution levels inside and outside the burette (P level difference) after the reaction was complete ( in units of kPa).
Can someone please show me how to do questions like this?
The pressure difference is given by
delta P = density*g*height
g is the acceleration due to gravity (9.81 meters/s/s), density in g/cc, h is height in meters. This gives delta P in kPa. I calculate 1.587 kPa for the 162 mm but that is more significant figures than we are allowed.