Zinc metal reacts with HCL similarly to magnesium: Zn(s) + 2HCL(aq) = ZnCl2(aq) + H2(g). the H2 gas produced was collected over water at 25 degrees Celsius and had a volume of 7.80L at 0.980 atm. How many grams of Zn were consumed in the reaction? (Vapor pressure of water at 25C = 23.8mmHg)

Question

Zinc metal reacts with HCL similarly to magnesium: Zn(s)  + 2HCL(aq) =  ZnCl2(aq)  +  H2(g). the H2 gas produced was collected over water at 25 degrees  Celsius and had a volume of 7.80L at 0.980 atm. How many grams of Zn were consumed in the reaction? (Vapor pressure of water at 25C = 23.8mmHg)

please show me how to get the answer

DrBob222 · Answer

Zn+ 2HCl ==> H2 + ZnCl2

Use PV = nRT and solve for n = number of mols H2.
Substitute [0.980 atm - (23.8/760)] for P.
Don't forget T must be in kelvin.

After you have obtained n, convert from mols H2 to mols Zn using the coefficients in the balanced equation. The g Zn = mols Zn x molar mass Zn.