Question

1) You weigh an empty gas buret, fill it to the 50.00 mL mark withdistilled water and weigh it again.
Experimental Data

Mass of empty gas buret 43.22 g
Mass of gas buret filled to 50 mL mark with water 96.89 g
Temperature of the water 28.7 °C
Density of water... @ 20.0 °C 0.9982 g/cc; D35 °C=0.9941 g/cc
Specific Gravity of Mercury... 13.55
Calculate:

a) Density of water at 28.7 °C (by interpolation) ______________g/cc
b) Volume of water filling buret to 50.00 mL mark ______________mL
c) Extra volume of water in addition to the 50.00 mL ______________mL
2) You are asked to make 128 mL of 1.199 M HCl starting with 9.0 MHCl.

d) The volume of 9.0 M HCl needed is (to 0.1 mL) ______________mL
3) You standardize the "1.199 M" HCl by pipetting a known amount ofit into a flask and titrating to the phenolphthalein endpoint withan NaOH solution of known concentration
Experimental Data:

Volume of "1.199 M" HCl used 4.06 mL
Concentration of NaOH used 0.1714 M
Initial buret reading 0.00 mL
Buret Reading at endpoint 28.69 mL
Calculate:

e) Exact molarity of your HCl ______________ M
4) You pipet a known amount of this standardized HCl into a 15 cmsample tube and float a "boat" containing your unknown.
You hook up the sample tube and contents to the gas buret.
You shake the tube to start the reaction.
When the metal unknown is completely dissolved, you read the gasburet and measure the height of the buret's meniscus above thewater level.
Experimental data:

Volume of standardized HCl used 4.04 mL
Weight of metal unknown used 34.9 mg
Gas buret reading after reaction is compete 26.62 mL
Height of meniscus above water level 11.9 cm
Atmospheric pressure 752.4 mmHg
Temperature of the water 23.3 °C
Calculate:

f) Vapor pressure of water at 23.3 °C
interpolate data at... http://genchem.rutgers.edu/vpwater.html______________ mmHg
g) Total volume of gas released ______________ mL
h) Partial pressure of hydrogen ______________ mmHg
i) Equivalent weight of metal
based on amount of hydrogen generated ______________ g/eq
5) The remaining solution in the 15 cm sample tube containing thereaction products and the unused HCl is quantitatively transferedto a flask and titrated to its endpoint with the standardNaOH.
Experimental data:

Initial volume of buret 0.16 mL
Final volume of buret 13.17 mL
Calculate:

j) Equivalent weight based on the amount of acid used up______________