A 1. 000g sample of unknown analyzed by Reaction 7-2 gave 2. 500g of Bi ( dimethylglyoximate ) Ni ( II ) . Find the wt % of Ni in the unknown. 7-8 ) The adult male in the VAT. Once upon a clip. a workingman at a dye mill fell into a VAT incorporating a hot concentrated mixture of sulphuric and azotic acids. and he dissolved! Because cipher witnessed the accident. it was necessary to turn out that he fell in so that the man’s married woman could roll up his insurance money. The adult male weighed 70kg. and a human organic structure contains about 6. 3 parts per 1000 P. The acid in the VAT was analyzed for P to see if it contained a dissolved homo. a ) The VAT had 8. 00 ten 10 rise to 3L of liquid. and 100. 0mL were analyzed. If the adult male did fall into the VAT. what is the expected measure of P in 100. 0mL? B ) The 100. 0mL sample was treated with a molybdate reagent that precipitates ammonium phosphomolybdate. ( NH4 ) 3 x 12H2O. This substance was dried at 110 degree C to take Waterss of hydration and heated to 400 degree C until it reached a changeless composing matching to the expression P2O5 x 24MoO3. which weighed 0. 3718g. When a fresh mixture of the same acids ( non from the VAT ) was treated in the same mode. 0. 0331g of P2O5 x 24MoO3 ( FM 3596. 46 ) was produced.Order now
This clean finding gives the sum of P in the starting reagents. The P2O5 x 24MoO3 that could hold come from the dissolved adult male is hence 0. 3718 – 0. 0331 = 0. 3387g. How much P was present in the 100. 0mL sample? Is this measure consistent with a dissolved adult male? 7-10 ) Finely ground mineral ( 0. 6324g ) was dissolved in 25mL of boiling 4M HCl and diluted with 175mL H2O incorporating two beads of methyl ruddy index. The solution was heated to 100 grade C. and 50mL of warm solution incorporating 2. 0g ( NH4 ) 2 C2O4 were easy added to precipitate CaC2O4. Then 6M NH3 was added until the index changed from ruddy to yellow. demoing that the liquid was impersonal or somewhat basic. After slow chilling for 1h. the liquid was decanted and the solid transferred to a filter crucible and washed with cold 0. 1wt % ( NH4 ) 2 C2O4 solution five times until no Cl negative anion was detected in the filtrate on add-on of AgNO3 solution. The melting pot was dried at 105 degree C for 1h and so at 500 degree plus minus 25 degree C in a furnace for 2h.
Ca positive 2 cation and below it there FM 40. 078. + C2O4 negative 2 anion Right Arrow and above it there 105 grade C. CaC2O4 x H2O ( s ) Right Arrow and above it there 500 grade C. CaCO3 ( s ) and below it there FM 100. 087. The mass of the empty melting pot was 18. 2311g and the mass of the crucible with CaCO3 ( s ) was 18. 5467g. a ) Find the wt % Ca in the mineral.
B ) Why is the unknown solution heated to boiling and the hasty solution. ( NH4 ) 2 C2O4. besides heated before easy blending the two? degree Celsiuss ) What is the intent of rinsing the precipitate with 0. 1wt % ( NH4 ) 2 C2O4? vitamin D ) What is the intent of proving the filtrate with AgNO3 solution? 7-12 ) Combustion of 8. 732mg of an unknown organic compound gave 16. 432mg of CO2 and 2. 840mg of H2O. a ) Find the wt % of C and H in the substance.
B ) Find the smallest sensible whole number mole ratio of C: H in the compound. 7-16 ) A mixture of Al2O3 ( s ) and CuO ( s ) weighing 18. 371mg was heated under H2 ( g ) in a thermohydrometric experiment. On making a temperature of 1000 grade C. the mass was 17. 462mg and the concluding merchandises were Al2O3 ( s ) . Cu ( s ) . and H2O ( g ) . Find the weight per centum of Al2O3 in the original solid mixture. Skoog: 5-7. 8. 11. 13. 17
5-7 ) Write an equation demoing how the mass of the substance on the left can be converted to the mass of the substance on the right. Sought:
a ) SO3
B ) In
degree Celsius ) CuO
vitamin D ) Na2B4O2 x 10H2O
a ) BaSO4
B ) In2O3
degree Celsius ) Cu2 ( SCN ) 2
vitamin D ) B2O3
5-8 ) Treatment of a 0. 4000g sample of impure K chloride with an surplus of AgNO2 resulted in the formation of 0. 7332g of AgCl. Calculate the per centum of KCl in the sample. 5-11 ) A 0. 7406g sample of impure magnesite. MgCO3. was decomposed with HCl ; the liberated CO2 was collected on Ca oxide and found to weigh 0. 1881g. Calculate the per centum of Mg in the sample. 5-13 ) The quicksilver in a 0. 7152g sample was precipitated with an surplus of paraperiodic acid ; H5IO6: Chemical Equation:
5Hg positive 2 cation. + 2H5IO6. Right Arrow. Hg5 ( IO6 ) 2 + 10H positive cation 5-17 ) A 0. 6407g sample incorporating chloride and iodide ions gave a silver halide precipitate weighing 0. 4430g. This precipitate was so strongly heated in a watercourse of Cl2 gas to change over the Agl to AgCl ; on completion of this intervention. the precipitate weighed 0. 3181g. Calculate the per centum of chloride and iodide in the sample.