Question

QUESTIONS (Show work for all problems involving calculations.) 1. Write the hydrate formula properly if the hydrate contains per molecule: a. One caicium, one sulfur, six oxygen and four hydrogen atoms RANO ItSwteR ప 2 H2U Cas Oq 2H2D b. One nickel, two nitrogen, twelve oxygen and twelve hydrogen atoms NINaaHo 2. Calculate the theoretical percent of water in: MASS Compoiena XIDO a. Na,co, 10H,0 Nazxa489 TOTNL WAleR 0880000-63.0% MASS WATER b. CoCl-6H,O Cor5845=S8.9 CIas35.4 70.89 HaO= 6x 18.0g-106.1g molAR WAIER TO TAL 37.7 10-45.49% 1 Atey t MASS 3. If, unknown to you, the hydrate decomposed while you were heating it. Which of the following would calculate higher and which lower than the true value. Explain. a. the weight of water in the hydrate ha werght of Water In the hydeate would ae duleR due to UARORARndueng heatng b. the weight of anhydrous salt The weght of anlydaus salt would behigar ho whter tu evA poRAe

Answer 1

1 Salphurs Hydrogen means genois 12 oxygen -o means 6 molecules of the ca 1 Calcium - Ca 7 4 Hate o two molecules of water (H₂O) ь охоп-0 ( Both Т. Two molecules of Ho (2nds) 4 Hydrogen I contain 20. > So Remaining oxygen ons * So it may be so 4. : Formula is casou 2H20 (gypsum (6) 1 Nickel-Ni Zot contains 12 Hydrogen 2 Nitrogen- means 6 molecules of tho. -H 7 6 molecules of the means 12 Hydrogen "I & oxygen atom. * Remaining oxygen are also 6 (Total=12) Ser Two nitrogen (N) present so, it can from Nom with oxygen. Canoan? - 60s * So Formula is Ni (103) •6tho? (2) Nazca. 10 H2O Molar mass = (2x 23) + 12+(3x1674 10 (2x1 + 16) 7 g/mol - (46 +12+48 + 180 g/mol = 286g/mol. molar mass of Howater) = (2x1 + 1810= 1899/mol = 180g/mol mas pexce macope of o = 180 |mol = 6-294 62.9% 2869/mol X100

water (b) Coche 6tho. Molar mals = 59+ @x35.5) 7 6 (2x1 +16). (Co) es (1) O : 59+71 +(68182 238.09Imol molar mass of 6 HO = 6x18 = 108 g/mol % of tho = logg/mol xion 238 g/mol = 45.4 % ② (a) The weight of water in hydrate would be lower as in the hydrate, the molecules are evaporating on heating and the hydrate loss its weight. ( Removal of Ho means decrease (the 18g/mol of mass). (b) the weight of water anhydrous salt semain constant because it has no water molecules to loss on heating. & Calcium Carbonate = CaCO3 molar maes of Caloz = (40+12+3 416) ghnol e loog/mol Afornic mals of Ca = 40gmol. Since 200g of caloz contains 40g. of ca (calium) or tog of Ca is contained by rog. of calo lg. of ca is contained by 100 of calor Art of ca is contained by 100/40 x 45g of calls

( = 1000 x 45 g. of Caloz = 112.5g. of call So, 112.5. of Call contain usg. of calcium. Impure Sulfide are contain 18. sog. of Rb Leader as Lead sulfide (Pbs). Molar mals of pbs (207 +32 ganol Atomic maos of Lead p2399lmal Pb) = 207 g/mol 207 g/mol of Lead (Pb)" contained by 239 g/mol of pbs 19 of Pb will contained by 239 g. of PbS. 18.59. of Pb will contained by 239 x 8.50 mais of Pbs is 21.35 which is contained by = 21.359. of pbs. the impuse sulfide ore. So, % of Leadsulfide - 24 mals of pbs -X100 in are(sample mass of ore 2. - 21-354._4.00 1599 = 13.78 %