Need some help on #3 d,e,f and #4 Help help help !!! A 1.000 g sample of an unkn
ID: 478691 • Letter: N
Question
Need some help on #3 d,e,f and #4
Help help help !!! A 1.000 g sample of an unknown hydrate of cobalt chloride is ently dehydrated 0.546 g. The cobalt is isolated and weighs 0.248 g. What is the empirical work formula of the hydrate? Report each answer Show your to the proper number of significant figures. a. Determine the number of moles of water lost from the hydrated unknown. /.000 3 0, S469 454 454 0,0 2519 0, 03 mol b. Determine the number of moles of cobalt collected. 0.248 a of 0,00 4208 0,00 421 gol c. Determine the number of moles of chloride in the compound. 35.43 Now, determine the empirical formula of the compound by finding the smallest set of integers b, c) by the the umber of moles of each component (i a the smallest of the values. In this particular case, the number of moles of co should be the smallest. If decimal values are obtained, round each value at whole numbers.) d. What is the mole ratio of cobalt to chloride (set cobalt equal to 1)? 1 e. What is the mole ratio of cobalt to water lost (set cobalt equal to 1)? 1 Write these mole ratios (parts d and e) to write the empirically determined chemical formula of the cobalt chloride hydrate. It will have the form z H20, where x, y, and z are the integers that you determined. Empirical formula of the unknown cobalt chloride hydrate: In this experiment, you will determine the formula of a copper chloride. Copper usually exists as 1+ or 2+ charged ions. Give the two possible chemical formulas and the corresponding chemical names you expect for CurCl, where x andy are integers.
Explanation / Answer
3) Given: Intial mass of hydrate of Cobalt Chloride = 1.000 g
Mass of dehydrated Cobalt Chloride (CoCl2)= 0.546 g
Mass of hydrade in hydrate of Cobalt chloride = 1.000 g - 0.546 g = 0.454 g
Mass of isolated Cobalt (Co) = 0.248 g
Mass of Chloride in Cobalt Chloride = 0.546 g - 0.248 g = 0.298 g
Molecular weight of (CoCl2) = 129.84 g/mol
Molecular weight of (Co) = 58.94 g/mol
Molecular weight of (Cl) = 35.5 g/mol
Molecular weight of (H2O) = 18 g/mol
(b) Number of moles of Water lost from hydrate = mass of water lost from hydrate / Mol. Wt. of H2O
= 0.454 g / 18 g/mol =25.22 * 10-3 Moles
Number of moles of Water lost from hydrate = 25.22 * 10-3 Moles Answer 3(a)
(b) Number of moles of Cobalt collected = mass of Co/ Mol. Wt. of Co = 0.248 g / 58.94 g/mol =4.21 * 10-3 Moles
Number of moles of Cobalt collected = 4.21 * 10-3 Moles Answer 3(b)
(c) Number of moles of Chloride = mass of Cl/ Mol. Wt. of Cl = 0.298 g / 35.5 g/mol = 8.394 * 10-3 Moles
Number of moles of Chloride = 8.394 * 10-3 Moles Answer 3(c)
No of moles of Cobalt = no of moles of CoCl2 = No. of moles of Cl2 /2 = 4.21 * 10-3 Moles
No of hydrate in hydrate of CoCl2 = No of moles of water / No. of moles of CoCl2 = 25.22* 10-3 / 4.21 * 10-3
No of hydrate in hydrate of CoCl2 = 6
So formula for hydrate of cobalt chloride = CoCl2.6H2O
d) mole ratio of Cobalt to Chloride = no of moles of Cobalt : no moles of chloride = 4.21 * 10-3 : 8.394 * 10-3
= 4.21 * 10-3 / 4.21 * 10-3 : 8.394 * 10-3/ 4.21 * 10-3
d) mole ratio of Cobalt to Chloride = 1 : 2 Answer (d)
e) mole ratio of Cobalt to water lost = no of moles of Cobalt : no moles of water lost = 4.21 * 10-3 : 25.22 * 10-3
= 4.21 * 10-3 / 4.21 * 10-3 : 25.22 * 10-3/ 4.21 * 10-3
e) mole ratio of Cobalt to water lost = 1 : 6 Answer (e)
f) Emprical Formula for Cobalt chloride hydrate is CoCl2.6H2O Answer (f)
Related Questions
drjack9650@gmail.com
Navigate
Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.