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Table 1 Data Calculations Run 1 Weight of weighing trayL. s Run 2 Run 3 Av 2.15

ID: 635262 • Letter: T

Question

Table 1 Data Calculations Run 1 Weight of weighing trayL. s Run 2 Run 3 Av 2.15 2 n.61t Weight of sample plus weighing tray Weight of sample Mass of filter paper for CaC03 lo. St 0.I2 o.tiis Mass of CaCOs formed plus filitere 0.u42 0.u7 paper Mass of CaCO3 formed Molar Mass of CacO3 g/moi Moles of CaCO3 formed Mole Ratio of CaCO3 to Ca Moles of Ca Measured Molar Mass of Ca Measured Mass of Ca in Sample Measured % Ca in sample Theoretical Mass % of Ca in Cact2- Theoretical Mass % of Ca in CaCl2.2H20 Formula of Unknown % error

Explanation / Answer

Trial 1

Mass of CaCO3 formed = Mass of CaCO3 formed plus filter paper - mass of filter paper

= 0.4932 - 0.2152

= 0.278 g

Molar mass of CaCO3 = 40 + 12 + 3*16 = 100 g/mol

Moles of CaCO3 = mass/molar mass

= 0.278/100 = 0.00278 mol

Mol ratio of CaCO3 to Ca = 1 : 1

Moles of Ca measured = 0.00278 mol

Molar mass of Ca = 40 g/mol

Measured mass of Ca = moles x molecular weight

= 0.00278 mol x 40 g/mol

= 0.1112 g

% Ca in sample = 0.1112*100/0.4890 = 22.74 %

Theoretical mass% of Ca in CaCl2 = 40*100/110.98 = 36.04 %

Theoretical mass% of Ca in CaCl2.2H2O = 40*100/146.98

= 27.21%

Formula = CaCl2.2H2O

% error = (27.21 - 22.74)*100/27.21

= 16.42 %

Similarly all trials can be calculated