What is the theoretical yield of Fe? Report your answer in grams, to three significant figures.
Fe2O3 (g) + 2AI(s) rightarrow AI2O3(s) + 2Fe(s) g Write a balanced net ionic equation for
the reaction between lead nitrate and sodium sulfate, in solution.. What is the molarity of a 1.30
L solution containing 6.00 g of NaCN? Report you to the correct number of significant figures.
M How many milliliters of 0.480 M NaOH would be required to titrate a 5.00 mL of 0.320
MH2SO4? Report your answer to the correct number of significant figures. mL. Write a
balanced chemical equation for the combustion of octane, C8H18. If the standard enthalpy of
formation (Delta Hf) of methanol,CH3OH, is - 238.6 kJ delta = - 394 kJ/mol, and Delta H
(H2O ) = 286 kJ/mol, calculate the combustion of methanol. Report your answer to the correct
number of significant. kJ/mol
Solution
1) 1 mole of Fe2O3 gives 2 moles of Fe
so
20/160 moles will give = 40/160 = 1/4 = .25 moles of Fe
so we get
56*.25 gm of Fe = 14 gm of Fe
2)Na2SO4 + Pb(NO3)2 ----> 2NaNO3 + PbSO4
3) 6 gm NaCN = 6/(49) moles of NaCN = .122 moles of NaCN
so Molarity = .122/1.3 = .0941 M
4)Let V volume be required so we get
V*0.48 = 2*5*.32
on solving we get
V = 6.67 mL
5) 2C8H18 + 25O2 ---> 16CO2 + 18H2O