Question

The thiocyanate polyatomic ion, SCN-, is commanly called a pseudohalogen because it acts very much like halide ions. For example, we know that pure halogens consists of diatiomic molecules, such as C12. Thiocanate ions form similar molecules in the following reaction2NaSCN +2H2SO4 + MnO2 -> (SCN)2 + 2H2O + MnSO4 + Na2SO4A) Write a conversion factor that could be used to convert between moles of NaSCN and moles of (SCN)2B) How many moles of (SCN)2 form when 0.05 moles of NaSCN react completely?C) What is the maximum number of moles of (SCN)2 that could form in the combination of 4 moles of NaSCN and 3 moles of MnSO4?D) Write a convertion factor that could be used to convert between moles of sulfuric acid, H2SO4 and moles manganese (II) sulfate, MnSO4.E) What is the minimum number of moles of H2SO4 that must react to form 1.7752 moles of manganese (II) sulfate?

Answer 1

Answer:

A) $\frac{1mol(SCN)_{2}}{2molNaSCN}$

B) 0.025 mol (SCN)₂

C) 2 mol (SCN)₂

D) $\frac{1molMnSO_{4}}{2molH_{2}SO_{4}}$

E) 3.5504 mol H₂SO₄

Explanation:

2NaSCN +2H₂SO₄ + MnO₂ → (SCN)₂ + 2H₂O + MnSO₄ + Na₂SO₄

A) A conversion factor could be $\frac{1mol(SCN)_{2}}{2molNaSCN}$ , as it has the units that we want to convert to in the numerator, and the units that we want to convert from in the denominator.

B) 0.05 mol NaSCN *  $\frac{1mol(SCN)_{2}}{2molNaSCN}$ = 0.025 mol (SCN)₂

C) With 4 moles of NaSCN and 3 moles of MnSO₄, the reactant is NaSCN so we use that value to calculate the moles of product formed:

4 mol NaSCN * $\frac{1mol(SCN)_{2}}{2molNaSCN}$ = 2 mol (SCN)₂

D) $\frac{1molMnSO_{4}}{2molH_{2}SO_{4}}$

E) 1.7752 mol MnSO₄ * $\frac{2molH_{2}SO_{4}}{1molMnSO_{4}}$ = 3.5504 mol H₂SO₄