Question

(Q#1) Hydroxyapatite has the formula Ca₅(PO₄)₃(OH) and is the main mineral component of dental enamel and bone, and encourages bone growth when placed as bone graft. Hydroxyapatite is prepared from aqueous acid and dilute calcium hydroxide solution. If you mix 115 g of 80.2 % by mass phosphoric acid solution with 74.8 g of calcium hydroxide, what mass in g of hydroxypatite is formed assuming the reaction goes to completion?

(Q#2) Seratonin is a chemical neurotransmitter in the brain and has a molecular weight . Low Seratonin levels have been linked to depression in humans. Given that seratonin has a molar mass of about 180g/mol and contains 68.2% C, 6.86% H, 15,9% N, and O, determine the mols of 154.85 g of seratonin.

(Q#3)Zirconium Oxalate K₂Zr(C₂O₄)₃(H₂C₂O₄)^.H₂O can be synthesized from ZrOCl₂^.8H₂O, H₂C₂O₄^.2H₂O, and excess KOH. A sample in the lab was prepared from 1.443 g of ZrOCl₂^.8H₂O mixed with 5.266 g of H₂C₂O₄^.2H₂O, and excess KOH. After 2 months storage in the laboratory, 1.119 g of product was obtained, along with aqueous KCl, and water. Calculate the percent yield of the synthesis.

(Q#4)Narceine a narcotic opium that crystallizes from solution as a hydrate that contains 10.8 % by mass water and has a molar mass of 499.52 g/mol. Determine the number of hydrates (i.e. the x in narceine^.xH₂O) in a 229.5 g sample of Narceine.

(Q#5) Tuolene is an additive compound to raise octane ratings of fuel. A picture of tuolene is shown below. Suppose 14.35 mL of toluene (d=0.809 g/mL) is consumed when a sample of it burns in air. How many total mols of gaseous products form if the reaction goes to completion?

*Note there's 2 pictures with the LEWIS STRUCTURE of Tuolene and Line Structure of Tuolene

(Q#6) Hydrocarbon mixtures are used as fuels. How many grams of CO₂(g) are formed when a 365.4 g mixture of 54.9 % CH₄ and the rest C₃H₈ are burned in excess oxygen?

(Q#7)

Aspiring (C₉H₈O₄) is made by reacting salicylic acid (C₇H₆O₃) with acetic anhydride [(CH₃CO)₂O] according to the equation

In a laboratory experiment, a student mixed 2.68 g of salicylic acid with 7.74 mL of acetic anhydride ( density = 1.064 g/mL) and produced 3.16 g of aspirin. What is the percent yield of this reaction?  

(Q#8)A copper wire has a mass of 2.196g g and reacts with excess sulfur to form a new compound. The excess sulfur was then burned to yield SO₂gas. The mass of the copper sulfide produced was 2.748g. Calculate the mols in 302.07 g of the copper sulfide compound.

Answer 1