Tutorial 3 (Due Monday September 16, 2002 by 12PM)                            CHEM 110

 

 

Name_______________________                                                     Score               /24

 

 

 

  1. Calculate the molar mass of each of the following:

(a)                Sr(OH)2

 

 

(b)               N2O

 

 

(c)                NaClO3

 

 

(d)               Cr2O3

 

 

 

  1. Calculate each of the following quantities:

(a)                Mass in kg of 3.8x1020 molecules of NO2

 

 

 

(b)               Moles of Cl atoms in 0.0425g of C2H4Cl2

 

 

 

(c)                Number of H- ions in 4.92g of SrH2

 

 

 

 

  1. Calculate each of the following:

(a)                Mass % of I in strontium periodate

 

 

 

(b)               Mass % of Mn in potassium permanganate

 

 

 

 

  1. One useful method for recycling scrap aluminum converts some of it to common alum [potassium aluminum sulfate dodecahydrate, KAl(SO4)2.12H2O], an important dye fixative and food preservative.

(a)                How many moles of potassium ions are in 352g of alum?

 

 

 

 

 

 

(b)               What is the mass % S in alum?

 

 

 

 

 

(c)                What is the maximum amount of alum (in metric tons) that can be prepared from 18.5 metric tons of scrap aluminum (1 metric ton = 1000kg)?

 

 

 

 

  1. Is MgCl2 an empirical or a molecular formula for magnesium chloride?  Explain.

 

 

 

 

 

  1. Acetaminophen (below) is one of the most popular nonaspirin, “over-the-counter” pain relievers.  What is the mass % of each element in acetaminophen?

 

            

 

 

 

 

 

 

 

 

 

 

  1. Write balanced equation for each of the following by inserting the correct coefficients in the blanks:

(a)                __Cu(NO3)2 (aq)  +  __KOH (aq)  ŕ __Cu(OH)2 (s)  +  ___KNO3(aq)

 

 

 

(b)               __BCl3 (g)   +  __H2O (l)  ŕ __H3BO3 (s)  +  ___HCl (g)

 

 

 

(c)                __CaSiO3(s)  +  __HF(g)  ŕ  ___SiF4(g)  +  ___CaF2(s)  + ___H2O(l)

 

 

 

(d)               __(CN)2(g)  +  __H2O(l)  ŕ  __H2C2O4(aq)  +  __NH3(g)

 

 

  1. Calculate each of the following quantities:

(a)                Volume of 18.0M sulfuric acid that must be added to water to prepare 2.00L of a 0.309M solution.

 

 

 

 

(b)               Molarity of the solution obtained by diluting 80.6mL of 0.225M ammonium chloride to 0.250L.

 

 

 

 

 

(c)                Volume of water added to 0.150L of 0.0262M sodium hydroxide to obtain a 0.0100M solution (assume the volumes are additive at these low concentrations).

 

 

 

 

 

(d)               Mass of calcium nitrate in each millimeter of a solution prepared by diluting 64.0mL of 0.745M calcium nitrate to a final volume of 0.100mL.