Ch.3 - Mass Relationships in Chemical Reactions
Back
Problem 124a
(a) Polychlorinated biphenyls (PCBs) were compounds used as coolants in transformers and capacitors, but their production was banned by the U.S. Congress in 1979 because they are highly toxic and persist in the environment. When 1.0 g of a PCB containing carbon, hydrogen, and chlorine was subjected to combustion analysis, 1.617 g of CO2. and 0.138 g of H2O were produced. What is the empirical formula?
Problem 124b
(b) If the molecular weight is 326.26, what is the molecular formula?
Problem 124c
(c) Can combustion analysis be used to determine the empirical formula of a compound containing carbon, hydrogen, oxygen, and chlorine?
- The symbol CO stands for carbon monoxide, but the sym-bol Co stands for the element cobalt. Explain.
Problem 136
- Correct the error in each of the following statements: (a) The formula of ammonia is NH3 (b) Molecules of potassium chloride have the formula KCl. (c) Cl-is a cation. (d) CH4 is a polyatomic ion
Problem 137
- When solid mercury(I) carbonate, Hg2CO3, is added to nitric acid, HNO3, a reaction occurs to give mercury(II) nitrate, Hg1NO322, water, and two gases A and B: Hg2CO31s2 + HNO31aq2¡ Hg1NO3221aq2 + H2O1l 2 + A1g2 + B1g2 (e) Write a balanced equation for the reaction of mercury(I) carbonate with nitric acid.
Problem 138
- The structural formula of isopropyl alcohol, better known as 'rubbing alcohol,' is shown. What is the chemical for-mula of isopropyl alcohol?
Problem 140
- A mixture of CuO and Cu2O with a mass of 10.50 g is reduced to give 8.66 g of pure Cu metal. What are the amounts in grams of CuO and Cu2O in the original mixture?
Problem 142
- Write formulas for the following binary compounds: (a) Potassium chloride (b) Tin(II) bromide (c) Calcium oxide (d) Barium chloride (e) Aluminum hydride
Problem 148
- Write formulas for compounds of calcium with each of the following: a) Chlorine b) Oxygen c) Sulfur
Problem 156
- Write formulas for compounds of rubidium with each of the following: (a) Bromine (b) Nitrogen (c) Selenium
Problem 157
- Give the formulas and charges of the following ions: (a) Sulfite ion (b) Phosphate ion (c) Zirconium(IV) ion (d) Chromate ion (e) Acetate ion (f) Thiosulfate ion
Problem 158
- Name the following binary molecular compounds: (a) CCl4 (b) ClO2 (c) N2O (d) N2O3
Problem 160
- Give systematic names for the following compounds: (a) NCl3 (b) P4O6 (c) S2F2
Problem 161
- Name the following binary compounds of nitrogen and oxygen: (a) NO (b) N2O (c) NO2 (d) N2O4 (e) N2O5
Problem 162
- Name the following binary compounds of sulfur and oxygen: (a) SO (b) S2O2 (c) S5O (d) S7O2 (e) SO3
Problem 163
- Fill in the missing information to give formulas for the fol-lowing compounds: (a) Na?SO4 (b) Ba?(PO4)? (c) Ga?(SO4)?
Problem 164
- Write formulas for each of the following compounds: (a) Sodium peroxide (b) Aluminum bromide (c) Chromium(III) sulfate
Problem 165
- The mass percent of an element in a compound is the mass of the element (total mass of the element's atoms in the com-pound) divided by the mass of the compound (total mass of all atoms in the compound) times 100%. What is the mass per-cent of each element in acetaminophen? (See Problem 2.170.)
Problem 171