# Practice Exam IA

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1. To the correct number of significant figures, (5.0 x 10-5)÷(2.00 x 10-2) is
 2.50 x 104 2.5 x 10-7 2.5 x 10-4 2.5 x 10-3 2.50 x 10-3 none of these
2. The density of mercury is 13.6 g/mL. How many pounds does one quart of mercury weigh? (1 pound is 454 g, 4 quarts are 3.7854 liters.)
 (13.6 x 454 x 1000 x 3.7854)/4 (13.6 x 1000 x 3.7854)/(454 x 4) (13.6 x 3.7854)/(454 x 1000 x 4) (13.6 x 1000 x 4)/(454 x 3.7854) (13.6 x 454 x 3.7854)/(1000 x 4) none of these
3. The fuel tank of a Toyota Tercel holds 11.4 gallons of gasoline. What is the equivalent volume in cubic centimeters? (1 gallon is 3.7854 liters).
 (11.4 x 1000)/3.7854 (11.4 x 3.7854)/1000 11.4 x 3.7854 x 1000 11.4/(3.7854 x 1000) 11.4 x 3.7854 x 100 none of these
4. Which of the following measurements are equivalent?
 10 micrograms and 0.1 milligrams 10 nL and 1000 pL 40 km and 40000 cm 0.01 mm and 1 x 10-3 cm all of these none of these
5. A crime lab analyzes two samples of a drug, sample A and sample B. Sample A is crystalline. Several microscopic samples taken from different points in Sample A are indistinguishable; all properties of the material seem uniform. Sample B has a slightly different color than sample A. Chromatographic techniques resolve sample B into separate components. Which of the following conclusions are valid?
1. Sample A is a pure substance.
2. Sample B is a mixture.
3. Sample A is not a heterogeneous mixture.
 2 and 3 1 and 2 1 and 3 all are valid none are valid
6. Which of the following lists of elements contains an alkaline earth metal, a transition metal, and a halogen, respectively?
 Rb, Y, I Ba, Fe, Br Sr, Zr, Xe K, Ni, O none of these all of these
7. A beam of particles is passed between a positively charged and a negatively charged plate. The beam splits into three parts while passing between the plates. Beam A is slightly deflected towards the negatively charged plate; Beam B is strongly deflected towards the positively charged plate, and beam C is undeflected. Which of the following conclusions is correct?
1. Particles in beam A are positively charged.
2. B particles are more massive than A particles.
3. C particles are negatively charged.
 1 and 3 2 only 3 only 1 and 2 1 only 2 and 3
8. Rutherford's alpha particle scattering experiments showed that while most alpha particles fired at a metal foil sample passed straight through, about 1 in 104 were scattered backwards. Rutherford realized that this phenomenon could be accounted for by assuming that
alpha particles must be ricocheting off the electrons
all of the positive charge and most of the mass of the atom is concentrated in a tiny kernel
atoms were indestructible and reflected alpha particles
alpha particles were annhilating the metal atoms
Thomson's plum pudding model was valid
none of the above
9. Bromine has two common isotopes, 79Br and 81Br. Which is the following statements is true?
 81Br has two more electrons than 79Br. 81Br has two more protons than 79Br. 81Br has two more neutrons than 79Br. 79Br has 79 neutrons. 79Br has 35 electrons and 44 protons. none of these
10. The average atomic mass of Cl is 35.453. About 75% of all Cl atoms are 35Cl. If there is only one other common isotope, it is most likely to be
 36Cl 37Cl 38Cl 34Cl 35.453Cl none of these
11. Which of the following compounds are correctly named?
 Cu(HCO3)2, copper (II) bicarbonate Ba3(PO4)2, tribarium diphosphate AgNO3, argentum nitrate SrSO3, strontium sulfate FeCO3, iron (III) carbonate none of these
12. Cadmium (II) selenide can be used to prepare solutions which have almost any color in the spectrum. If the selenide ion is Se2-, the formula for this compound is
 CdSe2 Cd2Se CdSe Cd2Se2 Cd-II-Se none of these
13. Which of the following is the formula for hydrosulfuric acid?
 HS H2S H2SO2 H2SO3 H2SO4 HSO4
14. The following equation for the combustion of glucose is NOT balanced:
C6H12O6(s) + O2(g) = CO2(g) + H2O(l)
If the equation is balanced with smallest integer coefficients, the coefficient of O2(g) is
 18 9 6 12 15 none of these
15. Mixing which of the following will produce a precipitation reaction?
 none of these HNO3(aq) and Sr(OH)2(aq) NaOH and KBr Zn and HCl AgNO3 and NaClO4 Na2SO4(aq) and Ba(OH)2(aq)
16. Which of the following species are present in an aqueous acetic acid solution?
 H3O+(aq) HC2H3O2(aq) C2H3O2-(aq) all of these OH-(aq) H2O(l)
17. Which of the following is the net ionic equation for the reaction between hydrochloric acid and potassium hydroxide?
HCl(aq) + KOH(aq) = H2O(l) + KCl(aq)
K+(aq) + Cl-(aq) = KCl(aq)
K+(aq) + Cl-(aq) = KCl(s)
K+(aq) + Cl-(aq) + H+(aq) + OH-(aq) = H2O(l) + K+(aq) + Cl-(aq)
H3O+(aq) + OH-(aq) = 2 H2O(l)
HClO4(aq) + KOH(aq) = H2O(l) + KClO4(aq)
18. A well near the beach is suspected to be contaminated with chloride ions from sea water. If chloride is present, which of the following will produce a cloudy suspension when mixed with the water?
 LiBr NaNO3(aq) KC2H3O2(aq) AgNO3(aq) acetic acid none of these
19. Ammonium nitrate is used as a nitrogen fertilizer. What is the percentage of nitrogen by mass in ammonium nitrate? (The atomic weights of N, H, and O are 14.0, 1.0, and 16.0, respectively.)
 43.8% 35.4% 17.5% 42.9% 35.0% none of these
20. A compound of sulfur and oxygen is 40.1% sulfur by mass. What is the empirical formula for the compound? The atomic weights of S and O are 32.07 and 16.00, respectively.
 SO SO4 SO2 S2O3 SO3 none of these
21. The first step in an analysis of water for dissolved oxygen involves the reaction
4 Mn(OH)2(aq) + O2(aq) + 2 H2O(aq) = 4 Mn(OH)3(s)
.If treatment of 1.000 L of water from a creek with excess Mn(OH)2(aq) produces 0.103 g of Mn(OH)3, how many grams of O2(aq) does one liter of the water contain? The molecular weights of Mn(OH)2 and Mn(OH)3 are 88.94 and 105.94, respectively.
 (0.103 x 32)/(88.94 x 4) (0.103 x 105.94 x 32)/4 (0.103 x 4 x 32)/105.94 (0.103 x 16)/(105.94 x 4) (0.103 x 32)/(105.94 x 4) (0.103 x 16)/(88.94 x 4)
22. Sucrose (table sugar) has empirical formula CH2O and molecular weight 360. The atomic weights of C, H, and O are 12, 1, and 16, respectively. The molecular formula of sucrose is
 C6H12O6 C12H24O12 C360H720O360 CH2O C12H12O12 none of these
23. Oxygen gas is converted to ozone gas by exposure to intense ultraviolet light:
3 O2(g) = 2 O3(g)
If an ultraviolet source converts oxygen to ozone with a 4% yield, how many grams of oxygen are required to produce 1 gram of ozone? The atomic weight of O is 16.
 1.5 g 0.04 g 1 g 25 g 0.06 g none of these

General Chemistry Online! Practice Exam IA