Hey guys. Here is another practice test that I got from my old SI leader Grady. This is the KEY
Good Luck. -Matt
Practice Test KEYSupplemental Instruction
Iowa State University / Leader: / Grady
Course: / Chem 177
Instructor: / Appy
Date:
- You weigh a container and its mass is 64.3 grams. It is then filled with water and its new mass is 114.9 grams. What is the volume of the container?
- 51 mL
- 50.6 cm3
- 50.69 cm3
- 50 mL
- What is the molar mass of propanol?
- 44 g
- 46 amu
- 60 g
- 46 g
- 60 amu
- What is the sum of all the coefficients after the equation is balanced? _2__H3PO4 + _3__Mg(OH)2 _1__Mg3(PO4)2 + _6__H2O
- 11
- 12
- 13
- 14
- Which of the following acid’s name and formula is NOT correctly paired?
- HClHydrochloric acid
- H2SO4Persulfuric acid
- H2CO3Carbonic Acid
- HNO2Nitrous Acid
- H3PO4Phosphoric acid
- What is the chemical formula for the ionic compound form from the stable ion of Barium and Arsenic?
- BaAs3
- Ba2As3
- Ba3As2
- BaAs2
- BaAs
- Wine is a ______
- Pure substance
- Homogeneous mixture
- Heterogeneous mixture
- Compound
- Which of the following are chemical properties?
I. flammable
II. reacts with O2
III. melting point at 400 K
- I only
- I and II
- II and III
- I and III
- All of them are
- What is NOT a diatomic element?
- Nitrogen
- Chlorine
- Flourine
- Carbon
- Hydrogen
- Name a metalloid
Silicon
- Name all the alkaline earth metals
- How many moles of Oxygen are there in 5 moles of a Carbonate ion?
- 5
- 10
- 15
- 20
- 25
- You run a 5.0k race in 32 min, what speed were you going in miles/hour (1600 meters in a mile)
5.0 km | 60 min | 1000 m | 1 mile _ = 5.9 miles/hour
32 min | 1 hour | 1 km | 1600 m
- If 50. g of sulfur dioxide (mm=64.07) reacts with 25 grams of water (mm=18.02) to for sulfurous acid (mm=82.07). Sulfur Dioxide is the limiting reagent.
- What is the chemical equation?
SO2(s) + H2O (l) H2SO3 (aq)
- How many grams of sulfurous acid is produced?
50 g SO2 |1 mol SO2 | 1 mol H2SO3 | 82.07 g H2SO3 = 64 g
64.07 g SO2 |1 mole SO2 | 1 mol H2SO3
- If the volume of sulfurous acid is 40 cm3 what is the density?
1 g = 1 cm3
D=g/V=64 g / 40 mL = 1.6 g/mL
- In lab you produce 35.7 g sulfurous acid. What is the percent yield?
35.7 g / 64 g = 56%
- Fill in the table:
symbol / 19F1- / 32O / 52Cr2+
Protons / 9 / 16 / 24
Neutrons / 10 / 16 / 28
Electrons / 11 / 16 / 22
Charge / -1 / 0 / 2+
- Fill in the blanks in the table:
Compound name / Compound formula / Ionic, Covalent, Ion, Organic or acid?
Manganese(III) oxide / Mn2O3 / Ionic
diphosphorus pentoxide / P2O5 / Covalent
Pernitric acid / HNO / Acid
Acetate Ion / CH3COO- / Ion
Hydrosulfuric acid / H2S (aq) / Acid
Cyanide / CN- / Ion
Heptane / C7H16 / Organic
1)Which of the following is not a strong acid?
- HBr
- HI
- HClO4
- HF
2)When 250ml of 2.0M HCl is diluted to 1.00L, what is the concentration of the resulting solution?
- 1.0M
- 0.50M
- 4.0M
- 2.0M
3)Using the dilution from problem 2 how many moles of HCl are in the final solution?
- 2.0 mol
- 0.50mol
- 4.0mol
- 1.0mols
4)Which of the following would make the light very bright in the conductivity experiment done in lecture?
(i) HNO3(ii) NH4NO3(iii) HC2H3O2(iv) KOH
- i,ii
- i, ii, iii
- i, iii, iv
- i, ii, iv
5)What is the oxidation state of the sulfur atom in the SO42- ion?
- -2
- +3
- +6
- +8
6)Complete and balance the following reactions, also name the type of reactions they are
- 2HCl(aq) +Ca(OH)2 (aq) 2H2O(l)+CaCl2(aq)
- What type(s) of reaction is in part (a)?
Neutralization and double displacment
- Write the net ionic equation of the rxn from part (a)
H+ (aq) + OH- (aq) H2O (l)
- Iron(II) solid reacts with aqueous Nickel(II)Nitrate
Fe (s) + Ni(NO3)2 (aq) Ni (s) + Fe(NO3)2 (aq)
- What type(s) of reaction is in aprt (b)
Single displacement and REDOX
- Circle the oxidized atom and underline the reduced atom in the balanced equation you gave above in (d) Iron Oxidized Ni reduced
7)Use the following reaction to answer the following:
3Fe (s) + 4CO2 (g) Fe3O4 (s) + 4 CO (g) ΔH = + 23.5 kJ
- The reaction is
- Exothermic
- Endothermic
- Isoentropic
- Isothermal
- Not enough information
- To produce Fe3O4 do you need to add heat to the system or is heat given off?
Need to add heat
8)Write the Molecular, Complete Ionic, and Net Ionic equations for the reaction between aqueous Silver (I) Nitrate and Barium Bromide.
2AgNO3(aq)+BaBr2(aq) Ba(NO3)2(aq)+2AgBr(s)
2Ag+(Aq) + 2NO3-(aq)+Ba2+(aq) + 2Br-(aq) Ba2+(aq) + 2NO3-(aq) + 2AgBr(s)
2Ag+(Aq) + 2Br-(aq) 2AgBr(s)
- What are the spectator ions?
Barium and Nitrate
- If you have 100.0 mL of both solutions, and both solutions are .83 Molar, which is the limiting Reagent?
- What is the concentration of the Barium Ion left?
0.0415 moles left over .415 Molar
9)If you dissolve 7.00 g of chloric acid (mm=84.5 g/mol) in water and titrate it with 17mL of Ca(OH)2. What is the Molarity of the Calcium Hydroxide?
10)In Which molecule does Chromium have the lowest oxidation number?
- Cr2O33+
- Na2Cr2O7+6
- CrSO42+
- Cr(III) ion3+
11)4 C6H6OH (g) + 25 O2 (g) 24 CO2 (g) + 14 H2O (g)∆H= -455 kJ
- Is the reaction exothermic or endothermic?
Exothermic
- What is the change in enthalpy given off when 63.4 g C6H6OH is burned (mm = 95 g/mol )
12)If 100.0 mL or 0.500 M HBr and 50.00 mL of 1.00 M NH4OH are mixed in a calorimeter, the temperature goes from 19.0ºC to 301K. You can assume the specific heat and density of the solution to be the same as water. What is the enthalpy change of the reaction: HBr (aq) + NH4OH (aq) H2O (l) + NH4Br (aq)?
qsol = m cs ( Tf - Ti ) = (150. g) (4.184 J/gK) ((301K – 273K) – 19.0C) = 5650 J
qrxn = -qsol = - 5650 J = -5.65 kJ
.100 L HBr * .50 M HBr = .05 mol HBr
.00500 L NH4OH * 1.00 M NH4OH = .05 mol NH4OH
****No limiting reagent******
-5.65 kJ is for .05 mol HBr and NH4OH
∆Hrxn = -5.65 kJ / .05 mol = -113 kJ
13)5.00 grams of a new snack is burned in a bomb calorimeter (Ccal = 43.6 kJ/K). The temperature increases from 32.1 C to 39.6 C. There are 25.00 grams of the snack per serving. How many Calories are in one serving of the new snack?
14)Using the given information:
(C (s) + O2 (g) CO2(g)ΔH = -394 kJ) * 3
(C3H8 (g) + 5O2 (g) 4H2O (l) + 3CO2 (g) ΔH = -2220 kJ) * -1
(H2(g) + 1/2 O2(g) H2O (l) ΔH = -286 kJ) * 4
Find ΔH for the reaction:
3C (s) + 4H2(g) C3H8(g)ΔH = -52 kJ
( 3 ) ( -394 ) + ( -1 ) ( -2220 ) + ( 4 ) ( -286 ) = -1128 + 2220 + -1144 = -106 kJ
15)Calculate the ∆Hrxn for the following equation using the enthalpies of formation?
3 PbBr2 (s) + 4 H2O (l) Pb3O4 (s) + 6 HBr (g) + H2 (g)
∆Hfº (H2(g)) + 6 ∆Hfº (HBr(g)) + ∆Hfº (Pb3O4) – ∆Hfº (H2O (l)) – 3 ∆Hfº (PbBr2)
[(0) + (6) (-36.2) + (1) (-734.7)] – [(3) (-277.0) + (4) (-285.8)]=1022kJ
Molecule / ∆Hfº (kJ/mol)HBr (g) / -36.2
H2O (g) / 241.8
H2O (l) / -285.8
PbBr2 (s) / -277.0
Pb3O4 (s) / -734.7
16)Which subshell contains 3 orbitals?
- 4s
- 6f
- 3p
- 3d
- 4d
17) If your microwave radiates waves with a wavelength of 0.34 dm, what is the energy of those waves?
5.9 x 10-24 J
18)Which transition of an electron requires the most energy to take place?
- n=3 n=4
- n=6 n=2
- n=1 n=5
- n=4 n=1
19)What is the change in energy when an electron is added to the third energy level of an H+ ion?
20) What would the energy of one mole of photons be if the photons were in the visible light spectrum and were yellow?
- 200000 J
- 12000 J
- 3.9*10-16 J
- 3.4*10-19 J
21)How many unpaired electrons are in an atoms of Co in its ground state?
- 1
- 2
- 3
- 7
22)For which element is the ground state electron configuration: [Kr]5s14d5?
Mo
1)Rank the following in size smallest to largest:
S2-Cl-ArK+Ca2+
Ca2+K+ArCl-S2-
2)What is the least electronegative atom?
a)Fr
b)F
c)H
d)Rn
3)What trends INCREASE together?
- Size
- Electro negativity
- First Ionization Energy
a)I and III
b)I, II, and III
c)II, III
d)None of the above
4)Which is not true about metals?
a)They usually have high densities
b)They tend to lose electrons
c)They conduct electricity well but don’t conduct heat very well
d)They same electron affinities close to 0
5)What is the difference…
a)between ionic and covalent?
Change in electronegativity more than 2 is ionic (metal and nonmetal)
b)Between polar and nonpolar?
Both are covalent but non polar is a change in electronegativity less than .3
6)Sulfur has ____10___ core electrons and ____6___valence electrons. If it bonds with 4 Bromine it has_5___ electron domains. It’s molecular geometry is __sawhorse__ while its electron geometry is _triganol bipyramidal_with bond angles of ____~120 and ~90___.
7)Which are acceptable resonance structures of SiNO-?
a)Only I
b)Only II
c)I and III
d)I and II
e)I, II and III
8)Which of the above resonance structures is the BEST one for SiNO-?
The second one because the formal charge of -1 is on Oxygen the most electronegative atom
9)Draw a lewis diagram and the resonance structures for ozone. Assign all formal charges also.
a)What is molecular geometry?
bent
b)What is the bond angle and is it polar or non polar?
<120 and polar
c)What is the average bond order for Oxygen bonds?
1.5
10)Calculate the enthalpy for the reaction
H-N / 391N-N / 163
N=N / 418
N=N / 945
O-H / 463
O=O / 498
2N2H2 + O2 2H2O + N2
2(418) + 4(391) – 4(463) – 1(945)
∆H = -397 kJ
11)Which bond is polar covalent?
a)C-H
b)Li-Br
c)O=O
d)N-F
12)Draw the resonance structures for the following:
a)SO2
b)
13)Draw lewis structures for the following a) Li b) Ba2+ c) C d) Cl-