chem lab 1211
Determine the formal charge of C in CH3-. a) +1 b) +4 c) 0 d) -1
-1
A 1.849g hydrated sample of barium chloride was heated, If 1.254g of sample remained after heating, how many moles of water were in the hydrated sample? a) 0.103 m b) 0.070 m c) 0.033 m d) not enough information
0.033 m
Convert 264 mm Hg to atm
0.35
Convert 75 cm Hg to atm
0.98
You should use a crucible tong when handling the evaporating dish instead of your hand, because a) the crucible is hot even if it does not appear to be b) the oils on your fingers can affect the mass values collected in this lab experiment c) the crucible tongs must always be used when handling crucibles d) #1 and #2 must always be followed when handling crucibles.
#1 and #2 must always be followed when handling crucibles
What charge will potassium have when it forms an ion? a) 18 b) -1 c) +1 d) +2
+1
A student removed his hot metal from the hot boiling water and places it into the calorimeter containing 25.250g of water. The initial temperature of the water was 8.3C and the final temperature of the solution was 28.4C. Calculate how much heat did the water absorb from the hot metal? a) 750 J b) -1067 J c) -2123 J d) not enough info is given
- 2123 J
A student generates two trendlines of y = -92257x + 10081 and y =-106240x + 12015 from her data. What is her calculated rydbergs constant? a) -106,240 b) -92,257 c) 106,240 d) 92,257
106,240
Calculate the theoretical yield of alum if a student was to react 0.25 moles of aluminum with 0.27 moles of KOH and 0.56moles of H2SO4 a) 132.72 grams b) 127.98 grams c) 59.25 grams d) 118.5 grams
118.5 grams
Calculate the corrected volume of hydrogen gas when the volume at 15mL has a pressure of 2.4 atm. The slope of the line = y = -0.457x + 1285 a) 36.457 b) 15.457 c) 17.857 d) 14.543
15.457
For the synthesis of alum a student reacts 12.14g of aluminum with 15 mL of 2.5M KOH and 10mL of 8.6M H2SO4. Calculate the theoretical yield of alum? a) 212.97 g b) 13.04 g c) 17.79 g d) 8.89 g
17.79 g
How many electrons will calcium have when it forms an ion? a) 18 b) 20 c) 22 d) 42
18
How many electrons will phosphorus have when it forms an ion? a) 15 b) 18 c) 12 d) 34
18
Calculate the molar mass of magnesium sulfate tetrahydrate: a) 312.76 g/mol b) 120.38 g/mol c) 156.38 g/mol d) 192.38 g/mol
192.38 g/mol
Which of the following compound(s) is polar? 1) NH4 2) H2O 3) AlF3 4) CO32- 5) SO2 a) 4 and 5 b) 2 and 4 c) 2, 4, and 5 d) 2 and 5
2 and 5
What charge will barium have when it forms an ion? a) 2- b) 2+ c) 4+ d) 56+
2+
A student generated a 79.43% yield of alum. If the student collected 19.67g of alum, calculate the theoretical yield of alum. a) 40.43g b) not enough information is given c) 15.62g d) 24.76g
24.76g
Determine the number of sigma and pi bonds in AlF3. a) 2 sigma and 2 pi b) 3 sigma bonds c) 3 sigma and 1 pi d) 2 sigma and 1 pi bond
3 sigma bonds
Convert 315 nm to cm
3.15x10^-5
A 2L container at 25C contains oxygen gas at a pressure of 1.65 atm. What is the volume, if the pressure is changed to 0.975 atm? a) 5.44 b) 1.18 c) 0.74 d) 3.38
3.38
Determine the number of sigma and pi bonds represented in the best Lewis structure for SO42-. a) 6 sigma bonds b) 4 sigma and 1 pi bond c) 4 sigma and 2 pi bonds d) 4 sigma bonds
4 sigma and 2 pi bonds
Convert 225 nm to cm-1
4.44x10^4
A 1.26L container at 25C contains oxygen gas at a pressure of 3.65 atm. What is the volume, if the pressure is changed to 0.975 atm? a) 5.44 b) 0.34 c) 3.42 d) 4.72
4.72
Convert 495 nm to cm
4.95x10^-5
Calculate the molar mass of iron (3) nitrate nonahydrate: a) 279.86 g/mol b) 515.55 g/mol c) 403.88 g/mol d) 259.88 g/mol
403.88 g/mol
For the synthesis of alum a student reacts 12.14g of aluminum with 15 mL of 2.5M KOH and 10mL of 8.6M H2SO4. A student collected 7.59g of crystals. Calculate the percent yield of alum. a) 3.56% b) 7.14% c) 42.67% d) 85.34%
42.67%
Determine the molar mass of alum that will be synthesized in experiment # 6. a) 258.205 g/mol b) 351.08 g/mol c) 474.205 g/mol d) 294.205 g/mol
474.205 g/mol
Estimate the atomic mass of an unknown metal. (c = 0.500 J/gC) a) not enough information is given b) 26 g c) 13 g d) 52 g
52 g
Using your periodic table, determine the element and the atomic mass of an unknown metal. (c = 0.441 J/gC) a) 58.97 g and Co b) 58.97 g and Ni c) 11.47 g and B d) not enough information is given
58.97 g and Co
A 1.849g hydrated sample of barium chloride was heated, If 1.254g of sample remained after heating, how many moles of salt were in the hydrated sample? a) 2.85x10^-3 m b) 7.26x10^-3 m c) 8.88x10^-3 m d) 6.022x10^-3 m
6.022 x10^-3 m
A student removed his hot metal from the hot boiling water and places it into the calorimeter containing 15.250g of water. The initial temperature of the water was 18.3C and the final temperature of the solution was 28.4C. Calculate how much heat did the water absorb from the hot metal? a) 255 J b) -750 J c) 644 J d) -1067 J
644 J
Helium gas is placed in a container. The p*v value at 128 mL is 954. What is the volume of the helium gas in the container? a) 4.1 b) 5.5 c) 1.28 d) 7.45
7.45
If a hydrated sample of copper (I) chloride has a mass of 2.016g, what is the percentage of salt in the sample if it was found to contain 0.378g fo water? a) not enough information given b) 83.48% c) 18.75% d) 81.25%
81.25%
Helium gas is placed in a container. The p*v value at 12 mL is 1067. What is the pressure of the helium gas in the container? a) 9.79 b) 88.92 c) 66.7 d) 97.9
88.92
Determine the formula for the insoluble salt formed for the reaction between sodium carbonate and barium chloride. a) NaCl b) Ba2CO3 c) BaCl2 d) BaCO3
BaCO3
Write the equation for the electron affinity of bromine: a) Br(g) --- Br- + e- b) Br(g) + e- --- Br-(g) c) 2Br- ---- Br2 + 2e- d) Br2 + 2e- ---- 2Br-
Br(g) + e- --- Br-(g)
Determine the central atom in HCN. a) carbon b) hydrogen c) nitrogen d) not enough info is given
Carbon
Write the reaction that occurs when iodide ion is placed in a solution containing chlorine in methylene chloride. a) Cl2 + 2l- --- no reaction b) 2Cl- + l2 --- no reaction c) 2Cl- + l2 --- Cl2 + 2I d) Cl2 + 2I- --- 2Cl- + l2
Cl2 + 2I- --- 2Cl- + l2
What product(s) is formed when calcium nitrate is reacted with ammonium oxalate? a) CaC2O4 and AmNO3 b) CaC2O4 and NH4NO3 c) CaO2O4 and NH3NO3 d)CaO2 and NH3NO3
CaC2O4 and NH4NO3
In step #1 of experiment 5 a reaction occurs between copper and nitric acid. Write the balanced equation for this reaction.
Cu + 4HNO3 --- 2NO2 + 2H2O + Cu(NO3)2
Write the balanced reaction for the decomposition of copper (II) hydroxide
Cu(OH)2 --- CuO + H2O
All of the following are chemical properties except: a) combustion b) rust c) corrosion d) ductility
Ductility
A student generates a trendline of y = -92257x + 23064 from her graph. Determine the series of the gas. a) paschen b) balmer c) lyman d) brackett
balmer
For the synthesis fo alum, a student reacts 4.325g of aluminum with 13mL of 4.5M KOH and 11mL of 8.6M H2SO4. What is the limiting reagent? a) aluminum b) H2SO4 c) KOH d) not enough information is given
H2SO4
For the synthesis of alum, a student reacts 8.75g of aluminum with 17mL of 4.5M KOH and 15 mL of 8.4M H2SO4. What is the limiting reagent? a) aluminum b) KOH c) H2SO4 d) not enough information is given
H2SO4
In experiment #7, during the analysis of the unknowns it can be concluded that unknown 303 is (chart): a)H2SO4 b) Na2S c) AgNO3 d) MnCl2
H2SO4
Write the balanced chemical reaction between sulfuric acid and sodium hydroxide
H2SO4 + 2NaOH --- Na2SO4 + 2H2O
Which of the following is NOT a strong acid? a) HF and H3PO4 b) HI and HNO3 c) HF and HCl d) HI
HF and H3PO4
In step #1 of experiment 5 a reaction occurs between copper and nitric acid. What is reduced in the equation? a) NO2 b) Cu+2 c) HNO3 d) copper
HNO3
Determine the molecular geometry for SO2. a) trigonal pyramidal b) tetrahedral c) bent d) linear
bent
Which element has the least electron affinity? a)N b)O c)P d)Si
N
Which element has the least electron affinity? a)N b)P c)F d)Br
N
Determine the spectator ion(s) in the chemical reaction between Ag (I) nitrate and sodium chloride. a) Na+ and NO3- b) NO3-, Ag+, and Cl- c) Ag+ and Cl- d) Na+, Ag+, NO3-
Na+ and NO3-
Which of the following salts are soluble in water? a) Na2SO4 and KCH3CO2 b) Na2CO3 and CaSO4 c) NaI and BaSO4 d) BaCl2 and AgCl
Na2SO4 and KCH3CO2
In part B of experiment 10, you will need to prepare a Cl2 in methylene chloride solution. How would you make it? a) chlorine and methylene chloride b) chlorine liquid, methylene chloride and water c) NaClO, methylene chloride and water d) NaClO, methylene chloride and hydrochloric acid
NaClO, methylene chloride and hydrochloric acid
What chemical method will be used in experiment #2? a) precipitation b) distillation c) filtration d) neutralization
Neutralization
Determine the electron domain geometry for XeF4. a) T-shaped b) octahedral c) tetrahedral d) square planar
Octahedral
To determine the dead volume you will plot a graph showing _________ on the y axis vs __________ on the x axis a) p vs 1/v b) P*V vs p c) P vs p*v d)p*v vs v
P*V vs p
Write the chemical name for the compound SeO2 a) silicon oxide b) selenium oxide c) sulfur dioxide d) selenium dioxide
Selenium dioxide
What product(s) is formed when strontium nitrate is reacted with ammonium oxalate? a) SrC2O4 and AmNO3 b) SrC2O4 and NH4NO3 c) SrO2 and NH3NO3 d) StO2O4 and NH3NO3
SrC2O4 and NH4NO3
Determine the electron domain geometry for NH3. a) trigonal planar b) trigonal pyramidal c) bent d) tetrahedral
Tetrahedral
An aqueous solution of halide X- is mixed with a methylene chloride solution containing halogen Y2. The aqueous layer in the test tube turns a light yellow and the methylene chloride layer turned red. Which of the following is NOT true? a) Y- is formed b) X- has a lower electron affinity than Y c) Y has a higher electron affinity than X d) Y has a lower electron affinity than X
Y has a lower electron affinity than X
In experiment 8, when should you add the hot metal to the calorimeter? a) after the metal has been in the hot boiling water for 5 minutes b) when the temperature of the water is 100C c) when it looks hot d) when the temperature of the of the water in the cup starts to be recorded
after the metal has been in the hot boiling water for 5 minutes
In experiment #6. why does the last step of the procedures call for the reaction to be cooled? a)cooling decreases solubility bring out yellow alum crystals out of solution b) cooling decreases solubility bringing the white alum crystals out of solution c) reaction is cooled to make alum d) cooling increases solubility making more white alum crystals
cooling decreases solubility bringing the white alum crystals out of solution
In step #1 of experiment 5 a reaction occurs between copper and nitric acid. What is the reducing agent in the reaction? a) NO2 b) Cu+2 c) copper d) HNO3
copper
In step #5 of experiment 5, a reaction occurs between copper (II) sulfate and zinc. What is the oxidizing agent in the reaction? a) zinc b) copper (2) sulfate c) zinc (2) sulfate d) copper
copper (2) sulfate
using table # 1.1 from your lab manual, determine the student's unknown. from the information provided below: A CHEM 1211 student's unknown boils at 77C and is soluble in all solvents. The density of the unknown is 0.89g/mL. a) ethanol b) ethyl acetate c) n-heptane d) 1-propanol
ethyl acetate
When an electron moves from a lower energy level to a higher energy level, that state is called the: ____________ a) normal state b) excited state c) low state d) ground state
excited state
In step #3 of experiment 5, what observation is observed for the decomposition of copper (II) hydroxide? a) form a blue solution b) form a black solution c) the precipitate disappears d) precipitate turns blue
form a black solution
In experiment #7, what observation is observed for the chemical reaction between sulfuric acid and barium chloride? a) no reaction b) formation of bubbles c) formation of a brown precipitate d) formation of a white precipitate
formation of a white precipitate
Which of the following is not a factor of a metathesis reaction? a) formation of a weak electrolyte b) formation of a gas c) formation of an electrolyte d) formation of a precipitate
formation of an electrolyte
In experiment #7, what observation is observed for the chemical reaction between unknowns 512 and 172 from your PowerPoint slides? a) no reaction b) formation of white precipitate c) formation of heat d) formation of clear solution
formation of clear solution
The first filtration technique you will use during experiment #6 is: a) vacuum filtration b) gravity filtration c) water filtration d) air filtration
gravity filtration
There should be no open flames in the lab because: a) nitrogen dioxide gas and hydrogen gas are produced at different steps b) nitrogen dioxide is produced c) hydrogen gas is produced d) no flames are needed in experiment 5
hydrogen gas is produced
In experiment #6, why should there be no open flames during this lab experiment? a) oxygen gas produced is flammable b) water gas produced is flammable c) hydrogen gas produced is flammable d) alum produced is flammable
hydrogen gas produced is flammable
The waste generated in lab #1 can be disposed of a) into a container marked recovered organics without halogens b) pour any remaining solvents back into the original bottle c) down the drain with plenty of water d) into a container marked recovered organics with halogens
into a container marked recovered organics without halogens.
An electron moves from an intial state of n =4 to an excited state of n = 1. What series would the electrons most likely be in? a) brackett b) lyman c) paschen d) balmer
lyman
In step #2 in experiment 5, two types of reactions occur, what are they? a) neutralization and reduction b) neutralization and metathesis c) oxidation and reduction d) metathesis and double displacement
neutralization and metathesis
An electron moves from an intial state of n = 6 to an excited state of n = 3 What series would the electrons most likely be in? a) lyman b) brackett c) balmer d) paschen
paschen
Your calculated rydberg's constant will be equivalent to: ___________ a) the slope of the graph b) the y intercept of the graph c) the true value of Rydberg's constant d) the -slope of the graph
the -slope of the graph
In lab #1, the boiling point of the liquid will be the temperature at which ____________. a) the bubbles stop emerging from the capillary tube b) the unknown liquid enters the capillary tube c) the bubbles start emerging from the capillary tube d) the highest temperature reading that is seen on the thermometer when the sample is boiling
the bubbles stop emerging from the capillary tube
Why are detergent solutions stored in plastic containers but not in containers made of aluminum? a) plastic is more readily available than aluminum b) plastic is cheaper than aluminum c) the detergent would be heavier in an aluminum container than plastic d) the detergent would react with aluminum
the detergent would react with the aluminum
In part A of experiment #2, how will the mass of the salt be affected if calcium carbonate is removed from the crucible while pouring off the salt solution? a) unaffected b) too high c) not enough information is given d) too low
too high
Hypothetically, if a sample pops when it is being dried with a cool flame; how will the popping affect the mass percent of the calcium carbonate in the crucible? a) not enough information is given b) too high c) too low d) unaffected
too low
in part A of experiment #2, how will the mass of the sand be affected if calcium carbonate is removed from the crucible while pouring off the salt solution? a) too high b) unaffected c) not enough information is given d) too low
unaffected
Is the density of 1L of oil equal to 50 mL of oil? a) Not enough information b) No, because density is an extensive property c) No, because the volume of 1L of oil is greater than 50 mL of oil d) Yes, because density is an intensive property
yes, because density is an intensive property
In step #5 in experiment 5, a reaction occurs between copper (2) sulfate and zinc. What substance is oxidized in the reaction? a) zinc b) copper c) copper (2) sulfate d) zinc (2) sulfate
zinc