CHEM 1 final exam

A sample of helium gas initially at 37.0∘ C, 785 torr and 2.00 L was heated to 58.0∘ C while the volume expanded to 3.24 L. What is the final pressure in atm? 517 0.681 1.79 3.21 none of the above

0.681

A balloon originally had a volume of 0.439 L at 44∘ C and a pressure of 729 torr. To what temperature must the balloon be cooled to reduced its volume to 378 mL if the pressure remained constant? -0∘ C -38∘ C -95∘ C -272∘ C none of the above

0°C

How many moles of water are made from complete reaction of 1.4 moles of hydrogen gas? Given the reaction: 2H₂ + O₂ ⟶ 2H₂O -1.4 -0.7 -2.8 -2.1

1.4

What is the theoretical yield of aluminum oxide if 2.80 mol of aluminum metal is exposed to 2.40 mol of oxygen?

1.40 mol

How many core electrons are in a chlorine atom? 1 17 10 7 none of the above

10

What is the theoretical yield of waffles if you have 5 cups of flour, 9 eggs and 3 tbs of oil? Given: 2 cups flour + 3 eggs + 1 tbs⟶ 4 waffles -12 -10 -6 -4 -not enough info

10

What is the angle between electron groups in the tetrahedral geometry? 90∘ 109.5∘ 120∘ 180∘ not enough information

109.5°

Suppose two chemical reactions are linked together in a way that the O2 produced in the first reaction goes on to react completely with Mg to form MgO in the second reaction. Reaction one: 2KClO₃⟶ 3O₂ + 2KCl Reaction two: 2Mg + O₂ ⟶ 2MgO If you start with 4 moles of KClO₃, how many moles of MgO could eventually form? -4 moles -6 moles -12 moles -2 moles -none of the above

12 moles

How many grams of water are needed to react with 27.2 grams of Li₂O? Given: Li₂O + H₂O⟶ 2 LiOH -0.09120 -1.51 -16.4 -38.94 -none of the above

16.4

Which orbital would the electron of a ground state hydrogen atom occupy? 1s 2p 0s 1p none of the above

1s

If the electron configuration of a ground state sodium atom is 1s²2s²2p⁶3s¹, the electron configuration of the sodium cation (Na+) would be:

1s²2s²2p⁶

What is the electron configuration for Kr?

1s²2s²2p⁶3s²3p⁶4s²3d¹⁰4p₆

How many electrons can exist in an orbital? 1 2 3 4 none of the above

2

How many subshells are there in the n=2 principal shell? 1 2 3 4 not enough information

2

What is the equivalent pressure of 1520 torr in units of atm? 203,000 380 2.00 1520 none of the above

2.00

If the theoretical yield of the reaction below corresponds to 25.3 g and the percent yield of the reaction is known to be reproducibly by 81.1%, calculate the actual yield. Given: Li₂O + H₂O⟶ 2 LiOH -81.1g -20.5g -48.9g -45.8g -none of the above

20.5 g

What is the initial temperature of a gas if the volume changed from 1.00 L to 1.10 L and the final temperature was determined to be 255.0∘ C? 480∘ C -41∘ C 232∘ C 207∘ C none of the above

207°C

What is the volume of 28.0 g of nitrogen gas at STP? 33.6 L 11.2 L 22.4 L 44.8 L none of the above

22.4 L

What is the molecular weight of a gas if a 21.0 g sample has a pressure of 836 mm Hg at 25.0∘ C in a 2.00 L flask? (R= 0.0821 L*atm/ mol * K) 243 amu 1.89 amu 234 amu 11.1 amu none of the above

234 amu

How many valence electrons are in the nitrate ion? 18 22 23 24 26

24

Which set of conditions reflect STP? 298 K, 1 atm 25∘ C, 14.7 psi 373 K, 760 torr 273 K, 1 Pa 273 K, 760 mm Hg

273 K, 760 mm Hg

What is the temperature (∘ C) of 2.48 moles of gas stored in a 30.0 L container at 1559 mm Hg? (R= 0.0821 L* atm/ mol * K) 302 189 29 -84 none of the above

29

How many electrons are unpaired in the orbitals of nitrogen? 14 5 9 3 none of the above

3

A chemist wishes to perform the following reaction: N₂ + 3 H₂⟶ 2NH₃ If only 14.0 g of N₂ is available, what is the minimum amount, in grams, of H₂ needed to completely react with this quantity of N₂? -1.01g -6.06 g -3.03g -1.51g -none of the above

3.03 g

If the theoretical yield of a reaction is 42.0 grams of a product and the percent yield is 75%. How many grams were actually produced? -32 -5400 -56 -1.8

32

How many grams of NO₃ are theoretically produced if we start with 1.2 moles of S and 9.90 moles of HNO₃? Reaction: S + 6HNO₃ ⟶ H₂SO₄+ 6 NO₃+ 2 H₂O -331 -786 -455 -7.20

331

How many moles of hydrogen gas would be needed to react with excess carbon dioxide to produce 19.1 moles of water vapor?

38.2 mol

How many subshells are there in the n=4 principal shell? 1 2 3 4 not enough information

4

Water can be formed according to the equation: 2 H2 (g) + O2 (g)⟶ 2 H2O (g) If 8.0 L of hydrogen is reacted at STP, exactly how many liters of oxygen at STP would be needed to allow complete reaction? 4.0 L 2.0 L 1.0 L 8.0 L none of the above

4.0 L

The theoretical yield of a reaction is 75.0 grams of product and the actual yield is 42.0 g. What is the percent yield? -56.0 -31.5 -none of the above -178 -75.0

56.0

How many moles of methane are produced when 59.6 moles of carbon dioxide gas react with excess hydrogen gas?

59.6 mol

What is the equivalent pressure of 0.905 atm in units of mm Hg? 688 840 0.905 13.3 none of the above

688

How many valence electrons are in a chlorine atom? 1 17 10 7 none of the above

7

Hydrogen gas produced in the laboratory by the reaction of zinc and hydrochloric acid was collected over water at 25∘ C. The barometric pressure at the time was 742.5 mm Hg. What is the pressure of dry hydrogen gas if the vapor pressure of water at 25∘ C is 23.8 mm Hg? 742.5 mm Hg 718.7 mm Hg 766.3 mm Hg 760.0 mm Hg none of the above

718.7 mm Hg

If 16.0 grams of aluminum oxide were actually produced, what is the percent yield of the reaction below given that you start with 10.0 grams of Al and 19.0 grams of O2? Reaction: 4 Al +3O₂⟶ 2Al₂O₃ -not enough info -100% -75% -84.7% -39.6%

84.7%

How many grams of the excess reactant remain assuming the reaction goes to completion and that you start with 15.5 g of Na₂S and 12.1 g of CuSO₄? Reaction: Na₂S+ CuSO₄ ⟶ Na₂SO₄ + CuS -15.45 -0.05 -not enough info -5.92 -9.58

9.58

The Lewis model predicts that the formula for a compound between barium and sulfur is: BaS Ba₂S BaS₂ BaS₃ none of the above

BaS

Which compound will have the highest boiling point? CH4 CH3CH3 CH3C(O)CH3 CH3CH2OH not enough information

CH₃CH₂OH

Which molecule below has hydrogen bonding? CH4 HCl H2 CH3CH2OH

CH₃CH₂OH

Which compound listed below will dissolve in carbon tetrachloride, CCl4? NaCl CS2 NH3 all of the compounds none of the compounds

CS₂

Which substance listed below is a polar molecule? NH4+ Cl₂O SiCl₄ all of the compounds none of the compounds

Cl₂O

Consider the following electronegativity values: H=2.1, Cl=3.0, F=4.0 Which molecule below would you expect to have the more polar bond? H2 Cl2 F2 HCl HF

HF

Which molecule listed below has a nonpolar covalent bond? NaCl H2O H2 all of the compounds none of the compounds

H₂

Which substance below is an ionic solid? Cu (s) H2O (s) MgO (s) C6H12O6 (s) none of the above

MgO (s)

Which substance would be expected to have the highest boiling point? N2 O2 CO2 CO not enough information

N₂

Consider the Lewis structures for the compound SO3 and the polyatomic ions SO32- and SO42-. Which of these must exist as a set of resonance structures? SO3 only SO32- only SO42- only all of these show resonance none of these show resonance

SO₃ only

What is the element in which at least one electron is in the d-orbital? -Ar -K -Ca -Sc -none

Sc

Which statement below does NOT follow the Bohr Model? -When energy is absorbed by atoms, the electrons are promoted to higher-energy orbits -When an atom emits light, electrons fall from a higher orbit into a lower orbit -The energy emitted from a relaxing electron can have any wavelength -Electrons exist in specific, quantized orbits -none of the above

The energy emitted from a relaxing electron can have any wavelength

What do the alkali metals all have in common? -They all undergo similar reaction -They all have similar physical properties -They all form +1 ions -They all have the same number of valence electrons -All of the above

all of the above

Which of the following is considered a single electron group? a lone pair of electrons a single bond a double bond a triple bond All of the above

all of the above

Which molecule listed below is a nonpolar molecule? CCl4 CO2 BH3 all of the compounds none of the compounds

all of the compounds

Which molecule listed below is a polar molecule? NH3 H2O HCN all of the compounds none of the compounds

all of the compounds

Which statement is NOT true about "p" orbitals? A subshell contains three "p" orbitals These orbitals are shaped like dumbells A 3p orbital has a higher energy than a 2p orbital All three of these statements are true none of the above

all three of these statements are true

What is the third most abundant component of dry air? carbon dioxide oxygen nitrogen argon smog

argon

If we supply additional heat to a solid in equilibrium with its liquid at the melting point, the thermal energy added is used to: overcome the intermolecular forces that hold the solid together expand the solid change the liquid back to solid change solid to liquid raise the temperature of the solid above its melting point

change solid to liquid

Gaseous water vapor can frost the windows of a car on a cold morning. This process of a gas changing directly into a solid is known as: deposition melting condensation sublimation none of the above

deposition

Which intermolecular force increases with increasing molar mass? dispersion forces dipole-dipole forces hydrogen bonding X-forces none of the above

dispersion forces

Which intermolecular forces are found in CCl4? dispersion forces dipole-dipole forces hydrogen bonding X-forces none of the above

dispersion forces

A chemical bond is classified as a covalent bond if it involves the transfer of electrons True False

false

An orbital is a probability map showing exactly where an electron can be found in an atom True False

false

Bromine has 17 valence electrons True False

false

Gas particles lose energy every time they collide with each other or the container wall. True False

false

If the number of gas particles is tripled, the volume will be 1/3 of the original given that temperature and pressure do not change True False

false

If you had a five liter balloon of argon gas and a five liter balloon of xenon gas, and you removed 10 grams of gas from each balloon, the balloons would both shrink down to the same size True False

false

Liquids can be easily compressed. True False

false

One of the advantages of burning fossil fuels is that it produces O₂ for humans to breathe

false

Sublimation is the process of a liquid being converted directly to a gas True False

false

The VSEPR theory predicts that the H-C-H angle in CH4 measures 120∘ True False

false

The correct Lewis structure for CO2 shows that the carbon atom has two sets of lone pair electrons True False

false

The electron geometry of a molecule is never the same as the molecular geometry True False

false

The heat of fusion for water is significantly more than the heat of vaporization for water because fusion requires complete separation of one molecule from another. True False

false

The higher the principal quantum number, the lower the orbital energy. True False

false

The primary source for the rising carbon dioxide levels is respiration of the Earth's growing population

false

The subshells s,p,d, and f all have the same energy as long as they are in the same energy as long as they are in the principal shell. True False

false

Which state of matter has a low density and an indefinite volume? solids liquids gases both solids and liquids none of the above

gases

The electronegativity value for Mg is 1.2 and the value for O is 3.5. Based on these values, what type of bond is expected for a compound formed between Mg and O? ionic pure covalent polar covalent not enough information none of the above

ionic

When you make ice cubes: it is an endothermic process it is an exothermic process the heat of vaporization must be removed the process is referred to scientifically as sublimation none of the above

it is an exothermic process

What is the molecular geometry of carbon dioxide, CO2? bent linear tetrahedral trigonal pyramidal not enough information

linear

Which state of matter has a high density and an indefinite shape? solids liquids gases both solids and liquids none of the above

liquids

Suppose a balloon was released from the ground and rose to such a height that both the atmospheric pressure and atmospheric temperature decreased. Which statement is TRUE? -Both the temperature and pressure changes act to increase the balloon's volume -Both the temperature and pressure changes act to decrease the balloon's volume -The temperature change acts to increase the balloon's volume -The pressure changes acts to decrease the balloon's volume -none of the above

none of the above

The opposite process of freezing is: evaporation sublimation boiling condensation none of the above

none of the above

What problem could happen if deep sea divers used pure oxygen in their tanks? hypoxia oxygen toxicity nitrogen narcosis rapture of oxygen none of the above

oxygen toxicity

The principal quantum number (n): -specifies the 3-D shape of the orbital -specifies the principal quantum number of the orbital -specifies the maximum number of electrons -specifies the principal shell of the orbital -none of the above

specifies the principal shell of the orbital

All of the following statements are consistent with the kinetic molecular theory of gases EXCEPT: -The size of the gas molecules is negligible compared to the total volume of the gas -The average kinetic energy of the molecules of a gas is proportional to the temperature of the gas in kelvins -The gas molecules collide with each other and with the surfaces around them -Strong attractive forces hold the gas molecules together -none of the above

strong attractive forces hold the gas molecules together

What is the molecular geometry of CCl4? bent linear tetrahedral trigonal pyramidal not enough information

tetrahedral

The electron geometry and the molecular geometry of water are, respectively: trigonal planar, bent tetrahedral, tetrahedral tetrahedral, trigonal pyramidal tetrahedral, bent none of the above

tetrahedral, bent

The reason for many of the unique properties of water is: dispersion forces the ability to form hydrogen bonds high surface tension and low volatility moderate viscosity and expanding upon freezing none of the above

the ability to form hydrogen bonds

Which of the following items is a physical property? -the corrosive action of acid rain on granite -the odor of spearmint gum -the combustion of gasoline -the tarnishing of a copper statue none of the above

the odor of spearmint gum

All intermolecular forces are broken when a liquid vaporizes into a gas. True False

true

Before determining conversion factors, it is necessary to make sure the equation is properly balanced

true

Given the following generic equation, 2A +3B ⟶ A₂B₃ Δ Hrxn = +444 kJ, if you completely reacted 1 mole of compound A,the amount of heat absorbed would be 222 kJ.

true

If some argon gas at 400 mm Hg pressure is forced into a gas cylinder that already contained only neon gas at 400 mm Hg pressure, the total pressure in a cylinder would now be 800 mm Hg. True False

true

If the kelvin temperature of a gas is doubled, the volume is double provided that the pressure and the number of particles remains constant True False

true

Liquids that are viscous flow more slowly than liquids that are not viscous. True False

true

Since heat must be supplied to melt ice, the melting of ice is an endothermic process and so has a positive enthalpy value.

true

The elements will lose or gain electrons as needed to have an electron configuration that matches a noble gas. True False

true

When you have 4 electron groups, the electron geometry is tetrahedral True False

true

The change of a substance from a liquid to a gaseous form is called: dynamic equilibrium heat of fusion condensation vaporization volatile

vaporization

The measure of the resistance to the flow of a liquid is called: vapor pressure sublimation viscosity condensation none of the above

viscosity

Given the balanced equation CO₂+Si→SiO₂+C, if you were to react 1 mole of CO₂ with one mole of Si, which statement is true? -the CO₂ is the limiting reactant -you have equal stoichiometric amounts of reactants -the Si is the limiting reactant -The SiO₂ is the limiting reactant -none of the above

you have equal stoichiometric amounts of the reactants