CHEM1311 | General Chemistry in Chemistry - Houston Community College

1. Determine the limiting reactant (LR) and the mass (in g) of nitrogen that can be formed from 50.0 g N2O4 and 45.0 g N2H4. Some possibly useful molar masses are as follows: N2O4 = 92.02 g/mol, N2H4= 32.05 g/mol.

N2O4(l)+ 2 N2H4(l) -> 3 N2(g)+ 4 H2O(g) A LR = N2H4,59.0 g N2 formed B LR = N2O4,105 g N2 formed C LR = N2O4, 45.7 g N2 formed D LR = N2H4, 13.3 g N2 formed Determine the theoretical yield of HCl if 60.0 g of BCl3 and 37.5 g of H2Oare reacted according to the following balanced reaction. A possibly useful molar mass is BCl3= 117.16 g/mol. BCl3(g) + 3 H2O(l) -> H3BO3(s) + 3 HCl(g) A 75.9 g HCl B 132 g HCl C 187 g HCl D 56.0 g HCl Determine the percent yield of a reaction that produces 28.65 g of Fe when 50.00 g of Fe2O3 react with excess Al according to the following reaction. Fe2O3(s)+ 2 Al(s) -> Al2O3(s)+ 2 Fe(s)

A 61.03%

B 28.65%

C 57.30%

D 81.93%

Determine the molarity of a solution formed by dissolving 4.00moles of KBr in enough water to yield 3.00 L of solution.

A 1.33 M

B 2.00 M

C .750 M

D 3.00 M

Determine the molarity of a solution formed by dissolving 97.7 g LiBr in enough water to yield 750.0 mL of solution.

A 1.50 M

B 1.18 M

C 0.130 M

D 0.768M

Choose the statement below which is TRUE, A a weak acid solution consists of mostly nonionized acid molecules B the term "strong electrolyte" means that the substance is extremely reactive C a strong acid solution consists of only partially ionized acid molecules D the term "weak electrolyte" means that the substance is inert Give the complete ionic equation for the reaction (if any) that occurs when aqueous solutions of lithium sulfide and copper(II) nitrate are mixed. A2 Li+(aq) + S2–(aq) + Cu2+(aq) + 2 NO3–(aq) ® Cu2+(aq) + S2–(aq)+ 2 Li+(aq) + 2 NO3–(aq) B 2 Li+(aq)+ S2–(aq) + Cu2+(aq) + 2 NO3–(aq) ® CuS(s) + 2 LiNO3(s) C 2 Li+(aq)+ S2–(aq) + Cu2+(aq) + 2 NO3–(aq) ® Cu2+(aq) + S2–(aq)+ 2 LiNO3(s) D 2 Li+(aq) + S2–(aq) + Cu2+(aq) + 2 NO3–(aq) ® CuS(s) + 2 Li+(aq)+ 2 NO3–(aq) Give the net ionic equation for the reaction (if any) that occurs when aqueous solutions of K2S and Fe(NO3)2 are mixed. A K+(aq) + NO3–(aq) -> KNO3(s) B Fe2+(aq) + S2–(aq) + 2 K+(aq) + 2 NO3–(aq) -> FeS(s) + 2 K+(aq) + 2 NO3–(aq) C Fe2+(aq) + S2–(aq) + 2 K+(aq)+ 2 NO3–(aq) -> Fe2+(aq) + S2–(aq) + 2KNO3(s) D Fe2+(aq) + S2–(aq) -> FeS(s) Define an Arrehenius acid A an electron pair donor B an electron pair receiver C produces H+ in aqueous solution D accepts H+ ions Identify the combustion reaction A 2 C3H7OH(l)+ 9 O2(g) -> 6 CO2(g) + 8 H2O(g) B 2 H2(g) + O2(g) -> 2 H2O(g) CC3H8(g) + 5 O2(g)-> 3 CO2(g) + 4 H2O D All of the reactions are examples of combustion reactions. Determine the oxidation state of P in PO33-

A+3

B+6

C+2

D0 What element is undergoing reduction (if any) in the following reaction? Zn(s) + 2 AgNO3(aq) -> Zn(NO3)2(aq)+ 2 Ag(s) A Zn

B N

C O

D Ag Identify the species reduced. 2 Al3+(aq) + 2 Fe(s) -> 2 Al(s) + 3 Fe2+(aq) A Al3+ B Fe C Al D Fe2+ What volume (in mL) of 0.0887 M MgCl2 solution is needed to make 275.0 mL of 0.0224 M MgCl2solution? A 72.3 ml B 91.8 ml C 10.9 ml D 69.4 ml Define pressure A force used to compress a gas B force applied to a gas to compress it C force exerted per unit area by gas particles as they strike the surfaces around them D force applied by a solid to the surrounding area An instrument used to measure atmospheric pressure is called a A barometer Bmanometer Csphygmomanometer Dspectrophotometer an instrument used to measure blood pressure is called a Abarometer Bmanometer Csphygmomanometer Dspectrophotometer The volume of a gas is proportional to the temperature of a gas is known as Aavagadro's law Bideal gas law Ccharles's law Dboyles's law The volume of a gas is proportional to number of moles of a gas is known as Aavogadro's law Bideal gas law Ccharles's law Dboyle's law The volume of a gas is inversely proportional to the pressure of a gas is known as Aavogadro's law Bideal gas law Ccharles's law Dboyle's law A child receives a helium balloon in a shopping mall. When he goes outside during a snowstorm, the balloon decreases in size. Which gas law is this an example of? Aavogadro's law Bideal gas law Ccharles's law Dboyles's law To what temperature must a balloon, initially at 25°C and 2.00 L, be heated in order to have a volume of 6.00 L?

A993 K

B403 K

C75K

D894 K

What pressure will 14.0 g of CO exert in a 3.5 L container at 75°C? A4.1 atm B5.0 atm C6.4 atm D1.1 atm What is the volume of 5.60 g of O2 at 7.78 atm and 415 K?

A1.53 L

B565 L

C24.5 L

D0.766 L

A 0.465 g sample of an unknown compound occupies 245 mL at 298 K and 1.22 atm. What is the molar mass of the unknown compound? A26.3 g/mol B33.9 g/mol C12.2 g/mol D38.0 g/mol The total pressure of a gas mixture is the sum of the partial pressure of its components is known as Aavogadro's law Bdalton's law Ccharles's law Dboyles's law Determine the theoretical yield and the percent yield if 21.8 g of K2CO3 is produced from reacting 27.9 g KO2 with 29.0 L of CO2 (at STP). The molar mass of KO2 = 71.10 g/mol and K2CO3 = 138.21 g/mol. 4 KO2(s) + 2 CO2(g) -> 2 K2CO3(s) + 3 O2(g) A 27.1 g, 80.4% yield B 179 g, 12.2% yield C 91.7 g, 23.8% yield D 206 g, 10.6% yield Which statement is TRUE about the kinetic molecular theory? Aa single particle does not move in a straight line Bthe size of the particle is large compared to the volume Cthe collisions of particles with one another is completely elastic Dthe average kinetic energy of a particle is not proportional to temperature The rate of effusion of two different gases is known as Aavogadro's law Bgraham's law Ccharles's law Dboyle's law Give the definition for diffusion Agas molecules mix equally Bgas molecules spread out in response to a concentration gradient Cgas molecules escape from a container into a vacuum through a small hole Daverage distance between collisions Define mean free path Aaverage distance that a molecule travels between collisions Bdiameter of a molecule Cdistance between molecules in a gas Dtime for effusion This equation is used to calculate the properties of a gas under nonideal conditions Acharles's law Bavogadro's law Cboyles's law D van der Waals equation