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Conceptual
Math
Mystery!
100

What is the highest form of radiation? 

Gamma Ray

100

157N under goes alpha decay. What is the result? 

157N = 42He + 115B

100

True or false, the rate-limiting step in a reaction is the slowest step in the reaction sequence? 

True
200

Which order describes the kinetics of the decay of radioactive isotopes? 

1st order 

200

The reaction below is first order 

 2H2O2(l)= 2H2O (l)+O2(g)  A solution originally at 0.600 M H2O2 is found to be 0.075 M after 54 min. The half-life for this reaction is________ min.

1st order equation: ln[A]t= -kt + ln[A]0

18 minutes

200

What happens to the mass number and the atomic number of an element when it undergoes beta decay?

The mass number stays the same and the atomic number increases by one

300
For each type of radiation, what offers sufficient protection from the rays?

Alpha? Beta? Gamma?  Hint: look in lecture slides for Chapter 20



Alpha: Paper

Beta: Wood

Gamma: Concrete

300

The reaction 2NOBr (g) = 2 NO (g) + Br2(g) is a second-order reaction with a rate constant of 0.80 M-1 s-1 at 11°C. If the initial concentration of NOBr is 0.0440 M, the concentration of NOBr after 6.0 seconds is?

2nd order equation: 1/[A]t= kt + 1/[A]0

0.0363 M 
300

Which of the following expressions is the correct equilibrium-constant expression for the reaction below?

CO2(s)+H2O (l)H+(aq) + HCO3-(aq)

[H+] [HCO3-] 

We only include aqueous and gaseous in our expression

400
When do we use the Q expression and when do we use the K expression? 

Q is for when you don't know if you are at equilibrium, K is for when you know you are at equilibrium

400

The value of Keq for the equilibrium H2(g)+I2(g)= 2HI (g) is 794 at 25°C. What is the value of Keq for the equilibrium below?  

1/2 H2(g)+1/2 I2(g) = HI (g)

28


400

The equilibrium constant for the gas phase reaction N2(g)+3H2(g)2NH3(g)is Keq=4.34×10-3 at 300°C. At equilibrium do the reactants or products predominate? 

The reactants predominate

500

If Q > K, which way does the reaction need to move in order to reach equilibrium? 

It needs to move backward and create more reactants. 

500

Acetic acid is a weak acid that dissociates into the acetate ion and a proton in aqueous solution: HC2H3O2(aq) = C2H3O2-(aq)+ H+ (aq) At equilibrium, a 0.100 M solution of acetic acid has the following concentrations:[HC2H3O2]=0.0990 M,[C2H3O2-]=1.33×10-3M, and [H+]=1.33×10-3 M.The equilibrium constant, Keq,for the ionization of acetic acid is: 

1.79 x 10-5

500

What is my favorite color?

Green