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. What is the half-life of a first-order reaction if the rate constant is 6.2 × 10–3 s–1?     a.     8.9 × 10–3 s     b.     0.097 s     c.     5.77 s     d.     1.1 × 102 s     e.     1.6 × 102 s

Which of the following types of radiation will pass through a piece of paper, but will be stopped by 0.5 cm of lead?    

What is the electron configuration of Cr2+?        

Who worked out the process for obtaining aluminum from bauxite ore?     

For the second-order reaction below, the initial concentration of A is 1.34 M. If k = 7.61 × 10−4 M1s−1, what is the concentration of A after 18.3 minutes?     2A → B    rate = k[A]2      

 What volume of 0.2045 M NaOH is necessary to titrate 50.00 mL of 0.1177 M acetic acid?       

What is the coordination number of the central metal ion in [Cr(en)2(OH)2]NO3? (en = H2NCH2CH2NH2)   

“If a chemical system at equilibrium is disturbed by adding a gaseous species (reactant or product), the reaction will proceed in such a direction as to consume part of the added species” is a statement of    

Predict the signs of ΔS and ΔH for the evaporation of water at 295 K.  

 An ore is