A reaction was shown to follow second-order kinetics. How much time is required for [A] to change from 0.500 M to 0.250 M? (k = 0.456 M⁻¹ s⁻¹)

The radioisotope ¹⁴C (half life = 5730 years) is used for carbon dating. What is the first order rate constant for ¹⁴C?

Match the slope of each line to the average, initial, or instantaneous reaction rate.

Considering the rate law, rate = k[A]²[B], which of the following statements is correct? A B C D E Add

Which species has the greatest rate of disappearance in the reaction below? CH₄ + 2 O₂ → CO₂ + 2 H₂O

Consider BrF5 molecule.  1) Use your own words, describe how chemical bonds are formed in Valence Bond Theory between Br and F atoms? 2) What’s the molecular geometry of the molecule (molecular geometry only)? Explain how you get your conclusion. Mark your answer next to words “Final answer is”.

Determine the enthalpy of reaction of the following equation using Hess’s Law.                           FeS2 +  5/2 O2      FeO  +  2 SO2 Given the following experimental data:  Fe + 2 S       FeS2   ∆H1 = -178.2 KJ/mol  ∆H2 = -272.0 kJ/mol ∆H3 = -296.8 kJ/mol   Mark your answer next to words “Final answer is”. You must follow significant figure rules.  Show your work here to receive full credit.  

12 month old Maggie’s mother has a friend whose 12 month old already has 15 words.  She asks if you think Maggie is a “late talker.”  You explain the characteristics of a late talker : (select all that apply)

At six months old, Noah’s parents should see the emergence and coordination of joint attention.  The clinician discusses joint attention with you and expects you to know the following terms for any upcoming screenings on 6-12 month old children.  Match the example with the key term.

Match the word learning principles/theory with the example.