The second step in an electrophilic aromatic substitution reaction is shown below, with some atoms (a1-a3) and bonds (b1-b3) labelled. + a1 H of b1 b2 a2 b31 a3 -Br Br One curly arrow is needed to show the mechanism of this reaction. Give the start and end of the arrow by typing the appropriate labels, e.g. a1, in the blanks. The arrow starts at A and ends at A/

Q5. Please answer the question and make sure it is correct, thank you.

I need help with calculations i need help by step by step show the work please  Below is a simple set of weights obtained while immersing potato slices in various sugar solutions over 30 minutes.  a. For each solution, calculate the rate of weight change over this 30-minute period. . Once you calculate these rates - . Write your answer in standard notation and use 3 digits past the decimal point - e.g. 0.005, 0.030. (Note that the last zero in an answer is considered to be a digit).  0.0 M sucrose = ____________________ g/min 0.4 M sucrose = _____________________ g/min 0.6 M sucrose = _____________________ g/min 0.8 M sucrose = _____________________ g/min 1.0 M sucrose = _____________________ g/min

Please help me with this. I will immediately give you a thumb up. Thank you so much!  briefly describe the main idea of the variational principal and how it is used in the variational method?

The solution calls for an exponent. How would I write that?

Which of the following molecules are antihistamines? Check all that apply. ► View Available Hint(s) U 0 H-N L CH,CH,NH,* But CH–O–CH,CH,−N CH,CH,NHNH, H 4

Can you redo the calculation ?

Signifi Bb My Bla Digital ng.cen Week Submit Answer HOME References Chemi ploymentid=5735112480241329813180832311&elSBN=9781305862883&id=1707785886&snaps... Û Min X Hb NCBM G The su L Use the References to access important values if needed for this question. The liquid bromopentafluorobenzene has a density of 1.98 g/mL at 25 °C. If a 2.99 kilogram sample of this compound is needed, how many liters of the liquid at 25 °C must be provided? Q Search this cou B

A. Draw all significant resonance structures of each compound below, using appropriate arrows, and then indicate the most significant contributor (multiple structures may be equal in significance). Briefly explain your reasoning in each case.

A particle is immersed in a gas. What would happen with the gas pressure the particleexperiences if the density of the gas was halved?. Explain.