Draw structures for the following: a. (S)-1-bromo-1-chlorobutane, b. (2R,3R)-2,3-dichloropentane, c. an achiral stereoisomer of 1,2-dimethylcyclohexane, d. a chiral stereoisomer of 1,2-dibromocyclobutane, e. two achiral stereoisomers of 3,4,5-trimethylheptane

One hundred grams of radium are stored in a container. The amount R(in grams) of radium present after t years can be modeled by $R=100e^-0.00043t$. After how many years will only 5 grams of radium be present?

Convert each perspective formula to a skeletal structure.

a. Using the wedge-and-dash notation, draw the nine stereoisomers of 1,2,3,4,5,6-hexachlorocyclohexane. b. From the nine stereoisomers, identify one pair of enantiomers. c. Draw the most stable conformer of the most stable stereoisomer.

Draw all possible stereoisomers for each of the following. Indicate if no stereoisomers are possible.

a. 1-bromo-2-chlorocyclohexane

b. 2-bromo-4-methylpentane

c. 1,2-dichlorocyclohexane

d. 2-bromo-4-chloropentane

e. 3-heptene

f. 1-bromo-4-chlorocyclohexane

g. 1,2-dimethylcyclopropane

h. 4-bromo-2-pentene

i. 3,3-dimethylpentane

j. 3-chloro-1-butene

k. 1-bromo-2-chlorocyclobutane

l. 1-bromo-3-chlorocyclobutane

Many printed airline tickets contain a 10-digit document number followed by a check digit. The check digit is chosen to be the sum of the first 10 digits mod 7. Determine whether the given number is a valid document number. 2373453867 6

Write an equation to solve this problem. Twelve percent of what number is 240?

A player shoots a basketball from a height of 7 ft with an initial vertical velocity of 18 ft/s. The equation

$$-16t^2 + 18t + 7 = 10$$

can be used to determine the time t in seconds at which the ball will have a height of 10 ft – the same height as the basket. (a). Solve the equation by using the Quadratic Formula. (b). To the nearest tenth of a second, when will the ball have a height of 10 ft? (c). Explain how you can check that your answers to part b are reasonable.

evaluate the expression. If it is not possible, explain why. [-11 16 19 , -7 -2 1] - [6 0 , 8 -4 , -2 10]

Write the numeral as a Roman numeral. 46,281

A solution of $0.50 \mathrm{~g}$ of (-)-epinephrine (see Figure 5-16) dissolved in $10.0 \mathrm{~mL}$ of dilute aqueous $\mathrm{HCl}$ was placed in a $20-\mathrm{cm}$ polarimeter tube. Using the sodium D line, the rotation was found to be $-5.1^{\circ}$ at $25^{\circ} \mathrm{C}$. Determine the specific rotation of epinephrine.

Draw all possible stereoisomers for each of the following compounds. Indicate if no stereoisomers are possible. a. 2-bromo-4-methylpentane e. 1-bromo-3-chlorocyclobutane b. 2-bromo-4-chloropentane f. 2-iodopentane c. 3-heptene g. 3,3-dimethylpentane d. 1-bromo-4-methylcyclohexane h. 3-chloro-1-butene

Tamoxifen slows the growth of some breast tumors by binding to estrogen receptors. Is tamoxifen an E or a Z isomer?

Two tuning forks having frequencies of 460 and 464 Hz are struck simultaneously. What average frequency will you hear, and what will the beat frequency be?