4. The rectangular framework shown is subjected to the indicated non concurrent system of forces. Determine the magnitude and direction of the resultant, also its moment arm relative to the origin O.

F 1=10 LB

F 2=40 LB

F 3=85 LB 

F 4=95 LB 

F 5=150LB

Rank the following compounds from strongest to weakest acid: CH_3 CH_2 OH CH_3 CH_2 NH_2 CH_3 CH_2 SH CH_3 CH_2 CH_3 For each of the following compounds, draw the form that predominates at pH = 3, pH = 6, pH = 10, and pH = 14: a. CH_3 COOH pK_a = 4.8 b. CH_3 CH_2 NH_3 pK_a = 11.0 c. CF_3 CH_2 OH pK_a = 12.4 Given the products of the following acid-base reactions and indicate whether reactants or products are favored at equilibrium. (Use the pK_a values that are given in Section 2.3.) a. CH_3 COH + CH_3 O^- b. CH_3 CH_2 OH +^- NH_2 c. CH_3 COH + CH_3 COH + CH_3 NH_2 d. CH+_3 CH_2 OH + HCI a. Rank the following alcohols from strongest to weakest acid. b. Explain the relative acidities. CH_2-CHCVH_2 OH CH_3 CH_2 CH_2 OH HC=CCH_2 OH A single bond between two carbons with different hybridizations has a small dipole. What is the direction of the dipole in the indicated bonds? a. b. For each compound, indicate the atom that is most apt to be protonated. a. b. c. Given the K_a values, estimate the pK_a value of each of the following acids without using a calculate (that is, is it between 3 and 4, between 9 and 10, and so on?): 1. nitrous acid (HNO_2), K_a = 4.0 times 10^-4 2. nitric acid (HNO_3), K_a = 22 3. bicarbonate (HCO_3^-), K_a = 6.3 times 10^-11 4. hydrogen cyanide (HCN), K_a = 7.9 times 10^-10 5. formic acid (HCOOH), K_a = 2.0 times 10^-4 6. phosphoric acid (H_3 PO_4), K_a = 2.1 b. Determine the exact pK_a values, using a calculator. c. Which is the strongest acid? Tenormin, a member of the group of drugs known as beta-blockers, is used to treat high blood pressure and improve survival after a heart attack. It works by slowing down the heart to reduce its workload. Which atom in Tenormin is the most basic?

The decomposition of N2O5 can be described by the equation Given these data for the reaction at 45degreeC in carbon tetrachloride solution, calculate the average rate of reaction for each successive time interval. Approximate the instantaneous rate of this reaction at time f = 40 s. The blue curve is the plot of the data. The orange line is tangent to the blue curve at t = 40 s. Consider the reaction described by the following equation. The rate law is What are the missing entries in the following table? What will the initial rate be if [A] is tripled and [B] is halved? Using the given data, determine the rate constant of this reaction. Using the given data, calculate the rate constant of this reaction. The rate constant for this first-order reaction is 0.620 s-1 at 400 degree C. How long (in seconds) would it take for the concentration of A to decrease from 0.770 M to 0.280 M? The rate constant for this zero-order reaction is 0.0120 M - s-1 at 300 degree C. How long (in seconds) would it take for the concentration of A to decrease from 0.800 M to 0.200 M? The rate constant for the reaction is 0.830 M 1 s-1 at 200 degree C. If the initial concentration of A is 0.00870 M, what will be the concentration after 795 s? For A products, time and concentration data were collected and plotted as shown here. Determine the reaction order, the rate constant, and the units of the rate constant. After 79.0 min, 40.0% of a compound has decomposed. What is the half-life of this reaction assuming first-order kinetics? A particular reactant decomposes with a half-life of 137 s when its initial concentration is 0.303 M. The same reactant decomposes with a half-life of 219 s when its initial concentration is 0.190 M. Determine the reaction order. What is the value and unit of the rate constant for this reaction? For each of the following cases, identify the order with respect to the reactant, A. The half-life of A decreases as the initial concentration of A decreases A threefold increase in the initial concentration of A leads to a ninefold increase in the initial rate. A threefold increase in the initial concentration of A leads to a 1.73-fold increase in the initial rate The time required for [A] to decrease from [A]0 to [A]o/2 is equal to the time required for [A] to decrease from [A]q/2 to [AJq/4.