91影视

Draw the R group of (a) glycine; (b) isoleucine; (c) tyrosine.

Write the sequence of the complementary DNA strand that pairs with each of the following DNA base sequences:

(a) TTAGCC

(b) AGACAT

Question: Write the sequence of the complementary DNA strand that pairs with each of the following DNA base sequences:

(a) GGTTAC

(b) CCCGAA

Which of the following scenes illustrate(s) the fact that compounds of chlorine (green) and oxygen (red) exhibit the law of multiple proportions? Name the compounds.

Liquid ammonia auto ionizes like water:

${\mathbf{\text{2NH}}}_{\mathbf{\text{3}}}\mathbf{\text{(l)}}\mathbf{鈫�}{\mathbf{\text{NH}}}_{\mathbf{\text{4}}}^{\mathbf{\text{+}}}{\mathbf{\text{(am) + NH}}}_{\mathbf{\text{2}}}^{\mathbf{\text{-}}}\mathbf{\text{(am)}}$

where (am) represents solvation by${\mathbf{\text{NH}}}_{\mathbf{\text{3}}}$.

(a) Write the ion-product constant expression, Kam.

b) What are the strongest acid and base that can exist in${\mathbf{\text{NH}}}_{\mathbf{\text{3}}}$(l)?

(c)${\mathbf{\text{HNO}}}_{\mathbf{\text{3}}}$and HCOOH are levelled in${\mathbf{\text{NH}}}_{\mathbf{\text{3}}}$(l). Explain with equations.

(d) At the boiling point($\mathbf{-}\mathbf{33}\mathbf{掳}\mathbf{C}$),${\mathbf{\text{K}}}_{\mathbf{\text{am}}}{\mathbf{\text{=5.1脳10}}}^{\mathbf{-}\mathbf{27}}$. Calculate [$\mathbf{\text{N}}{{\mathbf{\text{H}}}_{\mathbf{\text{4}}}}^{\mathbf{\text{+}}}$] at this temperature.

(e) Pure sulfuric acid also auto ionizes. Write the ion-product constant expression,${\mathbf{\text{K}}}_{\mathbf{\text{sulf}}}$, and 铿乶d the concentration of the conjugate base at$\mathbf{20}\mathbf{掳}\mathbf{C}$$\left({\text{K}}_{\text{sutf}}{\text{=2.7脳10}}^{-4}\text{补迟20掳颁}\right)$

Thiamine hydrochloride $\left({\text{C}}_{\text{12}}{\text{H}}_{\text{18}}{\text{ON}}_{\text{4}}{\text{SCl}}_{\text{2}}\right)$is a water soluble form of thiamine (vitamin B1; ${\mathbf{\text{K}}}_{\mathbf{\text{a}}}\mathbf{\text{= 3.37}}\mathbf{脳}{\mathbf{\text{10}}}^{\mathbf{\text{- 7}}}$. How many grams of the hydrochloride must be dissolved in 10.00mL of water to give a pH of 3.50?

At $\mathbf{50}\mathbf{掳}\mathbf{C}$and 1 atm,${\mathbf{\text{K}}}_{\mathbf{\text{w}}}\mathbf{\text{= 5.19}}\mathbf{脳}{\mathbf{\text{10}}}^{\mathbf{\text{- 14}}}$. At these conditions, 铿乶d

(a)$\left[{\text{H}}_{\text{3}}{\text{O}}^{\text{+}}\right]$in pure water,

(b)$\left[{\text{H}}_{\text{3}}{\text{O}}^{\text{+}}\right]$in 0.010 MNaOH , and

(c) [OH] in${\mathbf{\text{0.0010MHClO}}}_{\mathbf{\text{4}}}$.

(d) Find$\left[{\text{H}}_{\text{3}}{\text{O}}^{\text{+}}\right]$in 0.0100 MKOH at$\mathbf{100}\mathbf{掳}\mathbf{C}$and 1000atm (Kw = 1.101012).

(e) Find the pH of pure water at$\mathbf{100}\mathbf{掳}\mathbf{C}$and 1000atm

(a) Does the percent by mass of each element in a compound depend on the amount of compound? Explain.

(b) Does the mass of each element in a compound depend on the amount of compound? Explain.

The Group 5A(15)hydrides react with boron trihalides in a reversible Lewis acid-base reaction. When 0.15mol of${\mathbf{\text{PH}}}_{\mathbf{\text{3}}}{\mathbf{\text{BCl}}}_{\mathbf{\text{3}}}$ (s) is introduced into a3.0 -Container at a certain temperature,$\mathbf{\text{8.4}}\mathbf{脳}{\mathbf{\text{10}}}^{\mathbf{\text{- 3}}}$mol of${\mathbf{\text{PH}}}_{\mathbf{\text{3}}}$is present at equilibrium:

${\mathbf{\text{PH}}}_{\mathbf{\text{3}}}{\mathbf{\text{BCl}}}_{\mathbf{\text{3}}}\mathbf{\text{(s)}}\mathbf{鈬�}{\mathbf{\text{PH}}}_{\mathbf{\text{3}}}{\mathbf{\text{(g) + BCl}}}_{\mathbf{\text{3}}}\mathbf{\text{(g)}}$

(a) Find${\text{K}}_{\text{c}}$for the reaction at this temperature.

(b) Draw a Lewis structure for the reactant

A 1000m solution of chloroacetic acid$\left({\text{ClCH}}_{\text{2}}\text{COOH}\right)$freezes at $\mathbf{1}\mathbf{.}\mathbf{93}\mathbf{掳}\mathbf{C}$. Find the Ka of chloroacetic acid. (Assume the molarities equal the molalities.)