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Questions in chemistry

[Done] 3. Write an equation for the neutralization of HBr by KOH. $HBr(aq)+KOH(aq) \rightarrow KBr(aq)+H_2 O(1)$ 4. What is the function of an indicator in a titration?

[Done] Which of the Lewis electron dot representations is correct for the cyanide ion, CN⁻¹? [C=N]⁻¹ [C≡N]⁻¹

[Done] Which of the Lewis electron dot representations is correct for perchlorate, [tex]$ClO _4^{-}$[/tex]?

[Done] A chemist fills a reaction vessel with 0.536 g aluminum hydroxide $\left( Al ( OH )_3\right)$ solid, 0.337 M aluminum $\left( Al ^{3+}\right)$ aqueous solution, and 0.196 M hydroxide $\left( OH ^{-}\right)$aqueous solution at a temperature of $25.0^{\circ} C$. Under these conditions, calculate the reaction free energy $\Delta G$ for the following chemical reaction: $Al(OH)_3(s) \rightharpoonup Al^{3+}(aq)+3 OH^{-}(aq)$ Use the thermodynamic information in the ALEKS Data tab. Round your answer to the nearest kilojoule.

[Done] Which property do metalloids share with nonmetals? A. Both are gases at room temperature. B. Both can react to form acidic compounds. C. Both are very poor electrical conductors. D. Both can be pounded into thin sheets.

[Done] Complete the table below by writing the symbols for the cation and anion that make up each ionic compound. The first row has been completed for you. | Ionic compound | cation | anion | | -------------- | ------ | ----- | | NaCl | $Na { }^{+}$ | $Cl ^{-}$ | | $V _2( SO _4)_3$ | | | | $VF _2$ | | | | $Fe ( NO _3)_3$ | | | | $NH _4 I$ | | |

[Done] Your answer is wrong. In addition to checking your math, check that you used the right data and DID NOT round any intermediate calculations. Combustion of glucose $\left( C _6 H _{12} O _6\right)$ is the main source of energy for animal cells: $C_6 H_{12} O_6(s)+6 O_2(g) \rightarrow 6 CO_2(g)+6 H_2 O(l) \quad \Delta G_{r \times n}\left(37^{\circ} C\right)=-2872 . kJ$ One of the most important uses to which this energy is put is the assembly of proteins out of amino acid building blocks. The Gibbs free energy of formation of one peptide bond, joining one amino acid to another, is $21 kJ / mol$. Suppose some cells are assembling a certain protein made of 81 amino acids. (Note that the number of peptide bonds in the protein will be one less than the number of amino acids.) Calculate the minimum mass of glucose that must be burned to assemble $650 . \mu mol$ of this protein. Round your answer to 2 significant digits. $7.0 \times 10^{-2} . g$

[Done] A chlorine $(Cl)$ and bromine $(Br)$ atom are adsorbed on a small patch of surface (see sketch at right). This patch is known to contain 49 possible adsorption sites. The Cl and bromine $(Br)$ atoms have enough energy to move from site to site, so they could be on any two of them. Suppose the Br atom desorbs from the surface and drifts away. Calculate the change in entropy. Round your answer to 2 significant digits, and be sure it has the correct unit symbol. $-1.1 \times 10^{-25} \frac{J}{K}$

[Done] Which metalloid has three valence electrons? A. boron B. arsenic C. silicon D. lithium

[Done] Fill in the name and empirical formula of each ionic compound that could be formed from the ions in this table: | cation | anion | empirical formula | name of compound | |---|---|---|---| | [tex]$Sr ^{2+}$[/tex] | [tex]$P ^{3-}$[/tex] | | | | [tex]$Sr ^{2+}$[/tex] | [tex]$O ^{2-}$[/tex] | | | | [tex]$Sr ^{2+}$[/tex] | [tex]$s ^{2-}$[/tex] | | | | [tex]$Sr ^{2+}$[/tex] | [tex]$N ^{3-}$[/tex] | | |