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Questions in chemistry

[Jawaban] The names of the compounds $FeS , NaCl$, and $Al _3 O _2$ all end in the suffix A) -ic. B) -ite. C) -ate. D) -ide.

[Jawaban] Which of the following is a correct example of properly segregating cylinders? A. Oxygen cylinders stored next to flammable gases B. Full and empty cylinders stored together C. Cylinders stored by their hazard classification D. All of the choices are correct

[Jawaban] Decide whether each pair of elements in the table below will form an ionic compound. If they will, write the empirical formula of the compound formed in the space provided. | element #1 | element #2 | Forms ionic compound? | empirical formula of ionic compound | |---|---|---|---| | cesium | chlorine | yes | $\square$ | | rubidium | bromine | yes | $\square$ | | sulfur | strontium | yes | $\square$ | | calcium | cesium | yes | $\square$

[Jawaban] Which substance is a compound? A. water B. gold C. oxygen D. hydrogen

[Jawaban] ACTION 12.19: INTERACTION OF SALTS WITH AIR AND MOISTURE A salt that gives off part of its water of crystallization when exposed to air is called: An example of such salt is A compound absorbs water from the atmosphere when exposed to air without forming a solution. An example of such a compound is A substance that absorbs so much water from the atmosphere that it dissolves to form a solution is called An example of such compound is

[Jawaban] Combustion of glucose ($C_6H_{12}O_6$) is the main source of energy for animal cells: $C_6H_{12}O_6(s) + 6O_2(g) \rightarrow 6CO_2(g) + 6H_2O(l) \quad \Delta G_{rxn}(37^{\circ}C) = -2872. kJ$ 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.

[Jawaban] The formula for pH is [tex]$pH =-\log \left[ H ^{+}\right]$[/tex], where [tex]$\left[ H ^{+}\right]$[/tex] is the hydrogen ion concentration. The pH of a fruit juice is 3.1. What is the hydrogen ion concentration of the juice? The hydrogen ion concentration [tex]$\left[ H ^{+}\right]$[/tex] is approximately ______ moles per liter. (Round to the nearest tenth.)

[Jawaban] A flask filled to the 25.0 mL mark contained 29.97 g of a concentrated salt-water solution. What is the density of the solution?

[Jawaban] What is the percent error of the data? | Trial # | Density | |---|---| | 1 | 10.34 | | 2 | 10.58 | | 3 | 10.62 | | Average | 10.51 |

[Jawaban] One brand of vinegar has a pH of 4.5. Another brand has a pH of 5.0. The equation for the pH of a substance is [tex]$pH = - \log [H^+]$[/tex], where [tex]$H^+$[/tex] is the concentration of hydrogen ions. What is the approximate difference in the concentration of hydrogen ions between the two brands of vinegar? A. [tex]$2.2 \times 10^{-5}$[/tex] B. [tex]$3.2 \times 10^{-1}$[/tex] C. [tex]$3.2 \times 10^1$[/tex] D. [tex]$6.8 \times 10^4$[/tex]