Chemistry

Match the proper VSEPR shape to each of the following compounds. $CS_{2}$ $\square $ v $CO_{2}$ $\square $ v $SCl_{2}$ $\square $ $SO_{4}^{2}$ $\square $ v $PBr_{3}$ $\square $ v $SO_{3}^{2}$ $\square $ v $CH_{4}$ $\square $ $SD_{1}$ $\square $ $NH_{3}$ $\square $ v $SiF_{4}$ $\square $

4. Using your data what is the approximate hydronium ion concentration and hydroxide ion concentration in a cup of tea? Which is higher? (Refer back to the chart of pH if you need to.) (4 points)

Which of the following is NOT a sign of a chemical reaction? absorbing light when chemicals are contacted with each other emission of light when chemicals are contacted with each other All of the above are signs of a chemical reaction. absorbing heat when chemicals are contacted with each other emission of heat when chemicals are contacted with each other

Why is the aldol condensation to make dibenzalacetone carried out in a mixture of water (with $10\% $ NaOH) and alcohol instead of using just one solvent? Because water keeps the reaction cool and alcohol A adds flavor Because alcohol dissolves organic molecules, and B water dissolves NaOH Because NaOH only works in alcohol, and water C helps the smell Because the reaction only works in pure water or D pure alcohol

$2N_{2}O_{5}(aq)\rightarrow 4NO_{2}(aq)+O_{2}(g)$ Which choice represents the relative rate expression between $N_{2}O_{5}$ and $NO_{2}$ ? 1 $Rate=-\frac {1}{2}\frac {\Delta [N_{2}O_{5}]}{\Delta t}=\frac {1}{4}\frac {\Delta [NO_{2}]}{\Delta t}$ 2. $Rate=\frac {\Delta [N_{2}O_{5}]}{\Delta t}=\frac {\Delta [NO_{2}]}{\Delta t}$ 3 $Rate=-\frac {1}{4}\frac {\Delta [N_{2}O_{5}]}{\Delta t}=\frac {1}{2}\frac {\Delta [NO_{2}]}{\Delta t}$ 4 $Rate=2\frac {\Delta [N_{2}O_{5}]}{\Delta t}=4\frac {\Delta [NO_{2}]}{\Delta t}$

At high temperatures bromine molecules can dissociate into bromine atoms. For the reaction $Br_{2}(g)\rightleftharpoons 2Br\cdot (g)$ $K_{p}=2.48\times 10^{-3}$ at $1650^{\circ }C$ A 5.00 L vessel at $1650^{\circ }C$ is filled with $Br_{2}(g)$ at an initial pressure of 6.00 atm and allowed to come to equilibrium. What will be the pressure (in atm) of $Br\cdot (g)$ at equilibrium?

The boiling point of bromine is $59^{\circ }C$ Which of the following best predicts the boiling point of iodine monochloride, a polar compound? Higher than $59^{\circ }C$ because dipole-dipole interactions in iodine monochloride are stronger than dispersion forces in bromine. Lower than $59^{\circ }C$ because ionic bonding in bromine is stronger than covalent bonding in iodine monochloride. Lower than $59^{\circ }C$ because dipole-dipole interactions in iodine monochloride are weaker than in bromine. Higher than $59^{\circ }C$ because ionic bonding in iodine monochloride is stronger than H-bonding in bromine.

Under certain conditions the rate of this reaction is zero order in ammonia with a rate constant of $0.0026M\cdot s^{-1}$ $2NH_{3}(g)\rightarrow N_{2}(g)+3H_{2}(g)$ Suppose a 300. mL flask is charged under these conditions with 450.mmol of ammonia. How much is left 100 s later? You may assume no other reaction is important. Be sure your answer has a unit symbol,if necessary, and round it to the correct number of significant digits. $\square $

Cleaning chemicals are generally not health hazards True False

Identify the molecule or molecules containing polar covalent bonds. HF CsF $Br_{2}$ KH $N_{2}$