Which of the following correctly gives the correct coefficients for the reaction below? N_(2)H_(4)+H_(2)O_(2)arrow N_(2)+H_(2)O 2,4,2,4 2,4,2,8 1,2,1,1 1,2,1,4 1,4,1,4
Which gas has a lower flammability limit of 2.5 and an upper flammability limit of 100 while in air at 25^circ C and 101 kPa? Ammonia Acetylene Ethanol Acetone
All combustion reactions are exothermic. When substances burn they usually give off energy as heat and light. True False
Using Delta G calculate the value of the thermodynamic equilibrium constant K for: H_(2)(g)+Br_(2)(l)- -gt 2HBr(g)
An aqueous solution is saturated in both oxygen gas and potassium iodide at 80^circ C Determine what happens when the solution is cooled to room temperature. Nothing happens. All of the oxygen gas and potassium iodide remain dissolved in solution. Potassium iodide precipitates out of the solution. Oxygen gas bubbles out of the solution and potassium iodide precipitates out of the solution. Oxygen gas bubbles out of the solution.
Lucy: What's up with the other elements that are in group 8, like Krypton. Do they have anything in common? a) They have the same number of electron shells b) They have the same number of protons c) They have the same atomic mass d) They have the same number of valence electrons
Multiple Choice Question Salt is __ chloride by weight. 40% 50% 60% 70%
Calculate the cell potential, E_(cell) for the reaction below when [Cr^3+]=0.25M and [Pb^2+]=0.15M 2Cr(s)+3Pb^2+(aq)leftharpoons 2Cr^3+(aq)+3Pb(s) E_(cell)^circ =+0.61V E_(cell)=0.597V E_(cell)=0.573V E_(cell)=1.09V E_(cell)=1.21V E_(cell)=0.871V
What term describes a solution where a solid dissolves in a liquid? soluble insoluble immiscible indissolvable
6) When 2,400 mg zinc is added to hydrochloric acid, 450 mL of hydrogen gas forms at a temperature of 30^circ C What is the pressure of the gas (in atm)? underline ( )Zn(s)+underline ( )HCl(aq)arrow underline ( )ZnCl_(2)(aq)+underline ( )H_(2)(g)
$2N_{2}O_{5}(aq)\rightarrow 4NO_{2}(aq)+O_{2}(g)$ 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 $N_{2}$
A saturated solution holds the maximum amount of solute under the solution conditions. True False
Copper, a good conductor, has __ electron(s) in its valence shell. a. 1 b. 3 c. 4
To identify a chemical's hazards, check its: Smell Color MSDS
A 0.788 mole sample of ideal gas at $12^{\circ }C$ occupies a volume of 4.25 L. What is the pressure of the gas? $\square $
