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)
5) Determine the pressure (in mmHg) for the nitrogen gas sample that is collected when 53.0 g of NaN_(3) decomposes. The temperature of the gas is 25^circ C and the volume is 18.0 L. underline ( )NaN_(3)(s)arrow underline ( )Na(s)+underline ( )N_(2)(g)
22. When sugar is mixed with water equilibrium is reached when molecules of sugar stop moving the dissolved sugar molecules are evenly distributed throughout the
For which of the properties would aluminum have a greater value than gallium? 1. Atomic radius 2. Ionic radius 3. Electronegativity 4. Ionization energy
1A. Which of the following is most likely a significant cause of the general trend indicated by the graph? A. Reduction of ozone concentration in the upper atmosphere B. Reduction in size of polar ice caps C. Increase in energy output of the sun D. Increase in evaporation of ocean water E. Increase in consumption of fossil fuels 1B. Based on the results of the graph, which oceanic changes will be observed? A. pH will decrease, but the ocean will remain basic B. pH will increase and the ocean will become more basic C. pH will decrease and the ocean will become acidic D. pH will not significantly change 2A. When "strong," these dissociate completely in solution. A. Acid B. Base C. Both 2B. Is a proton-donor when dissolved in solution. A. Acid B. Base C. Both 2C. A solution with a pH greater than 7, up to 14. A. Acid B. Base C. Both 2D. A solution that contains more hydronium ions $(H3O+)$ than hydroxide ions $(OH-).$ A. Acid B. Base C. Both
Question 7 Match the definition with the correct term about the atom in relation to the periodic table. number of protons in the nucleus of an $\square $ atom [Choose] [Choose] total number of protons and neutrons in mass number the nucleus of an atom atomic mass atomic number $\square $ weighted, average mass of all isotopes of a naturally occurring element 1 pts
Properly identify the following ions (some answers will be used twice and some answers will not be used at all) magnesium $\square $ phosphate $\square $ ammonium $\square $ chloride $\square $ iron (III) $\square $ perchlorate $\square $
have gone into the field to take water samples from lakes in your town. note the following observations: Lake A contained many fish swimming in its waters. Lake B had very few fish swimming in its waters, and a few dead fish floating on the water. u return to your lab and take pH readings for each mple. Think about how acids and bases would affect the water quality in the two lakes. Which set of pH data would you expect to see based on your observations? Lake A: $pH=4.5$ Lake B: $pH=7.5$ Lake A: $pH=8.3$ Lake B: $pH=3.7$ Lake A: $pH=6.6$ Lake B: $pH=6.8$ Lake A: $pH=10.2$ Lake B: $pH=1.7$
A buffer consists of a weak acid and its conjugate hase in the same solution. Match the weak acid-conjugate base pairs that could be used to make a buffer. (Carvat does not show subscripts HCOOH $\square $ [Choose] $HC2H3O2$ $\square $ : HCN [Choose] H2O $NaCOOH$ $NaC2H3O2$ $NaOH$ $HCl$ $HaCN$ Question 9 aspts
${}_{2}^{4}He$ How many protons does He have? a b b C 2 d 6
Student B: At the beginning of the reaction the rate of the forward reaction was higher than the rate of the reverse reaction: ammonia and water were turning into ammonium hydroxide. But now, the rate of the reverse reaction is higher. Which student has the most accurate answer? Choose 1 answer: A Student A B Student B C Both students' answers are correct.
The number of atoms in a mole of something remains the same, but the mass of a mole depends on how many atoms you have the average atomic mass of the elements
