1. (XC5pt) Calculate the concentration of each species of X in a 0.551 M solution of Na_(2)X_(41)= 5.59e-2,K_(22)=1.96e-7 [H_(2)X]=underline ( ) [HX^-]=underline ( )[X^2-]=underline ( ) [H_(3)O^+]=underline ( ) [OH-]=underline ( )pH=underline ( )
What is the freezing point of a solution of 0.5 mol of LiBr in 500 mL of water? (K^f=1.86^circ C/m) -7.44C -3.72C -5.58C -1.86C
To which of the following variables is change in boiling point directly proportional? molarity of solution molality of solution percent by volume of solution percent (mass/mass) of solution
What is the molarity of a solution that contains 6 moles of solute in 2 liters of solution? 7M 6M 3M 12M
Which of the following usually makes a substance dissolve faster in a solvent? increasing the particle size of the solute agitating the solution decreasing the number of particles lowering the temperature
Based on its location on the periodic table , which metal is likely to be less reactive than rubidium and more reactive than calcium? potassium (K) cesium (Cs) magnesium (Mg) titanium (Ti)
How many neutrons do carbon -12 and carbon -13 have, respectively? A 6;7 B 12;13 C 7;6 D 13,11
Multiple Choice 1 point How many moles of NO are formed if 2.50 moles of N_(2)O_(4) completely react using the balanced equation below? N_(2)H_(4)+2N_(2)O_(4)arrow 6NO+2H_(2)O 15.0 moles 10.0 moles 5.00 moles 7.50 moles
24. How is the empirical formula different from the molecular formula?
Seawater has a density of 1.03g/mL What mass of seawater would fill a vessel with a volume 0.225 liters? 218 grams 232 grams 246 grams 225 grams 458 grams
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
