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Chem |! 151 |! Exam |! 1 |! with |! precise |!
detailed |! solutions
What |! are |! chemists' |! three |! central |! goals |! and |! what |! kind |! of |! questions |! should |! be |! asked? |! - |! Correct |! answer |! ✔Analysis- |! What |! is |! this? Synthesis- |! How |! do |! I |! make |! it? Modeling- |! How |! do |! I |! explain |! it? intensive |! property |! - |! Correct |! answer |! ✔DO |! NOT |! depend |! on |! the |! amount |! of |! material Melting |! point, |! boiling |! point, |! density, |! color CHARACTERISTIC |! of |! a |! material extensive |! property |! - |! Correct |! answer |! ✔Depend |! on |! the |! amount |! of |! material Length, |! Mass, |! Area |! Independent |! of |! the |! type |! or |! identity |! of |! the |! material |! Tell |! you |! HOW |! MUCH quantitative |! - |! Correct |! answer |! ✔any |! value |! recorded |! directly |! from |! a |! tool |! is |! considered |! quantitative |! data |! (numbers |! based) qualitative |! - |! Correct |! answer |! ✔It |! includes |! such |! descriptions |! as |! color |! as |! well |! as |! observations |! about |! texture |! changes |! and |! anything |! else |! that |! is |! actually |! an |! opinion |! (try |! describing |! the |! difference |! in |! color |! between |! two |! different |! blades |! of |! grass)
significant |! figures |! rules |! - |! Correct |! answer |! ✔1. |! Zeroes |! in |! the |! beginning |! of |! a |! number |! never |! count.
- |! Zeroes |! at |! the |! end |! of |! a |! number |! count |! only |! if |! there |! is |! a |! written |! decimal |! point.
- |! The |! digits |! 1 |! - |! 9 |! always |! count.
- |! Zeroes |! between |! the |! digits |! 1 |! - |! 9 |! always |! count. matter |! - |! Correct |! answer |! ✔anything |! that |! has |! mass |! and |! occupies |! space substance |! - |! Correct |! answer |! ✔that |! object |! which |! has |! mass |! and |! occupies |! space composition |! - |! Correct |! answer |! ✔the |! makeup |! of |! something |! (components) state |! - |! Correct |! answer |! ✔its |! physical |! form/condition three |! states |! of |! matter |! - |! Correct |! answer |! ✔gas, |! liquid, |! solid solid |! - |! Correct |! answer |! ✔-atoms |! or |! molecules |! pack |! close |! to |! each |! other |! in |! fixed |! locations -vibrate |! but |! do |! not |! move |! around |! or |! past |! each |! other -fixed |! volume |! and |! shape crystalline |! - |! Correct |! answer |! ✔case |! in |! solid |! state |! where |! atoms |! or |! molecules |! are |! in |! patterns |! with |! long-range, |! repeating |! order |! ex) |! salt |! and |! diamond amorphous |! - |! Correct |! answer |! ✔case |! where |! a |! solid's |! atoms |! or |! molecules |! do |! not |! have |! any |! long-range |! order. |! ex.) |! glass |! and |! plastic
Central |! Goals |! and |! Questions |! - |! Correct |! answer |! ✔Detection: |! Does |! the |! sample |! contain |! substance |! X? Identification: |! What |! is |! the |! identity |! of |! the |! substance |! in |! this |! sample? Separation: |! How |! can |! the |! substances |! present |! in |! the |! sample |! be |! separated? Quantitation: |! How |! much |! of |! substance |! X |! is |! in |! the |! sample? Three |! different |! perspectives |! - |! Correct |! answer |! ✔macroscopic, |! microscopic, |! symbolic Distillation |! - |! Correct |! answer |! ✔a |! process |! used |! to |! separate |! dissolved |! solids |! from |! a |! liquid, |! which |! is |! boiled |! to |! produce |! a |! vapor |! that |! is |! then |! condensed |! into |! a |! liquid -the |! mixture |! is |! heated |! to |! biol |! off |! the |! more |! volatile |! liquid -Based |! on |! the |! difference |! in |! boiling |! points. Extraction |! - |! Correct |! answer |! ✔Based |! on |! the |! difference |! in |! solubility |! in |! different |! solvents., |! Separation |! method |! exploiting |! solubility |! properties. |! Two |! solvents |! are |! usually |! used, |! one |! aqueous |! and |! one |! organic, |! and |! the |! component |! of |! interest |! will |! be |! soluble |! in |! one |! phase |! while |! the |! impurities |! will |! be |! soluble |! in |! the |! other |! solvent. solubility |! - |! Correct |! answer |! ✔the |! quantity |! of |! a |! particular |! substance |! that |! can |! dissolve |! in |! a |! particular |! solvent |! (yielding |! a |! saturated |! solution) Filtration |! - |! Correct |! answer |! ✔a |! process |! that |! separates |! materials |! based |! on |! the |! size |! of |! their |! particles |! by |! using |! a |! filter |! (homogenous) -Based |! on |! the |! difference |! in |! particle |! size.
chromatography |! - |! Correct |! answer |! ✔A |! technique |! that |! is |! used |! to |! separate |! the |! components |! of |! a |! mixture |! based |! on |! the |! tendency |! of |! each |! component |! to |! travel |! or |! be |! drawn |! across |! the |! surface |! of |! another |! material. Thermal |! analysis |! - |! Correct |! answer |! ✔analyzing |! the |! changes |! in |! the |! properties |! of |! a |! material |! as |! the |! temperature |! is |! increased. condensation |! - |! Correct |! answer |! ✔the |! process |! of |! changing |! from |! a |! gaseous |! to |! a |! liquid |! or |! solid |! state vaporization |! - |! Correct |! answer |! ✔Liquid |! to |! Gas sublimation |! - |! Correct |! answer |! ✔solid |! to |! gas deposition |! - |! Correct |! answer |! ✔gas |! to |! solid melting |! - |! Correct |! answer |! ✔solid |! to |! liquid freezing |! - |! Correct |! answer |! ✔liquid |! to |! solid triple |! point |! - |! Correct |! answer |! ✔the |! temperature |! and |! pressure |! conditions |! at |! which |! the |! solid, |! liquid, |! and |! gaseous |! phases |! of |! a |! substance |! coexist |! at |! equilibrium positive |! solid |! slope |! - |! Correct |! answer |! ✔more |! dense; |! sink negative |! solid |! slope |! - |! Correct |! answer |! ✔less |! dense; |! float
How |! is |! temperature |! related |! to |! Kinetic |! Energy? |! - |! Correct |! answer |! ✔Increasing |! T |! Increases |! Average |! KE KE |! formula |! for |! gases? |! - |! Correct |! answer |! ✔KE |! = |! 3/2 |! RT Temperature |! - |! Correct |! answer |! ✔measure |! of |! the |! "Average |! Kinetic |! Energy" |! per |! Particle Temperature |! and |! Kinetic |! Energy |! - |! Correct |! answer |! ✔At |! the |! same |! Temperature |! all |! particles |! have |! the |! same |! average |! Kinetic |! energy Kinetic |! Energy |! and |! Speed |! - |! Correct |! answer |! ✔Increasing |! KE |! Increases |! Speed; |! increasing |! temperature |! increases |! speed! KE |! = |! ½ |! mv2 |! - |! Correct |! answer |! ✔KE |! = |! ½ |! mv Increasing |! temperature |! increases |! what? |! - |! Correct |! answer |! ✔average |! speed temperature |! is |! proportional |! to? |! - |! Correct |! answer |! ✔average |! kinetic |! energy Increasing |! kinetic |! energy |! increases? |! - |! Correct |! answer |! ✔speed At |! the |! same |! temperature |! all |! particles |! have |! the |! same? |! - |! Correct |! answer |! ✔average |! kinetic |! energy What |! is |! the |! effect |! of |! mass |! on |! average |! speed? |! - |! Correct |! answer |! ✔Increasing |! Mass |! Decreases |! Speed
Does |! increasing |! mass |! effect |! KE? |! - |! Correct |! answer |! ✔No, |! just |! velocity/speed. |! t |! the |! same |! T, |! all |! gases |! have |! the |! same |! avg |! KE |! regardless |! of |! mass At |! same |! temp... |! - |! Correct |! answer |! ✔All |! particles |! have |! the |! same |! average |! KE, |! not |! all |! have |! the |! same |! velocity Pressure |! is |! equal |! to |! - |! Correct |! answer |! ✔Force |! / |! Area |! (intensive |! property) What |! happens |! to |! particles |! when |! temperature |! decreases? |! - |! Correct |! answer |! ✔The |! kinetic |! energy |! decreases. |! Attractive |! forces |! between |! particles |! are |! then |! able |! to |! hold |! them |! together. The |! intermolecular |! forces |! do |! not |! change The |! strength |! of |! the |! forces |! depend |! on |! distance The |! size |! of |! the |! particles |! do |! not |! change During |! a |! phase |! transition |! all |! the |! energy |! is |! invested |! (or |! lost) |! in |! the |! form |! of? |! - |! Correct |! answer |! ✔potential |! energy; |! Energy |! is |! needed |! to |! separate |! the |! particles, |! and |! is |! released |! when |! they |! come |! together. potential |! energy |! - |! Correct |! answer |! ✔energy |! stored |! due |! to |! an |! object's |! position |! or |! arrangement What |! happens |! to |! kinetic |! energy |! during |! a |! phase |! transition? |! - |! Correct |! answer |! ✔does |! not |! change
PV= |! - |! Correct |! answer |! ✔nRT nRT= |! - |! Correct |! answer |! ✔PV Ideal |! gas |! law |! - |! Correct |! answer |! ✔law |! that |! states |! the |! math |! relationship |! of |! pressure |! (P), |! volume |! (V), |! temperature |! (T), |! the |! gas |! constant |! (R), |! and |! the |! number |! of |! moles |! of |! a |! gas |! (n); |! PV=nRT. P |! = |! - |! Correct |! answer |! ✔nRT/V spectroscopic |! analysis |! - |! Correct |! answer |! ✔Light- |! Adding |! energy |! and |! looking |! at |! the |! light |! emitted. A |! spectrum |! can |! be |! used |! to |! obtain |! information |! about |! atomic |! and |! molecular |! energy |! levels, |! molecular |! geometries, |! chemical |! bonds, |! interactions |! of |! molecules, |! and |! related |! processes. |! Often, |! spectra |! are |! used |! to |! identify |! the |! components |! of |! a |! sample |! (qualitative |! analysis). |! Spectra |! may |! also |! be |! used |! to |! measure |! the |! amount |! of |! material |! in |! a |! sample |! (quantitative |! analysis). Diatomic |! molecule |! - |! Correct |! answer |! ✔a |! molecule |! consisting |! of |! two |! atoms; |! There's |! seven seven |! diatomic |! molecules |! - |! Correct |! answer |! ✔H₂, |! N₂, |! O₂, |! F₂, |! Cl₂, |! Br₂, |! I₂ Can |! particles |! that |! compose |! compounds |! be |! separated |! by |! physical |! methods? |! - |! Correct |! answer |! ✔no, |! only |! chemical |! methods. Letter |! arrangement |! molecular |! compounds |! - |! Correct |! answer |! ✔C |! first, |! then |! H, |! then |! alphabetical
Equal |! volumes |! of |! gas |! have? |! - |! Correct |! answer |! ✔same |! number |! of |! particles |! (this |! is |! how |! we |! determine |! the |! amount |! of |! atoms) Incandesence |! (fireworks) |! - |! Correct |! answer |! ✔Incandescence |! is |! the |! light |! produced |! from |! heat. Luminescence |! - |! Correct |! answer |! ✔Light |! emitted |! by |! means |! other |! than |! burning, |! such |! as |! chemical |! or |! biochemical |! action |! or |! radiation "1" |! prefix |! - |! Correct |! answer |! ✔mono "2" |! prefix |! - |! Correct |! answer |! ✔di "3" |! - |! Correct |! answer |! ✔tri "4" |! - |! Correct |! answer |! ✔tetra "5" |! - |! Correct |! answer |! ✔penta "6" |! - |! Correct |! answer |! ✔hexa "7" |! - |! Correct |! answer |! ✔hepta "8" |! - |! Correct |! answer |! ✔octa
