Pre lab 9 121 chemistry assignment chan PDF

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Pre lab 1. A. Stoichiometry B. STP C. Molar volume D. Atmospheric Pressure E. Vapor pressure F. Daltons Gas law G. Combined gas law H. Volume by displacement 2. It remains full of water due to atmospheric pressure. 3. It must be less than 0.09 g because if it weighed more the metal would produce more than 100 ml of gas, which exceeds the capacity of the graduated cylinder. 4. If the magnesium metal has reacted completely, there will be no small sparks observed when the crucible cover is lifted. 5. wet gas- Gas collected over water and contains water vapor. Dry gas-Gas does not contain water vapor. 6. Par t i al pr es s ur eofH2gas=t ot al pr es sur e-aqueoust ensi onat250C =766-23. 8 =742. 2mm Hg 7. Mg( s)+2HCl ( aq. )>MgCl 2( aq. )+H2( g) MassofMg=0. 0795g. Mol armassofMg=24g/ mol Numberofmol esofMg=0. 0795/24=0. 00331mol Accor di ngt ot heabov ebal ancedeqaut i on, 1molMgcanpr oduce1mol H2 Then,0. 00331molMgc anpr oduce0. 00331mol H2 Gi v ent hat ,Pr es sur eofH2,P1=766mm Hg=766/760at m =1. 008at m Vol umeofH2gas ,V1=88. 5mL=0. 0885L Temper at ur e,T1=25+273. 15=298. 15K AtSTP, P2=1at m

T2=273. 15K V2=? P1V1/ T1=P2V2/ T2 1. 008*0. 0885/298. 15=1*V2/273. 15 V2=0. 0817L Then,mol arv ol umeatSTP=0. 0817/0. 00331=24. 7L 8.t her ear emi norer r or s 9.goggl es ,gl ov es ,et c

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2. Weneedt ofi ndouthowmanymol esofhydr ogengas( H2)ar eev ol v ed. PV=nRT,wher eni smol es P=763mm Hgor1. 004at m V=92mLor0. 092Li t er s R=0. 0821Lxat m /( mol xK) andT=20Cor293K Rear r angi ngt hegasl awt osol v ef orn: PV=nRT n=PV/RT=( 1. 004at m) ( 0. 092L)/( 0. 0821Lat m /molK) ( 293K)=3. 84E3mol esH2 Fr om t hebal ancedr eac t i onequat i on,wear eev ol v i ng3mol esofH2f orev er y2mol esofmet al ( X) , s ot her ear e3. 84* 10^ 3molH2x( 2mol X/3molH2)=2. 56* 10^ 3mol esofXmet al i nt ot al . I ft hes ampl ewei ghs0. 130gr ams ,t hent heat omi cwei ghtofX=( 0. 130g)/( 2. 56* 10^ 3mol esofX) =50. 78g/mol ,I ti sr oughl yt heat omi cwei ghtofVanadi um....