Show all work No work no credit Answerin complete 1. Shont answer riefly explain
ID: 564510 • Letter: S
Question
Show all work No work no credit Answerin complete 1. Shont answer riefly explain the reasoning for the fidlewing 11, does not dissolve in water but cH Of does 2. Molecular solids have lower melting points than iomie ionic solids 3. In water 1 0M NaCI has a higher freezing point than 1 M CaCy 4. Copper conducts electricity but copper Il sulfate (Cuso not. 5. The barometer falls when rain is coming an when climbing a mountain A piece of hot metal at 100C water. The data for the experiment is given determine the specific heat heat of the metal. (Ignore the heat gained by the cup Mass of cup + water= 655g s placed in a coffee cup calorimeter filled wit below. Use this data to Mass of cup= 250g Mass of cup + water + metal = C (water) = 4.18J/g 93As Initial temp. of water = 220C 23Ag Final temp, of metal/water mixture = 263Explanation / Answer
1.
CH4 is not soluble in water as it is non-polar and we know that like dissolves like while methanol is polar and hence dissolves in water.
2.
true as the intermolecular force between molecules is very less in molecular solids compared to ionic compounds as it has very high intermolecular force to bind each other
3.
Tf = iKfm
Tf= depression in freezing point
i = vant hoff facor and depends upon dissociation of a molecules into ions and for very strong electrolytes
Kf= depression in freezing point constant
m = molaity
such NaCl , i = 2 ( 1 formula mass of NaCl gives 2 ions)
and for CaCl2 ,i = 3 (one formula mass gives 3 ions )
depression in freezing point depends on no. of particles
NaCl dissolve in water to form 2 ions
CaCl2 will give two ions 1 Ca2+ + 2Cl- and hence more depression in freezing point
4.
Cu has free electrons and hence it conducts electricity,while CuSO4(s) does not have free electrons or ions in solid state and hence cannot conduct electricity.
5.
when rain is coming,usually there is high speed wind and with high speed wind,according to hydrostatic law as we move up,pressure decreases.
B.
here :
heat gain by water + heat gain by cup(=0:given to ignore) = heat lost by metal
mwCpwT' = mmCpmT
mw = mass of water = mass of cup+water - mass of cup = 65.50g -2.50g = 63g
mm = mass of metal = mass of cup + water + metal - mass of cup+water = 93.4g - 65.5g = 27.9g
T' = (26.3 - 22) = 4.3 oC
T = (100 - 26.3) = 73.7 oC
putting the values in above equation
63.0g x 4.18J/g.oC x 4.3 oC = 27.9g x Cpm x 73.7 oC
Cpm = 0.550698 J/g.oC
Ans ~ 0.55J/g.oC