1and 1????
1) Calculate the molarity and molality of 20% aqueous of ethanol soln by volume (density of the soln=0.960g per cm3)
2) Calculate the volume of 80% H2SO4 (density=1.80g/cc) required to prepare 1L of 20% H2SO4 (density=1.25g/cc)
3) The solubility of Ba(OH)2.8H2O in water at 288K is 5.6g per 100g of water. What is the molarity of the hydroxide ions in the saturated solution f barium hydroxide at 288K? (at wt of Ba=-137, O=16, H=1)
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6 Answers
12)
80*v*1.8= 20*1.25*1000
v= 86.5 ml
3)
mole of barium hydroxide = 5.6/267 = 0.021 in 100 ml of water (assuming density of water 1g/cc)
[OH] = .42
11Q-1
let the total volume of solution be 100 cm3
density of soltion =0.96gm/cm3
therefore mass of solution = 96 gm
then according to question ethanol =20% by volume ie ethanol=20cm3
so volume of H2O in solution = 80cm3
now we know density of water =1gm/cm3
therefore mass of water in solution = 80gm
so mass of ethanol =16gm
moles of ethanol = 16/46 =8/23=0.348
therefore m(molality)= 0.34880*1000=4.35
now 1000cm3 =1 litre
therefore 100cm3(ie the volume of solution)=0.1 litre
therefore M(molarity)= 0.3480.1=3.48
i hope the answer is right
1Calculate the vapor pressure lowering of 0.1M aqueous solution of non-electrolytes at 75°C.