When 25 g of a non volatile solute is dissolved in 100g of water the vapour pressure is lowered by 0.225mm if the vapour pressure of water at 25 .C is 17.5mm.What is the molar mass of solute
Answers
What is the greatest number that divides 230, 1314, 1331, leaves a remainder of 5 in each case?
The question is the largest number that we can divide 230; 1314; and 1331 by and have a remainder of 5 in each case.
230 – 5 = 225
Factor 225 into prime numbers; 5 * 45 = 5 * 5 * 3 * 3
1314 – 5 = 1309
Factor 1309 into prime numbers; 7 * 187 = 7 * 11 * 17
1331 – 5 = 1326
Factor 1326 into prime numbers; 2 * 663 = 2 * 3 * 221 = 2 * 3 * 13 * 17
No common integer factors to all three numbers, therefore the solution is not an integer.
So we need to seek a real number solution to:
aX = (230 – 5); bX = (1314 – 5); cX = (1331 – 5) for integer values of a; b; and c
aX + 5 = 230; aX = 225, X = 225/a = 1314/b = 1326/c; 1/X = a/225 = b/1309 = c/1326
bX + 5 = 1314; bX = 1309
cX + 5 = 1331; cX = 1326
solve for X;
a; b; and c must be integers
a = 225b/1309 = 225c/1326; a = (2 * 2 * 3 * 3)b/(7 * 11 * 17) = (2 * 2 * 3 * 3)c/(2 * 3 * 13 * 17)
if b = 77; c = 78, then X = 225 * 77/1309 = 13.23529411764706; X = 225 * 78/1326 = 13.23529411764706
a = 17; b = 77; c = 78; X = 13.23529411764706 (approximately, this a real but not rational number); so divide the three numbers by 225 * 78/1326 or 2925/221or approximately 13.23529411764706