please help answer question 4 and 5

4. A mixture of table salt and ice is used to chill the contents of hand-operated ice-cream makers. What is the melting point of a mixture of 2.00 kg of NaCl and 12.00 kg of ice if exactly half of the ice melts? Assume that all the NaCl dissolves in the melted ice and that the van't Hoff factor for the resulting solution is 1.44.[4 points) 5. The hemoglobin found in human red blood cells has a molar mass of about 6.2 X 109 g/mol. What concentration range of hemoglobin will result in an osmotic pressure between 0.35 atm and 0.55 atm at 37C in aqueous solution? [4 points)