CHEM 1151L Lab Manual - Page 81 Post Lab: Additional Molarity Calculation Practi
ID: 695583 • Letter: C
Question
CHEM 1151L Lab Manual - Page 81 Post Lab: Additional Molarity Calculation Practice 1. Calculate the mass of NaCI needed to make 100. ml of solution that is 1.00 M in sodium cation (Na'). (We ask for the sodium cation concentration since once the salt has dissolved it has dissociated into Na and Cl. There is no "NaCI" in the solution anymore.) Calculate the mass of magnesium chloride needed to make 250. ml of a solution that is 0.240 M in chloride ion (Ch). Note that the formula for magnesium chloride has more than one chloride in each unit. This affects the amount you need to put into the solution. 2. Calculate the mass of iron (IIl) chloride needed to make 500. ml of a solution that is 0.0150M in Fe. Again the formula has more than one chloride in each unit. Does it affect the amount you need this time? 3.Explanation / Answer
1.weight(w)=molarity(M)*GMW*V/1000
W=1*58.5*100/1000=5.85gm
2.w=0.12*95*100/1000=2.85gm
3.w=0.015*162.5*500/1000=1021875gm