Classify the following as mistakes or errors. You touched the sample with your f
ID: 982460 • Letter: C
Question
Classify the following as mistakes or errors. You touched the sample with your fingers transferring some grease to the crucible you are weighing. The melting point apparatus was mis-calibrated, giving a value of.1*C higher than the accepted value. You incorrectly read the meniscus on a volumetric flask. You measure the same penny 4 different times on the same balance and get 4 slightly different readings. Determine the amount of NaCI you would weigh to make the solutions required for this experiment. Calculate the mass of NaCI needed to make 50 mL of a 5% w/v solution. (Record the mass on pg 17 of your lab procedure)Explanation / Answer
a) first one is error b)mistake c) mistake d) error
b) required 50 ml of 5 %vweight/ volume of solution
basis : 100 ml of solution it contains 5 wt% NaCl , hecne amonut of NaCl =5*100/100 =5 gms
50 ml contains 5*50/100= 2.5 gms of NaCl