CHEM 1111 Experiment 5 Name: Section: Score: Experiment 5 Prelab Assignment he m
ID: 543676 • Letter: C
Question
CHEM 1111 Experiment 5 Name: Section: Score: Experiment 5 Prelab Assignment he mass of an empty evaporating dish and watch glass is 62.549 g. After the addition of an unknown, the mass was 63.089 g. The evaporating dish and unknown were heated strongly for 10 minutes. After cooling, the mass of the evaporating dish and sample were found to be 62.928 g. A sample of the unknown was also submitted to a flame test, and found to produce a violet flame. Is the unknown NaHCOs, Na2COs, KHCO3, or K2CO3? Explain the reasoning used to arrive at your answer.Explanation / Answer
Answer== first weight = 0.54 sample (tray weight-after addition sample weight)
weight of sample before heat- weight after cooling
===63.089-62.928
==0.161
Sample change == 0.54-0.16 ===0.38 which near about potassium molar mass also give violet flame , while sodium give yellow test...
On heating sample carbonate give co2 release and sample remains only which K..