Question

Question 1: Ten drops of 1.0M Na2CO3 are placed into each of two small test tubes. To the first test tube, 2 drops of 0.1M Ca(NO3) is added, and to the second test tube, 2 drops of 0.1M Ma(NO3)2 is added. Describe the likely observation for each test tube and state how these results could or could not be used to distinguish between the cations.

Question 2: 6 drops of 0.5M bromine in organic solvent is placed in each of two small test tubes. To the first test tube, 15 drops of 0.1 NaBr is added.=, and to the second test tube, 15 drops of 0.1M NaI is added. Describe the likely observation for each test tube and state how these results could or could not be used to distinguish between the anions.

Answer 1

Q1.

a) tube 1

Na2CO3 + Ca(NO3)2 not likely to form any reaction, expect no change, other than change in volume

b) tube 2

Na2CO3 + Ma(NO3)2 not likely to form any reaction, expect no change, other than change in volume

Note that Ma+2 must be stated, since it is not a proper element

Q2.

a) test tube 1

Bromine in organic material + bormine in aquoeus

There is no reaction, only distribution between aqueous/organic layer

b) test tube 2.

I- and Br2(l) reacts, since there is redox reaction

I2 form and Br- forms