CHEM HELP PLEASE???!!! A solution containing ions of an unknown element X is divided into 3 samples. Identify X.?(multiple choice!)

Question

A solution containing ions of an unknown element X is divided into 3 samples. The following tests were performed on samples of the solution.

 

Sample              Test                   Observation

1                  Add H+ (aq)            No Change

2                  ADD OH-(aq)           No Change

3                 Add SO4-2 (aq)        No Change

 

A. Pb + 2 (aq)      B. Al + 3 (aq)       C. Ba +2 (aq)     D. Na + (aq)      E. CO3 -2 (aq)

 

Can you please help me? I need to learn why the correct answer is correct. I am just not sure how what to look for when trying to solve this. Is the fact there is no reaction for all three samples important? I think it is.

 

Thank you so much!

Answer 1

Hi, Angelica.

 

By no observable change they mean no precipitate and no gas bubbles. The key to precipitates is in the Solubility Rules, which can be found either in your text or online. Rule #1 about compounds of alkali metals should provide your answer. Also, carbonates tend to form gas when mixed with acids.

 

If you'd like further help on this or similar topics please contact me.

 

Bob K