A solubility investigation
...ss liquid NaCl Colourless liquid AgNO3 Colourless liquid Ba(NO3) 2 Colourless liquid RESULTS: Table Two – Results when one solution is added to the other Solution No. 6 5 4 3 2 1 Ions present Ba2+NO3- Ag+NO3- Na+Cl- K+NO3- K+CrO42- Na+CrO42- 1 Na+CrO42- Yellow precipitate formed in a colourless liquid Red/brown precipitate formed in a yellow liquid No observed change No observed change No observed change 2 K+CrO42- Yellow precipitate formed in a colourless liquid Red/brown precipitate formed in a yellow liquid No observed change No observed change 3 K+NO3- No observed change No observed change No observed change 4 Na+Cl- No observed change White precipitate formed in a colourless liquid 5 Ag+NO3- No observed change 6 Ba2+NO3- DISCUSSION: In the mixing of the six solutions, fifteen different combinations were formed. Of these combinations, only five solutions formed a new a substance, the remaining ten combinations having had no apparent change when the solutions were mixed. The solutions which did not form a precipitate were: 1+2 – a new combination of ions was not formed as both solutions contained CrO42- 1+3 – a new combination of ions was formed. 1+4 – a new combination of ions was not formed as both solutions contained Na+ 2+3 – a new combination of ions was not formed as both solutions contained K+ 2+4 – a new combination of ions was formed. 3+4 – a new combination of ions was formed. 3+5 – a new combination of ions was not formed as both solutions contained NO3- 3+6 - a new combination of ions was not formed as both solutions contained NO3- 4+6 – a new combination of ions was formed. 5+6 – a new combination of ions was not formed as both solutions contained NO3- The combinations of solutions which formed new ions (1+3, 2+4, 3+4, 4+6) showed that under these particular experimental conditions, K2CrO4, Na2CrO4, NaNO3 and BaCl2 are shown to be soluble. Only five combinations of solutions created a precipitate: 1+5 The precipitate formed was silver chromate - Ag2CrO4 Na2CrO4(aq) + 2AgNO3 (aq) Ag2CrO4(s) + 2NaNO3(aq) 2Na+(aq) + CrO42-(aq) + 2Ag+(aq) + 2NO3-(aq) Ag2CrO4(s) + 2Na+(aq) + 2NO3-(aq) CrO42-(aq) + 2Ag+(aq) 2AgCrO4(s) 1+6 The precipitate formed was barium chromate - BaCrO4 Na2CrO4(aq) + Ba(NO3)2 (aq) BaCrO4(s) + 2NaNO3(aq) 2Na+(aq) + CrO42-(aq) + Ba2+(aq) + 2NO3-(aq) BaCrO4(s) + 2Na+(aq) + 2NO3-(aq) CrO42-(aq) + Ba2+(aq) BaCrO4(s) 2+5 The precipitate formed was silver chromate - Ag2CrO4 K2CrO4(aq) + 2AgNO3 (aq) Ag2CrO4(s) + 2KNO3(aq) 2K+(aq) + CrO42-(aq) + 2Ag+(aq) + 2NO3-(aq) Ag2CrO4(s) + 2K+(aq) + 2NO3-(aq) CrO42-(aq) + 2Ag+(aq) Ag2CrO4(s) 2+6 The precipitate formed was barium chromate - BaCrO4 K2CrO4(aq) + Ba(NO3)2 (aq) BaCrO4(s) + 2KNO3(aq) 2K+(aq) + CrO42-(aq) + Ba2+(aq) + 2NO3-(aq) BaCrO4(s) + 2K+(aq) + 2NO3-(aq) CrO42-(aq) + Ba2+(aq) BaCrO4(s) 4+5 The precipitate formed was silver chloride – AgCl NaCl(aq) + AgNO3 (aq) AgCl(s) + NaNO3(aq) Na+(aq) + Cl-(aq) + Ag+(aq) + NO3-(aq) AgCl(s) + Na+(aq) + NO3-(aq) Cl-(aq) + Ag+(aq) AgCl(s) As both the chromate solutions provided with were yellow in colour, the yellow precipitate formed in combinations 1+6 and 2+6 (barium chromate) were presumed to be of the chromate solution. Because of this, the sodium nitrate and potassium nitrate created in the formation of ions proved to be the colourless solution in which the precipitate was suspended in. Due to the fact that the nitrate solutions provided with were colourless, in addition to the evidence gathered from this experiment, it can be assumed that all nitrates are colourless. Although combinations ...