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C2 ions testing
C2 precipitates and ions testing
Question | Answer |
---|---|
What is the chemical test for Ca+2 ion? | when the compound is placed in a flame, the flame turns red |
What is the chemical test for Cu+2? | when the compound is placed in a flame, the flame turns green |
What is the chemical test for Cl-? | Add Nitric acid then silver nitrate AND acid solution; a white precipitate forms |
What is the colour of the flame when you burn Na+ ions? | Yellow |
What is the colour of the flame when you burn K+ ions? | Lilac |
What is the chemical test for CO3-2? | Fizz on addition of HCl; the gas produced will turn limewater cloudy |
What is the chemical test for SO4-2? | add Hydrochloric acid then barium chloride solution; a white precipitates forms |
What kind of ions does a flame test help identify? | Metallic ions |
Lead iodide is an insoluble salt. Describe the steps needed to prepare a pure, dry sample of lead iodide from solutions of lead nitrate and potassium iodide. | mixing solutions in a beaker filtering off the precipitate, including apparatus washing the precipitate drying the precipitate (oven/between filter papers) |
Describe the tests you could carry out on a sample of water to show that it contained dissolved Potassium Carbonate | sodium (ions) cause a yellow flame(1) for chloride ions: add dilute nitric acid (1) add silver nitrate (solution) (1) white precipitate/solid forms (1) |
Lead Iodide is insoluble. What solution could you add to Lead Nitrate to make Lead Iodide? | Sodium Iodide. Or Potassium Iodide. |
What is the name of the precipitate formed when Barium Nitrate is added to Sodium Sulfate? | Barium Sulfate |
What is Barium Sulfate used for? | To help with X-rays of the intestines |
Why do we ask patients to eat Barium Sulfate when they need an X-Ray of the intestines and yet Barium ions are toxic? | Because Barium Sulfate is insoluble so there are no Barium ions able to go into the blood. |
What is a precipitate? | A precipitate is formed when two solutions are mixed and an insoluble compound forms; the precipitate is the insoluble compound |
Are Nitrate salts soluble or insoluble? | Soluble |
Are Sodium Salts soluble or insoluble? | soluble |
When barium chloride solution, BaCl2, is added to sodium sulfate solution, Na2SO4, a white precipitate of barium sulfate, BaSO4, is formed. Write the balanced equation for this reaction. | Word equation first: barium chloride + sodium sulfate --> barium sulfate + sodium chloride Formulae: BaCl2 + Na2SO4 --> BaSO4 + NaCl Balancing: BaCl2 + Na2SO4 --> BaSO4 + 2 NaCl |
What is the trick to remember the salts that are always soluble? | SNAP; Sodium Nitrate Ammonium Potassium salts are always soluble |
What are the 3 insoluble salts that you MUST remember? | Calcium Carbonate; Barium Sulfate and Silver Chloride |
When calcium chloride solution, CaCl2, is added to sodium carbonate solution, Na2CO3, a white precipitate of barium sulfate, CaCO3, is formed. Write the balanced equation for this reaction. | Word equation first: calcium chloride + sodium carbonate--> calcium carbonate + sodium chloride Formulae: CaCl2 + Na2CO3 --> CaCO3 + NaCl Balancing: CaCl2 + Na2CO3 --> CaCO3 + 2 NaCl |
What is the formula of Magnesium Chloride? | get the CHARGES from the Periodic table: Mg+2 and Cl-1; then SWAP THE NUMBERS and write at the bottom: Mg1Cl2 |
What is the formula of Magnesium Nitrate? | get the CHARGES from the Periodic table or LEARN special groups: Mg+2 and (NO3)-1; then SWAP THE NUMBERS and write at the bottom: Mg1(NO3)2 |
What is the formula of Sodium Sulfate? | get the CHARGES from the Periodic table or LEARN special groups: Na+1 and (SO4)-2; then SWAP THE NUMBERS and write at the bottom: Na2(SO4)1 |
What two solutions could you use to make a precipitate of Silver Chloride? | Silver nitrate and Sodium chloride; both chemicals are soluble because of SNAP |
What is the formula of Barium Sulfate? | get the CHARGES from the Periodic table or LEARN special groups: Ba+2 and (SO4)-2; then SWAP THE NUMBERS and write at the bottom: Ba2(SO4)2; check if you need to CANCEL when both subscripts are 2: Ba(SO4) |