Do not look directly at the flame. Save the ash in a small beaker for the next procedure. If magnesium is substance “A” in the general equation, what is AAA. Add a dropper-full of distilled water and a drop of phenolphthalein. The phenolphthalein is only an indicator for the presence of hydroxide ion and does not enter into the equation. Decomposition reactions Bal. Work under the hood! Weigh out exactly 0. 1 Goff ammonium dichloride and add to a test tube. Clamp and warm gently with a Bunsen burner. Two of he products of this reaction are and nitrogen gas.
Watch for evidence of the third product. BE. Place a few crystals of copper(al)sulfate penetrated in a test tube. Clamp the tube and heat in a horizontal position. One of the products is copper(al)sulfate. What is the other one? This decomposition reaction is easily reversible. Add a eyedropper of water to the tube when it cools. Record what happens. Replacement reactions CLC. Work under the hood! Place a piece of zinc in a test tube. Add about 5 ml of 6 M HCI and allow the zinc to effervesce. Ignite a wooden splint in a Bunsen runner flame and hold this flame to the mouth of the test tube.
If hydrogen is generated as one of the products, you will hear a “pop”. Note that the test for hydrogen is a combination reaction. What is the hydrogen combining with? CO. A) Place a small piece of zinc in a test tube containing about 3 ml of copper(al) sulfate solution. CO. B) In a second test tube, place a small piece of copper in about 3 ml of zinc chloride solution. Note the original appearance of the metals and colors of solutions. Put these test tubes aside for at least 5 minutes and then write down your observations.