We did a lab and we put a piece of zinc in hydrochloric acid, placed our thumb over the test tube for one minute, then put a piece of burning splint is over it. I don't understand WHY the chemical change happened. please help me!
2007-09-18 06:12:03 · 2 answers · asked by Stephanieeexoxo 2 in Science & Mathematics ➔ Chemistry
Do you know what the funny thing is....i did this lab like 3 days ago in the Putting it together lab thing. Ok well this is what happens. Zinc and Hydrochloric acid reacts together and has a single displacement reaction. This occurs because in the activity series (pg 20 of ur course pack if its the same) zinc can displace hydrogen. And since zinc displaces hydrogen, instead of zinc + hydrochloric acid, it's Hydrogen + Zinc Chloride. Now that hydrogen is out they want you to test if its there. You put ur finger over the tube because they want to give the zinc more time to react and they dont want the hydrogen to escape out of the tube. Now you test if there is hydrogen. This is by simply sticking a burning splint inside. and....POP!!! there is hydrogen!! check ur text boook for more understanding.
balanced Formula is
Zn + 2HCl --> H2 + ZnCl2
2007-09-21 07:27:11 · answer #1 · answered by H4X0Rshocks 3 · 0⤊ 0⤋
The oxidatiion potential of Zn is such that it is above H in the electromotive series. Hydrogen is flammable in air.
Zn + 2HCl ===> ZnCl2 + H2
2H2 + O2 ===> 2H2O
2007-09-18 06:18:37 · answer #2 · answered by steve_geo1 7 · 1⤊ 0⤋