To all chem buffs

[sam]

Can you help me get this done because, well I need help with my homework and the superbowl is starting soon etc. Thanks for your help you guys.

I need:
what type of chemical reaction is each experement,(single displacement decompisition, combustion etc) give a little to support your answer.

What is the role of phenolphthalein in experiment 3 and manganese dioxide in experiment 4

Here is the given information.

Experiment 1: Silver Nitrate and Sodium Iodide

Silver Nitrate – grey, hazey, translucent, liquid, sour odour.

Sodium Iodide – clear colourless liquid, foul odour.

Combined – smells like burning matches, opaque green liquid, thick like milk, some green chunks floating around.

Experiment 2: Calcium Metal and Water

Calcium Metal – grey rocks, solid, no odour

Water – clear colourless liquid, no odour

Combined – Bubbling, very hot, producing gas foaming, white, smells like chocolate

Experiment 3: Nitric Acid and Sodium Hydroxide

Nitric Acid – clear colourless liquid, no odour

Addition of phenolphthalein – clear colourless liquid, no odour

Sodium hydroxide – clear colourless liquid, no odour

Combined – No reaction, clear colourless liquid, no odour.

Experiment 4: Hydrogen Peroxide

Hydrogen peroxide – clear colourless liquid

Manganese dioxide – small black solid, sand like

Combined – bubbling black liquid, no smell, opaque, producing gas

Experiment 5: Magnesium Ribbon and Air

Magnesium Ribbon – black and white strips

Air – undetectable

Combined/set on fire – very bright white light, popped, flames and no smell.



Thanks you guys.

[Kurt_]

So you want me to do something like...this? It wasn't quite clear so I'm guessing:

Experiment 1: Silver Nitrate and Sodium Iodide

Silver Nitrate – grey, hazey, translucent, liquid, sour odour.

Sodium Iodide – clear colourless liquid, foul odour.

Combined – smells like burning matches, opaque green liquid, thick like milk, some green chunks floating around.

Double Displacement (I think) because the when silver reacts with iodine it produces a green milky substance that is insoluble in water. (Sorry I don't have my solubility table on me, don't quote me on this.)

Also, both the sodium and nitrate ions are soluble in water, so they will dissolve in the water and become unseen.

And that's what you need? That's IT?

[sam]

Thats it. Thanks so much for your help too.

[Kurt_]

I'm so bored, I'll find my old notes and do it FOR you.

[sam]

Kurt, you are my new favorite poster. Also, your from ontario you get bonus points. If there is anything I can do for you let me know.

[Kurt_]

Give me a solubility table Mine's gone. However I remember most of the substances an google's my friend.

Nevermind, got one.

[Xiro]

Ag(NO3)2+ NaI -> AgI2 + NaNO3

why dont you just write out the chemical formula for the reaction?

BTW: that is unbalanced

[sam]

Ag(NO3)2+ NaI -> AgI2 + NaNO3

why dont you just write out the chemical formula for the reaction?

BTW: that is unbalanced

My chem isnt what it used to be, I was in the hospital for a while and fell behind of the class and im trying to get my stuff back together. Also thank you Xiro.

[Kurt_]

I was just about to ask. Do you need the reaction?

@ Xiro: Once you have the reaction and reactants, you need to determine which ones are soluble in water.

[sam]

If you can, the reaction would be nice, but otherwise its not needed. (I would only use it to learn a bit more).

[Xiro]

In double replacement the 2 reactants are always aqueous (aq) and the result is always an aqueous (aq) and a solid (s) but on the solubility table it will say i for insoluble. If it says sS for slightly soluble ignore it and put aqueous

Edit: its also easy to memorize the table because certain elements such as sodium are ALWAYS soluble. therefore in my reaction i thought that it was implied the 2 reactants were aq and the sodium nitrate was soluble.

[Kurt_]

Experiment #2

Ca(s) + H20(l) => CaOH(aq) + H2(g)

Single Displacement

When any element from the alkali or alkaline groups react with water, hydrogen gas and a Hydroxide is produced. Therefore, the produced gas in the reaction is hydrogen.

[Xiro]

kurt dont forget the single displacement chart and make sure that it is possible for calcium to replace hydrogen, it is one of those wierd elements where sometime it can only be replaced when in an acid.

[Kurt_]

I'm quite aware. I did this stuff last semester, and I am the man at it. But thanks for the help.



Experiment #3

HNO3 + NaOH => H20 + NaNO3

When any acid and any base combine, water and a salt is formed. In this case, the salt is Sodium Nitrate.

The phenothalein in this reaction acts to determine if the reaction was complete. If an acid (or base, can't remember which) is present, the phenothalein will turn pink. However, if it is no longer present (a complete reaction occured) then the phenothalein turns clear.

[Xiro]

yea we did this last semester too. Now we are on nuclear reactions and light.