Chemical reaction question??

[nerflight]

Ok I have a question......here is what I am trying to do.....have a image put onto a surface but it will be unseen.....i then spray water or something onto the surface and make the image appear.

 

How can this be done????

[YT2095]

very easily, weak solns of potassium hexacyanoferate and and iron sulphate will do this.

[John Cuthber]

You could do it with very clean glass. Paint the image on with silicone oil then spray a fine mist of water onto it. The mist will stay as fine drops where the oil is but will spread out to a thin layer where the glass is clean.

That way you can really use water in the spray.

Otherwise you are basicly looking at the world of invisible inks and developers. I'm sure google will help you with that.

[nerflight]

thanks for the ideas....I tested out bug and tar...and car wax before...it made the image darker when wet with water but no color changes or anything.

 

 

I'm hoping to find something to make the image go from clear to maybe purple.....

 

 

I'll try out YT209's idea tomorrow.

[nerflight]

do i mix the two liquids together or do a i add water to any of the items you mentioned?

[YT2095]

you put either liquid onto the paper and let it dry, then spray the other liquid as a fine mist over it, whatever you wrote on the paper will show as a deep blue like ink.

 

for purple I seem to rem a carefully balanced mix of potassium permangante and iron sulphate added so as to Just make it turn clear as water, I forgot what the catalyst to make it purple again was though????

[nerflight]

I've been researching this method....I only found so far about the same thing you already told me.

 

 

 

1. Potassium manganate(VII) solution is chosen because manganate(VII) ions in acidic solution are a strong enough oxidising agent to oxidise Fe(II) to Fe(III) and the reaction is quick and quantitative.Secondly, because of the change of colour, from deep purple to almost colourless, when manganate(VII) forms Mn2+(aq), the titration is self-indicating. No indicator needs to be added as the (almost) colourless mixture turns pink at the end-point with the addition of the final drop of manganate(VII).

Potassium manganate(VII) is a solid that can be obtained reasonably pure - pure enough for work at school level. For very accurate analyses, however, it is not used as a primary standard and solutions need to be standardised, using e.g. oxalic acid.

[nerflight]

Here is what another person has told me....I'm not too chemistry savy....nothing too adavnced..but tell me what you make of this which a person told me today......would this mean something like a thing used in pools which change different colors after it is put into a pool????

 

 

Try an indicator solution and spray with the appropriate acid/base solution to turn a colorless indicator to a colored form. For example, an acidic solution of Phenolphthalien will be colorless, but will become a bright pink when exposed to a sufficiently strong base. The transition occurs at a pH of 8 - 10, so strong acids and bases are not required.

[Darkblade48]

Here is what another person has told me....I'm not too chemistry savy....nothing too adavnced..but tell me what you make of this which a person told me today......would this mean something like a thing used in pools which change different colors after it is put into a pool????

 

 

Try an indicator solution and spray with the appropriate acid/base solution to turn a colorless indicator to a colored form. For example, an acidic solution of Phenolphthalien will be colorless, but will become a bright pink when exposed to a sufficiently strong base. The transition occurs at a pH of 8 - 10, so strong acids and bases are not required.

 

I'm not sure whether pools are normally kept on the basic side of the pH scale, so I can't say for certain whether or not addition of phenolphthalien to a swimming pool will cause it to turn pink. In addition, I would imagine you'd need quite a bit of the indicator, since a swimming pool is usually quite large in terms of volume.

[nerflight]

I'm not talking about making a pool change colors hahahaha

 

I'm making a image appear on a object {non paper object}......pool supplies have test kits which go from clear to various colors.