After letters are written on white background with invisible borders we need to apply Phenolphthalein indicator which is a colourless solution. After letters are dried you can spray sodium hydroxide solution (a base) to the letters. Then it gives dark pink colour madam.
No madam, a chemical called phenolphthalein indicator should be used to write the invisible letters. Then you have to spray sodium hydroxide solution on the letters.
On white background you need to apply Phenolphthalein indicator which is a colourless solution to the letters. After letters are dried you need to spray sodium hydroxide solution, it gives dark pink colour madam.
Kon sa spray use kr rhe hai btaiye..
Pehele Letters ko phenolphthalein indicator lagana aur dry hone ke baad letters ko sirf sodium hydroxide(NaOH) solution spray karna Sir.
Good evening sir . Before using sodium hydroxide upon the board in which ink have you been written such that its invissibe
After letters are written on white background with invisible borders we need to apply Phenolphthalein indicator which is a colourless solution. After letters are dried you can spray sodium hydroxide solution (a base) to the letters. Then it gives dark pink colour madam.
Thank you sir
Can't we use soap or washing detergent solution instead of sodium hydroxide?
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Letter s should be written with Sketch?
No madam, a chemical called phenolphthalein indicator should be used to write the invisible letters.
Then you have to spray sodium hydroxide solution on the letters.
@@kalmeshdoddur thnq so much
Using which solution invisible letters are written
Phenolphthalein indicator is used for writing invisible letters.
Good evening.Can I know the spray used to see the hidden words
Sodium Hydroxide solution.
On what background the letters are written
On white background you need to apply Phenolphthalein indicator which is a colourless solution to the letters. After letters are dried you need to spray sodium hydroxide solution, it gives dark pink colour madam.