On putting few drops of an unknown liquid on pH strip, the colour of pH strip changed to green. The liquid taken?is likely to be (1)?water (2) dilute hydrochloric acid (3) lemon juice (4) dilute sodium hydroxide solutio
The green colour of pH strip indicates that the unknown substance is neutral that is neither acidic nor basic.
Hence the unknown substance in this case is water as it is neutral in nature.(pH = 7).