Subject :NSO Class : Class 8
Rohan burned a substance X and collected the evolved vapours in a test tube making sure that they do not
escape. Then he added small amount of water to the
test tube. The solution so formed turned blue litmus
red.
Rahul burned a substance Y, collected the white ash
formed and dissolved it in water. The solution so
formed turned red litmus blue. Substances X and Y
could be respectively
AP and Mg
BCa and P
CMg and S
DS and Mg