Kanika identified the nature of few substances with the help of three different indicators. She listed down her observations in the given table with some blanks.

S. No	Substance	Red litmus paper	Turmeric solution	China rose indicator
1.	Lime water	Blue	p	green
2.	Curd	no change	no change	q
3.	Table salt	no change	no change	no change
4.	Toothpaste	r	red	s
5.	Lemon juice	no change	no change	magenta

Identify p, q, r and s