Answer:
1. Sulphuric acid
2. Car battery acid
3. Washing up liquid
4. Milk of magnesia
5. Metal polish
6. Oven cleaner
Explanation:
Universal paper can determine the pH of a solution. It ranges from dark red (pH 0 - very acidic) to orange/yellow, to green (pH 7 - neutral) to blue, dark blue and purple (pH 14 - very alkaline)
Sulphuric acid has the lowest pH as the universal indicator is red.
The next is car battery acid which is pink - not as acidic as red.
The next is washing up liquid, which is yellow, around pH 3 or 4.
The next is milk of magnesia with light blue, around pH 9 or 10.
Metal polish is dark blue - around pH 11.
Oven cleaner is the darkest, with purple.