A reaction is said to have occurred;
1) when there is a color change
2) When a gas evolves
3) When a solid appears
A chemical reaction is said to have occurred when two or more substances interact to yield a new substance.
The question is incomplete as the bottles are not shown. However, a reaction is said to have occurred;
1) when there is a color change
2) When a gas evolves
3) When a solid appears
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