Asample of a white powder is given to you to identify. you can use the benedict test, the lugol test, the biuret test, and the sudan red test to identify it. if the white powder was an starch, how would each of the tests turn out

The test to confirm the presence of starch is Benedict's test

Explanation:

Benedict solution is used to test for simple carbohydrates (reducing sugars such as monosaccharides and some disaccharides). It has a blue colour because of the presence of copper (in the form of CuSO₄) in the benedict solution.

The white powder can be dissolved in water to make a saturated solution. When few drops of benedict's solution (blue colour) is added to about 1 ml of the white powdered solution and then subjected to heat (perhaps in a water bath), a green/yellow/orange/red precipitate will indicate the presence of starch (reducing sugar).

Biuret test is used to test for protein. It also has a blue colour which is also due to the presence of copper (in the form of CuSO₄) in the biuret solution.

When few drops of biuret solution is added to about 1 ml of the white powdered solution, there will be no colour change to violet/pink/purple which would have signified the presence of protein.

Sudan red test is used to identify/test for lipids. It has a red colour as evident from the name. It is a fat-soluble dye and would not dissolve in water. It basically stains lipids.

If few drops sudan red dye is added to the white powdered solution, the solution will not dissolve/stain the solution since it is not soluble in water.

From the above, it can be deduced that Benedict test will confirm the white powder to be starch

that is true   : ) hope this you