Question

to test for protein, you added biuret solution and observed color changes. suppose that the color data below was observed. the data above indicate an error. how do you know? what might have caused the error?

Explanation:

Answer:

The negative control (water) should not show a positive result (pink/purple) for protein. Possible causes: contamination of the water sample, incorrect use of Biuret solution (e.g., wrong concentration, expired reagent), or improper handling during the test (e.g., using the same pipette for both control and sample without proper cleaning).