Hi, can you post what you need help with??
Answer:
the law of multiple proportions, law of definite proportions, and law of conservation of mass.
Explanation:
(Hope this helps can I pls have brainlist (crown)☺️)
I'm assuming you're asking how to test for a starch,
To do so you do this thing called the "Iodine Test"
The potassium iodide aqueous solution will form this complex with starch to form a purplish-blue color.
However, watch out for the pH as hydrolysis of starch could occur to prevent the test from working out-- and the temperature as the greater it is, the less intense the color is
Answer: 
Explanation:
25.3% Mg
74.7% Cl
First step: change % to g
25.3g Mg
74.7g Cl
Second step: calculate g/mol of each compound. You can do this by using the atomic mass.


Third step: determine the lowest number and divide everything by it. Of the result, extract whole number only.


Fourth step: Write each compound with their respective number below.
This empirical formula should be: 