Answer:
A. percentage mass of iron = 5.17%
percentage mass of sand = 8.62%
percentage mass of water = 86.205%
B. (Iron + sand + water) -------> ( iron + sand) ------> sand
C. The step of separation of iron and sand
Explanation:
A. Percentage mass of the mixtures:
Total mass of mixture = (15.0 + 25.0 + 250.0) g =290.0 g
percentage mass of iron = 15/290 * 100% = 5.17%
percentage mass of sand = 25/290 * 100% = 8.62%
percentage mass of water = 250/290 * 100% = 86.205%
B. Flow chart of separation procedure
(Iron + sand + water) -------> separation by filtration using filter paper and funnel to remove water --------> ( iron + sand) -----------> separation using magnet to remove iron ------> sand
C. The step of separation of iron and sand by magnetization of iron will have the highest amount of error because during the process, some iron particles may not readily be attracted to the magnet as they may have become interlaced in-between sand grains. Also, some sand particle may also be attracted to the magnet as they are are borne on iron particles.
Answer: The final temperature will be 
Explanation:
To calculate the specific heat of substance during the reaction.

where,
q = heat absorbed =41840 J
c = specific heat = 
m = mass of water = 200 g
= final temperature =?
= initial temperature = 
Now put all the given values in the above formula, we get:


Thus the final temperature will be 
Sulfur is not a transition metal so it does not need a Roman numeral the correct answer is Trisulfur Dichloride
In order to determine, Order of reaction, we have to add all the exponents written in the Chemical form, on the Reactant species.
Hope this helps!
I think the answer would be Ga3+