The student would find the water and sand, because salt dissolves in water unless it was ocean water or sea water
Answer:
chemical change because a different solid substance is formed.
Chloropicrin is obtained by the reaction of nitric acid on chloroform.
The answer to this question would be: C) a single replacement reaction
In single replacement reaction the molecule made in just one with an element. In this case, the compound is just swapping its element with a more reactive one, results in a more stable compound.
Contrast to the single replacement reaction, double replacement reaction or metathesis is the reaction which results in two new compounds. The cation from the molecule reaction is switching with the cation from other molecules.
In contrast to the double replacement reaction,
To find the Percent Composition of an atom, you use this formula:
Mass of element in the compound you're studying on ( in this case it's 5 since there is 5 Hydrogens) over the mass of the compound (which is here 79), Multiplied by 100 since you want a percent.
So we get:

So you get about:


So, the percent composition of Hydrogen in NH4HCO3 is 6.3%
Hope this Helps! :D