Answer: 
Explanation:
According to the law of conservation of mass, mass can neither be created nor be destroyed. Thus the mass of products has to be equal to the mass of reactants. The number of atoms of each element has to be same on reactant and product side. Thus chemical equations are balanced.
Thus in the reactants, there are 2 atoms of hydrogen and 2 atoms of iodine .Thus there has to be 2 atoms of hydrogen and 2 atoms of iodine in the product as well. Thus a coefficient of 2 is placed in front of HI.
The balanced chemical reaction is:

The crust
1. divergent (moves away from each other)
2. convergent (moves towards each other)
3. transform (slides past each other)
We do a heat balance to solve this:
(m cp ΔT)water = -(m cp ΔT)metal
100.8 (4.18) (27 - 22) = -65 (cp)(27-100)
cp = 100.8 (4.18) (27 - 22) / (-65 (27-100))
cp = 0.44 J/ (°C × g)
The specific heat of the metal is 0.44 J/ (°C × g)
Answer: Percent composition by element
Element Symbol Mass Percent
Hydrogen H 6.498%
Carbon C 19.357%
Nitrogen N 22.574%
Oxygen O 51.571%
HOPE THIS HELPS
Barium nitrate and methane (CH4) are both soluble. They both will dissolve in water, however, barium nitrate will dissociate becoming barium 2+ ions and nitrate becoming NO3 1- ions. All nitrates are soluble and dissociate. CH4 is a weak base and does dissolves but doesn't dissociate. So in solubility terms.... they are both equally soluble just one happens to dissociate into its cations and anions. Hope this helps!