Answer:
The question is incomplete. The structures were not added to the question. Find attached of the structure and the given answer.
Explanation:
See the attached file for explanation
1. 2Pb(NO₃)₂ → 2PbO + 4NO₂ + O₂
2. CH₄ + 2O₂ → CO₂ + 2H₂O
3. Cu + 2AgNO₃ → Cu(NO₃)₂ + 2Ag
4. MnO₂ + 4HCl → MnCl₂ + 2H₂O + Cl₂
5. Pb(NO₃)₂ + 2NaCl → PbCl₂ + 2NaNO₃
1)

2)
CuSO_4+Cu_2Cl_2\neq>

Hey there!
In order to solve for the percentage of water in the compound, you will first need to find its total molar mass. You can do this by adding up the molar masses of each individual element in the compound. Then, you will divide the mass that you find of the water molecules by the total mass to get the percentage.
→ Na₂CO₃ ×<span> 10 H</span>₂<span>O
</span>→ Na₂ = 22.9898 × 2 = 45.9796
→ C = 12.0107
→ O₃ = 15.999 × 3 = 47.997
→ 10 H₂O = 18.015 × 10 = 180.15
Now, just add all of those numbers up for the total molar mass.
→ 45.9796 + 12.0107 + 47.997 + 180.15 = <span>286.1373
</span>
The last step is to divide the molar mass of the 10 water molecules by the total mass.
→ 180.15 ÷ 286.1373 = <span>0.62959 </span>≈ 0.63
Your answer will be about 63%.
Hope this helped you out! :-)
Substances can change state, usually when they are heated or cooled. For example, liquid water turns into steam when it is heated enough, and it turns into ice when it is cooled enough. ... The closeness, arrangement and motion of the particles in a substance change when it changes state.