Answer:Lithium
Explanation:Lithium has 3 protons, and 4 neutrons making it the lightest element that isn't a gas.
Answer:
1.
(NH4)2Cr2O7——>Cr2O7+N2+4H2O
2.
6CO2+6H2O——>C6H12O6+6O2
1. For the first question, we must find the mass of the anhydrous salt, MgSO₄. The molar mass for MgSO₄·7H₂O is 246.47 g/mol, while that of MgSO₄ is 120.37 g/mol.
7.834 g MgSO₄·7H₂O * 1 mol MgSO₄·7H₂O/246.47 g * 1 mol MgSO₄/1 mol MgSO₄·7H₂O * 20.37 g MgSO₄/mol = <em>0.647 g MgSO₄</em>
2. Mass of Water = Mass of sample - Mass of anhydrous sale
Mass of water = 7.834 - 0.647 = 7.19 g
Percent Water in Hydrate = 7.19/7.834 * 100 = <em>91.74%</em>
