Answer:
Na₂CO₃•H₂O
Explanation:
After it is heated, the remaining mass is the mass of sodium carbonate.
30.2 g Na₂CO₃
Mass is conserved, so the difference is the mass of the water:
35.4 g − 30.2 g = 5.2 g H₂O
Convert masses to moles:
30.2 g Na₂CO₃ × (1 mol Na₂CO₃ / 106 g Na₂CO₃) = 0.285 mol Na₂CO₃
5.2 g H₂O × (1 mol H₂O / 18.0 g H₂O) = 0.289 mol H₂O
Normalize by dividing by the smallest:
0.285 / 0.285 = 1.00 mol Na₂CO₃
0.289 / 0.285 = 1.01 mol H₂O
The ratio is approximately 1:1. So the formula of the hydrate is Na₂CO₃•H₂O.
Q = ?
Cp = 0.397 J/ºC
Δt = 40.3 - 21.0<span> => 19.3</span><span> ºC</span>
m = 15.2 g
Q = m x Cp x Δt
Q = 15.2 x 0.397 x 19.3
Q ≈ 116.46 J
<span>hope this helps! </span>
<span> the first ionization </span>energy<span> of an element is the </span>energy<span> needed to</span>remove<span> the outermost, or highest </span>energy<span>, </span>electron<span> from a neutral </span>atom<span> in the gas phase.</span>
<span>s sublevel = s orbital
p sublevel= p orbitals
the level tells you which orbitals exactly,
so level 3,
sub level p = 3p orbitals </span>
