Evaporation!
-Melting is a solid to a liquid
-sublimation is directly from a solid to a gas
-condensation gas to liquid
The combustion reaction is as expressed,
CxHy + O2 --> CO2 + H2O
The mass fraction of carbon in CO2 is 3/11. Hence,
mass of C in CO2 = (3.14 g)(3/11) = 0.86 g C.
Given that we have 1 g of the hydrocarbon, the mass of H is equal to 0.14 g.
moles of C = 0.86 g C / 12 g = 0.0713
moles of H = 0.14 g H / 1 g = 0.14
The empirical formula for the hydrocarbon is therefore, CH₂.
The Balanced chemical equation of reaction of Borane with oxygen is as follow,
B₂H₆ + 3O₂ -----> 2HBO₂ + 2H₂O
According to this equation 27.66 g (1 mole) of B₂H₆ reacts with oxygen to produce 36 g (2 moles) of water.
The amount of water produced when 19.2 g of B₂H₆ reacted is calculated as follow,

=

Solving for x,
x = (36 g of H₂O ₓ 19.2 g of H₂B₆) / 27.66 g of B₂H₆
x =
24.98 g of H₂O
Result:
24.98 g of water is produced when 19.2 g of B₂H₆ is reacted with excess of oxygen.
Answer:
Formula Weight of gas sample = 20.1 g/mole => Neon (Ne)
Explanation:
Use Ideal Gas Law formula to determine formula weight and compare to formula weights of answer choices.
PV = nRT = (mass/fwt)RT => fwt = (mass/Volume)RT = Density x R x T
Density = 0.900 grams/L
R = 0.08206 L·atm/mole·K
T = 0.00°C = 273Kfwt = (0.900g/L)(0.08206L·atm/mole·K )(273K)
= 20.1 g/mol => Neon (Ne)