Okay I did the math and I'm guessing around 18*C
3Si + 2N2 --> Si3N4 (as given)
n(Si) = m/MM = 38.25/28.085 = 1.3619 mol
n(N2) = 14.33/2*14.007 = 0.5115 mol
Therefore, N2 is limiting and Si is in excess
The molar ratio of 2N2:Si3N4 is 2:1
So, 0.0575 mol of silicon nitride is formed (dividing 0.5115 by 2)
m of silicon nitride= n*mm = 0.0575*140.283 = 8.06627... g
= 8.066g (4 significant figures)
(hopefully it is right, but double check in case i did something wrong) :)
+2
Barium has a positive charge of 2
Answer:
See explanation
Explanation:
The substance under analysis must be a polar organic substance of high molecular mass. We must remember that as the magnitude of dispersion forces increases with increase in molecular mass, the melting point increases accordingly. Also polar organic substances have very high melting points due to the presence of polar bonds in the molecule..
Hence the intramolecular forces in the substance are covalent bonds while the intermolecular forces are both dispersion forces and dipole forces.
The substance may likely be 1,2,3,4,6,7,8-Heptachlorodibenzo-p-Dioxin which a white powder and melts at 264 °C.
