Delta T= T final - T initial
Tfinal= -101.1 °C
Tinitial= -0.5 °C
•Delta T = -101.1°C - (-0.5°C)
=100.6°C
Kelvin= °C + 273
= -100.6 + 273
= 172.4 Kelvin
Chromium has the electron configuration [Ar]4s13d5 and exhibits oxidation numbers 2+, 3+, and 6+. When chromium loses two electrons, it forms the Cr2+ ion and has the configuration [Ar]3d4.
The Answer is B. [Ar]3d4
Answer:
The volume of hydrogen gas produced at STP is 4.90 liters.
Explanation:
Moles of aluminium =
According to reaction , 2 moles of aluminium gives 3 moles of hydrogen gas.
Then 0.1333 moles of aluminium will give:
of hydrogen gas
Volume of 0.2 moles of hydrogen gas at STP = V
Temperature at STP = T = 298.15 K
Pressure at STP = P = 1 atm
n = 0.2 mol
PV = nRT (Ideal gas equation)
The volume of hydrogen gas produced at STP is 4.90 liters.
Answer:
23.2 g of Al will be left over when the reaction is complete
Explanation:
2Al + 3S → Al₂S₃
1 mol of Al = 26.98 g
1 mol of S = 32.06 g
Mole = Mass / Molar mass
63.8 g/ 26.98 g/m = 2.36 mole of Al
72.3 g / 32.06 g/m = 2.25 mole of S
2 mole of Aluminun react with 3 mole of sulfur
2.36 mole of Al react with (2.36 .3)/2 = 3.54 m of S
As I have 2.25 mole of S, and I need 3.54 S, is my limiting reagent so the limiting in excess is the Al.
3 mole of S react with 2 mole of Al
2.25 mole of S react with (2.25 m . 2)/3 = 1.50 mole
I need 1.50 mole of Al and I have 2.36, that's why the Al is in excess.
2.36 mole of Al - 1.50 mole of Al = 0.86 mole
This is the quantity of Al without reaction.
Molar mass . mole = Mass → 26.98 g/m . 0.86 m = 23.2 g
