I believe that it is 187.56 g/mol
Answer:
- 13,150.6kJ
Explanation:
CH4 + 2 O2 ------> CO2 + 2 H2O ΔH= – 890 kJ
The ΔH is enthalpy change of combustion , which is the heat is either absorbed or released by the combustion of one mole of a substance.
ΔH=−890 kJ/mol (released in the combustion of one mole of methane)
using the molar mass (in grams )of methane to get moles of sample
(237g × 1 mole of CH4)/16.04g=14.776 moles of CH4
Since 1 mole produces 890 kJ of heat upon combustion, then 14.776 moles will produce
ΔH = 14.776moles of CH4 × 890kJ/1mole of CH4
=13,150.6kJ
Therefore ΔH = - 13,150.6kJ
See the correct answer is b.)PbS
Amorphous is the answer. A glass is an amorphous solid.
Answer:
The molarity of the solution is 7.4 mol/L
Explanation:
From the question above
0.400 ml of water contains 1.00 g of hydrochloride form of cocaine
Therefore 1000 ml of water will contain x g of hydrochloride form of cocaine
x = 1000 / 0.400
x = 2500 g
2500g of hydrochloride form of cocaine is present in 1000 ml of water.
Mole of hydrochloride form of cocaine = mass /molar mass of hydrochloride
Mole of hydrochloride form of cocaine = 2500/339.8
= 7.4 mol
Molarity = mol/ volume in liter (L)
molarity = 7.4 /1
Molarity = 7.4 mol/L
