Question

a) Calculate the number of moles in 17.8 g of the antacid magnesium hydroxide, Mg(OH)2.

b) A 0.850-mole sample of nitrous oxide, a gas used as an anesthetic by dentists, has a volume of 20.46 L at 123°C and 1.35 atm. What would be its volume at 468°C and 1.35 atm?

Answer 1

Mg --> 24.3 g/mol
2 O --> 32
2 H --> 2
sum = 58.3 g/mol

17.8 g * (1 mol/ 58.3 g) = .305 Mol
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123 + 273 = 396 deg K
468 + 273 = 741 deg K

P1 V1/T1 = n R = P2 V2/T2

V2 = V1 (P1/P2) (T2/T1)

V2 = 20.46 (1.35/1.35) (741/396)

Answer 2

Brad