please i want these solve thank you 8- a) Calculate the molar volume (the volume
ID: 540983 • Letter: P
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please i want these solve
thank you
8- a) Calculate the molar volume (the volume occupied by one mole) of sodium metal, Na. The density of Na is 0.971 g/mL b) The liquid CHBr, has a density of 2.89 g/mL. What volume of this liquid contains a total of 3.40 x 10 molecules? Elemental Perecent of Mass by Formula 9- ) Calculate the mass percent of water in the ionic hydrate ZnSO 7H20 b) Calculate the mass of nitrogen in 30.0 g of the amino acid glycine, H2N-CH2-CO,H c) What is the mass of oxygen contained in 5.50 g of KCIO, d) Which contains more sulfur, 40.8 g calcium sulfate, CaSO, or 35.2 g of sodium sulfite, Na,SO,?Explanation / Answer
Solution:- (8) (a) Given density of Na is 0.971 g/mL. Let's convert this to mol/L.
(0.971 g/mL) x (1mol/22.99 g) x (1000 mL/1L) = 42.2 mol/L
From this, the volume of 42.2 moles of Na the volume is 1 L. What would be the volume of 1 mol of Na? We can use the proportion for this.
42.2 mol/L = 1mol/X
on cross multiply...
X = 1mol x 1 L/42.2 mol = 0.0237 L = 23.7 mL
(b) Convert molecules to moles then grams and finally using density convert the grams to mL and finally Liters.
3.40 x 1024 molecules x (1mol/6.022 x 1021 molecules) x (252.72 g/1mol) x (1 mL/2.89 g) x (1L/1000mL) = 49.4 L
(9) (a) mass percent of water = (mass of water/mass of hydrate) x 100
There are 7 water molecules of water(H2O) in one molecule of the hydrate.
Molar mass of water is 18.02, so the mass of water in hydrate = 7(18.02) = 126.14 g
Mass of hydrate would be molar mass of hydrate here.
mass of hydrate = 65.38 + 32.06 + 4(16) + 7(18.02)
= 65.38 + 32.06 + 64 + 126.14
= 287.58 g
mass percentage of water = (126.14/287.58) x 100 = 43.86%
(b) Molar mass of glycine = 2(12.01) + 5(1.01) + 1(14.01) + 2(16)
= 24.02 + 5.05 + 14.01 + 32 = 75.08 g/mol
From given formula of glycine, 1 mol of it has 1 mol of N.
So, 30.0 g glycine x (1mol/75.08 g) x (1mol N/1mol glycine) x (14.01 g/1mol) = 5.60 g nitrogen
(c) Molar mass of KClO3 = 39.098 + 35.45 + 3(16) = 122.548 g/mol
1 mol of KClO3 has 3 moles of O. So,....
5.50 g KClO3 x (1mol/122.548 g) x (3 mol O/1 mol KClO3) x (16 g/1mol) = 2.15 g oxygen
(d) molar mass of CaSO4 = 40.078 + 32.06 + 4(16) = 136.138 g/mol
1 mol of CaSO4 has 1 mol of S. So......
40.8 g CaSO4 x (1mol/136.138 g) x (1 mol S/1 mol CaSO4) x (32.06 g/1mol) = 9.61 g sulfur
molar mass of Na2SO3 = 2(22.99) + 32.06 + 3(16) = 126.04 g/mol
1 mol of Na2SO3 has 1 mol of S. So....
35.2 g Na2SO3 x (1mol/126.04 g) x (1 mol S/1 mol Na2SO3) x (32.06g/mol) = 8.95 g sulfur
From calculations, 40.8 g CaSO4 has more sulfur.
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