how many grams are in 8.44 moles of Ar?
How many moles are in 288g of ZnCl2?
What is the mass in grams of 6.750 moles of CH3CH2OH2, ethanol?
How many grams of F2(g) are needed to react with 5.40 grams of Na(s)?
2006-11-18 08:42:40 · 3 answers · asked by Anonymous in Science & Mathematics ➔ Chemistry
1. molar mass of Ar: Mr = 40, so
m = n x Mr = 8.44 x 40 = 337.6 g
2. molar mass of ZnCl2: Mr = 136.4, so
n = m/Mr = 288/136.4 = 2.11 mol (approx)
3. The right formula of ethanol is CH3CH2OH and it's molar mass: Mr = 46, so
m = n x Mr = 6.75 x 46 = 310.5 g
4. Atomic mass of Na: Ar = 23, so we have:
n = m/Ar = 5.4/23 = 0.235 mol of Na.
According to the chem. equation:
2Na + F2 --> 2NaF
2 mol of Na react with 1 mol of F2, so
0.235 mol of Na react with 0.235/2 = 0.117 mol of F2
Molar mass of F2: Mr = 19
m = n x Mr = 0.117 x 19 = 2.23 g of F2
2006-11-18 10:21:50 · answer #1 · answered by Dimos F 4 · 0⤊ 0⤋
mass = moles * molar mass
mass = 8.44 * 39.9
mass of Ar is 336.756 grams
moles = mass/molar mass
moles = 288g/136.4
moles of ZnCl2 is 2.11 moles
mass = moles * molar mass
mass = 6.750 * 47
mass of ethanol is 317.25 grams
F2 + Na ---> NaF2
moles of Na = mass/molar mass
moles of Na = 5.40g/23
moles of Na = 0.235
the moles ratio between F2 and Na is 1 : 1
so same moles is needed for F2
moles = mass/molar mass
0.235 = mass/ 38
mass of F2 = 8.92 grams
2006-11-18 09:24:00 · answer #2 · answered by Treat 2 · 0⤊ 1⤋
336,756 grams Ar
2 moles
??
4,46grams
2006-11-18 09:03:32 · answer #3 · answered by a b 1 · 0⤊ 0⤋