 # Chemistry help! Anonymous
timer Asked: Oct 21st, 2013
account_balance_wallet \$5

### Question Description

the density of ethanol (C2H5OH) is 0.789 g/ml at room temperature. how many H atoms are present in 10.56 cubic meter of ethanol at this temperature?

duingpung
School: Cornell University   Solution:

Density of ethyl alcohol = mass / volume
Hence,
mass = density * volume
mass = 0.789 g/mL * 200 mL
mass = 157.8 g

Note: volume of solution in above case = 100mL + 100 mL = 200 mL

We know,
Number of moles of ethyl alcohol ( n ) = mass / molecular mass
n = 157.8 / 46
n = 3.43 mol

Note: molecular mass of C2H5OH = 2*12 + 5*1 + 16*1 + 1 = 46 g

Molarity of ethyl alcohol ( M ) = number of moles of ethyl alcohol / total volume (in Litres)
M = 3.43/ 0.2
M = 17.15 g/L

Note: In molarity volume should always be in Litres. Hence, above, Volume = (100 + 100) mL = 200 mL = (200/1000) L = 0.2 L.

flag Report DMCA  Review Anonymous
Good stuff. Would use again. Brown University

1271 Tutors California Institute of Technology

2131 Tutors Carnegie Mellon University

982 Tutors Columbia University

1256 Tutors Dartmouth University

2113 Tutors Emory University

2279 Tutors Harvard University

599 Tutors Massachusetts Institute of Technology

2319 Tutors New York University

1645 Tutors Notre Dam University

1911 Tutors Oklahoma University

2122 Tutors Pennsylvania State University

932 Tutors Princeton University

1211 Tutors Stanford University

983 Tutors University of California

1282 Tutors Oxford University

123 Tutors Yale University

2325 Tutors