Answer:
x= 138.24 g
Explanation:
We use the avogradro's number
6.023 x 10^23 molecules -> 1 mol C2H8
26.02 x 10^23 molecules -> x
x= (26.02 x 10^23 molecules * 1 mol C2H8 )/6.023 x 10^23 molecules
x= 4.32 mol C2H8
1 mol C2H8 -> 32 g
4.32 mol C2H8 -> x
x= (4.32 mol C2H8 * 32 g)/ 1 mol C2H8
x= 138.24 g
Answer: molecular formula = C12H16O8
Explanation:
NB Mm CO2= 44g/mol
Mm H2O= 18g/mol
Moles of CO2 = 36.86/44=0.84mol
0.84mole of CO2 has 0.84 mol of C
Moles of H2O = 10.06/18= 0.56mol
1mol of H20 contains 1mol of O and 2 mol H,
Hence there are 0.56mol O and (0.56×2)mol H
Hence the compound contains
C= 0.84 mol H= 1.12mol O=0.56mol
Divide through by smallest number
C= 0.83/0.56= 1.5mol
H= 1.12/0.55= 2mol
O= 0.56/0.56= 1mol
Multiply all by 2 to have whole number of moles = 3:4:2
Hence empirical formula= C3H4O2
(C3H4O2)n = 288.38
[(12×3) + 4+(16×2)]n= 288.38
72n=288.38
n= 4
:. Molecular formula=(C3H4O2)4= C12H16O8
To determine the Ka of the acid, we can use the equation for the pH of weak acids which is expressed as:
pH = -0.5 log Ka
2.67 = -0.5 log Ka
Ka = 4.571x10^-6
Weak acids are acids that do not dissociate completely in solution. The solution would contain the cations, anions and the acid itself as a compound. Hope this helps.
