Molality of the solution is defined as the number of moles of a substance dissolved divided by the mass of the solvent:
Molality = number of moles / solvent mass
From the concentration of 39% (by mass) of HCl in water, we construct the following reasoning:
in 100 g solution we have 39 g hydrochloric acid (HCl)
number of moles = mass / molecular weight
number of moles of HCl = 39 / 36.5 = 1.07 moles
solvent (water) mass = solution mass - hydrochloric acid mass
solvent (water) mass = 100 - 39 = 61 g
Now we can determine the molality:
molality = 1.07 moles / 61 g = 0.018
2 <span>KOH +1 H3AsO4 →1 K2HAsO4 + 2 H2O</span>
All organisms need four types of organic molecules: nucleic acids, proteins, carbohydrates and lipids; life cannot exist if any of these molecules are missing.
Atomic mass Hg = 200.59 u.m.a
200.59 g --------------- 6.02x10²³ atoms
( mass Hg ) ----------- 1.20 x10²² atoms
mass Hg = ( 1.20x10²² ) x 200.59 / 6.02x10²³
mass Hg = 2.407x10²⁴ / 6.02x10²³
= 3.998 g of Hg
hope this helps!
Answer:
The answer is 3-Phenylpropanoic acid (see attached structure)
Explanation:
From spectral data:
3005 cm-1 ⇒ carboxylic acid (broad band)
1670 cm-1 ⇒ C=C
1603 cm-1 ⇒ Aromatic C-C bond
H NMR frequency at 2.6 ppm, singlet, ⇒ OH with no surrounding protons, possible deshielding (clearer investigation of spectrum would be expedient).
Hence, our C9H10O2 compound has an aromatic ring and carboxylic acid group attached to it.