Answer:
0.576M and 0.655m
Explanation:
<em>...Dissolves 15.0g of styrene (C₈H₈) in 250.mL of a solvent with a density of 0.88g/mL...</em>
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Molarity is defined as moles of solute (Styrene in this case) per liter of solution whereas molality is the moles of solute per kg of solvent. Thus, we need to find the moles of styrene, the volume in liters of the solution and the mass in kg of the solvent as follows:
<em>Moles styrene:</em>
Molar mass C₈H₈:
8C = 12.01g/mol*8 = 96.08g/mol
8H = 1.005g/mol* 8 = 8.04g/mol
96.08g/mol + 8.04g/mol = 104.12g/mol
Moles of 15.0g of styrene are:
15.0g * (1mol / 104.12g) = 0.144 moles of styrene
<em>Liters solution:</em>
250mL * (1L / 1000mL) = 0.250L
<em>kg solvent:</em>
250mL * (0.88g/mL) * (1kg / 1000g) = 0.220kg
Molarity is:
0.144 moles / 0.250L =
<h3>0.576M</h3>
Molality is:
0.144 moles / 0.220kg =
<h3>0.655m</h3>
Answer:
Explanation:
Please, find the image with the pictured molecule for this question attached.
The molecule has one oxygen atom (red) covalently bonded to one hydrogen atom (light grey), one nitrogen atom (blue) covalently bonded to two hydrogen atoms (light grey), and two carbon atoms (dark grey) bonded each to two hydrogen atoms (light grey).
<em>Hydrogen bondings</em> are intermolecular bonds (bonds between atoms of two different molecules not between atoms of the same molecule). The hydrogen bonds are attractions between the positive end of one hydrogen atom and the negative end of a small atom of other molecule (N, O, or F).
Since, nitrogen and oxygen are much more electronegative than hydrogen atoms, you conclude that:
- The two hydrogen atoms covalently bonded to the nitrogen atoms have considerably partial positive charge.
- The hydrogen atom covalently bonded to the oxygen atom also has a a relative large partial positive charge.
So, those are three ends of the molecule that can form hydrogen bonds with water molecules.
The hydrogen bondings are only possible when hydrogen is covalently bonded to N, O or F atoms.
Answer:
CH4
- 4 electron
- 0 electron
- the geometry of Ch4 is tetrahedral
AlF3
- 3 electron
- 0 electron
- the geometry is trigonal planar
CCl4
- 4 electron
- 0 electron
- the geomotry is tetrahedral
SeH2
- 2 electron
- 2 electron
- the geometry is V shape
Silver has to give up one electron in order to achieve a pseudo-noble gas electronic configuration.<span />