Answer:
There is 0.92 g of glucose in 100 mL of the final solution.
Explanation:
Initially, 11.5 g of glucose is added to the volumetric flask
Water is then added to 100 mL Mark,
The flask was then shaken until the solution was uniform.
The shaking of the mixture makes the concentration of glucose to become uniform all through the solution.
At this point, the concentration of this solution in g/mL is (11.5/100) = 0.115 g/mL
A 40.0 mL sample of this glucose solution was diluted to 0.500 L.
40.0 mL of the already mixed solution is then diluted to 0.500 L.
The mass of glucose in 40.0 mL of the mixed solution with concentration 0.115 g/mL is then given as
Mass = (conc in g/mL) × (volume) = 0.115 × 40 = 4.6 g
So, this mass is then diluted to 0.500 L mark.
New concentration = (mass)/(conc In mL) = (4.6/500) = 0.0092 g/mL
How many grams of glucose are in 100. mL of the final solution
Mass = (conc in g/mL) × (Volume in mL) = 0.0092 × 100 = 0.92 g
Hope this Helps!!!
To know this you pretty much do have to kind of memorize a few electronegativities. I don't recall ever getting a table of electronegativities on an exam.
From the structure, you have:
I remember the following electronegativities most because they are fairly patterned:
EN
H
=
2.1
EN
C
=
2.5
EN
N
=
3.0
EN
O
=
3.5
EN
F
=
4.0
EN
Cl
=
3.5
Notice how carbon through fluorine go in increments of
~
0.5
. I believe Pauling made it that way when he determined electronegativities in the '30s.
Δ
EN
C
−
Cl
=
1.0
Δ
EN
C
−
H
=
0.4
Δ
EN
C
−
C
=
0.0
Δ
EN
C
−
O
=
1.0
Δ
EN
O
−
H
=
1.4
So naturally, with the greatest electronegativity difference of
4.0
−
2.5
=
1.5
, the
C
−
F
bond is most polar, i.e. that bond's electron distribution is the most drawn towards the more electronegative compound as compared to the rest.
When the electron distribution is polarized and drawn towards a more electronegative atom, the less electronegative atom has to move inwards because its nucleus was previously favorably attracted to the electrons from the other atom.
That means generally, the greater the electronegativity difference between two atoms is, the shorter you can expect the bond to be, insofar as the electronegative atom is the same size as another comparable electronegative atom.
However, examining actual data, we would see that on average, in conditions without other bond polarizations occuring:
r
C
−
Cl
≈
177 pm
r
C
−
C
≈
154 pm
r
C
−
O
≈
143 pm
r
C
−
F
≈
135 pm
r
C
−
H
≈
109 pm
r
O
−
H
≈
96 pm
So it is not necessarily the least electronegativity difference that gives the longest bond.
Therefore, you cannot simply consider electronegativity. Examining the radii of the atoms, you should notice that chlorine is the biggest atom in the compound.
r
Cl
≈
79 pm
r
C
≈
70 pm
r
H
≈
53 pm
r
O
≈
60 pm
So assuming the answer is truly
C
−
C
, what would have to hold true is that:
The
C
−
F
bond polarization makes the carbon more electropositive (which is true).
The now more electropositive carbon wishes to attract bonding pairs from chlorine closer, thereby shortening the
C
−
Cl
bond, and potentially the
C
−
H
bond (which is probably true).
The shortening of the
C
−
Cl
bond is somehow enough to be shorter than the
C
−
C
bond (this is debatable).
PV=nRT
P= ? atm
V= 2 L
T= 423 K
n= 2.3 moles
R= 0.08205
(P)(2)=(2.3)(0.08205)(423)
P= (79.826445)/(2)
P= 39.9132225 atm
Answer:
4th Option
Explanation:
HNO3 is an acid, KOH is a base and they react to produce KNO3 which is a salt and H2O water.
So this reaction is a neutralisation reaction.