Answer:
I believe that there are 70.2
Explanation:
There are 2 atoms in sodium chloride so I x 35.1 by 2 and got 70.2
Answer: 581 gmol
0.581 kmol
Explanation:
According to avogadro's law, 1 mole of every substance occupies 22.4 L at STP and contains avogadro's number 
of particles.
To calculate the moles, we use the equation:
1. The conversion for mol to gmol
1 mol = 1 gmol
581 mol= 
2. The conversion for mol to kmol
1 mol = 0.001 kmol
581 mol= 
3. The conversion for mol to lbmol
1 mol = 
581 mol= 
Answer:
Explanation:
The chemical equation is:
There are several definitions of acid and bases: Arrhenius', Bronsted-Lowry's and Lewis'.
Bronsted-Lowry model defines and <em>acid</em> as a donor of protons, H⁺.
In the given equation HNO₃ is such substance: it releases an donates its hdyrogen to form the H₃O⁺ ion.
On the other hand, a <em>base</em> is a substance that accepts protons.
In the reaction shown, H₂O accepts the proton from HNO₃ to form H₃O⁺.
Thus, H₂O is a base.
In turn, on the reactant sides the substances can be classified as acids or bases.
H₃O⁺ contain an hydrogen that can be donated and form H₂O; thus, it is an acid (the conjugated acid), and NO₃⁻ can accept a proton to form HNO₃; thus it is a base (the conjugated base).
(a)
pH = 4.77
; (b)
[
H
3
O
+
]
=
1.00
×
10
-4
l
mol/dm
3
; (c)
[
A
-
]
=
0.16 mol⋅dm
-3
Explanation:
(a) pH of aspirin solution
Let's write the chemical equation as
m
m
m
m
m
m
m
m
l
HA
m
+
m
H
2
O
⇌
H
3
O
+
m
+
m
l
A
-
I/mol⋅dm
-3
:
m
m
0.05
m
m
m
m
m
m
m
m
l
0
m
m
m
m
m
l
l
0
C/mol⋅dm
-3
:
m
m
l
-
x
m
m
m
m
m
m
m
m
+
x
m
l
m
m
m
l
+
x
E/mol⋅dm
-3
:
m
0.05 -
l
x
m
m
m
m
m
m
m
l
x
m
m
x
m
m
m
x
K
a
=
[
H
3
O
+
]
[
A
-
]
[
HA
]
=
x
2
0.05 -
l
x
=
3.27
×
10
-4
Check for negligibility
0.05
3.27
×
10
-4
=
153
<
400
∴
x
is not less than 5 % of the initial concentration of
[
HA
]
.
We cannot ignore it in comparison with 0.05, so we must solve a quadratic.
Then
x
2
0.05
−
x
=
3.27
×
10
-4
x
2
=
3.27
×
10
-4
(
0.05
−
x
)
=
1.635
×
10
-5
−
3.27
×
10
-4
x
x
2
+
3.27
×
10
-4
x
−
1.635
×
10
-5
=
0
x
=
1.68
×
10
-5
[
H
3
O
+
]
=
x
l
mol/L
=
1.68
×
10
-5
l
mol/L
pH
=
-log
[
H
3
O
+
]
=
-log
(
1.68
×
10
-5
)
=
4.77
(b)
[
H
3
O
+
]
at pH 4
[
H
3
O
+
]
=
10
-pH
l
mol/L
=
1.00
×
10
-4
l
mol/L
(c) Concentration of
A
-
in the buffer
We can now use the Henderson-Hasselbalch equation to calculate the
[
A
-
]
.
pH
=
p
K
a
+
log
(
[
A
-
]
[
HA
]
)
4.00
=
−
log
(
3.27
×
10
-4
)
+
log
(
[
A
-
]
0.05
)
=
3.49
+
log
(
[
A
-
]
0.05
)
log
(
[
A
-
]
0.05
)
=
4.00 - 3.49
=
0.51
[
A
-
]
0.05
=
10
0.51
=
3.24
[
A
-
]
=
0.05
×
3.24
=
0.16
The concentration of
A
-
in the buffer is 0.16 mol/L.
hope this helps :)
There are 6.02 × 10²³ formula units of CaCl2 in 111 g CaCl2. Details about formula units can be found below.
<h3>What is a formula unit?</h3>
Formula unit refers to the empirical formula of an ionic compound for use in stoichiometric calculations.
According to this question, there are 111g of CaCl2. The formula units can be calculated by multiplying the number of moles by Avogadro's number.
no of moles in CaCl2 = 111g ÷ 111g/mol = 1mol
Formula units of CaCl2 = 1mol × 6.02 × 10²³ = 6.02 × 10²³ formula units.
Therefore, there are 6.02 × 10²³ formula units of CaCl2 in 111 g CaCl2.
Learn more about formula units at: brainly.com/question/21494857
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