Calculate the volume of 0.5 mol dm\(^{-3}\) H\(_2\)SO\(_4\) that is neutralized by 25 cm\(^3\) of 0.1 mol dm\(^3\) NaOH?
5.0 cm3
2.5 cm3
0.4 cm3
0.1 cm3
Explanation
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Discussions (24)

CA VA /CB VB = na/nb
H2SO4+ 2NaOH—— Na2SO4+2H2O
1 : 2
CA=0.5
VA=?
CB=0.1
VB=25
na=1
nb=2
...0.5×VA/0.1×25= 1/2
0.1×25×1=0.5×2×CB
...CB=0.1×25×1/0.5×2
CB=2.5

The equation is ;
H2SO4 + 2NaOH •••••••••> NaSO4 + 2H2O
| |
1mol 2mol
Using the formula: CaVa/CbVb = Na/Nb
Ca = 0.5mol|dm³
VA = ?
Cb = 0.1mol|dm³
Vb = 25cm³
Na = 1
Nb = 2
Using the formula
CaVa / CbVb = Na / Nb
Therefore
VA = CbVbNa / CaNb
= 0.1* 25 * 1 / 0.5 * 2
= 2.5 / 1
= 2.5
Hence VA= 2.5cm³

CaVa/CbVb=na/nb....Ca=0.5, Va=?, Cb=0.1, Vb=25cm....
NaOH + H2SO4 = Na2So4 + H2O,
therefore ratio of no of moles of Acid to Base is 1:1...
CaVa x nb=CbVb x na...Va=CbVb x na/Ca x na ...
Va=0.1 x 25 x 1/0.5 x 1= 5

no ur equation is nt balanced....it is 2:1...xo d ans..is 2.5...myschool God bless u

H2SO4 + 2NAOH== NA2SO4+2H20
1Mol 2mol 1mol 2mol
CaVa/CbVb=1/2
0.5Va=1
0.1×25=2
2×0.5Va=1×0.1×25
1va=2.5
Va=2.5

2NAOH+H2So4 > 2NASO4 +2H2
2. : 1
NaOH=Base
H2So4=Acid
Concentration of acid =0.5mol dm-3
concentration of base =0.1mol dm-3
volume of acid = ?
volume of base =25Cm2
Ca Va/Cb Vb =Na/Nb
0.5*Va/0.1*25 =1/2
cross multiply
Va=0.1*25/0.5*2
Va=2.5/1
Va=2.5cm3

To calculate the volume of
0.5
mol dm
−
3
0.5mol dm
−3
H₂SO₄ neutralized by
25
cm
3
25cm
3
of
0.1
mol dm
−
3
0.1mol dm
−3
NaOH, we can use the concept of stoichiometry.
The balanced chemical equation for the neutralization reaction between sulfuric acid (H₂SO₄) and sodium hydroxide (NaOH) is:
H
2
SO
4
+
2
NaOH
→
Na
2
SO
4
+
2
H
2
O
H
2
SO
4
+2NaOH→Na
2
SO
4
+2H
2
O
From the equation, we can see that 1 mole of H₂SO₄ reacts with 2 moles of NaOH.
Given that the concentration of NaOH is
0.1
mol dm
−
3
0.1mol dm
−3
and the volume used is
25
cm
3
25cm
3
(which can be converted to
0.025
dm
3
0.025dm
3
), we can calculate the number of moles of NaOH used:
moles of NaOH
=
concentration
×
volume
moles of NaOH=concentration×volume
=
0.1
mol dm
−
3
×
0.025
dm
3
=0.1mol dm
−3
×0.025dm
3
=
0.0025
moles
=0.0025moles
According to the stoichiometry of the reaction, 1 mole of H₂SO₄ reacts with 2 moles of NaOH. Therefore, the number of moles of H₂SO₄ neutralized is half the number of moles of NaOH used.
moles of H
2
SO
4
=
1
2
×
moles of NaOH
moles of H
2
SO
4
=
2
1
×moles of NaOH
=
1
2
×
0.0025
moles
=
2
1
×0.0025moles
=
0.00125
moles
=0.00125moles
Now, we can use the concentration of H₂SO₄ to calculate the volume of H₂SO₄ required to neutralize this amount of moles:
volume
=
moles
concentration
volume=
concentration
moles
=
0.00125
moles
0.5
mol dm
−
3
=
0.5mol dm
−3
0.00125moles
=
0.0025
dm
3
=0.0025dm
3
Finally, we can convert this volume from dm³ to cm³:
volume
=
0.0025
dm
3
×
1000
cm
3
/
dm
3
volume=0.0025dm
3
×1000cm
3
/dm
3
=
2.5
cm
3
=2.5cm
3
Therefore, 2.5 cm³ of
0.5
mol dm
−
3
0.5mol dm
−3
H₂SO₄ is neutralized by
25
cm
3
25cm
3
of
0.1
mol dm
−
3
0.1mol dm
−3
NaOH.


