### In the reaction between sodium hydroxide and sulphuric acid solutions, what volume of 0.5 molar...

In the reaction between sodium hydroxide and sulphuric acid solutions, what volume of 0.5 molar sodium hydroxide would exactly neutralise 10cm3 of 1.25 molar sulphuric acid?

• A. 5cm3
• B. 10cm3
• C. 20cm3
• D. 25cm3
• E. 50cm3
##### Explanation

$$2NaOH + H_{2}SO_{4} = Na_{2}SO_{4} + 2H_{2}O$$
V x 0.5M = 2(10 x 1.25)
0.5V = 2 x 12.5
0.5V = 25
V = $$\frac{25}{0.5}$$ = $$50cm^{3}$$

#### Contributions (113)

Yes the best formula is CaVaNb= CbVbNa / CbNa we have CaVa Nb/CbNa hence 1.25x10x2/0.5x1= 25/0.5 =50cm3
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• Lilian: please how did they got v=250.5=50cm3
1 year ago
• Salawu,sodiq: Is Nt 250.5 Is 25 Divide By O.5 Recheck
1 year ago
• Elbrain: In this kind of question you will have to state the balanced chemical equation of the reaction before doing the calculation.
H2SO4 + 2NaOH ---> Na2SO4 + 2H2O;
Using the formula:-
(CaVa)/(CbVb) = na/nb
Where;
Ca (conc of the acid) = 1.25M
Cb (conc of the base) = 0.5M
Va (volume of acid) = 10cm3
Vb (volume of base) = Unknown
na (number of moles of acid) = 1
nb (number of moles of base) = 2
Substituting the values in the equation we have;
(1.25M x 10cm3)/(0.5M x Vb) = ½
Making Vb the subject of formula we have;
Vb = (1.25M x 10cm3 x 2)/(0.5M x 1)
Vb = 50cm3, Therefore the correct answer is option E
11 months ago
• Mary stephanie: But;
10*1.25/0.5vb=1/2
making vb d subject formular:
vb=2(10*1.25)/5
=50/5 and dat z 25.
pls am comfused here!
7 months ago
• Mary stephanie: I mean 10 nt 25
7 months ago
• Emmandez: That's 25/0.5=50
6 months ago
Usin cava/cbvb:na/nb therefore,ca=1.25,va=10cm,cb=0.5,vb=?,na=1 from d equation ,and nb=2 frm d equation therefore,goin to d formular 1.25*10/0.5*vb=1/2 wen u crossmultiply,d ansa u get is 50cm
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• Esiayo: How do they get no of A. and no of B.
1 year ago
• Abubakar: Thearis difference for this answer b/t a.b
1 year ago
• gbemisola: exactly
1 year ago
• Nappyboy: U will get number of na and nb from the reaction
9 months ago
• francis obi: The NA and NB IS USUALLY CONSTANT 1/2
5 months ago
Really enjoy u guys,u all try,bt my advice 2 u is 2. use d 2nd formulae 4 fast steppings nd answer
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• Herbeehorler: Do u know dat in chemistry by showing d equation it is anoda mark.
3 years ago
• Esiayo: Na jamb b dis wic kind 4mula den dey mark
2 years ago
• Elijah: Huh
1 year ago
• Blessing Lawrence: the formula for this question is cava/cbvb= na / nb
1 year ago
• james: Nice
11 months ago
It'z quite easy. Using the volumetric analysis formulae, CaVa/CbVb =Na/Nb where C, V and N are the concentrations, volumes and moles of the reactants, we get:( 1.25x10)/(0.5Vb) = 1/2. Calculating that will give us 50cm cube. NB: Don't 4get to multiply by 2.
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• faith timothy: why using 2
6 years ago
• faith timothy: why are we using 2
6 years ago
• emili: We r using 2 cus the Na at the product side is diatomic (2) so the reactant Na should be 2 too so we balance the equation, using the volumetric analysis formula (CaVa/CbVb=na/nb) nb=2 since we r looking for Vb, make it the subject of the formula,..
6 years ago
• Caezer John: Dia z no need for multiplyin wit 2 cos. dat 2 is already added in d formula as d mole ratio of base NaOH.
4 years ago
• Biola: Fantastic
1 year ago
• Candy: What are we multipling with 2
4 weeks ago
Since 2 was added to NaOH to balance the equation, in the calculation why is d 2 use to multiplied both volume and mole of the acid??
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Pls myschool your step on solving that question is very bad, pls correct yourself
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2 was gotten Hypothetical. A product of imagination nd conjecture.
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pls. Can explain more 2 me. Especialy how u derived d equation of reaction nd d formulae used. Pls guys.
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9c1 bro
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yes the ans is correct
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The equation is fully balance
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• Abubakar: M boy can you explain me simple reaction for this equation
1 year ago
well done guy... you did the better job
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yea. 50cm is the right ans.
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To derived NA2SO4 as d product, u av to add two @d back of sodium hydroxide(Naoh) to make d eqtn balance..so we derived two as d mole numba of naoh in d frmula of cava/cbvb=na/nb...u gat me rgt.?
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• Dancapable: So dat 2 is 4 NaOH is wic a base nd 1 4 d acid
6 years ago
• joseph ifezy: guys accordin 2 ma workings i got 20cm.
5 years ago
• dammy5: Joseph re calculate d ansa is 50cm
4 years ago
So dat's hw u'll gt 2.
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• bryb: u can use civi=cfvf
9 months ago