Question

20 mL of a solution containing Na2CO3 and NaHCO3 requires 10 mL of 0.1 N H2SO4 for neutralization using phenolphthalein as an indicator. Methyl orange is then added when a further 10 mL of 0.2 N H2SO4 is required. Molar concentration of Na2CO3 and NaHCO3 in the solution respectively are

Solution

Correct option is

0.05 and 0.05 M

 

Phenolphthalein end point :

Eq. mass of Na2CO3 = molar mass

Methyl orange end point :

Then, 20×M(NaHCO3) = (20 – 10)×0.1

SIMILAR QUESTIONS

Q1

For the reaction : 2H3PO2 → H3PO4 +PH3 , the equilvant mass of H3PO2 is

Q2

1 mole of equimolar mixture of ferric oxalate and ferrous oxalate will require x mol of KMnO4 in acidic medium for complete oxidation. is

Q3

If g is the mass of NaHC2O4 required to neutralize 100 mL of 0.2 MNaOH and y g that required to reduce 100 mL of 0.02 KMnO4 in acidic medium, then

Q4

A mixture of K2C2O4 and KHC2O4 required equal volumes of 0.1 M K2Cr2O7 for oxidation and 0.1 M NaOH for neutralization in separate titrations. The molar ratio of K2C2O4 and KHC2O4 in the mixture is :

Q5

An equilmolar mixture of Na2C2O4 and H2C2O4 required V1L of 0.1 M KMnO4 in acidic medium for complete oxidation. The same amount of the mixture required V2L of 0.1 M NaOH for neutralization. The ratio of V1 to V2 is

Q6

 

In an iodometric estimation, the following reactions occur

0.15 mol of CuSO4 of 80% purity was added to excess of KI solution and the liberated iodine required 12 mL 120mL of hypo. The molarity of hypo solution was

Q7

A mixture of NaOH and Na2CO3 required 25mL of 0.1 M HCl using phenolphthalein as indicator. However, the same amount of the mixture required 30mL of 0.1 M HCl when methyl orange was used as the indicator. The molar ratio of NaOH and Na2CO3 in the mixture was

Q8

A 1.70 g sample of H2O2 solution containing x% H2O2 by mass requires xmL of KMnO4 solution for complete oxidation under acidic condition. The molarity of KMnO4 solution is

Q9

What volume at STP of gaseous ammonia will be required to be passed into 100mL of 0.5 M H2SO4 to bring down its strength to 0.25 M?

Q10

A mixture containing 0.05 mol of K2Cr2O7 and 0.02 mol of KMnO4 was treated with excess of KI in acidic medium. The liberated iodine required 2.0 L of Na2S2O3 solution for titration. Concentration of Na2S2O3solution was