A solution contains Na2CO3 and NaHCO3. 10 mL of the solution required 2.5 mL of 0.1 M H2SO4 for neutralisation using phenolphthalein as indicator. Methyl orange is then added when a further 2.5 mL of 0.2 M H2SO4 was required. The amount of Na2CO3 and NaHCO3 in 1 litre of the solution is:

(a) 5.3g and 4.2g

(b) 3.3g and 6.2g

(c) 4.2g and 5.3g

(d) 6.2g and 3.3g

Concept Questions :-

Equivalent Concept
High Yielding Test Series + Question Bank - NEET 2020

Difficulty Level:

A sample of pure Cu (3.18g ) heated in a stream of oxygen for some time gains in mass with the formation of black oxide of copper (CuO). The final mas is 3.92 g. What per cent  of copper remains unoxidised?

1.$\approx$6.5

2.$\approx$6.9

3. $\approx$7.6

4. $\approx$7.9

Concept Questions :-

Equation Based Problem
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Difficulty Level:

One mole of a mixture of CO and CO2 requires exactly 20g of NaOH in solution for complete conversion of all the CO2 into Na2CO3. How much NaOH would it require for conversion into Na2CO3, if the mixture (one mole) is completely oxidised to CO2?

(a) 60g

(b) 80g

(c) 40g

(d) 20g

Concept Questions :-

Equivalent Concept
High Yielding Test Series + Question Bank - NEET 2020

Difficulty Level:

The mass  of 50% (w/w) solution of HCl required to react with 100g of CaCO3 would be:

(a) 73g

(b) 100g

(c) 146g

(d) 200g

Concept Questions :-

Equivalent Concept
High Yielding Test Series + Question Bank - NEET 2020

Difficulty Level:

Versene, a chelating agent having chemical formula C2H4N2(C2H2O2Na)4. If each mole of this compound could bind 1 mole of Ca2+, then the rating of pure versene expressed as mg of CaCO3 bound per g of chelating agent is:

(a) 100 mg

(b) 163 mg

(c) 200 mg

(d) 263 mg

Concept Questions :-

Equation Based Problem
High Yielding Test Series + Question Bank - NEET 2020

Difficulty Level:

A gas is found to have the formula (CO)x. Its VD is 70. The value of x must be:

(a) 7

(b) 4

(c) 5

(d) 6

Concept Questions :-

Moles, Atoms & Electrons
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Difficulty Level:

100 mL of PH3 when decomposed produces phosphorus and hydrogen. The change in volume is:

(a) 50  mL increase

(b) 500 mL decrease

(c) 900 mL decrease

(d) none of these

Concept Questions :-

Equation Based Problem
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Difficulty Level:

The molality of 1M solution of NaCl ( specific gravity 1.0585 g/mL ) is:

(a) 1.0585

(b) 1.0

(c) 0.10

(d) 0.0585

High Yielding Test Series + Question Bank - NEET 2020

Difficulty Level:

The total molarity of all the ions containing 0.1 M of CuSO4 and o.1M of Al2(SO4)3 is:

(a) 0.2M

(b) 0.7M

(c) 0.8M

(d) 1.2M

Concept Questions :-

Concentration Based Problem
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Difficulty Level:

Equal volumes of 0.1 M AgNO3 and 0.2 M NaCl are mixed. The concentration of N${\mathrm{O}}_{3}^{-}$ ions in the mixture will be:

(a) 0.1M

(b) 0.05M

(c) 0.2M

(d) 0.15M

Concept Questions :-

Concentration Based Problem