Forty millilitre of CO was mixed 100 mL of O₂ and the mixture was exploded. On cooling, the reaction mixture was shaken with KOH. What volume of gas is left?

• 80 ml of O₂

• 60 ml of O₂

• 80 ml of CO₂

• 50 ml of CO₂

42.

Arrange the following (I to IV) in the order of increasing masses:

I. 0.5 mole of O₃

II. 0.5 g atom of oxygen

III. 3.011 x 10²³ mlecules of O₂

IV. 5.6 l of CO₂ at STP

• II < IV < III < I

• IV < III < I < II

• II < I < IV < III

• I < II < III < IV

75 c.c. of N/5 H₂SO₄, 10 c.c. of N/2 HCl and 30 c.c. of N/10 HNO₃ are mixed together. The strength of the resulting acid mixture is:

• 0.1N

• 0.2N

• 0.3N

• 0.4N

One mole of FeC₂O₄ is oxidised by x moles of Cr₂${\mathrm{O}}_7^{2-}$ in acidic medium , x is:

• 0.5

• 1.0

• 1.5

• 2.0

One gram of mass is equal to :

• 9 x 10²⁰ ergs

• 7 x 10¹⁵ ergs

• 5 x 10¹⁰ ergs

• 3 x 10⁵ ergs

Vapour density of a volatile substance is 4 (CH₄ = 1). Its molecular weight would be:

• 2

• 8

• 64

• 128

20 mL of 0.5 N HCl and 35 mL of 0.1 N NaOH are mixed. The resulting solution will :

• be neutral

• be basic

• turn phenolphthalein solution pink

• turn methyl orange red

A bivalent metal has an equivalent mass of 32. The molecular mass of the metal nitrate is :

• 182

• 168

• 192

• 188

35.4 mL of HCl is required for the neutralization of a solution containing 0.275 g of sodium hydroxide. The normality of hydrochloric acid is?

• 0.97 N

• 0.142 N

• 0.194 N

• 0.244 N

The value of amu is which of the following?

• 1.57 $\times$ 10^-24 kg

• 1.66 $\times$ 10^-24 kg

• 1.99 $\times$ 10^-23 kg

• 1.66 $\times$ 10^-27 kg