Which of the following has a maximum number of molecules?

1. 7g N₂ 

2. 2g H₂ 

3. 16g NO₂ 

4. 16g O₂ 

How much oxygen gas (O₂) at standard temperature (0°C) and pressure (1 atm) is required to completely combust 1 liter of propane gas (C₃H₈) under the same conditions?

Volume occupied by one molecule of water (density = 1gcm^-3) is 

1. 9.0 x 10^-23 cm³

2. 6.023 x 10^-23 cm³

3. 3.0 x 10^-23 cm³

4. 5.5 x 10^-23 cm³

A metal oxide has the formula Z₂O_3. It can be reduced by hydrogen to give free metal and water. 0.1596g of the metal oxide requires 6 mg of hydrogen for complete reduction. The atomic weight of the metal is

1. 27.9

2. 159.6

3. 79.8

4. 55.8

How many moles of lead (II) chloride will be formed from a reaction between 6.5 g of PbO and 3.2 g of HCl?

1. 0.044

2. 0.033

3. 0.011

4. 0.029

The product of atomic mass and specific heat of metal is approximately 6.4. This was given by:

1. Dalton's law

2. Avogadro's law

3. Newton's law

4. Dulong Petit's law

Which of the following represents the correct order of mass fractions (ω) of gases when 1 L of N₂, 7/8 L of O₂, and 1 L of CO are mixed under identical conditions of temperature and pressure?

1. ${\mathrm{\omega }}_{{\mathrm{N}}_2}={\mathrm{\omega }}_{{\mathrm{O}}_2}>{\mathrm{\omega }}_{\mathrm{CO}}$ 

2. ${\mathrm{\omega }}_{{\mathrm{N}}_2}={\mathrm{\omega }}_{\mathrm{CO}}>{\mathrm{\omega }}_{{\mathrm{O}}_2}$ 

3. ${\mathrm{\omega }}_{{\mathrm{N}}_2}={\mathrm{\omega }}_{{\mathrm{O}}_2}={\mathrm{\omega }}_{\mathrm{CO}}$

4. ${\mathrm{\omega }}_{\mathrm{CO}}>{\mathrm{\omega }}_{{\mathrm{N}}_2}>{\mathrm{\omega }}_{{\mathrm{O}}_2}$

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:

1. 5.3g and 4.2g

2. 3.3g and 6.2g

3. 4.2g and 5.3g

4. 6.2g and 3.3g

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:

1. 100 mg

2. 163 mg

3. 200 mg

4. 263 mg

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

1. 7 

2. 4

3. 5

4. 6