Kinetics and organic chem revision

• 1,2 and 3 are correct

• 1 and 2 only are correct

• 2 and 3 only are correct

• 1 only is correct

• 1,2,3 and 4

• 1 and 2 only

• 3 and 4 only

• none

Which molecule contains a total of two sp hybridised atoms?

• HC≡CH

• H₂C≡CH₂

• HC≡C–C≡CH

• H₂C=CH–CH=CH₂

Which statement is correct to describe constitutional isomers?

•  

  C₄H₁₀ has three constitutional isomers

• But–1–ene and pen–1–ene are examples of constitutional isomers

• Constitutional isomers may differ in their chemical properties.

• Constitutional isomers may have different molecular formulae.

Propyne, C₃H_4, has the following structure.

H–C≡C–CH₃

Which of the following choices correctly decribes the bonding and hybridisation in a molecule of propyne?

• 1 pi bond; 1 sp C atom; 1 sp² C atom

• 2 pi bonds; 2 sp C atoms; 0 sp² C atom

• 2 pi bonds; 2 sp C atoms; 1 sp² C atom

• 3 pi bonds; 3 sp C atoms; 0 sp² C atom

Ethers have the general structure R₁–O–R₂ where R₁ and R₂ are hydrocarbon groups.

 

What is the lowest number of carbon atoms an ether molecule must contain to have a chiral carbon atom?

• 4

• 5

• 6

• 7

Four carbon-carbon bonds are labelled in the diagram.

Which bonds are made up of an sp²-sp² overlap?

• w and y only

• w, x and y only

• w, x, y and z

• x, y and z only

10. The rates of chemical reactions can often be increased by increasing the concentration of reactants or raising the temperature.

Which statements are correct?

1,Increasing the concentration increases the rate constant.

1. 2.Increasing the concentration increases the proportion of particles having energy greater than the activation energy.

2. 3.Increasing the temperature increases the rate constant.

3. 4. Increasing the temperature increases the proportion of particles having energy greater than the activation energy.

• 1,3 and 4

• 1 and 2

• 2,3 and 4

• 3 and 4

A reaction between P and Q produces a gas.

This reaction is first order with respect to P and second order with respect to Q. Two experiments were carried out.

In the first experiment, at given concentrations of P and Q, 100 cm3 of gas were produced in the first minute of the reaction.

In the second experiment, under the same external conditions, the initial concentration of P is doubled and that of Q is halved.

What volume of gas will be produced in the second experiment, in the first minute of the reaction?

• 25 cm3

• 50 cm3

• 100 cm3

• 200 cm3

The decomposition of hydrogen peroxide in aqueous solution is a first order process.

If 10% of the hydrogen peroxide in a solution of concentration 0.1 mol dm−3 decomposes in 5 minutes at a certain temperature, what percentage of the hydrogen peroxide in a solution of concentration 0.2 mol dm−3 would decompose in 5 minutes at the same temperature?

• 5%

• 10%

• 19%

• 20%