Practice Paper 1A (SL IB Chemistry)

The atomic number of an element gives the number of protons in the nucleus which is also equal to the number of electrons. Which statement explains why atoms are neutral?

What is the correct sequence for the orbitals shown in an atom of vanadium in order of decreasing energy?

A hydrated carbonate of an unknown Group 1 metal has the formula X₂CO₃∙10H₂O and is found to have a relative formula mass of 286.19                              

What is the Group 1 metal?

The ideal gas equation below summarises the gas laws.

pV = nRT

Which statement below is correct?

Aluminium iodide, Al₂I₆ is a dimer and exists as a solid at room temperature. When it is a vapour it can exist as an AlI₃ molecule. 

How many valence electrons are in an aluminium iodide, AlI₃, molecule?

Below are four molecules. Which is the most polar molecule present?

Which of the following metals will have the greatest ability to conduct electricity?

A compound has an empirical formula of C₂H₆O and a molar mass of 92.16.

What is the molecular formula of this compound?

The correct order of increasing boiling points for the following compounds is

The properties of alloys can be explained in terms of metals having

1. Non-directional bonding
2. Delocalised electrons
3. Ions of different size

Which features about the members of a homologous series are correct?

1.  all members have the same general formul
2.  the members have similar chemical properties
3.  the members show a gradual change in physical properties

Which of the following statements is true as you move down Group I?

What is the correct IUPAC name for the molecule shown?

The x-axis of the graph below is the atomic number of the elements in Period 3.

Which variable could represent the y-axis?

Which statement is true about all exothermic reactions?

A basic definition of Hess’s Law states that the overall enthalpy change for a reaction is the same independent of the route taken. 

The addition of which of the following statements makes the definition of Hess’s Law more complete? 

1. Providing that the reactants are the same
2. Providing that the products are the same
3. Providing that the conditions at the start and the end of the reaction are the same

Which compound has an M_r of 84.18 and will react with HBr to give a product with an M_r of 165.09?

Some bond energy values are listed below.

These bond energy values relate to the following four reactions. 

What is the correct order of enthalpy changes of the above reactions from most negative to most positive? 

A hydrocarbon, X, was burned in excess oxygen to give carbon dioxide and water as the only products. 0.1mol of X produced 9.08dm³ of carbon dioxide at standard conditions.

What is the molecular formula of X?

Which sample contains the largest amount, in mol, of atoms?

The energies of the reactants, the products and the transition state of a reaction are shown in the reaction pathway diagram below.

Which expression correctly represents how to calculate the activation energy of the forward reaction?

Bleach solution contains sodium chlorate (I) which naturally decomposes according to the equation below:

2NaClO (aq)  → 2NaCl (aq)  +  O₂ (g)

The bleach decomposes faster as the temperature increases. A 100 cm³ sample of 10% bleach was heated to 40 C and the amount of oxygen evolved was measured against time.

The experiment was repeated under the same conditions, but this time using a 100 cm³ sample of 20% bleach. If the first experiment produces the dotted line, which line is produced by the second experiment?

The reaction between nitrogen and hydrogen produces ammonia gas:

N₂ (g) + 3H₂ (g)    2NH₃ (g)

If the equilibrium constant for the reaction is x, what is the equilibrium constant for the following reaction?

2N₂ (g) + 6H₂ (g)    4NH₃ (g)

Perbromic acid, HBrO₄ , is an example of a strong acid when dissolved in water. What is true about perbromic acid?

In which compound are there two different elements with the same oxidation number?

When sulfuric acid and sodium iodide react, one of the reactions that takes place is shown by the equation below: 

            8NaI  +  9H₂SO₄  →  8NaHSO₄  +  4I₂  +  H₂S  +  4H₂O 

Which species has been oxidised in this reaction?

Isomers X and Y both react with HBr.

 A mixture of X and Y is reacted with HBr.

Which three structures represent three different possible products of this reaction?

Which statements about the chlorine free radical are correct?

1. It has 17 electrons.
2. It is an uncharged species.
3. It is formed by homolytic fission.

In the hydrolysis of bromoethane by aqueous sodium hydroxide, what is the nature of the attacking group and of the leaving group?