Where are the transition metals found in the periodic table?
On the left of the periodic table, in groups 1 and 2
In the middle of the periodic table, between groups 2 and 3
On the right of the periodic table, in groups 7 and 8
What two things must be present for iron to rust?
Why are alloys typically stiffer than pure metals?
The metallic bonding is stronger in alloys
The metal atoms are all very regularly arranged in an alloy
The layers of metal atoms in the alloy cannot slide over each other very easily
A student had calculated the theoretical yield of a product was 8 g. The actual yield obtained was 6 g. What was the percentage yield?
Which of the following could explain why the percentage yield in a chemical reaction was less than 100%?
The top pan balance was faulty
The reaction forms more than one product
Some of the product was lost during pouring liquids
The RFM of the desired product in a reaction is 95. The sum of the RFM values for the reactants is 113. What is the atom economy for this reaction?
A solution has a volume of 650 cm3. What is the volume of this solution in dm3?
A solution of NaOH has a concentration of 0.2 mol/dm3. Calculate its concentration in g/dm3. The RFM of NaOH is 40.
A sample of methane gas has a volume of 120 cm3 at room temperature and pressure. The molar volume is 24 dm3. How many moles of methane are present in the sample?
What does NPK stand for in terms of fertilisers?
P - phosphorous
Which of the following statements about dynamic equilibrium is true?
The reaction has finished
The forwards and reverse reactions occur at the same rate
The concentration of reactants is the same as the concentration of products
Which of these factors does not affect the choice of reaction pathway in an industrial chemical manufacturing process?
The yield of product formed
The relative formula mass of the products
The uses for any by-products formed
What is the only chemical product when hydrogen and oxygen are reacted together in a fuel cell?
Rusting is a specific example of corrosion, and requires both and water for iron to rust. There are three ways to prevent iron from rusting:
- exclusion of (by either using an atmosphere of or argon)
- exclusion of (by storing with a desiccant)
- sacrificial protection (when a more reactive than iron is attached to the object to prevent from rusting)
Fuel cells will produce a voltage continuously, provided they have a constant supply of fuel and oxygen (from the air).