C2B Quiz

In Chemistry, we use the suffix (aq) to represent
1. that water has been formed in the reaction
2. that the substance is dissolved in water
3. that the substance is insoluble in water
4. that water acts as a catalyst
This reaction is a precipitation reaction.
Sodium thiosulphate + hydrochloric acid --> Sulphur dioxide + sulphur + sodium chloride + water
Which one substance is the precipitate?
1. Sodium thiosulphate?
2. Sulphur dioxide
3. Sulphur
4. Sodium chloride
In the precipitation reaction, which one of these methods is used to monitor the rate of reaction with the LEAST uncertainty?
1. Using a data-logger and a light sensor
2. Placing the flask on a piece of paper with a black cross on it, and watching the cross disappear.
3. Using a precision balance to find the mass of sulphur dioxide lost at ten second intervals
4. Taking samples at ten second intervals to measure the concentration of sodium chloride.
Which one of these events is the only one that results in a reaction?
1. Particles collide
2. Particles drift.
3. Particles dissolve.
4. Particles are made smaller
On which one of these does the rate of reaction depend?
1. How badly the particles are dented by the collisions
2. The noise caused by the collisions.
3. The time taken in the collisions
4. The frequency of collisions
Which one of these does NOT increase the rate of reaction?
1. Adding a catalyst.
2. Increasing the pressure.
3. Increasing the size of particles.
4. Increasing the temperature.
Before a reaction can start, it has to be given a push. This is called the:
1. activation energy
2. kinetic energy
3. potential energy
4. internal energy
Catalysts increase the rate of reaction by:
1. reacting with the reactants
2. increasing the energy needed to start the reaction.
3. breaking up particles into smaller particles, increasing the rate of reaction.
4. weakening bonds between atoms.
Biological catalysts are called:
1. Hormones
2. Enzymes
3. Proteins
4. Nucleic acids
At which temperature in degrees Celsius do biological catalysts work best?
1. 23
2. 37
3. 42
4. 85
An anomalous result is one that:
1. lies exactly on the curve.
2. lies slightly outside the curve, but is well within the uncertainty of the experiment.
3. does not fit the pattern of the rest of the results.
4. is used as a reference point.
If smaller particles are used in a rate of reaction experiment, which one of these statements is true?
1. The rate of reaction with the smaller particles is faster to start with, but a smaller amount of products is formed in the end
2. The rate of reaction with the smaller particles is faster to start with, but the same amount of products is formed in the end
3. The rate of reaction with the smaller particles is slower to start with, but the same amount of products is formed in the end
4. The rate of reaction with the smaller particles is the same to start with, but the same amount of products is formed in the end
To measure the rate of reaction when a gas is given off, we need to plot a graph of change of mass against time. Which feature of the graph gives us the rate of reaction at any point?
1. The mass lost at any given time.
2. The area under the graph
3. The gradient of the graph at any point
4. The gradient of the graph from the start time to the end time
We can increase the concentration of a reactant. How does that affect the initial rate of reaction and the amount of product formed?
1. The increased concentration leads to a decreased rate of reaction and less product.
2. The increased concentration makes no difference at all to the rate of reaction and the amount of product is the same.
3. The increased concentration leads to a decreased rate of reaction, but an increased amount of product.
4. The increased concentration leads to an increased rate of reaction, and the same amount of product.
Which catalyst is used in car exhausts?
1. Iron
2. Platinum
3. Vanadium pentoxide
4. Manganese oxide
The reaction calcium carbonate --> calcium oxide + carbon dioxide can be carried out by heating the calcium carbonate in a sealed box. The effect of this is that:
1. the reaction doesn't happen at all.
2. the reaction goes to completion
3. the sealed box could explode due to the pressure of carbon dioxide.
4. there is a balanced state in which the forward reaction goes at the same rate as the reverse reaction.
In the reaction calcium carbonate --> calcium oxide + carbon dioxide the carbon dioxide is allowed to escape. What affect will this have on the reaction.
1. The reaction will remain in equilibrium.
2. More calcium carbonate will be formed.
3. More calcium oxide will be formed.
4. The reaction will stop
If an exothermic equilibrium reaction is in a closed system, what happens if you heat the reaction mixture?
1. More reactants are formed.
2. More products are formed.
3. The equilibrium is not affected at all.
4. The reaction is stopped.
In a closed system, what is the effect of increasing the pressure?
1. The amount of reactants increases
2. The amount of products increases
3. The equilibrium point is not affected.
4. The reaction stops
What effect will adding a catalyst have on an equilibrium reaction?
1. It will increase the rate of reaction and the equilibrium is moved in favour of the products.
2. It will increase the rate of reaction, but equilibrium is moved in favour of the reactants.
3. It will increase the rate of reaction, but the equilibrium stays the same.
4. It will increase the rate of reaction by being used up in the reaction because it is very reactive itself
In the Haber Process, the activation energy is high. This is because
1. The nitrogen molecule has a triple bond which is hard to break.
2. The nitrogen atom already has a noble gas electron structure, so it is very unreactive.
3. Nitrogen has to form N³⁺ ions.
4. Nitrogen has to form N^3- ions
Which process is the only one which will decompose sodium chloride?
1. Heating in the presence of hydrogen.
2. Heating very strongly in a crucible
3. Reduction with carbon
4. Electrolysis
Which one of these ions is attracted to the anode when a current is passed through a sodium chloride electrolyte?
1. Sodium
2. chloride
3. hydroxide
4. hydrogen
In electrolysis of sodium chloride, why is hydrogen gas given off at the cathode rather than sodium metal?
1. Sodium metal deposited at the cathode immediately reacts with the water, releasing hydrogen.
2. Hydrogen ions are less reactive than sodium, so accept the electrons more readily than sodium ions.
3. Water is a more unstable compound than sodium chloride
4. The heat from the electric current is making the water boil, so that the gas given off is not hydrogen, but water.
A reaction in which some substances are oxidised while others are reduced is called:
1. Radioactive reaction.
2. Radar reaction
3. Radox reaction
4. Redox reaction
Which one of these is a use for sodium hydroxide?
1. Adding flavour to foods.
2. Making soap.
3. Melting snow and ice on roads
4. An alternative method for extracting aluminium from its ore, without having to use electrolysis.
When lead bromide decomposes with electrolysis, the half equations are:
Pb²⁺ + Xe^- --> Pb
XBr^- --> Br₂ + Xe^-
What is the value of X?
1. 2
2. 3
3. 1
4. 1.5
Complete the equation:
metal + acid --> _____ + _____
1. base + hydrogen
2. base + water
3. salt + hydrogen
4. salt + water
In this reaction: magnesium oxide + hydrochloric acid --> magnesium chloride + water, which one is the base?
1. Magnesium oxide
2. Hydrochloric acid
3. Magnesium chloride
4. Water
A strong acid is one that is:
1. very reactive
2. very concentrated
3. dissociates completely into ions.
4. gives of hydrogen when it reacts with a metal.
Antacids are used to treat indigestion. Which one of the following is used as an antacid?
1. sodium hydroxide
2. hydrogen cyanide
3. magnesium oxide
4. ammonium hydroxide
A precipitate is:
1. an insoluble solid that has formed from two (or more) clear soluble solutions reacting.
2. a solution formed when two or more insoluble compounds react.
3. an insoluble gas given off as a result of a reaction
4. a soluble gas given off as a result of a reaction
Which one of these is not a precipitate?
1. lead sulphate
2. silver bromide
3. calcium carbonate
4. copper sulphate
When you live in a hard water area like St Neots, which one of these explains why there is scum left around your bath?
1. The tap water is quite dirty.
2. The calcium ions leave a precipitate of calcium stearate on the bath.
3. The calcium ions react with the sodium stearate to leave insoluble precipitate of sodium carbonate around the bath
4. You were particularly grubby when you got in the bath.
Adding silver nitrate to an unknown solution leads to a yellow precipitate. The solution is most likely to be:
1. Sodium sulphate
2. Sodium chloride
3. Sodium bromide
4. Sodium iodide