The rate of a reaction was monitored by recording the volume of gas produced every 5 seconds.
What is the mean rate of reaction in the first 10 seconds of the reaction, in cm3/s?
2.9
3.0
3.5
2.5
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The rate of a reaction was monitored by recording the volume of gas produced every 5 seconds.
What is the mean rate of reaction in the first 10 seconds of the reaction, in cm3/s?
2.9
3.0
3.5
2.5
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Hydrogen peroxide, H2O2, quickly decomposes to produce water and oxygen when a catalyst is added to the solution:
2H2O2 (aq) → 2H2O (l) + O2 (g)
The volume of gas produced was measured and is shown in the graph below:
Which statement is not true for this reaction?
The reaction finishes after 30 seconds
The mean rate of reaction in the first 5 seconds is 2.5 cm3/s
The final volume of gas produced is 60 cm3
The concentration of the hydrogen peroxide decreases during the reaction
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Magnesium metal reacts with an excess of hydrochloric acid solution to form magnesium chloride and hydrogen:
Mg (s) + 2HCl (aq) → MgCl2 (aq) + H2 (g)
Which of the following will not increase the rate of this reaction?
Increase the temperature of the acid
Increase the surface area to volume ratio of the pieces of magnesium
Increase the concentration of the hydrochloric acid
Increase the volume of hydrochloric acid solution used
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Catalysts are often used in chemical reactions.
Which letter represents two correct features of catalysts?
Feature 1 | Feature 2 | |
A | Lower activation energy for the reaction | More products made in total |
B | Alternative pathway for the reaction is provided | Not used up over the course of the reaction |
C | Makes industrial processes cheaper | Metal catalysts are cheap to buy |
D | Reduce the overall energy change of the reaction | Can be present in biological systems as enzymes |
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Calcium carbonate reacts with hydrochloric acid to produce calcium chloride, water and carbon dioxide:
CaCO3 (s) + 2HCl (aq) → CaCl2 (aq) + H2O (l) + CO2 (g)
Which statement is not true if the temperature of the reaction decreases?
The frequency of the collisions between particles decreases
The collisions are less energetic
The activation energy increases
There are fewer particles with the minimum energy to react
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Magnesium reacts with hydrochloric acid to produce magnesium chloride and hydrogen gas:
Mg (s) + 2HCl (aq) MgCl2 (aq) + H2 (g)
During the first 10 s of the reaction, 1.2 g of magnesium was used up.
Calculate the mean rate of reaction in mol/s for this part of the reaction.
Relative atomic masses (Ar): Mg= 24 H= 1 Cl= 35.5
2.9 mol/s
2.0 mol/s
0.05 mol/s
0.005 mol/s
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