The most commonly used reactions are reactions with: (a) water (in which hydrogen is displaced from water to produce hydrogen gas) (b) non-oxidizing acids such as dilute hydrochloric acid or dilute sulfuric acid (in which hydrogen is displaced from acid to produce hydrogen gas).
Do you know this? Join AUS-e-TUTE! Play the game now! Question 1. A piece of clean magnesium is placed in a beaker with dilute hydrochloric acid.
Yes, hydrogen gas will be produced. Question 2. A piece of clean copper is placed in a beaker with dilute sulfuric acid.
No, hydrogen gas will not be produced. Question 3. A student pours 100 mL of 0.1 mol L-1 hydrochloric acid into each of two 250 mL beakers labelled A and B. A thermometer is suspended in each beaker, and the initial temperature of each acidic solution recorded. To beaker A the student adds a clean piece of iron. To beaker B the student the adds the same amount of clean zinc. In which beaker, A or B, would you expect the greatest temperature increase in the first minute of the experiment?
The greatest temperature increase will be recorded for beaker B.
Do you understand this? Join AUS-e-TUTE! Take the test now! Question 1. A piece of clean zinc is placed in a solution containing copper ions.
Yes, a reaction occurs. Question 2. A clean piece of lead is placed in a solution containing sodium ions.
No, a reaction will not occur. Lead will not displace sodium from the solution. Question 3. Consider the following experimental set-up:
Beaker A produces more energy.
Can you apply this? Join AUS-e-TUTE! Take the exam now! Question 1. Clean sodium and clean zinc will both react with oxygen gas to form metal oxides.
Sodium will react faster than zinc. Question 2. Under certain conditions, both copper and magnesium will react with oxygen gas to form oxides. One of these reactions occurs slowly at room temperature, the other metal will not react with oxygen gas unless it is heated. Which of the two metals will only react with oxygen gas if it is heated?
Copper, being less active than magnesium, is more likely to have the slower reaction rate and therefore is more likley to require heat to speed up the rate of reaction.
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