Hydrogen burns in air at a temperature well above 100 °C to form water - Edexcel - GCSE Chemistry - Question 4 - 2018 - Paper 1
Question 4
Hydrogen burns in air at a temperature well above 100 °C to form water.
(i) The boiling points of hydrogen and water are shown in Figure 3.
Use this information to... show full transcript
Worked Solution & Example Answer:Hydrogen burns in air at a temperature well above 100 °C to form water - Edexcel - GCSE Chemistry - Question 4 - 2018 - Paper 1
Step 1
Add the missing state symbols to the equation for the reaction taking place as the hydrogen burns.
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Answer
The correct equation with state symbols is:
2H2(g)+O2(g)ightarrow2H2O(l)
In this equation, hydrogen is in the gaseous state (g) and water is in the liquid state (l), considering the temperature is above 100 °C.
Step 2
State how the equation shows that the atom economy is 100%.
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Answer
The equation shows that the atom economy is 100% because all the reactants (hydrogen and oxygen) are converted into the desired product (water) without producing any by-products. Therefore, there are no waste products, indicating complete conversion of reactants.
Step 3
Calculate the atom economy for the production of lead in this reaction.
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Answer
To calculate the atom economy, we first need to determine the molar masses and then apply the formula for atom economy:
