Year 10 Science · Unit 2 · Lesson 12
Foundation Worksheet
Learning Goals
True or False? Fix the false ones
Circle T or F for each statement. If the statement is false, rewrite it correctly on the line below.
Increasing the concentration of HCl from 0.5 mol/L to 2.0 mol/L increases the number of H⁺ ions per litre, leading to more frequent collisions with CaCO₃ and a faster reaction rate.
Correct it:
Powdering marble chips and using large chunks of the same mass will produce different total amounts of CO₂ gas, because the powder reacts faster.
Correct it:
When comparing two experiments with the same reactant mass but different particle sizes, the final volume of gas produced will be the same, only the rate differs.
Correct it:
A steeper initial gradient on a reaction rate graph always means a smaller total amount of product is eventually produced.
Correct it:
Read the bar chart
The bar chart below shows the volume of CO₂ gas produced in the first 60 seconds when marble chips (CaCO₃) react with hydrochloric acid (HCl) at four different concentrations. Study the chart and answer the questions.
Data: Simulated school lab investigation, CaCO₃ chips + HCl, 25°C, 60 s reaction window.
(a) Describe the trend shown in the graph. What happens to the volume of CO₂ produced as concentration increases?
(b) Between which two concentrations is the increase in gas volume the greatest? Calculate the difference in mL.
(c) Use collision theory to explain WHY the volume of CO₂ collected in 60 s is greater at 2.0 mol/L than at 0.5 mol/L.
1. If you ran the 0.5 mol/L and 2.0 mol/L experiments for long enough (say, 10 minutes), would the total amount of CO₂ eventually be the same or different? Explain your answer.
Wrap Up
In one sentence, what was the main idea of this lesson?