Year 9 Science Assignment - Term 1 by Christie Lee

Question 1: Describe what a neutralization reaction is.

leechristie_15 — 2018-04-04 06:31:52 UTC

To understand neutralisation reactions, you first need to know what acids and bases are.
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Go to the suggested resources to get a basic understanding of Acids and Bases:

1. Introduction to Acids and Bases:
Watch the 9 short youtube videos associated with this link.

2. Acids, Bases and pH: Click here for more information link here.

3. BBC Bitesize: Click here to read the page shown.

4. Pearson 9 Textbook: Chapter 2.3 - Acids and Bases
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You are now equipped to learn about neutralisation reactions. Review the suggested resources.

1. Pearson 9 Textbook: Chapter 3.2 - Acid Reactions

2. BBC Bitesize: Click here for more information.
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You are now able to answer question 1.

Hint: The word 'describe' means 'to write about and/or draw the characteristics' of something.

Therefore, an A standard answer will include at least one sentence, plus the general chemical equation for a neutralisation reaction, as well as a specific example of this type of reaction.

Question 2: List three commercially available antacid products and their chemical compositions.

leechristie_15 — 2018-04-04 06:38:29 UTC

The three commercially available antacid products that were used in the experiment were:

Mylanta Liquid
Rennie Tablets
Quick-eze Tablets

You now need to research the chemical compositions (ingredients) of these 3 products.
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Hint: In google, the suggested search parameter to use is "ingredients of "

Question 3: List which of these ingredients would neutralize stomach acid.

leechristie_15 — 2018-04-04 06:38:34 UTC

To answer this question you need to remember that bases neutralise acids and that bases are generally any chemicals that have the name "carbonate" (CO₃)or "hydroxide" (OH) in them.
e.g. ammonium hydroxide, zinc carbonate etc.
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Hint: Research and write down both the word names and the chemical formulas for each of the ingredients you have identified as being capable of neutralising stomach acid.

Question 4: Justify why these ingredients would neutralize stomach acid.

leechristie_15 — 2018-04-04 06:38:39 UTC

To answer this question you need to refer back to your research regarding acids, bases and neutralisation reactions.
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Hint: Remember, to justify means to provide reasons for your answer.

Question 5: List the chemical equations for the possible neutralisation reactions between an acid and antacid.

leechristie_15 — 2018-04-04 06:38:43 UTC

The general equations for neutralisation reactions are:

Acid + Base --> Salt + Water
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When the base is a metal hydroxide, the general equation for the reaction taking place is:

Acid + Metal Hydroxide --> Salt + Water
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When the base is a carbonate, the general equation for the reaction taking place is:

Acid + Carbonate --> Salt + Water + Carbon Dioxide
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The unbalanced chemical equations for the neutralisation reactions taking place in this experiment are shown below:
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Quick-eze Equation:
Hydrochloric Acid + Calcium Carbonate --> Calcium Chloride + Water + Carbon Dioxide.

HCl + CaCO₃ --> CaCl₂ + H₂O + CO_{2
................................................................................}Rennie Tablet:
Hydrochloric Acid + Magnesium Carbonate --> Magnesium Chloride + Water + Carbon Dioxide.

HCl + MgCO₃ --> MgCl₂ + H₂O + CO₂
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Mylanta:
Hydrochloric Acid + Aluminium Hydroxide --> Aluminium Chloride + Water

HCl + Al(OH)₃ --> AlCl₃ + H₂O
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You now need to balance the three unbalanced chemical reactions listed. Write the balanced equations onto your assignment sheet.

Question 2

leechristie_15 — 2018-04-06 09:23:39 UTC

Write a testable question.
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A testable question is one that can be answered by doing an experiment.

On the front of your assignment sheet the task is explained. I have reproduced it below. Carefully read this task and underline the sentence that describes the question your are answering (i.e. the goal/aim of the experiment).
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_{YOUR TASK}_{The stomach creates acid to help break down food. Heartburn is a condition where the stomach may produce too much acid or where the acid travels up into the oesophagus causing pain. To balance out this acid you can take antacids. Antacids are actually weak bases that can be bought in chemists or supermarkets. In this task you will design an experiment to determine the most effective brand of antacid. You will present your findings in a scientific report.}............................................................
Use the sentence you have underlined to write your testable question. The question I want to answer is ...

Question 3: Using the background information, state your hypothesis.

leechristie_15 — 2018-04-06 09:29:54 UTC

............................................................Use your 'testable question' to create your hypothesis.
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Hint:
A hypothesis has three parts:
"If...
then...
because..."
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Examples of a Good Hypothesis:

If salt is added to a plant’s soil then the plant will die because salt will dry out the soil so that there is not enough water left for the plant.
If people spend more time in the sun then they will be more likely to get skin cancer because exposure to ultraviolet light in sunlight causes skin cancer.

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To write the hypothesis for this assessment, first decide which antacid you think will be the most effective at neutralising hydrochloric acid.

If is the most effective brand of antacid, then because .
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Note: The reason you provide in your hypothesis must be based on your researched background information.

Question 4: Plan for a fair test.

leechristie_15 — 2018-04-06 10:22:03 UTC

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First, download and carefully read the method used in the experiment.

Question 4: Plan for a fair test.

leechristie_15 — 2018-04-06 12:41:19 UTC

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A fair test is conducted when only one factor/condition has changed during a series of related experiments. All other factors/conditions of the experiment must be controlled and kept the same for the test to be fair.
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Factors that can be either controlled, measured, or changed in an experiment are called variables. The three different kinds of experimental variables are called: the independent variable, the dependent variable and the controlled variable.
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The independent variable is the one factor/condition that you want to change during a series of related experiments.

To work out what the independent variable is, make a list of the different chemicals poured into beakers 1, 2, 3 and 4.

Which chemical was poured into all of the beakers? _{This chemical cannot be classified as the independent variable because it was used (the same) in ALL of the four reactions.}
Which chemicals were not poured into all of the beakers? _{These were the factors that changed in each of the four reactions.}
If you grouped the chemicals that were changed under one name, what would they be called?

Write this information in the 'My Independent Variables' column of the assignment sheet.
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The controlled variables are all of the factors/conditions kept the same in a series of related experiments.

We have already identified one factor/condition that was kept the same in each reaction. _{Can you remember what it was?}

Re-read the method to identify other conditions/factors that were kept the same. Write these factors/conditions into the 'My Controlled Variables' column of the assignment sheet.
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The dependent variable is the factor/condition that you want to measure in a series of related experiments.

What factors/conditions do we want to measure in each of the reactions that will take place?

How many dependent variables will be used in this experiment?

Write the factors/conditions that will be measured in the 'My Dependent Variables' column of the assignment sheet.

Question 5: List the equipment or materials will you need for this experiment.

leechristie_15 — 2018-04-06 14:04:24 UTC

Refer to the experimental method provided to complete this question.

Question 6: Identify risks and explain management strategies for your investigation.

leechristie_15 — 2018-04-06 14:06:32 UTC

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Have a look at the equipment and materials that are being used to conduct the experiment.

Which ones pose a potential hazard to your safety and health?

To successfully complete the risk assessment table you need to be able to:

1. Identify at least three hazards associated with performing this experiment.

2. For each hazard identified, state why it is considered a risk.

3. Come up with a plan to minimise/manage each hazard that has been identified.

Download the file below for an example of a completed risk assessment table.

Question 7: Design a table to collect your results.

leechristie_15 — 2018-04-06 14:08:45 UTC

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Below is a copy of the expected results for this experiment.
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pH of HCl alone was 3
pH of HCl and Mylanta combined was 5
pH of HCl and Rennie combined was 7
pH of HCl and Quickeze combined was 6
pH of HCl and Bicarbonate Soda combined was 7
Reaction time (seconds) of HCl and Mylanta was 153.94
Reaction time (seconds) of HCl and Rennie was 198.87
Reaction time (seconds) of HCl and Quick-eze was 573.41
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Design a table that will clearly and succinctly display these results.

For extra marks, tabulate and graph the results.
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Remember: All tables/graphs should be labelled, with appropriate units where necessary, and titled.

Question 1: Analyse the results you have observed and provide an explanation as to why they occurred.

leechristie_15 — 2018-04-06 14:10:10 UTC

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To analyse means to identify components and the relationship between them, or to draw out and relate implications.

In other words, analysing helps us to make sense of the results and what was seen in the experiment.
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Download the file below to learn how to analyse a set of results.

Question 3. Evaluate your conclusions based on the reliability and validity of the method.

leechristie_15 — 2018-04-07 11:13:45 UTC

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To answer this question you need to state whether the aim of the experiment was satisfied and justify why.
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Some great sentence starters could be:

"Overall, the experiment was successful/unsuccessful because …"

"The aim of the experiment was satisfied/unsatisfied because …"

"The results obtained from this experiment supported/rejected the hypothesis because …"
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Question 4. Identify sources of uncertainty that may have affected the reliability of the results.

leechristie_15 — 2018-04-07 11:14:37 UTC

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To answer this question you need to state all of the errors that were made in carrying out the experiment and the recording of the results.

Question 2. State whether the hypothesis was proven or disproven.

leechristie_15 — 2018-04-07 11:15:17 UTC

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State whether your hypothesis was supported or rejected. For extra marks, justify why.
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A great sentence starter you can use is:
"The results obtained from this experiment supported/rejected the hypothesis because …"

Question 5. Discuss specific ways to improve the investigation.

leechristie_15 — 2018-04-07 11:18:23 UTC

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To answer this question you need to:
Suggest ways to improve the method and/or improve the accuracy of the results.
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Some great sentence starters you could use are shown below:

"Although successful, some errors were made. These include …"

"The experiment was unsuccessful and some errors were made. Some of these errors were … "

"This experiment could be improved by … or made more accurate by …"
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Structure of the Final Copy of your Report.

leechristie_15 — 2018-04-07 11:25:03 UTC

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Your report must:

be written in third person.
be written in past tense.
include headings for each section.

All tables/graphs/diagrams should be numbered and titled.
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The last page of your assignment task sheet displays the format you need to follow so that the final copy of your report is correctly structured.
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Further tips regarding the information you need to include under each heading is listed below.

Title:
Introduction (200-400 words): Information obtained from the research you conducted in section 1 (Q.1-5) can be rewritten for inclusion within the introduction.
Aim (2 sentences max):
This is where you include information about the testable question. Sentence starters you could use are:

"The aim of this experiment was to ..."
This was done by .... and measuring/observing ..."

Hypothesis (50-100 words):
Method:
Make sure you include your materials list AND the numbered set of steps that show the procedure followed.
Results:
Place the completely labelled table of results here.
Discussion (300-500 words):
Information from Section 3 (Q. 1 - 5) should be placed here.
Conclusion (50-100 words)
References (3 minimum)
Appendix (optional)