Acidic, basic, or neutral

Acidic, basic, or neutral

Online interactive
Overview
Using this Resource
Connecting to the Curriculum
Marking Student Responses
Working with Students
Further Resources
This task is about using a pH scale.
pH scale
The pH scale measures how acidic or basic a substance is.

Question Change answer

Jane used universal indicator to find the pH of some common substances. Here are her results.

Put the substances she tested into the group where they belong. 
Battery acid pH 2
Lemon juice pH 3
Rain water pH 6.5
Tea pH 5
Distilled water pH 7
Salt water pH 7
Blood pH 7.5
Dishwasher powder pH 11
Oven cleaner pH 10
Shampoo pH 8
Acidic
Neutral
Basic

Question 1Change answer

diagram of labelled ph scale
The arrows in the diagram of the pH scale show the direction of increasing strength for acids and bases. 
Substances tested pH
Tea 5
Dishwasher powder 11
Distilled water 7
Lemon juice 3
Battery acid 2
Oven cleaner 10
Salt water 7
Shampoo 8
Blood 7.5
Rainwater 6.5
From the substances shown which substance is the most basic? Tea pH 5Dishwasher powder pH 11Distilled water pH 7Lemon juice pH 3Battery acid pH 2Oven cleaner pH 10Salt water pH 7Shampoo pH 8Blood pH 7.5Rainwater pH 6.5
From the substances shown which substance is the most acidic? Tea pH 5Dishwasher powder pH 11Distilled water pH 7Lemon juice pH 3Battery acid pH 2Oven cleaner pH 10Salt water pH 7Shampoo pH 8Blood pH 7.5Rainwater pH 6.5
Task administration: 
This task can be completed online only.
Level:
5
Curriculum info: 
Science, Knowledge, Material World
Keywords: 
properties, acids, bases, alkalis, pH scale
Description of task: 
Task: Using the given pH, classify 10 common substances as acidic, basic, or neutral. Assessment focus: knowledge of the pH scale
Curriculum Links: 
Science capabilities
The capabilities focus is brought about by the conversations you have and the questions you ask.
Capability: Interpret representations
This resource provides opportunities to to discuss how science is represented in diagrams such as pH scales.
Answers/responses: 

  

Y10 (09/2001)

a)

Acidic

Basic

Neutral

Battery acid
Lemon juice
Rain water
Tea

Blood
Dishwasher powder
Oven cleaner
Shampoo

Distilled water
Salt water

10 correct – very difficult

8-9 correct – moderate

6-7 correct – easy

b)

Dishwasher powder

moderate
c) Battery acid not trialled
Teaching and learning: 
 

Common errors

a)

Blood – 47% of students classified this as neutral.
Distilled water – 21% classified this as basic.
Oven cleaner – 18% classified this as acidic.
Rain water – 47% classified this as neutral, and 21% stated it was basic.
Salt water – 25% classified this as basic.
Shampoo – 26% classified this as neutral.
Tea – 23% classified this as basic, and 20% stated it was neutral.