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Explain how alkalis affect litmus, thymolphthalein, and methyl orange indicators.

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Cambridge IGCSE ChemistryAcids, bases and saltsCore content

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Explain how alkalis affect litmus, thymolphthalein, and methyl orange indicators

This point belongs to The characteristic properties of acids and bases, especially The characteristic properties of acids and bases outcomes.
You need to be able to explain how alkalis affect litmus, thymolphthalein, and methyl orange indicators.
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Description

Effect of Alkalis on Indicators

Alkalis affect the color of various indicators used in chemistry. Litmus, thymolphthalein, and methyl orange are common indicators that change color in response to pH levels.

a
State the color change of litmus when it is added to an alkaline solution.
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Explain the key properties of acids based on their reactions with metals, bases, and carbonates.
The characteristic properties of acids and bases outcomes
Explain how acids affect litmus, thymolphthalein, and methyl orange indicators.
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Identify bases as metal oxides or hydroxides, and recognize that alkalis are soluble bases.
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Explain the key properties of bases based on their reactions with acids and ammonium salts.
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Recognize that solutions of acids contain positive hydrogen ions and solutions of alkalis contain negative hydroxide ions.
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