Edexcel IGCSE Chemistry Acids and Bases

What are the properties of acids?

• The properties of acids include bitter taste, inability to change the color of litmus paper, and the ability to react with metals to produce carbon dioxide gas.

• The properties of acids include sweet taste, ability to turn red litmus paper blue, and the ability to react with metals to produce oxygen gas.

• The properties of acids include sour taste, ability to turn blue litmus paper red, and the ability to react with metals to produce hydrogen gas.

• The properties of acids include salty taste, ability to turn blue litmus paper red, and the inability to react with metals.

What are the properties of bases?

• Bases have a bitter taste, feel slippery, turn red litmus paper blue, and have a pH greater than 7.

• Bases have a sweet taste, feel rough, turn blue litmus paper red, and have a pH less than 7.

• Bases have a sour taste, feel slimy, turn blue litmus paper red, and have a pH greater than 7.

• Bases have no taste, feel sticky, turn red litmus paper blue, and have a pH less than 7.

Explain acid-base reactions.

• Acid-base reactions happen when a base donates a proton to an acid.

• Acid-base reactions occur when an acid and a base react with each other to form a salt and water. The acid donates a proton (H+) to the base, forming the salt, while the base accepts the proton.

• Acid-base reactions occur when two acids react with each other to form a base.

• Acid-base reactions result in the formation of a gas and a solid.

What is the pH scale and how is it measured?

• The pH scale measures the temperature of a solution using a thermometer

• The pH scale is a measure of the saltiness of a solution, ranging from low to high

• The pH scale is a measure of acidity or alkalinity of a solution, ranging from 0 to 14. It is measured using a pH meter or pH paper, which indicates the concentration of hydrogen ions in the solution.

• The pH scale is a measure of the color of a solution, ranging from red to green

What are indicators and how are they used in chemistry?

• Indicators are used to measure temperature in chemistry experiments

• Indicators are substances that change color in response to a change in the conditions of a solution, such as pH. They are used in chemistry to determine the endpoint of a titration or to indicate the presence of a specific substance.

• Indicators are only used in biology, not in chemistry

• Indicators are substances that have no effect on the conditions of a solution

Give an example of a strong acid and a strong base.

• Strong acid: Vinegar, Strong base: Baking soda

• Strong acid: Hydrochloric acid (HCl), Strong base: Sodium hydroxide (NaOH)

• Strong acid: Lemon juice, Strong base: Ammonia

• Strong acid: Battery acid, Strong base: Bleach

Explain the concept of neutralization in acid-base reactions.

• Neutralization happens when an acid and a base react to form oxygen and a salt.

• Neutralization occurs when an acid and a base react to form carbon dioxide and water.

• Neutralization in acid-base reactions occurs when an acid and a base react to form water and a salt.

• Neutralization is the process of combining an acid and a base to form a new acid.

How do acids and bases react with metals?

• Acids and bases both react with metals to produce salt and hydrogen gas

• Acids react with metals to produce salt and hydrogen gas, while bases do not react with metals.

• Acids react with metals to produce water and oxygen

• Acids and bases both do not react with metals

What is the difference between a strong acid and a weak acid?

• Weak acids are more corrosive than strong acids

• Strong acids have a lower concentration than weak acids

• The main difference is that strong acids completely dissociate in water, while weak acids only partially dissociate.

• Strong acids have a higher pH than weak acids

How do acids and bases affect the color of indicators?

• Acids and bases have no effect on the color of indicators

• Acids and bases can change the color of indicators due to their ability to change the concentration of hydrogen ions (H+) or hydroxide ions (OH-) in a solution, which in turn affects the structure of the indicator molecule and its absorption of light.

• The color change in indicators is caused by temperature, not by acids and bases

• Indicators change color on their own without any influence from acids and bases