Science Half-Yearly Yr9 Flashcards
(21 cards)
What are acids?
Acids are chemical substances that release H+ (hydrogen ion) when dissolved in water. They are corrosive substances that react with solid materials like metals.
What happens when strong acids come in contact with skin?
Strong acids, such as sulfuric acid, break down proteins and fats in living tissue, causing an acid burn that takes time to heal.
What are examples of weak acids?
Bee and ant stings are weaker acids that may cause pain but result in little lasting damage. Citrus fruits and vinegar are also safe acids.
What are bases?
Bases are chemical substances that release OH- (hydroxide ion) when dissolved in water. They have a bitter taste and feel slippery or soapy.
What are some common uses of bases?
Bases are used in shampoo, toothpaste, cleaning agents, dishwashing liquid, and caustic soda.
What are the properties of acids?
Acids are sour in taste, strong acids are corrosive, turn blue litmus red, vary in color from green to orange in universal indicator, and have a low pH (0 - 6.9/7).
What are the properties of bases?
Bases are bitter in taste, strong bases are corrosive, slippery to touch, turn red litmus blue, vary in color from green to violet in universal indicator, and have a high pH (6.9/7 - 14).
What are some similarities between acids and bases?
Both can neutralize each other, react with indicators, are soluble in water, can be corrosive if strong, conduct electricity, and are made up of ions.
What does the pH scale measure?
The pH scale measures how acidic or alkaline a substance is, ranging from 0 to 14.
What does a low pH indicate?
Low pH numbers (below 7) indicate that substances are acidic.
What does a high pH indicate?
High pH numbers (above 7) indicate that substances are basic or alkaline.
What is the pH of a neutral substance?
A substance with a pH of 7 is considered neutral.
What are some common acids?
Common acids include hydrochloric acid, nitric acid, sulfuric acid, citric acid, carbonic acid, and acetic acid.
What are some common bases?
Common bases include sodium hydroxide (caustic soda), ammonia, and sodium bicarbonate (baking soda).
How can pH be measured?
The pH of a substance can be measured using a pH meter or indicators that change color depending on the pH.
What is neutralization?
Neutralization is the process of stopping an acid or base from having an effect by adding the opposite substance.
What are the products of an acid-base reaction?
When an acid and a base react, they produce water and salt.
What happens when an acid reacts with a metal?
An acid reacting with a metal produces a salt and hydrogen gas.
How does the body use alkalis?
The body uses alkalis to neutralize acidity in the digestive system, such as bile neutralizing stomach acid.
How does pH affect swimming pools?
The pH of swimming pool water needs to be maintained between 7.2 and 7.8 to ensure safety and cleanliness.
Why is pH important in industry?
pH is crucial for product safety, effectiveness, quality control, and environmental protection.
