What does "pH" actually stand for, anyway?!?!
The German "potenz H(ydrogen)", which means the power of the hydrogen-ion concentration.
A substance contains an excess of OH- ions. What is its pH?
It is alkaline, so it is higher than 7.
Acids have a pH of _____ than __.
less than 7
Acids turn litmus paper _____.
red
The more acidic the solution, the ______ the pH.
lower
The acidic oxides of sulfur, phosphorus, and carbon produce acids when dissolved in water. When pure, they are ________ molecules.
covalent
Non-metals generally form _______ oxides that dissolve in water to form _______ solutions.
acidic
A substance turns the Universal Indicator bright red. What does this "indicate"?
It is very acidic.
Alkalis turn litmus paper ______.
blue
What adjective is the opposite of "dilute"?
concentrated
Alkalis have a pH _________ than __.
greater than 7
Name a pH indicator other than litmus or Universal Indicator.
methyl orange or phenolphthalein (also hydrangea flowers, turmeric, and anthocyanins)
How can we use litmus paper to test the pH of gases?
The litmus paper must be damp.
What adjective is the opposite of "concentrated"?
dilute
What is the most accurate method to measure pH?
Use a pH meter which uses an electrode to measure pH electrically.
What kind of acid is in the atmosphere of Venus?
sulphuric acid (due to volcanic activity)
Give an exception to the rule that "Oxides of non-metals are acidic oxides."
Water. It can be considered hydrogen oxide and a neutral oxide.
What is an OH- ion called?
a hydroxide ion
Universal Indicator is green in the presence of a substance. What does this indicate?
The substance is neutral.
Metals form oxides that are solids. If they dissolve in water, these oxides give _______ solutions.
alkaline
A substance contains an excess of H+ ions. What is its pH?
It is acidic, so it is lower than 7.
What acid is present in vinegar?
acetic acid (ethanoic acid)
What adjective means "can eat through material"
corrosive
Which acid is present in orange juice?
citric acid