Which of the following is a base?
vinegar
lemon juice
stomach acid
baking soda
baking soda
What feature makes water a polar molecule?
A water molecule is positively charged.
A water molecule is negatively charged.
The ends of the water molecule have opposite electrical charges.
The middle of the water molecule contains opposing charges.
The ends of the water molecule have opposite electrical charges.
Which is the term for numbers that appear in the chemical formulas of some compounds?
subscripts
coefficients
square roots
exponents
subscripts
How does the composition of a water molecule affect its charge?
It makes the molecule nonpolar.
It makes the molecule a positive ion.
It makes the molecule polar.
It makes the molecule a negative ion.
It makes the molecule polar.
Which is true of hydroxide ions?
They dissociate to form protons.
They are not found in pure water.
They have a negative charge.
They contain two hydrogen atoms.
They have a negative charge.
What kind of change causes iron to rust?
freezing reaction
physical change
chemical change
state change
chemical change
How does the presence of an acid in a water solution affect the pH of the solution?
It neutralizes the pH.
It does not affect the pH.
It raises the pH.
It lowers the pH.
It lowers the pH.
What is true of every water molecule?
It is made of two water atoms.
It is made of two hydrogen atoms and one oxygen atom.
It is made of one hydrogen atom and two oxygen atoms.
It is made of one water atom and one DNA atom.
It is made of two hydrogen atoms and one oxygen atom.
Which is an example of a chemical change?
a candle burns
a teaspoon of salt dissolves
a burner gets red hot
a pan of water boils
a candle burns
When NaOH is added to water, the hydroxide concentration increases. What can you conclude about NaOH?
It donates H + ions.
It has a low pH.
It releases protons.
It is a base.
It is a base.
What is a radical?
a group of ions that have no charge
a group of ions that break up during a reaction
a group of atoms that act like one atom
a group of atoms that give off radiation
A radical is a group of atoms that act like one atom.
How many oxygen atoms are in one unit of the compound Ba(OH) 2 ?
1
4
2
3
2
A(n) _____ bond forms when two atoms share one or more pairs of electrons.
electrical
covalent
molecular
ionic
covalent
What type of bond forms between a slightly positive hydrogen atom in one molecule and a slightly negative atom in another molecule?
covalent bond
ionic bond
hydrogen bond
atomic bond
hydrogen bond
Which formula for sulfuric acid is written correctly to show one sulfur atom, two hydrogen atoms, and four oxygen atoms?
H 2 (SO 2 ) 2
(HS) 2 O 4
H 2 SO 4
HS 2 O 4