Clicker #1
You have two beakers on your lab table. Beaker #1 contains 32.07 g
of sulfur and Beaker #2 contains 74.92 g of arsenic (As). Which
beaker contains the greatest number of atoms? Choose the best
answer.
A) Beaker #1 because one sulfur atom weighs less than one arsenic
atom so you need more of the sulfur atoms to fill the beaker.
B) Beaker #1 because it contains more moles of sulfur atoms versus
the number of moles of arsenic atoms in Beaker #2.
C) Beaker #2 because arsenic has a greater mass than sulfur.
D) Beaker #2 because it contains more moles of arsenic atoms
versus the number of moles of sulfur atoms in Beaker #1.
E) Beakers #1 and #2 contain the same number of atoms because
there is one mole in each.
Clicker #2
Does a methane molecule (CH4) consist of
more hydrogen or carbon?
A) hydrogen
B) carbon
C) depends
Clicker #3
What is the percent composition (by mass)
of carbon in 2 moles of CH4?
A)
B)
C)
D)
2.00% C
37.45% C
74.9% C
149.8% C
Note: I did not get to this in lecture but I’m
posting this anyway for practice
Clicker #4
The molecular formula (actual formula) for water
is H2O. What is its empirical formula?
A)
B)
C)
D)
E)
HO½
H2O
H2O2
H4O2
Cannot be determined without knowing the
percent mass of each.