Deleon Chemistry- Chapter 7 test answers

(Calculate the molar masses and percentage composition of each of the following compounds) Ca(OH)2

74.82 Ca=53.57% O2= 43.23% H2= 2.73%

How many molecules are in 25 grams of NH3?

8.85 x 1023 molecules

A compound with an empirical formula of CFBrO and a molar mass of 254.7 grams per mole

C2F2Br2O2

(btw this is problem 1) What's the empirical formula of a molecule containing 65.5% carbon, 5.5% hydrogen, and 29.0% oxygen?

C3H3O

A compound with an empirical formula of C2OH4 and a molar mass of 88 grams per mole

C4O2H8

(based on problem 1)If the molar mass of the compound in problem 1 is 110 grams/mole, what is the molecular formula?

C6H6O2

A compound with an empirical formula of C4H4O and a molar mass of 136 grams per mole

C8H8O2

(btw this is based on problem 3)If the molar mass of the compound in problem 3 is 73.8 grams/mole, what is the molecular formula?

Li2CO3

(btw this is problem 3) What's the empirical formula of a molecular compound containing 18.7% lithium, 16.3% carbon, and 65% oxygen?

Li2CO3

How many grams are in 8.200 x 1022 molecules of N2I6?

107.5 grams

(Calculate the molar masses and percentage composition of each of the following compounds) (NH4)2SO4

132.17 N2= 21.2% H8= 6.11% S= 24.26% O=48.42%

How many grams are in 4.500 moles of Li2O?

134.46 grams

(Calculate the molar masses and percentage composition of each of the following compounds) CaSO4

136.15 Ca= 29.44% S= 23.55% O4= 47.01%

(Calculate the molar masses and percentage composition of each of the following compounds) Mg(NO3)2

148.33 Mg= 16.39% N2= 18.89% O6= 64.72%

(Calculate the molar masses and percentage composition of each of the following compounds) Zn3(PO4)2

386.11 O8= 33.15% P= 16.04% Zn3= 50.81%

How many moles are in 3.4 x 1023 molecules of H2SO4?

.56 mole

How many moles are in 25 grams of water?

1.39 moles

How many molecules are in 23 moles of oxygen?

1.39 x 1025 molecules