MOLES AND MASS Name _

14.

ti

Oeterm!ne the number of males In each of the quantities below.

25g of NaC!

100. g of KMn04

74 9 ofKCI

Determine the number of grams in each of the quantities below.

11. 2.5 moles of Noel

1.70 moles of KMn04

0.25 moles of KCI

5. 3.2 moles of CuS04.5H20

Chemistry IF8766 50 ©Instructional Fair, Inc.

1

I r-j.~

!i

Ii-.

:~

II

~,i .;~

------.---------------------------------------------

THE MOLE AND VOLUME Name _

FDfS:Jsesat STP (273 K and 1atm pressure), one mole occupies a volume of 22,4 L. Whatyohrme will the following quantities of gases occupy at STP?

1. 1.00mole of H2

A., 3.20 moles of 02

3, 0.750 mole of N2

4. 1.75moles of CO2

5. 0.50 mole of NH3

G. 5.0 g of H2

7. 100.g of 02

\

g.. 28.0 g of N2,"{

;

~1~ Q. 60. g of CO2i.!

II

! '0 10.g of NH3t : I •

!

!I

')..'\ >;emistry IF8766 51 ©Instructionai Fair, Inc.

-------------------------------- ---- ---

THE MOLE ANDAVOGADRO'S NUMBER

Name _

lone mole of a substance contains Avogadro's Number (6,02 x 10") of molecules.

How many molecules are in the quantities below?

1. 2.0 moles

2. 1.5moles

3. 0.75 mole

4. 15 moles I5. 0.35 mole I·

II!!t

How many moles are in the number of molecules below?

L 6.02 X 1023 !,i

I

2. 1.204x 1024 tj

t3. 1.5 x 1()2°

II\

4. 3.4 X lQ26

5, 7.5 X 1019

Chemistry IF8766 52 ©tnstructionaJ Fair, lnc.

I

ill 1. How many grams are the, e In 1.5 x 1()25 molecules of COz?

l•

J:iT, inc. ,)\

MIXED MOLE PROBLEMS Name _

Solve the following problems.

2. What volume would the CO2 in Problem 1 occupy at STP?

3. A sample of NHs gas occupies 75.0 liters at SIP. How many molecules is this?

4. What is the mess of the sample of NH3.in Problem 3?

5. How many atoms are there in 1.3 x 1022 molecules of N02?

6, A 6.0 g sample of 021s in a container at STP.What volume isthe container?

7, How many molecules of 02 are in the contolner in Problem 6? How many atomsof oxygen?

Chemistry IF8766 53 ©Instructionai Fair, lnc,

PERCENTAGE COMPOSITION Name _

Determine the percentage composition of each of the compounds below.1, KMn04

K = _

Mn = _0= _

2, HelH = -

CI = _

3. Mg(N0J)2Mg = _

N = ----0= _

4, (NH4)104N = _H = _p = ----0= _

5. AI2(S04)3AI = _S = _0= _

Solve the following problems.

6. How many grams of oxygen can be produced from the decomposition of 100. gof KCI0

3? _

7. How much iron can be recovered from 25.0 g of Fe203? _

~') 8. How much silver can be produced from 1259 of A92S? _

Chemistry IF8766 54 ©Instructional Fair,·

DETERMININGEMPIRICAL FORMULAS

Name _

What isthe empirical formula (lowest whole number ratio) of the compounds below?

1. 75% carbon, 25% hydrogen

2. 52.7% potassium, 47.3% chlorine

3. 22.1% olurnlnum. 25.4% phosphorus, 52.5% oxygen

4, 13% magnesium, 87% bromine

5. 32.4% sodium, 22.5% sulfur,45,1% oxygen

g 6, 25.3% copper, 12.9% sulfur, 25.7% oxygen, 36.1% water

II Fair.!e Chemistry'IF8766 55 ©Instructional Fair, inc.

)4·::~!{",>:' Chemistry IF8766

~~~~1&~~~~]~;n1;rrtir~c"'~f::V'iW&j:i,c0:7"'''':'' '.'",'

r"·'~,'(:,

'!.>':."''.'

~

I:"

r.iJ::t>r'rt1::'

~

Lf -;rt

DETERMINING MOLECULARFORMULAS (TRUE FORMULAS)

Name _

Solve the problems below.

1. The empirical formula of a compound isN02. Its molecular moss is92 g/mol.What is its molecular formula?

2. The empirical formula of a compound isCH2• Its molecular moss is 70g/mol.What is its molecular formula?

3. A compound is found to be 40.0% carbon, 6.7%hydrog~n end 53.5% oxygen.Its rnoleculor moss is60.g/mol. What is its molecular formula?

4. A compound is64.9% corbon. 13.5% hydrogen and 21.6% oxygen. Its mOlecUlar;~mass is 74 g/moL What is its molecular formula?:,;

5. A compound is54.5% carbon! 9.1% hydrogen and 36.4% oxygen. Its molecularmass is88 g/mol. What is its molecular formula?

-~-~.-::-\i.';----~,;'" ',:,,-.."".;:-t

--------------------------------~:~,1,.56 ©Instructional Fa:!/lc

"

::·~·~~;;'·-.~;@0;:!9i~1«~fri~~_ I