Atoms Worksheet #2 (The Mole)

Name______

Atoms Worksheet #2 (The Mole)

1. Counting Atoms– How many atoms are in the following compounds?

a) CaCl2______b) NH4OH______c) NaCl______d) N2O7______e) P2O5______

f) Zn(NO3)2______g) Al2(CO3)3______h) 4 Na3PO4_____ i) 3 Mg(NO3)2______

2. Calculate the molar mass of the following compounds:

a) Na3PO4______b) Fe2O3______c) Mg(OH)2______

d) (NH4)2SO4______e) Ca3(PO4)2______

3.Mole-to-Gram/Gram-to-Mole Conversions (One Step Problems)

a)How many grams of CaI2 are present in 3.28 moles?

b)How many grams of SO2 are present in 5.39 moles?

c)How many moles of AgCl are there in 4.98 gram?

d) How many moles of MgS are present in 3.03 x 10-2 grams?

4. Conversions using Avogadro’s number (One Step Problems)

a)How many atoms are present in 34.69 moles of Mg?

b)How many atoms are present in 0.529 moles of Li?

c)How many moles of Mn3P2 are present in 4.09 x 1024 particles of Mn3P2?

d)How many moles of NiS are present in 5.88 x 1019particles?

5. Grams↔Moles ↔Particles ORAtomsORMolecules(Two Step Problems)

a)Calculate the number of molecules in 8.33 grams of O2

b.)Calculate the number of atoms in 43.33 grams of iron, Fe?

c) Calculate the number of particles in 32.8 grams of Cu2S.

e)Calculate the number of grams of Li2NO3 in 5.44 x 1021particles of lithium nitrate.

f) Calculate the number of grams of SO3in 3.92 x 1025 molecules of sulfur trioxide.

Name______

Atoms Worksheet #3 (More Practice Problems)

SHOW ALL WORK USING DIMENSIONAL ANALYSIS!!!!!

l. Calculate the following:

a. molecules in 5.00 moles of nitrogen gas, N2

b. molecules in 8.78 moles of oxygen gas, O2

c. particles in 4.89 moles of calcium chloride, CaCl2

d. atoms in 6.0 moles of nitrogen gas, N2

e. ions of chlorine in 3.0 moles of magnesium chloride, MgCl2

2. Calculate the number of grams represented by the following:

a. 3.0l X l023particles of sodium hydroxide, NaOH

b. l.20 X l024 atoms of sulfur

c. 3.99 X l0l8particles of ammonium carbonate (NH4)2CO3

d. l.44 X l026 molecules of carbon dioxide CO2

3. How many particles are there in 2.73 X l0-2 moles of magnesium iodide, MgI2?

4. How many moles of SO3 are in 2.4 X l024 molecules of SO3?

5. The chemical formula for aspirin is C9H8O4. What is the mass in grams of 0.40 moles of aspirin?

6. How many particles are there in 2.4 pounds of calcium acetate, Ca(C2H3O2)2? (1 pound = 454 grams)

7. How much would l.00 X l026 atoms of aluminum weigh in pounds?(1 pound = 454 grams)

8. 65.3 grams of lithium oxide, Li2O, would contain how many lithium ions?

9. A sample of potassium sulfide, K2S, contains 7.00X1026 ions of potassium. What is the mass in grams of this sample?

Atoms Test Review

Read (and understand) notes and be able to complete all mole problems from the Atoms Worksheets.

1._____How many neutrons in an atom with an atomic number of 42 and mass number of 96.

2._____How many electrons are present in an atom of mercury-201?

3._____Calculate the number of protons in an atom with a mass number of 19 and 10 neutrons.

4._____How many electrons are in an atom with a mass number of 75 and 42 neutrons.

5. How did the results of the gold foil experiment lead Rutherford to recognize the existence of the atomic nuclei?

6. Explain why atoms are neutral.

7._____Which has less mass: an electron or a proton?

8. What information about an atom is provided by the atoms atomic number? The atoms mass number?

9. Write the complete nuclear symbols for isotopes of uranium that have 142 neutrons, 143 neutrons, and 146 neutrons.

10. _____Write the nuclear symbol and hyphen notation for two isotopes of carbon. Both isotopes have six protons. One isotope has six neutrons, while the other has seven neutrons.

11._____All barium atoms have 56 protons. One isotope of barium has 74 neutrons, and another isotope has 81 neutrons. Write the nuclear symbols for these two isotopes of barium.

12._____Precidt which isotope of nitrogen is more commonly found, nitrogen-14 or nitrogen-15.

13._____Write the nuclear symbol for the following ion: 25 protons, 28 electrons, and 30 neutrons.

14. Explain why different atoms of the same element always have the same atomic number but can have different mass numbers.

15. What is an ion?

16. What are the charges of an electron, a proton, and a neutron?

17. State the law of conservation of mass, law of determine proportions, and law of multiple proportions.

18. Calculate the average atomic mass for each of the following elements assuming that each consists of the isotopic mixture shown.

(A)99.76% Oxygen-16, 0.04% Oxygen-17, 0.20% Oxygen-18

(B)96.941% Calcium-40, 0.647% Calcium-42, 0.135%Calcium-43, 2.086% Calcium-44, 0.004% Calcium-46, 0.187% Calcium-48

19. Understand the modern atomic theory including Daltons’ Postulates, Thomson’s discovery of electron properties, Rutherford’s nuclear atom, and Bohr’s nuclear atom.