Name_____Answers________________________________period____________IB Chemistry
Ch. 1A worksheet
Read chapter 1 up to percentage yield (pg. 17)
1. Indicate whether the following are measurements of length, area, volume, mass, density, time or temperature
a. 5 ns
b. 3.2 kg/dm3 c. 88 pm
d. 540 km2
e. 173 K
f. 2 mm3
Seconds
density
length
area
temp.
volume
1. What is a mole?
The amount of atoms in 12 g of C-12
2. What is the symbol for a mole?
mol
3. How many particles are in a mole?
6.02 x 1023
4. What is a molecular formula?
Tell the number of atoms and what types of atoms are bonding together in a molecule
5. Calculate the molecular mass for the following
a. CH4
b. C3H7OH
c. C3H6
16 amu
60 amu
42 amu
6. Calculate the formula mass for the following
a. Cu
b. N2O5
c. Ca(C2H3O2)2
63.5 amu
108 amu
158 amu
7. Find the molar mass for the following
a. Sodium hydroxide
b. magnesium chloride
c. aluminum nitrate
40 g/mol
93.4 g/mol
213 g/mol
8. Find the number of particles in the following
a. 5.1 mol of K
b. 10.80 g of Ca
c. 4.0 x 103 mg Mg
3.1 x 10 24
1.63 x 10 23
9. Find the number of moles in the following
a. 54.3 g of Ag
b. 4.40 x 1023 atoms of C
0.503 mol
9.9 x 10 22
0.731 mol
10. Find the number of grams in the following
a. 13.20 mol Fe
b. 5.50 x 1023 atoms of Al
736.6 g
11. The formula for aspartame is C14H18N2O5.
a. What is the molar mass of aspartame
294 g/mol
24.7 g
c. 1.3 kg of Na
57 mol
c. 0.050 mol Cu
3.2 g
b. How many moles of aspartame are present in 1.00 mg of aspartame?
3.4 x 10-6 mol
c. How many molecules of aspartame are present in 1.00 mg of aspartame?
2.05 x 1018
d. How many hydrogen atoms are present in 1.00 mg of aspartame?
12. Find the number of grams in the following
a. 8.90 mol H2O
b. 0.0089 mol of N2O5
160 g
0.96 g
13. Find the number of moles in the following
a. 15.0 g of Ca(NO3)2
0.100 mol
b. 345.0 mg KCl
.0002492 mol
14. Which of the following are empirical formulas?
a. N2O
b. MgCl2
c. C2H6
15. Determine the empirical formula for each
a. 0.104 mol K, 0.052 mol C, and 0.156 mol O
K2CO3
b. 87.5 % N, 12.5% H
NH2
16. What is the molecular formula of each of the following compounds?
a. Empirical formula, CH2, molar mass = 84 g/mol
C6H12
b. Empirical formula, NH2Cl, molar mass = 51.5 g/mol
NH2Cl
17. Determine the empirical and molecular formula
a. Ibuprofen contains 75.69% C, 8.80% H, and 15.51% O; molar mass about 206 g
C13H18O2 / C13H18O2
b. Adrenaline contains 59.0% C, 7.1% H, 36.2% O, and 7.7% N; MW about 180 amu
C9H13O3N
18. Describe the phases of matter by the closeness of the atoms
a. Solids very close
b. Liquids close
c. Gases very far apart
19. Convert
a. 300 K to ⁰C
b. 98 C to K
c. 100K to ⁰C
27 C
371 C
-173 C
20. In which sample do molecules have the lowest average kinetic energy?
a. Helium and 100 K
b. Hydrogen at 200 K
c. Oxygen at 300 K
d. Water at 400 K
21. What happens to the kinetic energy of a substance while it is boiling? Explain.
Stays the same. The temperature doesn’t change all the energy goes into breaking the molecules apart.
22. What happens to the distance between molecules while a substance is boiling?
Increases
23. Balance the following equations
a. 2CO + O2  2CO2
b. Cr(OH)3 + 3 HClO4  Cr(ClO4)3 +
3H2O
24. Write a balance equation to correspond to each description
a. When solid potassium chlorate is heated, it decomposes to form solid potassium chloride and oxygen
gas. 2KClO3  2KCl + 3O2
b. When liquid phosphorus trichloride is added to water it reacts to form aqueous phosphorous acid
(H3PO3) and aqueous hydrochloric acid (HCl)
PCl3 +3 H2O  H3PO3 + 3HCl
25. The formation of glucose, C6H12O6 produces ethyl alcohol, C2H5OH and CO2:
C6H12O6  2C2H5OH + 2CO2
a. How many moles of carbon dioxide are produced when 0.300 mol of glucose reacts?
0.600 mol
b. How many grams of glucose are needed to form 2.00 g of methyl alcohol?
3.91 g
c. How many grams of carbon dioxide form when 2.00 g of methyl alcohol are produced?
1.91 g
26. Aluminum sulfide reacts with water to form aluminum hydroxide and hydrogen sulfide.
a. Write the balanced equation for this reaction.
Al2S3 + 6H2O  2Al(OH)3 +3 H2S
b. How many grams of aluminum hydroxide are formed from 10.5 g of aluminum sulfide?
10.9 g
c. What is the percent yield if the mass obtained of aluminum hydroxide was 3.4 g?
32%
27. Automotive air bags inflate when sodium azide, NaN3, rapidly decomposes.
2NaN3 (s)  2 Na (s) + 3 N2 (g)
a. How many moles of nitrogen gas are produced by the decomposition of 1.50 moles of sodium azide?
2.25 g
b. How many grams of NaN3 are required to form 5.00 g of nitrogen gas?
7.74 g
c. How many grams of NaN3 are required to produce 10.0 ft3 of nitrogen gas if the gas has a density of 1.25
g/L?
548 g
28. Why are the amounts of the product formed in a reaction determined only by the amount of limiting reaction?
The limiting reactant regulates the amount of products because it is completely used up during the reaction; no more
product can be made when one reactant is unavailable.
29. The fizz produced when an alka-seltzer tablet is dissolved in water is due to the reaction between sodium
bicarbonate and citric acid, H3C6H5O7
3NaHCO3 + H3C6H5O7  3 CO2 + 3 H2O + Na3C6H5O7
In a certain experiment 1.00 g of sodium bicarbonate and 1.00 g of citric acid are allowed to react.
a. Which reactant is the limiting reactant?
NaHCO3
b. How many grams of carbon dioxide form?
0.524 g
Review:
c. How much of the excess reactant remains after the limiting reactant is completely consumed?
0.238 g
30. Fill in the gaps
Symbol
Protons
Neutrons
Electrons
Mass number
39
K
19
20
19
39
55
112
137
207
25
48
56
82
30
64
81
125
25
48
56
82
55
112
137
207
Mn
31. Label each as a metal, nonmetal, or metalloid
a. He
b. silver
c. phosphorus
Nonmetal
metal
nonmetal
Cd
d. arsenic
metalloid
32. What are basic properties of metals, metalloids, and nonmetals?
Metals-good conductors, malleable, ductile, shiny
Nonmetals- poor conductors
Metalloids-semiconductros
33. Determine the name of the group each belong to
a. Potassium
b. chlorine
c. neon
Alkali metal
halogens
noble gas
Ba
e. calcium
metal
Pb
f. Al
e. hydrogen
metal nonmetal
d. magnesium
alkaline earth metal
e. gold
transition metal
34. Based on their position on the periodic table, predict which atom of the following pairs will have the largest first
ionization energies.
a. O, Ne
b. Mg, Sr
c. K, Cr
d. Br, Sb
e. Ga, Ge
b.
35. Predict whether each of the following oxides is ionic or molecular: SO2, MgO, Li2O, N2O, XeO3
36. Which of the following forms molecules?
Molecular, ionic, ionic, molecular, molecular
a. K2CO3
b. F2
c. AlCl3
d. H2O
e. Fe2O3
37. What is the most common charge when each become ions
a. Mg +2
b. O -2
c. Al +3
d. P -3
e. K +1
f. Br -1