# chem

```Name: ___________________________
Score: __________
Section: ___________
Date: ___________
I.
Enumeration:
1-5 Subbranches of Chem
6-7. properties of matter
1.
6.
2.
7.
3.
8-10 types of heterogeneous mixture
4.
8.
5.
9.
II.
Identify how many significant digits are present
___1. 0.5789
___6. 27.00
___2. 1000000.01
___7. 04.68 x 1023
___3. 1.805 x 108
___8. 562
___4. 100023.00
___9. 29.00
___5. 50.00
___10. 72.00001
III.
Conversion
1. 39.2 tons -&gt; tg
2. 45.74 inch -&gt; miles
3. 98213 lbs -&gt; ng
10.
IV.
Specific heat
1.A block of aluminum weighing 140 g is cooled from 98.4&deg;C to 62.2&deg;C with the release of 1080
joulesof heat. From this data, calculate the specific heat of aluminum.
2.100.0mL of 4.0&deg;C water is heated until its temperature is 37&deg;C. If the specific heat of water is 4.18
J/g&deg;C, calculate the amount of heat energy needed to cause this rise in temperature.(Note: 1 ml of
water = 1 gram)
3.Object A specific heat is 2.45 J/g∙&deg;C and object B specific heat is 0.82 J/g∙&deg;C. Which object will heat
up faster if they have the same mass and equal amount of heat is applied? Explain why.
V.
STOICHIOMETRY
a. Convert the following number of moles of chemical into its corresponding mass in grams.
1. 0.436 moles of ammonium chloride
2. 2.360 moles of lead (II) oxide
3. 0.031 moles of aluminium iodide
4. 1.077 moles of magnesium phosphate
5. 0.50 moles of calcium nitrate
b. Convert the following masses into their corresponding number of moles.
6. 23.5 g of sodium chloride
7. 0.778 g of sodium cyanide
8. 0.250 g of water
9. 169.45 g of calcium acetate
10. 79.9 g of potassium permanganate
11. Using the following equation:
Fe2 O3+ H2 -------------&gt; Fe + H2O
Calculate how many grams of iron can be made from 16.5 grams of Fe2O3 by the following equation.
12. Using the following equation:
I2 + KIO2 + HCl ---------&gt; ICl + KCl + H2O
Calculate how many grams of iodine are needed to prepare 28.6 grams of ICl by this reaction.
13. Using the following equation:
KNO2 + KMnO4 + H2SO4 ------&gt; KNO3 + MnSO4 + K2SO4 + H2O
How many moles and how many grams of KMnO4 are needed to carry out this reaction on 11.4 grams of
KNO2?
VI. Percent yield
1. If, in the reaction below 32 grams of C2H6 produces 44 grams of CO2, what is the % yield?
2C2H6 + 7O2 -&gt; 4CO2 + 6H2O
2. If, in the reaction below, 80 grams of Cl2 produces 38 grams of CCl4 what is the % yield
CS2 + 3Cl2 -&gt; CCl4 + S2Cl2
3. If, in the reaction below, 49 grams of Fe3O4 produces a 78.25 % yield of Fe. How many grams are
produced?
Fe3O4 + 4H2 -&gt; 3Fe + 4H2O
VII. Limiting Reactants
1.BALANCE the equation first.
FeCl3 +
O2 -&gt;
Fe2O3 +
Cl
a. How many moles of chlorine gas can be produced if 4 moles of FeCl3 react with 4 moles of O2?
b. What is the limiting reactant?
c. What is the excess reactant?
2.Use the following BALANCED equation.
2 C2H6 + 7 O2 -&gt; 4 CO2 + 6 H2O
a.If 15 g of C2H6 react with 45 g of O2, how many grams of water will be produced?
b. What is the limiting reactant?
c. What is the excess reactant?
```