Exam 1C
1)According to the kinetic-molecular theory of matter, particles in a liquid
a) are packed closely together in a regular array.
b) move slower as the temperature increases.
c) expand to fill their container.
d) vibrate back and forth about an average position.
e) are packed closely together, but are not confined to specific positions.
2) The combustion of propane produces carbon dioxide and steam.
C3H8(g) + 5 O2(g) → 3 CO2(g) + 4 H2O(g)
All of the following statements concerning this reaction are correct EXCEPT
a) three molecule of carbon dioxide are formed per one molecule of propane consumed.
b) four moles of steam are formed per five moles of oxygen consumed.
c) three grams of carbon dioxide are formed per five grams of oxygen consumed.
d) the combined mass of reactants consumed equals the mass of products formed.
e) five molecules of oxygen are consumed per one molecule of propane consumed.
3) All of the following are examples of chemical change EXCEPT
a) the condensation of steam.
b) the rusting of iron.
c) the combustion of butane gas.
d) the tarnishing of silver.
e) the decomposition of water to hydrogen gas and oxygen gas.
4) Dinitrogen trioxide, a blue solid, dissociates to form nitrogen monoxide and nitrogen dioxide gases. What mass of nitrogen dioxide is formed from the decomposition of 35.7 g of dinitrogen trioxide? (Hint: write balanced equation)
a) 7.93gb) 21.6 g c) 6.55 gd) 12.8 ge) 5.17 g
5)According to the kinetic-molecular theory of matter, particles in a gas
a) are packed closely together in a regular array.
b) are packed closely together like solids, but they are not confined to specific positions.
c) move slower as the temperature increases
d) expand to fill their container.
e). vibrate back and forth about an average position.
6) How many protons, neutrons, and electrons are in an nitrogen-13 atom?
a) 6 protons, 8 neutrons, 7 electron
b) 7 protons, 7 neutrons, 6 electrons
c) 7 protons, 6 neutrons, 7 electrons
d) 7 protons, 13 neutrons7 electrons
e) 7 protons, 14 neutrons, 13 electrons
The picture below shows two metal plates that have been electrically charged, one with a positive charge and one with a negative charge.
7) The plate with a positive charge is
a)anodeb) cathodec) both plates
d)can’t tell
8) The positive ion is attracted to
b)anodeb) cathodec) both plates
e)can’t tell
9) The mass of one atom of chromium is
a) 3.07E25b) 3.07E-25c) 8.64E-23d) 4.55E-22e) 5.19E-22
10) Suppose you have 30.00 cm3 ice at 0.00C. Then the volume of your sample at 100C is ______cm3.
- 31.35
- 31.43
- 26.13
- 28.71
- 25.00
11) Which one of the following is a homogeneous mixture?
a) baked beansb) a jar of chunky peanut butterc) chocolate chip ice cream
d) chicken noodle soupe) sugar dissolved in water
12). ) All of the following statements are true EXCEPT
a) electrons and protons have equal mass, but opposite charges.
b)isotopes of an element have identical atomic numbers.
c) the mass number is the sum of the number of protons and neutrons.
d) the atomic number equals the number of protons.
e) for any neutral element, the number of protons and electrons are equal.
13) A compound containing only C and H is analyzed by means of combustion. If the products of combustion are 3.701 CO2 and 2.272 g H2O, the empirical formula of the compound is
a) C2H3b) CHc) CH2d) CH3e) C2H5
14)The molecular model below depicts a molecule composed of carbon (black), oxygen (gray), and hydrogen (white) atoms. What is the correct molecular formula?
a) CHOb) C6H6O3c) C6H7Od) C7H6Oe) C7H6O2
15) The formula in the last problem is ______an empirical formula.
a) notb) also
.
Free- response questions: Clearly show your work No work shown = 0. Unreadable responses = 0.
PRINT your Name______
1) Consider the reaction, 2 B5H9 + 12 O2 5 B2O3 + 9 H2O
(Molar masses, g/mol: 63.126 31.998 69.619 18.0148
______g of B2O3 is the maximum that can be produced from a reaction mixture of 5.00 g B5H9 and 14.0 g O2 ; the limiting reactant is ______(10 pts)
2) The coefficients of the balanced equation, when C6H10O3 is burned in air are ______(5 pts)
3) When 1.500 g of a metal oxide is heated, the compound decomposes and 0.1035 g O2 is produced. (See equation below.) Considering all M+1 possibilities for metal ions, what is the identity of the metal M? (10 pts)
2 M2O(s) → 4 M(s) + O2(g)
Avogadro’s number = 6.022E231