Topic 9: Chemical Equations and Stoichiometry
What is the name for a single step reaction?
A rock is dropped off a cliff. What best describes the energy conversion during the fall? _____ (gravitational potential/ chemical potential/ kinetic) energy is converted to _____ (gravitational potential/ chemical potential/ kinetic) energy.
1. Gravitational potential
2. Kinetic
An alpha particle consists of _____ proton(s) and _____ neutron(s).
2 protons and 2 neutrons
Control rods are often made of which element? Boron, Steel, Concrete, or Uranium
Boron
What is the name for a combination of reactions?
Overall reaction
Is the formula C₃H₇ the empirical or molecular formula for this hydrocarbon?
Empirical
Which type of energy is transferred between the two objects due to the difference in their average kinetic energies between them?
Heat
If a nucleus decays by alpha, alpha and beta (-) decay, the atomic number of the final product will be _____ (higher/ lower) by _____ (3/4) from the original atomic number.
Lower by 3
What can be used as a source of nuclear power? Coal, Titanium, Uranium, or Oil
Uranium
Freebie!
Cool!
Fe(s) + S₈(s) FeS(s)
If 16.0 grams of sulfur reacts with excess iron, how many grams of FeS are produced? Be sure that your answer has the proper number of significant figures. ________ grams FeS
Balance the equation for this reaction. ____ Fe(s) + ____ S₈(s) ____ FeS(s)
1. 44
2. 8, 1, 8
The formation reaction shown below is _____________. 2NO(g) + O₂(g) 2NO₂(g) + 113 kJ
1- Endothermic / Exothermic
2- Releases / Absorbs energy
Exothermic / Releases energy
True or false? In gamma decay the parent nucleus and the daughter nucleus have the same number of protons and neutrons
True
In a nuclear reactor, control rods are used to absorb extra _____ to keep the system from overheating and regulate the output of the reactor.
neutrons
electrons
protons
gamma rays
1. neutrons
You have a 10-g piece of graphite and a 10-g piece of iron sitting in the sun. Which one will warm by 5°C first?
Iron
NaOH(aq) + Al(s) Na₃AlO₃(s) + H₂(g)
What mass in grams of aluminum is required to produce 17.5 L of hydrogen (d=0.89 g/L)? _____ g Al
Balance the equation for this reaction. ___ NaOH(aq) + ___ Al(s) ___ Na₃AlO₃(s) + ___ H₂(g)
1. 139
2. 6, 2, 2, 3
A piece of iron metal is heated to 155°C and placed into a calorimeter that contains 50.0 mL of water at 18.7°C. The temperature of the water rises to 25.4°C. How much heat was released by the iron?
1610 J
In B- decay, _____.
A. The parent and daughter nuclei have the same number of protons.
B. The daughter nucleus has one proton less than the parent nucleus.
C. The daughter nucleus has one proton more than the parent nucleus.
D. None of the above.
C. The daughter nucleus has one proton more than the parent nucleus.
Plutonium-239 undergoes the fission process below after absorbing a neutron. What is missing from the products side of the equation? 23994Pu + 10n 13758Ce + 9936Kr
A. 4 neutrons B. 4 electrons C. 4 positrons D. 4 protons
A. 4 neutrons
A 23.7 piece of iron at 54.9°C is cooled and releases 338 J of heat. The specific heat of iron is 0.450 J/g°C. What is the final temperature of the iron?
23.2
Cu(s) + AgNO₃(aq) Cu(NO₃)₂(aq) + Ag(s)
If 89.5 grams of Ag were produced, how many moles of copper were used in the original mixture? ______ mol Cu
If 89.5 grams of Ag were produced, how many moles of silver nitrate were used in the original mixture? ______ mol AgNO₃
Balance the equation for this reaction. ___ Cu(s) + ___ AgNO₃(aq) ___ Cu(NO₃)₂(aq) + ___ Ag(s)
1. 0.415
2. 0.83
3. 1, 2, 1, 2
Which relationship between chemical bonds and energy is observed in an endothermic reaction?
A. More energy is required to form new bonds in the products than is released by breaking bonds in the reactants.
B. More energy is required to break bonds in the reactants than is released by forming new bonds in the products.
C. More energy is released by breaking bonds in the reactants than is required to form new bonds in the products.
D. More energy is released by forming new bonds in the products than is required to break bonds in the reactants.
B. More energy is required to break bonds in the reactants than is released by forming new bonds in the products.
In electron capture, _____.
A. The daughter nucleus has two protons less than the parent nucleus.
B. The parent and daughter nuclei have the same number of protons.
C. The daughter nucleus has one proton more than the parent nucleus.
D. The daughter nucleus has one proton less than the parent nucleus.
D. The daughter nucleus has one proton less than the parent nucleus.
What is the missing mass number A in the following nuclear equation? 29592U + 10n A55Cs + 9937Rb + 210n
A. 133 B. 134 C. 135 D. 136
C. 135
What type of nuclear decay is shown in the following equation? 146C 147N + 0-1e
A. B- decay B. B+ decay C. alpha decay D.gamma decay
A. B- decay