Chemistry Basics
When writing a chemical equation, the substances on the left hand side of the arrow are the _____, while those on the right hand side are the ______.
A) formulas; products
B) reactants; products
C) elements; atoms
D) products; reactants
B) reactants; products
An exothermic reaction:
A) releases energy to the environment
B) absorbs energy from the environment
C) causes burns
D) occurs on its own
A) releases energy to the environment
To balance a chemical equation, it is permissible to adjust the:
A) coefficients
B) formulas of the products
C) subscripts
D) number of reactants
A) coefficients
What is the mass of one mole of Calcium?
A) 29 g
B) 34 g
C) 40 g
D)74 g
C) 40 g
The correct formula for a compound made from potassium and oxygen is:
A) OK
B) KO2
C) K2O
D) PO2
C) K2O
A chemical change can be described by using a:
A) chemical reaction
B) chemical equation
C) chemical formula
D) numbers and arrows
B) chemical equation
If the addition of heat is required to make this reaction take place the reaction must be?
A) endothermic
B) catalytic
C) exothermic
D) nuclear
A) endothermic
To balance this reaction the coefficient that needs to be placed before the Potassium sulfate is:
Al2(SO4)3(aq) + KOH(aq) -> Al(OH)3(s) + K2SO4(aq)
A) 2
B) 3
C) 4
D) 6
B) 3
One mole of water (H2O) would have a mass of:
A) 17 g/mol
B) 18 g/mol
C) 33 g/mol
D) 34 g/mol
B) 18 g/mol
In the compound copper II oxide, the roman numeral II indicates
A) The number of copper ions
B) The number of oxide ions
C) The charge on the oxygen ions
D) The charge on the copper ions
A) The number of copper ions
A chemical equation must be balanced so that it:
A) is easy to read
B) is not missing any reactants
C) looks good
D) obeys the law of conservation of mass
D) obeys the law of conservation of mass
Which would cause a reaction's rate, involving a solid to increase the most?
A) raise the temperature and break the solid into small pieces
B) lower the temperature and break the solid into small pieces
C) lower the temperature and keep the solid as a lump
D) raise the temperature and keep the solid in a lump
A) raise the temperature and break the solid into small pieces
Consider the following unbalanced equation. When the equation is balanced, the coefficient for sodium chloride would be:
___FeCl2 + ___Na2CO3 -> ___FeCO3 + ___NaCl
A) 6
B) 2
C) 3
D) 4
B) 2
What is the molar mass of Ca(OH)2 ?
A) 29 g
B) 34 g
C) 40 g
D)74 g
D)74 g
Which of the following would be a correct name for Na2CO3?
A) sodium carbonate
B) nitrogen carbon trioxide
C) sodium bicarbonate
A) sodium carbonate
A group of atoms bonded together and carrying a charge is called a:
A) molecule
B) polyatomic ion
C) plasma
D) atom
A) molecule
A substance that speeds up a reaction, but is not changed in the reaction is:
A) not involved in the reaction
B) changing the concentrations present
C) a catalyst
D) always slows down a reaction
C) a catalyst
Balance the following equations and classify each reaction according to type
Al + HCl -> AlCl3 + H2 Type?
2 Al + 6 HCl -> 2 AlCl3 + 3 H2
Type- Single Replacement
Stoichiometry
Use the equation to perform the stoichiometric calculations that follow:
C3H8 + 5O2 -> 3CO2 + 4H2O
If 3.13 moles of C3H8 react completely how many grams of C3H8 will be formed?
138.1 g of C3H8
Write the formula
Potassium iodide
KI
The atomic number of an element is determined by the number of:
A) protons
B) neutrons
C) electrons
D) protons + neutrons
A) protons
An increase in temperature generally increases the reaction rate because the molecules collide:
A) more frequently and with less energy
B) more frequently and with more energy
C) less frequently and with less energy
D) less frequently and with more energy
B) more frequently and with more energy
Balance the following equation and classify each reaction according to type
C2H6 + O2 -> CO2 + H2O Type?
1 C2H6 + 4 O2 -> 2 CO2 + 3 H2O
Type- Combustion
A certain reaction produces 86.5 L of hydrogen gas at STP. How many moles of hydrogen were produced? (1 mol = 22.4 L)
3.86 mol H2
Iron (III) carbonate
Fe3(CO3)3