Chem 120 Quiz 3 Questions with
complete solution 2025
in the following reaction, HCl is the _____; and NaCl is.
NaOH+HCl à NaCl + H20 - correct answer ✔reactant; product
Which of the following coefficients is placed in front of H2O to balance the
following equation?
Ca(OH)2 + HCl ---> CaCl2+ _____ H20 - correct answer ✔2
Which coefficient is placed in front of CaO to balance the following equation?
CaCO3 à _____ CaO + CO2 - correct answer ✔1
Sodium reacts with oxygen to form sodium oxide and has the following
balanced equation: 4 Na + O2 ---> 2 Na2O.
How many moles of oxygen gas (O2) are needed to react with 2.0 moles of
Na? - correct answer ✔0.5 moles
Magnesium reacts with oxygen to form magnesium oxide and has the
following balanced chemical equation: 2 Mg + O2 ---> 2 MgO. How many
moles of MgO are produced when 4 moles O2 reacts completely? - correct
answer ✔8 moles
(a). Determine the number of atoms for each element present in the following
molecule: Cu (CN)2.
(b). Using the periodic table of elements, determine the molar mass for this
molecule. Show your work. - correct answer ✔a. Number of atoms: Cu=1,
N=2, C=2
b. Atomic Mass: Cu=63.546, N=14.007(2), C=12.01(2)
complete solution 2025
in the following reaction, HCl is the _____; and NaCl is.
NaOH+HCl à NaCl + H20 - correct answer ✔reactant; product
Which of the following coefficients is placed in front of H2O to balance the
following equation?
Ca(OH)2 + HCl ---> CaCl2+ _____ H20 - correct answer ✔2
Which coefficient is placed in front of CaO to balance the following equation?
CaCO3 à _____ CaO + CO2 - correct answer ✔1
Sodium reacts with oxygen to form sodium oxide and has the following
balanced equation: 4 Na + O2 ---> 2 Na2O.
How many moles of oxygen gas (O2) are needed to react with 2.0 moles of
Na? - correct answer ✔0.5 moles
Magnesium reacts with oxygen to form magnesium oxide and has the
following balanced chemical equation: 2 Mg + O2 ---> 2 MgO. How many
moles of MgO are produced when 4 moles O2 reacts completely? - correct
answer ✔8 moles
(a). Determine the number of atoms for each element present in the following
molecule: Cu (CN)2.
(b). Using the periodic table of elements, determine the molar mass for this
molecule. Show your work. - correct answer ✔a. Number of atoms: Cu=1,
N=2, C=2
b. Atomic Mass: Cu=63.546, N=14.007(2), C=12.01(2)
