Chemistry 1.19: Unit 4 Review

Multiple Choice

What is the mass of 1 mole of nitrogen atoms?

• 14 kg

• 7 kg

• 7 g

• 14 g

Multiple Choice

A Student is 183 cm tall. Which equation shows the height of the student in inches? (1 in = 2.54 cm)

• $$183\ cm\ x\ \frac{1\ in}{2.54\ cm}\ =\ 72\ in$$  

• $$183\ cm\ x\ \frac{2.54\ cm}{1\ in}\ =\ 72\ in$$  

• $$183\ cm\ x\ \frac{2.54\ cm}{1\ in.}\ =\ 457.5\ in$$  

• $$183\ cm\ x\ \frac{2.54\ in}{1\ cm}\ =\ 457.5\ in$$  

Multiple Choice

A 2L sample of water has 3 mol of salt in it. What is the molarity of the solution?

• 2M

• 3 M

• 1. 5 M

• 0.67 M

Multiple Choice

A 100 g sample of a compound has the following amounts of moles:

C - 4.5 mol

H - 9.1 mol

O - 2.28 mol

What is the empirical formula for the compound?

• $$CHO$$  

• $$CH_2O$$  

• $$C_2H_4O$$  

• $$CHO_4$$  

Multiple Choice

The empirical formula is  $$C_2H_4O$$  and the molar mass is 88 g/mol. What is the molecular formula of this compound? (Atomic mass C = 12 g/mol, H = 1 g/mol, O = 16 g/mol)

• $$C_4H_8O_2$$  

• $$C_2H_4O$$  

• $$C_4H_4O$$  

• $$C_6H_{12}O_4$$  

Multiple Choice

Identify the type of reaction:

$$2SO_3\left(g\right)\ \rightarrow\ 2SO_2\left(g\right)\ +\ O_2\left(g\right)$$  

• Synthesis

• Decomposition

• Single Replacement

• Double Replacement

Multiple Choice

Identify the type of reaction:

$$2Na\left(s\right)\ +\ Cl_2\left(g\right)\ \rightarrow\ 2NaCl\left(s\right)$$  

• Synthesis

• Decomposition

• Single Replacement

• Double Replacement

Multiple Choice

Given the following complete ionic equation, what are the spectator ions:

$$2Na^+\left(aq\right)\ +\ SO_4^{-2}\left(aq\right)\ +\ Ba^{+2}\left(aq\right)\ +\ 2Cl^-\left(aq\right)\ \rightarrow\$$  

$$BaSO_4\left(s\right)\ +\ 2Na^+\left(aq\right)\ +\ 2Cl^-\left(aq\right)$$  

• $$Na^+\ and\ Cl^-$$  

• $$Ba^{+2}\ and\ SO_4^{-2}$$  

• $$Ba^{+2}\ and\ Cl^-$$  

• $$Na^+\ and\ SO_4^{-2}$$  

Multiple Choice

Given the following complete ionic equation, what is the net ionic equation:

$$2Na^+\left(aq\right)\ +\ SO_4^{-2}\left(aq\right)\ +\ Ba^{+2}\left(aq\right)\ +\ 2Cl^-\left(aq\right)\ \rightarrow\$$  

$$BaSO_4\left(s\right)\ +\ 2Na^+\left(aq\right)\ +\ 2Cl^-\left(aq\right)$$  

• $$Na^+\left(aq\right)\ +\ 2Cl^-\left(aq\right)\ \rightarrow\ BaSO_4\left(s\right)$$  

• $$SO_4^{-2}\left(aq\right)\ +\ Ba^{+2}\left(aq\right)\ \rightarrow\ \ BaSO_4\left(s\right)$$  

• $$SO_4^{-2}\left(aq\right)\ +\ Ba^{+2}\left(aq\right)\ \rightarrow\ NaCl\left(s\right)$$  

Multiple Choice

What are the reactants in a combustion reaction?

• oxygen and water

• water and heat

• carbon dioxide and oxygen

• oxygen and a carbon-based compound

Multiple Choice

What type of drawing is pictured here?

• Ball and stick model

• Structural

• Skeletal

• None of the above

Multiple Choice

Sodium metal reacts with water according to the following reaction:

$$2Na\left(s\right)\ +\ 2H_2O\left(l\right)\ \rightarrow\ 2NaOH\left(aq\right)\ +\ H_2\left(g\right)$$  

You have 4 mol of sodium. Which conversion correctly allows you to calculate the moles of hydrogen produced?

• $$4\ mol\ Na\ \ x\ \ \frac{2\ mol\ H_2O}{1\ mol\ H_2}\ =$$  

• $$4\ mol\ Na\ \ x\ \ \frac{2\ mol\ Na}{1\ mol\ H_2}\ =$$  

• $$2\ mol\ Na\ \ x\ \ \frac{1\ mol\ H_2}{2\ mol\ Na}\ =$$  

• $$4\ mol\ Na\ \ x\ \ \frac{1\ mol\ H_2}{2\ mol\ Na}\ =$$  

Multiple Choice

You react 0.10 mol of  $$Fe_2O_3$$   with 0.39 mol of CO. Using the balanced equation, determine the limiting reagent:

$$Fe_2O_3\left(s\right)\ +\ 3CO\left(g\right)\ \rightarrow\ 2Fe\left(l\right)\ +\ 3CO_2\left(g\right)$$  

• $$Fe_2O_3\left(s\right)$$  

• $$CO$$  

Multiple Choice

  $$Fe_2O_3$$   is the limiting reagent. Find the number of moles of Fe produced (given that 0.10 mols of $$Fe_2O_3\left(s\right)$$   were reacted):

$$Fe_2O_3\left(s\right)\ +\ 3CO\left(g\right)\ \rightarrow\ 2Fe\left(l\right)\ +\ 3CO_2\left(g\right)$$  

• $$0.10\ mols$$  

• $$0.20\ mols$$  

• $$0.39\ mols$$  

• $$0.78\ mols$$  

Multiple Choice

The theoretical yield of Fe is 11 g. If 10 g are actually produced, what is the percent yield?

• 110 %

• 91 %

• 50 %

• 0 %