Q: How many molecules are present in 0.50 mol of $CO_2$? ($N_A = 6.02 \times 10^{23}$ molecules/mol)

$3.01 \times 10^{23}$ molecules

Question 1

Which of the following best describes a redox reaction?

Accepted Answer

A reaction in which electrons are transferred between substances.

Question 2

Which of the following is the correct balanced equation for the combustion of methane ($CH_4$) in oxygen?

Accepted Answer

$CH_4 + 2O_2 \rightarrow CO_2 + 2H_2O$

Question 3

Which of the following statements about oxidation and reduction is correct?

Accepted Answer

Oxidation is the loss of electrons, and reduction is the gain of electrons.

Question 4

In the reaction $2Na + Cl_2 \rightarrow 2NaCl$, which element is oxidized?

Accepted Answer

Sodium ($Na$)

Question 5

Avogadro's number is used to determine:

Accepted Answer

The number of particles in one mole of a substance.

Question 6

How many molecules are present in 0.50 mol of $CO_2$? ($N_A = 6.02 	imes 10^{23}$ molecules/mol)

Accepted Answer

$3.01 	imes 10^{23}$ molecules

Question 7

Which of the following is the correct molar mass of $H_2SO_4$?

Accepted Answer

$98.1\ g/mol$

Question 8

If you have 18.0 g of water ($H_2O$), how many moles do you have? (Molar mass of $H_2O = 18.0\ g/mol$)

Accepted Answer

$1.00$ mol

Question 9

A chemical reaction has the following balanced equation: $2Al + 3Cl_2 \rightarrow 2AlCl_3$. If you start with 4.0 mol of $Al$ and excess $Cl_2$, how many moles of $AlCl_3$ can be produced?

Accepted Answer

$4.0$ mol

Question 10

Which of the following best describes an exothermic reaction?

Accepted Answer

A reaction that releases energy to the surroundings.

Question 11

In a reaction, 2.0 mol of $H_2$ react with 1.0 mol of $O_2$ to produce water. What is the limiting reactant?

Accepted Answer

$O_2$

Question 12

Which of the following is the correct mole ratio for $N_2 + 3H_2 \rightarrow 2NH_3$?

Accepted Answer

$1:3:2$

Question 13

A patient receives 0.90 g of $NaCl$ in an IV solution. How many moles of $NaCl$ did the patient receive? (Molar mass of $NaCl = 58.5\ g/mol$)

Accepted Answer

$0.015$ mol

Question 14

Which of the following is NOT a sign that a chemical reaction has occurred?

Accepted Answer

Dissolving sugar in water.

Question 15

If 2.0 mol of $KClO_3$ decompose according to the equation $2KClO_3 \rightarrow 2KCl + 3O_2$, how many moles of $O_2$ are produced?

Accepted Answer

$3.0$ mol

Question 16

Which of the following best describes the reactant that is completely consumed in a chemical reaction?

Accepted Answer

Limiting reactant

Question 17

A reaction has a theoretical yield of 10.0 g, but only 7.5 g of product is actually obtained. What is the percent yield?

Accepted Answer

$75\%$

Question 18

Which of the following reactions is an example of a single replacement reaction?

Accepted Answer

$Zn + 2HCl \rightarrow ZnCl_2 + H_2$

Question 19

Which of the following best describes the process of balancing a chemical equation?

Accepted Answer

Adjusting the coefficients to ensure the same number of each atom on both sides.

Question 20

Which of the following is the correct definition of molar mass?

Accepted Answer

The mass of one mole of a substance, expressed in grams per mole.

Chapter 7: Chemical Reactions and Quantities – Study Notes

Study Guide - Practice Questions

Study Guide - Flashcards