$$C_{final} = \frac{(0.200 \times 50.0) + (0.100 \times 150.0)}{50.0 + 150.0} = 0.125\,M$$

$$V_2$$ = \frac{$$P_1$$ $$V_1$$}{$$P_2$$} = \frac{1.00 \times 2.00}{2.00} = 1.00\,L$$

Question 1

Which of the following best describes the difference between a physical change and a chemical change?

Accepted Answer

A chemical change involves the formation of new substances, while a physical change does not.

Question 2

A student mixes 50.0 mL of 0.200 M NaCl with 150.0 mL of 0.100 M NaCl. What is the final concentration of NaCl in the mixture?

Accepted Answer

$$C_{final} = \frac{(0.200 	imes 50.0) + (0.100 	imes 150.0)}{50.0 + 150.0} = 0.125\,M$$

Question 3

Which statement about the periodic table is correct?

Accepted Answer

Elements in the same group have the same number of valence electrons.

Question 4

Which of the following is the correct balanced equation for the reaction of aluminum with oxygen to form aluminum oxide?

Accepted Answer

$$4Al + 3O_2 \rightarrow 2Al_2O_3$$

Question 5

A sample of gas occupies 2.00 L at 1.00 atm and 300 K. What will be its volume at 2.00 atm and 300 K?

Accepted Answer

$$V_2$$ = \frac{$$P_1$$ $$V_1$$}{$$P_2$$} = \frac{1.00 	imes 2.00}{2.00} = 1.00\,L$$

Question 6

Which of the following best explains why ionic compounds tend to have high melting points?

Accepted Answer

Ionic compounds have strong electrostatic attractions between oppositely charged ions.

Question 7

Which of the following is the correct formula for calculating the molarity of a solution?

Accepted Answer

$$M = \frac{moles\,of\,solute}{volume\,of\,solution\,(L)}$$

Question 8

A chemical reaction has an equilibrium constant $$K_{eq} = 1.5 	imes 10^5$. What does this indicate about the reaction at equilibrium?

Accepted Answer

The reaction favors the formation of products at equilibrium.

Question 9

Which of the following is a correct statement about acids and bases according to the Brønsted-Lowry theory?

Accepted Answer

An acid is a substance that donates a proton.

Question 10

A solution is prepared by dissolving 0.50 mol of NaCl in enough water to make 1.00 L of solution. What is the molarity of the solution?

Accepted Answer

$$M = \frac{0.50}{1.00} = 0.50\,M$$

Question 11

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 type of atom on both sides.

Question 12

Which of the following is the correct formula for calculating percent yield?

Accepted Answer

$$\%\,yield = \frac{actual\,yield}{theoretical\,yield} 	imes 100$$

Question 13

Which of the following statements about gases is correct according to the kinetic molecular theory?

Accepted Answer

Gas particles are in constant, random motion and collisions are perfectly elastic.

Question 14

A reaction has $$\Delta H = -250\,kJ. $$What does this indicate about the reaction?

Accepted Answer

The reaction is exothermic and releases heat.

Question 15

Which of the following is the correct formula for the ideal gas law?

Accepted Answer

$$PV = nRT$$

Question 16

Which of the following is a correct statement about solubility?

Accepted Answer

Solubility of solids in liquids generally increases with increasing temperature.

Question 17

A student needs to prepare 250 mL of 0.10 M HCl from a stock solution of 1.0 M HCl. What volume of stock solution is required?

Accepted Answer

$$M_1$$ $$V_1$$ = $$M_2$$ $$V_2$$ \Rightarrow $$V_1$$ = \frac{$$M_2$$ $$V_2$$}{$$M_1$$} = \frac{0.10 	imes 250}{1.0} = 25\,mL$$

Question 18

Which of the following is the correct net ionic equation for the reaction between aqueous NaCl and AgNO$$_3$$?

Accepted Answer

$$Ag^+ (aq) + Cl^- (aq) \rightarrow AgCl (s)$$

General Chemistry I: Course Syllabus and Chapter Overview

Guida di studio - Domande di pratica