Base your answers to questions 1 and 2 on the information below and on your knowledge of chemistry.

The equation below represents an equilibrium system of SO_{2}(g), O_{2}(g), and SO_{3}(g).

The reaction can be catalyzed by vanadium or platinum.

2SO_{2}(g) + O_{2}(g) ↔ 2SO_{3}(g) + energy

Base sus respuestas a las preguntas de la 1 y 2 en la siguiente información y su conocimiento de química.

La siguiente ecuación representa un sistema en equilibrio compuesto de SO_{2}(g), O_{2}(g), y SO_{3}(g). La reacción puede ser catalizada por vanadio o platino.

2SO_{2}(g) + O_{2}(g) ↔ 2SO_{3}(g) + energía

**Problem 1**

Compare the rates of the forward and reverse reactions at equilibrium.

Compare las velocidades de las reacciones directa y reversa en equilibrio.

*Discussion and Solution:*

Since this is a reversible reaction, at equilibrium, the rates of the forward and reverse reactions are equal. The rates are the same.

**Problem 2**

State how the equilibrium shifts when SO_{3}(g) is removed from the system.

Exponga como el equilibrio cambia cuando el SO_{3}(g) es removido del sistema.

*Discussion and Solution:*

When SO3(g) is removed from the system: The equilibrium will shift to favor the formation of SO_{3}; The rate of the forward reaction is greater than the rate of the reverse reaction; The equilibrium will shift to favor the forward reaction; The equilibrium will shift to the right; and The concentrations of the reactants will decrease.

**Problem 3**

Determine the volume of 2.00 M HCl(aq) solution required to completely neutralize 20.0 milliliters of 1.00 M NaOH(aq) solution.

Determine el volumen de una solución de 2.00 M HCl(aq) requerido para neutralizar completamente 20.0 mililitros de una solución de 1.00 M NaOH(aq).

*Discussion and Solution:*

We need to use the following equation, where M_{a} = molarity of the acid, V_{a} = volume of the acid, M_{b} = molarity of the base, and V_{b} = volume of the base:

M_{a}V_{a} = M_{b}V_{b}

Since we are looking for Va, we divide both sides by M_{a} and substitute in what values we know and then simplify.

V_{a} = = 10.0 ml

**Problem 4**

Given the balanced equation representing a reaction:

6Li + N_{2} → 2Li_{3}N

Which type of chemical reaction is represented by this equation?

(1) synthesis

(2) decomposition

(3) single replacement

(4) double replacement

Dada la ecuación balanceada representando una reacción:

6Li + N_{2} → 2Li_{3}N

¿Qué tipo de reacción química es representada por esta ecuación?

(1) síntesis

(2) decomposición

(3) desplazamiento simple

(4) doble desplazamiento

*Discussion and Solution:*

Since we are starting off with two elements (Li and N) and ending up with a compound (Li_{3}N), this is an example of a synthesis reaction.

Choice (1)

In choice (2), we would have to start off with a compound and end up with two elements.

In choice (3), we would have to start off with an element and a compound. The element would then replace one of the elements found in the compound.

In choice (4), we would start off with two compounds, who would switch elements with each other.

**Problem 5**

A rigid cylinder with a movable piston contains 50.0 liters of a gas at 30.0°C with a pressure of 1.00 atmosphere. What is the volume of the gas in the cylinder at STP?

(1) 5.49 L

(2) 45.0 L

(3) 55.5 L

(4) 455 L

Un cilindro rígido con un pistón movible contiene 50.0 litros de un gas a 30.0°C con una presión de un 1 atmósfera. ¿Cuál es el volumen del gas en el cilindro en STP?

(1) 5.49 L

(2) 45.0 L

(3) 55.5 L

(4) 455 L

*Discussion and Solution:*

For this we would use the combined gas law, where V_{I} would be the initial volume of the gas, V_{F} would be the final volume, P_{I} would be the initial pressure, P_{F} would be the final pressure, T_{I} would be the initial temperature (in Kelvin), and T_{F} would be the final temperature (in Kelvin).

V_{F} = = 45.0 L

Choice (2)