Ch 7
What happens during an exothermic reaction? Draw an example.
The chemical reaction released energy
According to the kinetic molecular theory, how does the temperature of a gas affect the speed of its particles?
The kinetic molecular theory states that the average kinetic energy of gas particles is directly proportional to the temperature of the gas in kelvins. As the temperature increases, the kinetic energy of the particles also increases, causing the particles to move faster. Conversely, at lower temperatures, the particles move more slowly.
If sodium bicarbonate (NaHCO3) dissolves in water, what ions will form in solution?
Na+ and HCO3-
What is activation energy (Ea) and how does it relate to the rate of a reaction?
Activation energy determines how easily a reaction can occur. A high activation energy means a slower reaction rate, while a low activation energy allows for a faster reaction rate. Represents a barrier that must be overcome for reactants to become products.
The combustion of butane reacts with oxygen gas to produce carbon dioxide and water:
2C4H10+13O2→8CO2+10H2O
If 88.0 g of CO2 is produced, how many grams of O2 were consumed in the reaction?
104.0 g
A 3.0 L sample of a gas is kept at 300 K under 1.5 atm of pressure and consists of 0.25 moles. What will the volume of this gas be if the temperature is increased to 600 K and the pressure is raised to 4.0 atm?
2.25 L
At 50 °C, the solubility of KNO₃ is 150 g per 100 g of water. If 180 g of KNO₃ is added to 120 g of water at 50 °C, is this solution saturated or unsaturated?
Saturated
What are the 3 factors that can increase the rate of a chemical reaction?
1. Temperature
2. concentration of reactants
3. presence of a catalyst
The reaction between hydrogen gas and oxygen gas produces 36.0 g of water. How many grams of oxygen gas reacted?
The balanced equation is:
2H2+O2→2H2O
32.00 g
A sample of ammonia gas (NH3) has a pressure of 850 mmHg and occupies a volume of 250 mL at a temperature of 310 K. How many moles of ammonia gas are present in the sample?
0.0110 moles
What is the mass percent (%m/m) of NaOH in a solution prepared by dissolving 40.0 g of NaOH in 60.0 g of water?
40%
Write the equilibrium expression for the following reaction:
CO(g)+H2(g)⇌CO2(g)+H2(g)
Kc=[CO(g)][H2(g)]/[CO2(g)][H2(g)]
If 5.00 g of C2H4 (ethylene) and 12.00 g of O2 are the initial reactants, how many moles of carbon dioxide can be produced, and what is the limiting reactant?
The balanced equation for the reaction is:
C2H4+3O2→2CO2+2H2O
A gas mixture contains 5.0% hydrogen (H2), 70.0% oxygen (O2), and 25.0% nitrogen (N2) by volume. The total pressure of the mixture is 1.8 atm.
What is the partial pressure of each gas in the mixture?
When solutions of barium chloride (BaCl₂) and sodium sulfate (Na₂SO₄) are mixed, a reaction occurs. Determine the precipitate formed, and write both the complete ionic equation and the net ionic equation.
Describe the conditions that must be met for a chemical reaction to occur.
1. collisions
2. orientation of the particles
3. must provide sufficient Ea to break and form bonds
A chemist is performing the reaction between nitrogen gas and hydrogen gas to produce ammonia. They start with 10.0 g of N2 and 5.0 g of H2. The balanced chemical equation for the reaction is:
N2+3H2→2NH3
Under standard conditions, a chemist collects 44.8 liters of carbon dioxide gas (CO2) produced from the reaction of calcium carbonate (CaCO3) with hydrochloric acid (HCl) according to the reaction:
CaCO3+2 HCl→CaCl2+CO2+H2O
How many moles of CO2 gas are produced at STP?
If the chemist started with 5.0 moles of HCl, which reactant is the limiting reactant?
Sulfuric acid (H₂SO₄) is normally purchased as a concentrated solution of 18.0 M. What volume (in mL) of this acid is needed to prepare 1.00 L of a 0.500 M H₂SO₄ solution?
27.8 mL
What is the equilibrium expression (Kc) for the following reversible reaction?
2SO2(g)+O2(g)⇌2SO3(g)
Kc=[SO3(g)]2/[SO2(g)]2[O2(g)]