S2 Final Exam practice

Would the following reaction be endothermic or exothermic? How do you know?

• endothermic because ΔH is negative
• exothermic because ΔH is negative
• endothermic because ΔH is written off to the side
• exothermic because ΔH is written off to the side

Given the following test question: "Consider the reaction: H2 + Cl2 ---> 2 HCl ^H = -183 KJ What amount of energy is released when 94.5 grams of HCl is produced?" HOW would you solve this problem?

• 1 step: convert 94.5 grams directly to KJ
• 2 steps: convert 94.5 grams to moles, then to KJ
• 1 step: convert 94.5 grams to moles
• 1 step: convert 94.5 grams to molecules

What is the molarity of a solution containing 100 L of water and 25 moles of NaCl? (M=mol/L)

• 0.25 M
• 4 M
• 40 M
• 100 M

When a system (chemical reaction) is at equilibrium,

• both the forward and reverse reactions have stopped.
• the forward reaction has stopped
• the reverse reaction has stopped
• neither the forward nor the reverse reaction has stopped

When you are given KJ and asked for GRAMS, what are the steps to solve the problem?

• 1 step: KJ to grams
• 1 step: KJ to moles
• 2 steps: KJ to grams to moles
• 2 steps: KJ to moles to grams

Which of the following ranks radioactive decay by DECREASING size?

• beta, alpha, gamma
• alpha, beta, gamma
• gamma, alpha, beta
• gamma, beta, alpha

What is the instrument used to measure the HEAT associated with a chemical reaction?

• thermometer
• bjorkometer
• calorimeter
• barometer

Which of the following ranks radiation types by increasing strength?

• alpha, beta, gamma
• beta, alpha, gamma
• gamma, beta, alpha
• gamma, alpha, beta

What are 3 factors that can change the equilibrium of a system? (Choose 3)

• temperature change
• pressure/volume change
• concentration change
• lifestyle change
• catalyst addition

In a heating curve, how do you find the melting point of the substance?

• the first diagonal line
• the first plateau
• the second diagonal line
• the second plateau
• the third diagonal line