Test 2 - 6th 6wks

Endothermic

Exothermic

Radioactive Decay
Fission
Fusion

pH Scale

• Power of Hydrogen

• Measures the amount of hydrogen in a solution

• Use -LOG to calculate pH

• Use 10 to the negative superscript to calculate molarity of hydrogen ions

Multiple Choice

What is the energy of moving objects, or the energy of moving parts of a machine?

• mechanical

• kinetic

• chemical

• elastic

Endothermic Reminders

• Endothermic reactions absorb heat from the surroundings

• Endothermic reactions have positive joules

• Energy is found in the reactants

• Products have more energy than reactants

Exothermic Reminders

• Exothermic reactions release heat to the surrounding

• Exothermic reactions have negative joules

• Energy is found in the products

• Reactants have more energy than products

Multiple Select

Click on ALL of the reactions that are exothermic.

• 2 H2(g) + O2(g) → 2 H2O(ℓ) ΔH = −570 kJ

• CO2(g) + H2(g) + 42 kJ → CO(g) + H2O(g)

• 28 kJ are released

• NaOH (aq) + HCl(aq) → NaCl(aq) + H2O(ℓ) + 56 kJ

• 88 Joules absorbed

Calorimetry

Heat Calculations

Multiple Choice

What unit do you use to measure Thermal Energy?

• Joules

• grams

• heat

• J/gC

Multiple Choice

A water bottle is placed in a freezer.

Which way does energy (heat) flow?

• into the freezer

• into the water

• neither

• both

Fill in the Blanks

A 891.6 g sample of tin is subjected to a temperature change of

-34.25 °C. The specific heat capacity of tin is 0.227 J/(g·°C).

How many joules of heat were transferred by the sample?

Use the the correct rounding sig fig rules for the final answer.

Fill in the Blanks

A 894.5 g sample of neon absorbs 532.2 joules of heat. The specific heat capacity of neon is 1.0301 J/(g·°C).

By how much did the temperature of this sample change, in degrees Celsius?

Round the calculator answer using the correct sig fig rounding rules.