Thermochemistry

During an endothermic reaction in a beaker if we are part of the surroundings and touched the beaker, it would feel _______.

• Warm

• Cold

• Bubbly

• Damp

Tags

NGSS.MS-PS1-4

NGSS.MS-PS3-4

H₂ + Cl₂ --> 2 HCl + 1845 kJ
Is this reaction endothermic or exothermic?

• Endothermic 
• Exothermic

Tags

NGSS.HS-PS1-4

NGSS.HS-PS3-1

H₂ + 2 C + N₂ + 270.3 kJ --> 2 HCN
Is this reaction endothermic or exothermic?

• Endothermic 
• Exothermic

Tags

NGSS.HS-PS1-4

Heat flows from _______ to ______ objects

• cooler to warmer
• warmer to warmer
• warmer to cooler
• cooler to cooler

Tags

NGSS.HS-PS3-4

The specific heat(c) of copper is 0.39 J/g °C. What is the temperature change(∆t) when 100 Joules of heat(Q) is added to 20 grams?

• 12.82 °C
• 24.12°C
• 351 °C

Tags

NGSS.HS-PS3-1

NGSS.HS-PS3-2

The first law of thermodynamics states that energy is

• created
• destroyed
• conserved
• created and destroyed

A chemical reaction that absorbs heat from the surroundings is said to be __________ and has a __________ ΔH at constant pressure.

• endothermic; positive
• endothermic; negative
• exothermic; negative
• exothermic; positive

Tags

NGSS.HS-PS1-4

The amount of heat energy required to change the temperature of 12 g of gold from 45°C to 15°C is -47 J. What is the specific heat capacity of gold?

• 0.13 J/(g°C)

• 17,000 J/(g°C)

• 1600 J/(g°C)

• 0.065 J/(g°C)

Tags

NGSS.MS-PS3-4

What is the formula for calculating heat?

• q = mcΔT

• H = ΔH x moles

• H = ΔH x grams

• products - reactants

Convert 42 kJ into joules

• 0.042 J

• 175.73 J

• 42000 J

• 10.04 J