Unit 6 Chemistry Review

Which of the following is an exothermic process?

• Melting Ice

• Eating Food

• Cooking Eggs

• Photosynthesis

Tags

NGSS.HS-PS3-1

NGSS.HS-PS1-4

In an endothermic reaction, heat is...

• taken in or absorbed

• given out or released

Tags

NGSS.HS-PS1-4

In an exothermic reaction, how does the heat flow?

• From the surroundings to the system

• From the system to the surroundings

• Within the system only

• No heat flow occurs

Tags

NGSS.HS-PS3-4

The specific heat is defined as:

• The heat required to raise the temperature of 1 g of a substance by 1°C

• The heat released when a substance changes phase

• The rate at which a chemical reaction occurs by 1°C

• a set amount of heat that is used to create chemical changes

Tags

NGSS.HS-PS3-4

Calculate the heat required to raise 500 g of water from 20°C to 80°C (specific heat of water = 4.18 J/g°C):

• a) 12540

• b) 125400 J

• c) 1254

• d) 2090 J

Tags

NGSS.HS-PS3-1

On the heating curve, the flat sections represent...?

• Solid phase

• Liquid phase

• Gas phase

• Phase changes

Tags

NGSS.MS-PS1-4

How much heat is required to vaporize 100 g of water at 100°C? (Heat of vap = 2260 J/g)

• 22,600 J

• 226,000 J

• 2,260 J

• 4,520 J

Tags

NGSS.HS-PS3-1

The reaction rate is defined as:

• a) The speed at which reactants are consumed

• b) The activation energy required

• c) When reactants and products have no tendency to change

• d) The heat absorbed or released in a chemical reaction

For the equilibrium: N2(g) + 3H2(g) ⇌ 2NH3(g) + heat

Adding more N2 would...?

• a) Not affect the equilibrium

• b) Shift equilibrium to the left

• c) Shift equilibrium to the right

• d) Completely prevent the reverse reaction

How do catalysts speed up chemical reactions?

• by speeding up chemical reactions, it increases opportunity for collisions

• It creates more heat energy which creates more faster moving molecules

• by lowering activation energy

• It uses its activation energy with the catalyst to create product reactants