U4 Entropy

What is entropy?

• non spontaneous

• endothermic

• neat and orderly

• messy and disorganized

Tags

NGSS.HS-PS3-4

Which phase of matter has the most entropy?

• solid

• liquid

• aqueous

• gas

Tags

NGSS.HS-PS3-4

Which thermochemical equation is nonspontaneous (based on heat)?

• C₅H₁₂ + O₂ -> CO₂ + H₂O + heat

• Co₂O₃ + heat -> 4 Co + 3 O₂

• Ni + Fe₂O₃ -> Fe + NiO + 938J

• H₂O + SO₃-> 83kJ + H₂SO₄

Tags

NGSS.HS-PS1-4

Which molecule has the least amount of entropy?

• H₂O

• NaCl

• Fe₂O₃

• Ni

This reaction is spontaneous because...

2PbSO₄ + heat -> 2PbSO₃ + O₂

• it's endothermic

• it makes smaller molecules (size)

• it makes more stuff/molecules (amount)

• it changes to a liquid

• it makes less stuff/molecules (amount)

Tags

NGSS.HS-PS1-4

Which reaction shows the greatest increase in entropy based on amount of molecules?

• 2H₂O₂ --> 2H₂O + O₂

• 2 Co₂O₃ + heat -> 4 Co + 3 O₂

• Cu(OH)₂ -> H₂O + CuO

• H₂O + SO₃-> H₂SO₄

C₆H_{12 (l)} + 9 O_{2 (g)} -> 6 CO_{2 (g)} + 6 H₂O _(g) + heat

Which statement is true? This reaction is...

• spontaneous because it is exothermic

• spontaneous because it changes to all gases

• spontaneous because it makes less molecules (amount)

• spontaneous because it makes smaller simpler stuff (size)

• spontaneous because it is endothermic

Tags

NGSS.HS-PS1-4

What are the signs of a nonspontaneous reactions (a decrease in entropy)

• formation of a gas

• releasing heat

• formation of a solid

• absorbing heat

• making more stuff that is smaller

Tags

NGSS.HS-PS1-4

The change from a liquid to a gas shows

• nothing

• an increase in entropy

• a decrease in entropy

• not enough information

Forming smaller simpler products such as O₂, shows

• an increase in entropy (spontaneous)

• a decrease in entropy (nonspontaneous)