couple more physics questions

3.

Which of the following systems shows an increase in entropy?

building a house of cards

water freezing into ice

spilling a jar of pennies

steam condensing to liquid water

would it be C?

4.

Making a heat engine that uses its exhaust heat to do work is restricted according to which principle?

second law of thermodynamics

conservation of matter

first law of thermodynamics

conservation of energy

woul it be A?

This seems to indicate that  your answer to  the first one is  good  :

https://en.wikipedia.org/wiki/Rudolf_Clausius

I don't know anything  about this.....but.....for the second one.....I believe  that  we have this  :

W =  Q_H -  Q_L

So

Q_H =  W + Q_L