A entropia é uma função de estado que indica o grau de desordem de um sistema. Considerando que, em uma transformação reversível e isotérmica, o sistema absorveu 4,5 kcal a uma temperatura de 67°C, a variação de entropia é, aproximadamente, A) –13,23 cal/K B) +12,43 cal/K C) –12,43 cal/K D) +0,8 cal/K E) +13,23 cal/K

Which of the following is a testable hypothesis? a. if i brush my teeth, i will get fewer cavities than if i don't brush my teeth. b. green toothpaste tastes better than blue toothpaste or red toothpaste. c. smart, careful, healthy people always brush their teeth. d. it's wrong to not brush your teeth before you have an important conversation with someone.

What is the mass of 8 moles of sodium atoms

A50.0g sample of liquid water at 0.0 c ends up as ice at -20.0 c. how much energy is involved in this change?