Answer:
C. A combination of 3 or more different substances that do not chemically combine
An increase in thermal energy, changes the state of matter from solid to liquid to gas.
An alum is a double salt where you have a trivalent metal sulfate and a monovalent metal sulfate. Meanwhile, a crystal of potassium aluminum sulfate is potash alum!
Here, Molar mass of N2O4 = 92.02 g/mol
So, Number of molecules in 1 mole (92.02 g) = 6.023 * 10²³
Number of molecules in 76.3 g = 6.023 * 10²³ / 92.02 * 76.3
= 6.023 * 10²³ / 1.20
= 5 * 10²³
In short, Your Answer would be approx. 5 * 10²³ molecules
Hope this helps!
"The vapor pressure<span> of water is relatively </span>low<span> because it is held together through hydrogen bonds. This means that the molecules in a glass of water do not evaporate from the water very easily, as the molecules are attracted to each other."</span>
