Is every mixture also a solution? is every solution also a mixture?

Harvey kept a balloon with a volume of 348 milliliters at 25.0˚c inside a freezer for a night.  when he took it out, its new volume was 322 milliliters, but its pressure was the same.  if the final temperature of the balloon is the same as the freezer’s, what is the temperature of the freezer? the temperature of the freezer is  kelvins.

In a spacecraft, the following reaction occurs: co2(g) + 2lioh(s) -> lico3(s) + h2o(i) (i attached picture of equation) how many liters of carbon dioxide will 4 moles of lithium hydroxide (lioh) absorb? (one mole of any gads occupies 22.4 l under certain conditions of temperature and pressure. assume those conditions for this equation.) 45l 6.0l 3.0l 34l

How many moles of magnesium is 3.01 x10^22 atoms of magnesium?