Answer:
The pure crystals were soluble in the wash solvent.
Explanation:
The pure crystals on the funnel dissolved because they were soluble in the solvent used for washing. They were carried into the filter flask by the solvent.
Answer: c. +4
Explanation:
For formation of a neutral ionic compound, the charges on cation and anion must be balanced. The cation is formed by loss of electrons by metals and anions are formed by gain of electrons by non metals.




Here manganese is having an oxidation state of +4 called as cation and oxygen forms an anion with oxidation state of -2. Thus they combine and their oxidation states are exchanged to give
which written in simplest whole number ratios to give neutral 
The answer is 44.0095. We assume you are converting between grams CO2 and mole.
I believe that the answer is A, continental-continental.