Answer:
Mg combines with SO2 to create MgO and S. When magnesium ribbon is burned in a sulphur dioxide-rich environment, the element magnesium reacts with the oxygen atom in the sulphur dioxide and burns constantly. This is a redox reaction (oxidation-reduction). Mg is a reducing agent, while SO2 is an oxidising agent.
The chemical reaction would be written as:
2HgO = 2Hg + O2
We use this reaction and the amount of the reactant to calculate for the moles of oxygen produced. THen, we use avogadro's number to convert it to molecules. We do as follows:
12.5 g HgO (1 mol / 216.59 g) (1 mol O2 / 2 mol HgO) ( 6.022x10^23 molecules O2 / 1 mol O2 ) = 1.74x10^22 molecules O2 produced
precipitate is the answer
Explanation:
A non-electrolyte is defined as a solution which does not contain any ions and hence, it is unable to conduct electricity.
For example, when a non-polar substance like 
is dissolved in water then it will not dissociate into ions.
As electricity is the flow of ions or electrons. So, a non-electrolyte solution is not able to conduct electricity.
Similarly, a compound that is insoluble in water will not dissociate into ions. Hence, this type of solution will not be able to conduct electricity.
The density is calculated as mass per volume, so if we want to solve for mass, we would multiply density by volume.
For Part A: if we have a density of 0.69 g/mL, and a volume of 280 mL, multiplying these will give a mass of: (0.69 g/mL)(280 mL) = 193.2 g. Rounded to 2 significant figures, this is 190 g gasoline.
For Part B: if we have a density of 0.79 g/mL, and a volume of 190 mL, multiplying these will give a mass of: (0.79 g/mL)(190 mL) = 150.1 g. Rounded to 2 significant figures, this is equal to 150 g ethanol.
