Answer:
C. grinding the reactants into finer grains
Explanation: I just took the assignment.
It is a combustion reaction. C3H8 will react with oxygen to form carbon dioxide and water.
Sodium phosphate has a chemical formula
Na2PO4
Calculating the concentration of sodium phosphate given a concentration of sodium ions can be done using dimensional analysis
0.60 moles/L Na+ (1 mole Na2PO4 / 2 moles Na+) = 0.30 moles/L Na2PO4
= .030 M Na2PO4