Isooctane is a fuel additive that prevents premature and spontaneous ignition under the heat and pressure...

23. Isooctane is a fuel additive that prevents premature and spontaneous ignition under the heat and pressure of an engine's cylinder. The combustion of isooctane is shown below:
2 C8H18(l) + 25 O2(g) -> 16 CO2(g) + 18 H2O(g)
How many grams of water (H2O, MM = 18.015 g/mol) are produced when 393 g of isooctane (C8H18, MM = 114.23 g/mol) reacts with excess oxygen?
24. What volume, in milliliters, of 0.78 M H3PO4(aq) is needed to completely react with 637 mL of 0.58 M Mg(OH)2(aq) solution?
2 H3PO4(aq) + 3 Mg(OH)2(aq) -> 6 H2O(l) + Mg3(PO4)2(aq)
A. 473 mL H3PO4
B. 425 mL H3PO4
C. 316 mL H3PO4
D. 711 mL H3PO4
25. Historians believe that ancient people produced copper metal from cuprite (Cu2O) according to the balanced chemical reaction below:
2 Cu2O(s) + C(s) -> 4 Cu(s) + CO2(g)
If a mixture contains 1000. grams of Cu2O (145.00 g/mol) and 445.0 grams of C (12.011 g/mol), what is the limiting reactant?
A. Cu2O
B. C
C. Cu
D. CO2