Question

What will the coefficient be for NaOH in the chemical equation listed below when the equation is balanced? H3PO4 (aq) + NaOH(aq) → Na3PO4 (aq) + H20 (1) d) 4 a) 1 b) 3 c) 2 8. How many grams of metallic Na will be needed to produce 25.43 grams of H2 upon reaction with H2O? 2 Na (s) +2H20 (1) + NaOH (aq) + H2 (8) a) 578.8 g b) 868.3 g c) 289.4 g d) 45.98 g 9. How many grams of CO2 could be produced from the combustion of 1.26 g of C2H2 in the presence of 3.39 g of O2? C2H2 + 502 + 4CO2 + H2O a) 5.54 g b) 4.58 g (c) 3.73 g d) 6.30g - c-2 c-2 H-2 H-2 0-4 0-5 How many grams of H2O will be produced if 10.00 g of CH4 are combusted in the presence of 20.00 g of O2 and the reaction yield is 85.0%? CH4 (g) + O2(g) → CO2 (g) + H20 (1) a) 9.57 g b) 19.1 g c) 4.79 g d) 18.02 g 10.

Answer 1

7. balanced reaction : H₃PO₄ + 3 NaOH $\rightarrow$ Na₃PO₄ + 3 H₂O

b) 3

8. Equation : 2 Na + H₂O $\rightarrow$ 2 NaOH + H₂

Moles of H₂ = mass / molar mass = 25.43 / 2 = 12.72 moles

Moles of Na = 2 * moles of H₂ = 2 * 12.72 = 25.43 moles

Mass of Na = moles * molar mass = 25.43 * 23 = 578.8 g