Question

1- a. If 50.00 grams of octane react with 60.00 grams of oxygen at 75% yield, what is the mass of the water produced?

2. What is the mass of the excess reagent?

2- When 50.00 mL of A (aq) was titrated with .6754 M B (aq), the buret reading changed from 88 mL to 35.25 mL. What is the concentration of A?

2 A (aq) + 5 B(aq) → 6 D (g) + 3 E (aq)

3- If 26.25 mL of HCl were required to react completely with 15.00 g of Zn, what is the concentration of the HCl?

Zn (s) + 2 HCl → ZnCl₂ (aq) + H₂ (g)

Answer 1

o Octane reacts with oxygen and produce colad H2O. The chemical reaction is as follows, C8 Hi8 + 202 = 8C02+9 H20 Molar masses 114.23 gtl 16 g/mol 18.01g/mol . From the chemical reaction we can see that 114.23 g i od octane reacts with (25 x 16 g = 200g of oxygen and produce (8x18:01) y = 162.09g of water. . Hence the oxygen is the limiting reagent. So 60 g Oz should produce 162.09 60 g of water. 200 1. . = 48.627 g of water. The yield of the reaction is 75%. Hence the actual yield of water is 48.627 x 7.6 g 1. = 136.47 g of woter 6 200g of a reacts with 14.23 g of octane. 60 g of Oz " " 114.23 % 60 god octane. = 34.269 g of octane 200 so the excess mass of excess reagent (here octare) is (50-34.269) g = 15.73 g.