Question

1. (9 points) Balance the following reactions: H3PO4(1) + HCIE) C4H3 + O2 CO2 + H2O PC15(s) + H2O LizNs) LiOH) + NH3(g) C3H12 + O2 CO2 + H2O 2. (12 points) Write and balance the equation based upon the following information. + H2O(1) Include the states of matter: a. Solid aluminum sulfate, carbon dioxide gas and liquid water are produced by the reaction of an aqueous solution of sulfuric acid and solid aluminum carbonate. b. The reaction of fluorine gas is reacted with solid aluminum oxide to produce solid aluminum fluoride and oxygen gas. c. Solid nickel(II) phosphate and aqueous sodium chloride are produced when aqueous solutions of nickel(II) chloride and sodium phosphate are mixed. 3. (14 points) n-Heptane (C7H16) is an undesirable component of gasoline because it burns explosively and contributes to engine “knocking.” Write the balanced combustion reaction of C7H16. Calculate the number of grams of C7H16 that react if 225 g CO2 (44.01 g/mol) are produced. 4. (14 points) Calcium carbide (CaC2, 64.10 g/mol) reacts with water (18.02 g/mol) to produce acetylene gas (C2H2, 26.04 g/mol), which is used in welding applications. The other reaction product is calcium hydroxide (Ca(OH)2, 74.10 g/mol). How many kilograms of C2H2 can be produced from 75.0 kg CaCz?

Answer 1

1)

a)

$C_{4}H_{8} +6 O_{2} \to 4 CO_{2} (g) +4 H_{2}O$

b)

PCI5 (S) + 4H2O(1) + H3PO4(1) + 5HCl g)

c)

$Li_{3}N (s) +3 H_{2}O (l) \to 3 LiOH (l) + NH_{3} (g)$

d)

$C_{5}H_{12} +8 O_{2} \to 5 CO_{2} (g) +6 H_{2}O$

2)

a)

$Al_{2}(CO_{3})_{3} (s) +3 H_{2}SO_{4} (aq) \to Al_{2}(SO_{4})_{3} (s) +3 H_{2}O (l) + 3CO_{2} (g)$

b)

$6 F_{2} (g) +2 Al_{2}O_{3} (s) \to 4 AlF_{3} (s) + 3 O_{2} (g)$

c)

$3 NiCl_{2} (aq) +2 Na_{3}PO_{4} (aq) \to Ni_{3}(PO_{4})_{2} (s) +6 NaCl (aq)$

3)

Combustion of n- heptane is

$C_{7}H_{16} (l) + 11 O_{2} (g) \to 7 CO_{2} (g) +8 H_{2}O (g)$

Molar mass of n-heptane is 7*12+16*1 = 100 g/mol

100 g of n-heptane on Combustion gives 7*44 g of Carbon dioxide.

How many grams of n-heptane on Combustion gives 225 g of carbon dioxide.

= 225 g * 100 g/7 *44 g

= 73.05 g

4)

Hydrolysis of calcium carbide is

$CaC_{2} (s) + 2H_{2}O (l) \to C_{2}H_{2} (g) + Ca(OH)_{2} (s)$

Molar mass of Calcium carbide is 1*40+2*12 = 64 g/mol

Molar mass of acetylene = 2*12+2*1 = 26 g/mol

64 g of calcium carbide on Hydrolysis gives 26 g of acetylene.

75000 g of calcium carbide on hydrolysis gives ? g of acetylene.

= 75000 g * 26 g/64 g

= 30468.75 g

= 30.5 Kg