Chapter 4
An equation is balanced when the same number of each element is represented on the reactant and product sides. Equations must be balanced to accurately reflect the law of conservation of matter.
(a) (b) (c) (d) (e) (f) (g) (h)
(a) (b) (c) (d)
(a) Ba(NO 3 ) 2 , KClO 3 ; (b) (c) (d)
(a) (b) complete ionic equation: net ionic equation:
(a)
(b)
(c)
(a) oxidation-reduction (addition); (b) acid-base (neutralization); (c) oxidation-reduction (combustion)
It is an oxidation-reduction reaction because the oxidation state of the silver changes during the reaction.
(a) H +1, P +5, O −2; (b) Al +3, H +1, O −2; (c) Se +4, O −2; (d) K +1, N +3, O −2; (e) In +3, S −2; (f) P +3, O −2
(a) acid-base; (b) oxidation-reduction: Na is oxidized, H + is reduced; (c) oxidation-reduction: Mg is oxidized, Cl 2 is reduced; (d) acid-base; (e) oxidation-reduction: P 3− is oxidized, O 2 is reduced; (f) acid-base
(a) (b)
(a) (b) (c) (d)
(a) (b) (a solution of H 2 SO 4 ); (c)
(a) (b)
(a) step 1: step 2: (b) (c) and
(a) (b) (c) (d) (e) (f) (g) (h)
(a) (b) (c) (d) (e)
(a) (b) (c)
(a) 0.435 mol Na, 0.217 mol Cl 2 , 15.4 g Cl 2 ; (b) 0.005780 mol HgO, 2.890 10 −3 mol O 2 , 9.248 10 −2 g O 2 ; (c) 8.00 mol NaNO 3 , 6.8 10 2 g NaNO 3 ; (d) 1665 mol CO 2 , 73.3 kg CO 2 ; (e) 18.86 mol CuO, 2.330 kg CuCO 3 ; (f) 0.4580 mol C 2 H 4 Br 2 , 86.05 g C 2 H 4 Br 2
(a) 0.0686 mol Mg, 1.67 g Mg; (b) 2.701 10 −3 mol O 2 , 0.08644 g O 2 ; (c) 6.43 mol MgCO 3 , 542 g MgCO 3 (d) 768 mol H 2 O, 13.8 kg H 2 O; (e) 16.31 mol BaO 2 , 2762 g BaO 2 ; (f) 0.207 mol C 2 H 4 , 5.81 g C 2 H 4
(a) (b) 1.25 mol GaCl 3 , 2.2 10 2 g GaCl 3
(a) 5.337 10 22 molecules; (b) 10.41 g Zn(CN) 2
4.50 kg SiO 2
5.00 10 3 kg
1.28 10 5 g CO 2
161.4 mL KI solution
176 g TiO 2
The limiting reactant is Cl2.
Convert mass of ethanol to moles of ethanol; relate the moles of ethanol to the moles of ether produced using the stoichiometry of the balanced equation. Convert moles of ether to grams; divide the actual grams of ether (determined through the density) by the theoretical mass to determine the percent yield; 87.6%
The conversion needed is Then compare the amount of Cr to the amount of acid present. Cr is the limiting reactant.
Na 2 C 2 O 4 is the limiting reactant. percent yield = 86.56%
Only four molecules can be made.
This amount cannot be weighted by ordinary balances and is worthless.
3.4 10 −3 M H 2 SO 4
9.6 10 −3 M Cl −
22.4%
The empirical formula is BH 3 . The molecular formula is B 2 H 6 .
49.6 mL
13.64 mL
0.0122 M
34.99 mL KOH
The empirical formula is WCl 4 .