Problems B
185
weight and (n) volume of this commercial acid are needed for the production of 720 g of SO 2 gas
17
(k) Assume that an excess of metallic aluminum is added to a solution contain
mg 100 g NaOH, and that as a result all the NaOH is used up When the
reaction is complete, the excess aluminum metal is filtered off and the
excess water evaporated How many grams of NaAlO 2 are obtained
7
24 How many grams of aluminum are needed for the preparation of 5 50 liters of
H 2 at standard conditions'
7 The reaction is
2A1 + 3H 2 SO 4 ^ A1 2 (SO4) 3 + 3H 2
25 What weight of (NH,i) 2 SC> 4 is needed for the preparation of 5 00 moles of NH 3
gas
9 The reaction is
(NH 4 ) 2 S0 4 + Ca(OH) 2 ^ CaSO 4 + 2NH 3 + 2H 2 O
26 What volume of O 2 at 0 90 atm and 75°F is needed to burn 21 0 liters of
propane gas, C 3 H 8 , under the same conditions'
7 The reaction is
C 3 H 8 + 50 2 -^ 3C0 2 + 4H 2 O
27 What volume of NO can react with 100 liters of air (21 0% O 2 by volume) at
the same conditions of temperature and pressure The reaction is
2ND + 0 2 -^ 2NO 2
28 An interesting lecture demonstration is the Vesuvius ' experiment, in which
a small mound of (NH^CrjO? is heated to commence decomposition It then
continues its decomposition unaided, gives off heat light and sparks, and
leaves a 'mountain' of Cr 2 O 3 The reaction is
(NH 4 ) 2 Cr 2 O 7 -^ N 2 + 4H 2 O + Cr 2 O 3
What volume of N 2 at 730 torr and 31°C is produced from 1 60 moles of
(NH 4 ) 2 Cr 2 0 7 ''
29 What volume of H 2 S at 720 torr and 85°F is needed for the precipitation of the
bismuth in 50 0 g of Bid^ The reaction is
2BiCl 3 + 3H 2 S -* Bi 2 S 3 + 6HC1
30 What volume of H 2 S at 740 torr and 20°C is needed to precipitate the nickel
from 50 0 g of Ni,(PO 4 ) 2 7H 2 O as NiS
7
31 HCN gas is fatal at a concentration of 1 part per ^00 by volume and is very
dangerous within one hour at a concentration of 1 part per 10,000 by volume
What weight of NaCN is needed to fill a classroom 20 ft x 1 5 ft x 9 ft with
HCN at a concentration of 1 part per 10,000^ (The barometric pressure is 740
torr, and the temperature is 80°F ) The reaction is
2NaCN + H 2 SO 4 ^ Na 2 SO 4 + 2HCN
32 (a) How many grams of aluminum are needed for the production of 5 50 liters
of H 2 over H,O at 730 torr and \8°C">
185
weight and (n) volume of this commercial acid are needed for the production of 720 g of SO 2 gas
17
(k) Assume that an excess of metallic aluminum is added to a solution contain
mg 100 g NaOH, and that as a result all the NaOH is used up When the
reaction is complete, the excess aluminum metal is filtered off and the
excess water evaporated How many grams of NaAlO 2 are obtained
7
24 How many grams of aluminum are needed for the preparation of 5 50 liters of
H 2 at standard conditions'
7 The reaction is
2A1 + 3H 2 SO 4 ^ A1 2 (SO4) 3 + 3H 2
25 What weight of (NH,i) 2 SC> 4 is needed for the preparation of 5 00 moles of NH 3
gas
9 The reaction is
(NH 4 ) 2 S0 4 + Ca(OH) 2 ^ CaSO 4 + 2NH 3 + 2H 2 O
26 What volume of O 2 at 0 90 atm and 75°F is needed to burn 21 0 liters of
propane gas, C 3 H 8 , under the same conditions'
7 The reaction is
C 3 H 8 + 50 2 -^ 3C0 2 + 4H 2 O
27 What volume of NO can react with 100 liters of air (21 0% O 2 by volume) at
the same conditions of temperature and pressure The reaction is
2ND + 0 2 -^ 2NO 2
28 An interesting lecture demonstration is the Vesuvius ' experiment, in which
a small mound of (NH^CrjO? is heated to commence decomposition It then
continues its decomposition unaided, gives off heat light and sparks, and
leaves a 'mountain' of Cr 2 O 3 The reaction is
(NH 4 ) 2 Cr 2 O 7 -^ N 2 + 4H 2 O + Cr 2 O 3
What volume of N 2 at 730 torr and 31°C is produced from 1 60 moles of
(NH 4 ) 2 Cr 2 0 7 ''
29 What volume of H 2 S at 720 torr and 85°F is needed for the precipitation of the
bismuth in 50 0 g of Bid^ The reaction is
2BiCl 3 + 3H 2 S -* Bi 2 S 3 + 6HC1
30 What volume of H 2 S at 740 torr and 20°C is needed to precipitate the nickel
from 50 0 g of Ni,(PO 4 ) 2 7H 2 O as NiS
7
31 HCN gas is fatal at a concentration of 1 part per ^00 by volume and is very
dangerous within one hour at a concentration of 1 part per 10,000 by volume
What weight of NaCN is needed to fill a classroom 20 ft x 1 5 ft x 9 ft with
HCN at a concentration of 1 part per 10,000^ (The barometric pressure is 740
torr, and the temperature is 80°F ) The reaction is
2NaCN + H 2 SO 4 ^ Na 2 SO 4 + 2HCN
32 (a) How many grams of aluminum are needed for the production of 5 50 liters
of H 2 over H,O at 730 torr and \8°C">