Page 316 - Theory and Problems of BEGINNING CHEMISTRY

APP.] SCIENTIFIC CALCULATIONS 305

A.11. Simplify each of the following:

1lb
(a) 23.50 dollars
3.50 dollars

1gal
(b) 350.0 mi
31.4mi
Ans. (a) 6.71 lb (b) 11.1 gal

A.12. What unit does the answer have in each of the following:

(a) 2 cm is subtracted from 1 cm (c) 2 cm is multiplied by 1 cm 2
(b) 2 cm is multiplied by 1 cm (d)2 cm is divided by 1 cm
3
Ans. (a)cm (b)cm 2 (c)cm 3 (d)cm 2

A.13. (a) Solve M = n/V for n (d) Solve d = m/V for V
(b) Solve πV = nRT for T P 1 P 2
(e) Solve = for P 2
(c) Solve PV = nRT for R T 1 T 2
Ans. (a) n = MV (d) V = m/d
πV P 1 T 2
(b) T = (e) P 2 =
nR T 1
PV
(c) R =
nT
A.14. (a) Solve d = m/V for m (e) Solve P 1 V 1 = P 2 V 2 for V 1
(b) Solve PV = nRT for V ( f ) Solve πV = nRT for n
(c) Solve M = n/V for V (g) Solve
t = k b m for m
P 1 P 2 (h) Solve E = hv for h
(d) Solve = for T 1
T 1 T 2
Ans. (a) m = dV (e) V 1 = P 2 V 2 /P 1
nRT
(b) V = ( f ) n = πV/(RT )
P
(c) V = n/M (g) m =
t/k b
(h) h = E/v
P 1 T 2
(d) T 1 =
P 2
A.15. What unit does the answer have in each of the following?
(a) 2 g is divided by 1 cm 3
(b) 2 g is divided by 1 cm and also by 2 cm 2

Ans. (a)g/cm 3 (b)g/cm 3

A.16. What unit does the result have when each of the following expressions is simplified?

12 in. 4.95 dollars (c) (6.22 cm ) × (1.37 cm)
2
(a)4.00 ft
2
1ft 1in. (d) (6.22 cm )/(1.37 cm)
3
(b) (12.0cm )/(2.00 cm)
Ans. (a) Dollars (b)cm 2 (c)cm 3 (d)cm