Page 322 - Theory and Problems of BEGINNING CHEMISTRY

APP.] SCIENTIFIC CALCULATIONS 311

A.46. Determine the value of x in each of the following:
(a) x = log 42.1
(b) log x = 42.1
√
(c) x = 3 216
(d) x = (100.0) 5
√
(e) x = 4.48 × 10 18
Ans. (a) 1.624 (b)1 ×10 42 (c) 6.00 (d)1.000 × 10 10 (e)2.12 × 10 9

A.47. Determine the values of a, b, and c in each of the following quadratic equations after you put the equation in the
2
form ax + bx + c = 0. Then calculate two values for each x.
−5
2
−3
(a) x + (−4.5 × 10 )x − (3.8 × 10 ) = 0
x 2
(b) = 2.23 × 10 −2
0.100 − x
Ans. a b c x
(a) 1 −4.5 × 10 −3 −3.8 × 10 −5 8.8 × 10 −3 and −4.3 × 10 −3
(b) 1 2.23 × 10 −2 −2.23 × 10 −3 3.74 × 10 −2 and − 0.0597