Question

Calculate the total amount of Na+ (in grams) in the ocean (see Table 4.7). The mass of seawater = 1.4 x 1024g.

Table 4.7 Average Composition of Water in Streams and in the Oceans in micrograms per gram Seawater Elemens Classificationr S Seawaler erichm 1.7×10-a MORT 3x10-, 56.7 1 × 10 1 × 10-3 2 x10 0.02 6.3 x 10 1.6 × 10 108 x10 1714 1.29 x 10 5.0 × 10, 2×10-2 7.1 ×10-2 90×101 243 1.95 x0 200 3.99 x 10 173 4.13 x 10 3.6 4.0 × 104 5.0 x 10 15 4 x10 0 017 3 × 10-3 <9.6 x 10-4 9x10-. 1.2×10-3 1.3 1.3 x 10 2.5×10' 1.6 x 102 7.9 x 10 1.6 × 10, 32 x 10 69×10-1 x102 x 00.2 7x10-, 3x10". 004 4 x 10 6x10", 00015 3x10-4 7×10 2 x 10 5x10-+ 3 × 10-4 1.7 1.6 x 1 9 × 10-5 7.9 x 10 5 × 10-6 2x10→ 6×10-s 2x10° 1x10-, 7×10 1.7×10ー 1.3×10-4 67x10, 1.2×10-i 085 2.2 3350 120 63 x 10 79 x 10 7.9 × 105 4 x10- ai8 3 x 10 5 × 1.6 × 102 2.5 × 102 110183 3x 1027 100009 x10- 108 2.0×104 7.9 x 10 x10 0013 1.3 x 102 7×10-5 1.5×10-4 21 7xio., 5.6 x 100: 8 2 x 29x10-*1 4.0 x 10 2 x 10-2 14 x 10-2 48 X 10-345x1004 .9 x103.5x 10 0.044 5.0 x 10 7.9 x 10 3.2 × 10

Answer 1

as per table given

micrograms of sodium present per gram of sea water

Na ----_------- Sea water

1.08x10⁴ micrograms of sodium present in = 1 gram of sea water

hence we can write

for 1.4x10²⁴ gram sea water will contain

= 1.08 x10​​​​^{​​​​4} x 1.4 x 10²⁴ micrograms of Na

= 1.512 x 10²⁸ micrograms = 1.512x10²² grams of sodium present in given sea water