Question

The graph below shows how solubility changes with temperature.

A graph with the horizontal axis showing temperature ranging from 0 to 10 in units of 10 and the vertical axis solubility in grams of salt per 100 grams of water. Several compounds are shown. All data are approximate. The substances and their coordinates are as follows: upper N a upper C l: 0, 38; 10, 38; 20, 38; 30, 38; 40, 39; 50, 39; 60, 39; 70, 40; 80, 40; 90, 40; 100, 40. Upper N a subscript 2 upper H upper A s upper O subscript 4: 0, 5; 10, 18; 20, 28; 30, 39; 40, 49; 60, 65; 80, 82. Upper B a (upper N upper O subscript 3) subscript 2: 0, 5; 10, 8; 30, 12; 40, 15; 50, 18; 60, 20; 80, 28; 100, 33. Upper N a subscript 2 upper S upper O subscript 4: 0, 5; 5, 8; 10, 10; 15, 15; 20, 20; 25, 20; 28, 35; 30, 40; 32, 49; 33, 50; 35, 50; 40, 48; 50, 47; 60, 46; 70, 45; 80, 43; 90, 32; 100, 40. Upper C 3 subscript 2 (upper S upper O subscript 4) subscript 3 dot 9 upper H subscript 2 upper O: 0, 18; 20, 10; 30, 8; 50, 5; 60, 3; 80, 1; 100, 0.

How many grams of NaCl will be needed to form 600 mL of a saturated solution at 100°C?
15 g
24 g
40 g
240 g

Answer 1

240 g

Reason: At 100°C NaCl solubility ≈ 40 g per 100 g water. 600 mL water ≈ 600 g, so required NaCl = 40 × (600/100) = 240 g.