Passage VII

Consider an aqueous solution separated from pure H2O by a membrane permeable to H2O but impermeable to solute particles. H2O will flow from the region of lower particle concentration (the pure H2O) into the region of higher particle concentration (the solution). The pressure associated with this flow is the osmotic pressure, π, given in atmospheres (atm) by the equation:

π = 0.0821 × T × i × C

Table 1 defines the 3 variables in the equation.

Table 2 lists, for 8 substances, the value of i and the molar mass (the mass of 1 mole of a substance).

Figure 1 shows how π varies with C for aqueous NaCl solutions and aqueous glucose solutions at 3 temperatures.

40. Suppose a new line showing how π varies for aqueous MgCl2 solutions at 340 K were added to Figure 1. How would this new line compare to the lines shown in Figure 1 for aqueous NaCl solutions and aqueous glucose solutions at 340 K ?

Answer and Explanation

Your Answer is

Correct Answer is F

Explanation

Comparing the line segments of NaCl at 340K and glucose at 340K in figure 1, it is found that the larger i is, the larger π will be.

According to table 2, i=3 of MgCl2 is larger than i=2 of NaCl, so the π corresponding to MgCl2 is larger, and the line segment The slope is larger. And because the starting point of the line segment is (0,0), the intercept on the y-axis is the same