Question

SEP Use Graphs Look at the data in Figure 1. Sea water has an average salinity of 3.5%. What is the surface tension for water with 3.5% salinity?

Answer 1

I don’t have Figure 1 — could you upload or paste it? I need to see the plotted data to read or interpolate the surface-tension value at 3.5% salinity.

If you can’t upload it, here’s how you can read it yourself:
- Find 3.5% on the x‑axis (or 35 ppt if the axis uses parts per thousand).
- Move vertically from 3.5% to the curve and then read the y‑axis value for surface tension.
- If 3.5% falls between two plotted points, do a linear interpolation between those two y values.
- Make sure to note the units (mN/m or N/m) and the temperature at which the data were taken (surface tension depends on temperature).

For reference, typical literature values for natural seawater (salinity ≈ 3.5% or 35 ppt) at about 20 °C are around 72–73 mN/m (0.072–0.073 N/m), but your Figure 1 may give a slightly different value depending on experimental conditions. If you upload the figure I’ll read/interpolate the exact value from it.