When impurities are added to a liquid it's surface tension

a) always increases

b) always decreases

c) If impurities are sparingly soluble surface tension decreases

d) If impurities are highly soluble surface tension increases

Surface tension of the liquid is impacted by the presence of contaminants, whether they are dissolved inside it or on its surface. Highly soluble compounds increase the surface tension of water, whereas sparingly soluble substances decrease the surface tension of water.