Which of the following shows the correct relationship among ...

[piesebel]

Which of the following shows the correct relationship among density, volume, and mass? 1. Density = volume/mass 2. Volume = density/mass 3. Mass = (density)/(volume) 4. Weight density = weight/volume
 
  a. 1 and 3 c. 4
  b. 1 and 4 d. 3 and 4

Question 2

What will happen to the surface tension of water droplets when a surface-active agent is added?
 
  a. Nothing will hap-pen. c. It will decrease.
  b. It will increase. d. It will be eliminat-ed.

[ilianabrrr]

Answer to Question 1

ANS: D
Given density, d = mass (m)/volume (v), the equation can be solved for each variable: m = dv, v = m/d. When mass is substituted by weight, dw = w/v.

Answer to Question 2

ANS: C
Surface tension is the force exerted by like molecules at the liquid's surface. The introduction of a surface-active agent (e.g., soap) would decrease the cohesive forces between the water drop-lets, thus reducing their surface tension at the surface. With liquids (e.g., water), surface tension can be made to increase or decrease, but it cannot be eliminated. See Figure 1-9.

[piesebel]

Gracias!

[flexer1n1]

Excellent