Ascience class is studying how things change when they are mixed together. study the data table below. results of mixing different substances together mixture created color change temperature change formation of bubbles salt and water clear no change no change no change acid and base clear no change warm to the touch no change lemon juice and red cabbage juice dark purple to pale pink no change no change baking soda and vinegar clear to white warm to the touch foamy bubbles based on the data, which of the following is a valid conclusion? a. mixing acid and base only makes a physical change. b. mixing lemon juice and red cabbage juice makes a chemical change. c. mixing baking soda and vinegar only makes a physical change. d. mixing salt and water makes a chemical change.

it should be p1 v1 = p2 v2

the best answer is d because the strong cohesion is caused by the ability of water molecules to undergo hydrogen bonding.

a is incorrect because when water solidifies, it becomes   ice, which expands and occupies a bigger volume for the same mass of water in its liquid state.

b is incorrect because water has high surface tension. besides bonding to itself it hydrogen bonds to other molecules at the top decreasing possibility for breaking of attractive forces.

c is incorrect because the water molecule has oxygen which is highly electronegative and so pulls the electron pair towards itself creating a dipole moment, making the molecule polar.

e is incorrect because water has strong adhesion, ability to stick to other molecules such as glass because of this molecules having stronger hydrogen bonding than water.