6) At constant temperature, the pressure of a gas is 780 mmHg and
volume of the gas is 2.0 L. Calculate the volume of the gas when
pressure decreases to 620 mmHg.

2.52 L

Explanation:

Step 1:

The following data were obtained from the question:

Initial pressure (P1) = 780 mmHg

Initial volume (V1) = 2.0 L.

Final pressure (P2) = 620 mmHg.

Final volume (V2) =?

Step 2:

Determination of the final volume of the gas.

From the question given, we discovered that the temperature is constant. Since the temperature is constant, the gas is simply obeying Boyle's law.

Applying the Boyle's law equation, the final volume of the gas can be obtained as follow:

P1V1 = P2V2

780 x 2 = 620 x V2

Divide both side by 620

V2 = (780 x 2) /620

V2 = 2.52 L

Therefore, the volume of the gas when the pressure decreases to 620 mmHg is 2.52 L

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.