How many moles are in 45.8 g of calcium nitrate, Ca(NO3),?

the number of moles is 0.279

Explanation:

The calculation of the number of moles of calcium nitrate, is given  below;

As We know that

Number of moles = mass of substance ÷ molecular weight

where

Mass of substance is 45.8g

And, the molecular weight is 164.088

so,

= 45.8 g ÷ 164.088

= 0.279moles

Thus , the number of moles is 0.279

We simply used the above formula so that the accurate value could arrive

the answer is definitely c.

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.