What is the molarity of a soln containing 0.5 mols NaOH in 5 L ?

Explanation:

1 mol NaOH = atomic mass of Na + atomic mass of O + atomic mass of H = 23 + 16 + 1 = 40g.

0.5 g NaOH = 0.5 / 40 mol NaOH = 0.0125 mol of NaOH

500 ml of water = 500/1000 = 0.5 L

Now, molarity = number of moles of solute / total volume of the solvent

= 0.0125 / 0.5 = 0.025 mol/L.

you need to take a look at the periodic system in order to sort these elements into pairs that would most likely exhibit similar chemical properties. first, you need to find elements that are found in the same group (groups are vertical in the periodic system), and then to see whether they have the same valence number. if they meet these criteria, they will have similar properties.

the first pair: ne (neon) and kr (krypton), are noble gases found in group 8

the second pair: li (lithium) and k (potassium), found in group 1

the third pair: s (sulfur) and te (tellurium), found in group 6

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.