A substance W has a concentration of 0.02mol when its molar mass was found to be74.0gmol-1 .Another valenve V contains 1.00×10^23 atom and has molar mass of 40.g mol^-1. which of the two substance has greater mass +in grams) ? [l= 6.02×10^23]

ii) A 250Cm^3solution contains 14.65g of sodium chloride(Nacl) . calculate concentration of the solution in mol dm^3. [Na2=23 ,cl = 35.5].

answer; natural resources;

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.

it would be b. 6co2 + 6h2o --> c6h12o6 + 6o2

percent abundance for cu-63 can be shown as:

63 x + 65 (1-x) = 62.9296

65 - 62.9296 = 2 x

x = 1.035

thus, percent abundance for cu-63 is 1.035

percent abundance for cu-65 can be shown as:

63 x + 65 (1-x) = 64.9278

65 - 64.9278 = 2 x

x = 0.0361

thus, percent abundance for cu-63 is 0.0361

the mass spectrum of cu-63 showing the intense peak as, this isotope is found in nature more abundantly around 92.38 % in comparison to cu-65 which is found 62.58 % naturally