Answer:
To prepare 1.00 L of 2.0 M urea solution, we need to dissolve 120 g of urea in enough water to produce a total of 1.00 L solution
Explanation:
Molarity of a solute in a solution denotes number of moles of solute dissolved in 1 L of solution.
So, moles of urea in 1.00 L of a 2.0 M urea solution = 2 moles
We know, number of moles of a compound is the ratio of mass to molar mass of that compound.
So, mass of 2 moles of urea = 
Therefore to prepare 1.00 L of 2.0 M urea solution, we need to dissolve 120 g of urea in enough water to produce a total of 1.00 L solution
So, option (C) is correct.
<span>The
density of an object is defined to be its mass divided by the volume it
occupies. For this problem, the mass of the cube was given to be 25 g while its
volume is 125 cm</span>³. Thus, we simply divide 25 g by 125 cm³ to get the object’s density. We then calculate that the cube has a density of
0.2 g/ cm³.
Water
hydrogen ions+hydroxide=water
which can be verified by dark reaction of photosynthesis