Answer:
a)The total number of platinum atoms are
.
b)The radius of a Pt atom is 138.7 pm.
Explanation:
a) Let the total number of platinum atoms be x
And mass of x atoms of platinum be m
Edge length of platinum cube ,s= 1.0 cm
Volume of the cube = 
Density of the platinum cube = 
Mass = Density × Volume

Mass of an atom of platinum = 


b) If only 74 percent of the space inside the cube is taken up by Pt atoms.
Volume occupied by platinum atoms = 74% of 

Volume occupied by
atoms is
.



The radius of a Pt atom is 138.7 pm.
If the force is applied to lift the box, then there is no work done as the displacement of the box is not in the same direction of the box.
However, if the force is being applied to move the box in the direction of the force, then the work done is:
Work = force x distance
Work = 1500 x 3
Work = 4,500 Joules
Answer:
When the solution (with phenolphthalein) changes to colorless
Explanation:
When titrating with HCl is common to add phenolphthalein as an acid-base indicator.
Phenolphthalein is pink or fucsia when added into a basic solution. On the other hand when it is in acid solutions, is colorless.
So, when titrating, the NaOH solution will be initialy pink due to the phenolphthalein and when reaching the equivalence point, that color will fade out into colorless. This is how you know you hace reached the equivalent point.
Answer:
A)16.3% (Hexane's formula is C6H14)