Well ask yourself why don't we count it in moles and you should get your answer.
Answer:
you need to send us the figure
Explanation:
Mass of lead (II) chromate is 51 g. The molecular formula is
and its molar mass is 323.2 g/mol
Number of moles can be calculated using the following formula:

Here, m is mass and M is molar mass.
Putting the values,

Therefore, number of moles of lead (II) chromate will be 0.1578 mol.
We can calculate the mass percent of an element by dividing its atomic mass by the mass of the compound and then multiply by 100:
% by mass of element = (mass of element/mass of compound) x100%
Impurities like n-eicosane with the molecular formula C20H42 could account for the low percent by mass of oxygen in the sample because it has a zero percent oxygen based on its compound formula which indicates that it does not have the element oxygen.
<span>The density of an iceberg is less than that of water and that is why it floats. It is the same as ice cubes floating on water too. Water is a very unique substance in that it is one of few compounds where cooling it past freezing point decreases its density (study hydrogen bonds). The possible answers are therefore A or C. If the majority of the ice is below the water then it should be clear from common sense that A is the correct answer as it would mostly float on the top with just a little under the surface if the answer were as low as C. See Archimedes Principle for an explanation of how much of the ice floats and how much is underwater.</span>