Given information : Sample of 
We need to find the moles of Chlorine in the given sample.
We can say that we need to find moles from the given atoms.
Relation between mole and atom is given by : 
Where
is Avogadro number.


On solving the above equation , atoms(unit) gets cancelled out and we get 0.0286 mol.
In the given sample the moles of Chlorine (Cl) is 0.0286 mol , so option A is correct.
Answer:
C) differ in the arrangement of their atoms about a double bond
Explanation:
Cis-trans isomers -
Isomers are the molecules which have the same molecular formula but they differ in their arrangement of atoms.
The two isomers possible are the cis and the trans isomer .
1. Cis - isomer - The priority group or the similar group are at same side of the double bond .
2. trans - isomer - The priority group or the similar group are at different side of the double bond . ( the group are diagonally present )
Hence , the option about cis - trans isomer is ( c ) .
Answer:
323.99 mg
Explanation:
We need to find the mass of the aspirin tablet that contains 5.0 grains of aspirin.
1 pound = 7000 grains


We know that, 1 pound = 453.592 grams
Also, 1 pound = 453592 mg

Hence, 4 grains of aspirin contains 323.99 mg.