How many atoms are represented?
KBr
C12H22O11
KAlSi3O8
Ag3PO4
CH3CO2C6H4COOH

Explanation:

An atom is the smallest indivisible particle that takes part in any chemical reaction. They are easily identified distinctively as elements in a compound.

The subscripts accompanying a chemical symbol shows the number of atoms of elements combining to give a compound:

 Compound                       Elements                         Number of atoms

     KBr                            K                Br                                 2

C₁₂H₂₂O₁₁                  12(C)      22(H)    11(O)                  12 +  22 + 11 = 45

KAlSi₃O₈                  1(K)     1(Al)    3(Si)   8(O)               1 + 1 + 3 + 8  = 13

Ag₃PO₄                       3(Ag)     1(P)        4(O)                3+ 1 + 4        = 8

CH₃CO₂C₆H₄COOH     9(C)    8(H)    4(C)                     9+8+4  = 21

consider the reaction below.

 no rx

at 500 k, the reaction is at equilibrium with the following concentrations.

[pci5]= 0.0095 m

[pci3] = 0.020

[ci2] = 0.020 m

what is the equilibrium constant for the given reaction?

0.042

0.42

2.4

24