What does a chemical mole let us do in a real world setting?what is the most common way we use it?

Why hydrochloric acid neutralized first when you titrate a mixture of hcl& ch3cooh against standard sodium hydroxide

Which of the following represents a balanced nuclear equation showing bismuth-212 undergoing alpha decay followed by beta decay? (2 points) superscript 212 over subscript 83 bi yields superscript 4 over subscript 2 he + superscript 208 over subscript 81 tl yields x−superscript 208 over subscript 82 pb + superscript 0 over subscript -1 beta superscript 212 over subscript 83 bi + superscript 0 over subscript -1 beta yields superscript 4 over subscript 2 he + superscript 208 over subscript 81 tl yields x−superscript 208 over subscript 82 pb superscript 216 over subscript 85 as yields superscript 4 over subscript 2 he + superscript 216 over subscript 85 as yields superscript 216 over subscript 85 pb + superscript 0 over subscript -1 beta superscript 212 over subscript 83 bi yields superscript 0 over subscript -1 beta + superscript 208 over subscript 81 tl yields superscript 208 over subscript 82 pb + superscript 4 over subscript 2 he

William has eight more nickels than dimes in his pocket for a total of $2.50. which equation could be used to determine the number of x dimes in his pocket?