Answer:
(b)90mg/lb
Explanation:
The child can consume a maximum of 23 tablets with 80mg of acetaminophen, the total acetaminophen ingest is:

This value is for 8 hours, 8 hours is 1/3 of one day. This means that the dose that can be consumed in 24 hours is 3 times 1840mg.

To obtain the maximum allowable dose in mg per pound of body weight, divide this last value by the weight of the child in pounds.
Conversion of units: 

This is a single replacement reaction. So the final products are a metal and a salt with replaced cation. In this case, the final products are copper (metal) and iron sulfate (salt).
Answer:
C6H12O6 + 6O2 → 6CO2 + 6H2O.
Explanation:
The columns of the periodic table, also referred to as "groups" contain elements with similar reactive properties, due to these elements having a similar configuration of electrons in their outer shell.
Solution with a pH of 3 has 10⁻³ moles of H⁺, solution with a pH of 4 has 10⁻⁴ moles of H⁺ and solution with a pH of 5 has 10⁻⁵ moles of H⁺ (in dm³) so the solution with a pH of 3 has 10 times more H⁺ ions than the solution with a pH of 4 and 100 times more H⁺ ions than the solution with a pH of 5.