Stoichiometry Worksheet 1. Na2SIO3 (s) + 8 HF(aq) → H2SiFs (aq) + 2 NaF(aq) + 3 H20 (1)
a. How many moles of HF are needed to react with 0.300 mol of Na2SiO3?​

answer: the enthalpy of the overall chemical reaction is +87.88 kj or +88 kj.

according to hess's law, the overall enthalpy of a reaction is the difference between the sum of enthalpy values of all the products and the sum of enthalpy values of all the reactants.

δh(reaction) = ∑nδh(products) - ∑nδh(reactants)

δh(reaction) = [δh +δh] - [δh]

δh(reaction) = [1(-287.02) + 1(0) ] - [1(-374.9)] kj = +87.88 kj

here, δh (pcl3) = -287.02 kj, δh(cl2) = 0, δh(pcl5) = -374.9 kj

therefore, enthalpy of the overall reaction is +87.88 kj or +88 kj.

am i too late?

explanation:

"record the time to complete a chemical reaction" would most likely be part of a lab procedure.