A sample of pure lithium nitrate contains 10.1% lithium by mass. What is the % lithium by mass in a sample of pure lithium carbonate that has twice the mass of the frost sample?

The % lithium by mass in a sample of pure lithium carbonate : 18.79%

Proust states the Comparative Law that compounds are formed from elements with the same Mass Comparison so that compounds have a fixed composition of elements

% Lithium (Li) in Li₂CO₃(lithium carbonate) will remain the same even if the mass amount of Li₂CO₃ changes

Ar of Li = 6.941 g/mol

MW of  Li₂CO₃  = 73.891 g/mol

answer: enthalpy

explanation:

for a exothermic reaction, the energy is released i.e. the energy of the products is lower than the energy of the reactants.

= enthaply

= energy of products

= energy of reactants

as , thus comes out to be negative. negative value of enthalpy shows that the reaction is exothermic.