Final answer:
To react "evenly" with 40 g of Na2CO3, 61.89 grams of Ca(NO3)2 is required based on the stoichiometry of the reaction between Na2CO3 and Ca(NO3)2.
Step-by-step explanation:
To find out how many grams of Ca(NO3)2 are needed to react "evenly" with 40 g of Na2CO3, we need to consider the stoichiometry of the chemical reaction, which is not provided in the question but generally has the form:
Na2CO3 + Ca(NO3)2 → CaCO3 + 2 NaNO3
The molar mass of Na2CO3 is 105.99 g/mol, and the molar mass of Ca(NO3)2 has been calculated to be 164.10 g/mol. Given 40 g of Na2CO3, we first convert this mass to moles:
40 g Na2CO3 × (1 mol Na2CO3 / 105.99 g Na2CO3) = 0.377 moles Na2CO3
Now we use the stoichiometry of the reaction, which tells us that one mole of Na2CO3 reacts with one mole of Ca(NO3)2, to find the mass of Ca(NO3)2 needed:
0.377 moles Na2CO3 × (164.10 g Ca(NO3)2 / 1 mol Ca(NO3)2) = 61.89 g of Ca(NO3)2
Therefore, 61.89 grams of Ca(NO3)2 is required to react evenly with 40 g of Na2CO3.