To calculate the empirical formula of a compound, we have to follow some steps:
Step 1: Calculate the number of moles of K and O.
For this we need to know the molar mass of K and O.
Molar mass of K=39.0983 g/mol
Molar mass of O=16 g/mol
Given mass of K= 32.3 g
Given mass of O= 6.61 g
Number of moles=Mass /molar mass
So, Number of moles of O=Mass /molar mass
=6.61/16
=0.41
Number of moles of K =Mass /molar mass
=32.3/39
=0.82
Step 2: Find the lowest number of moles and divide each element's moles by it:
Here the lowest number of moles are of oxygen(O) so dividing each element's moles by its mole number will give:
K =0.82/0.41
= 2
O = 0.41/0.41
= 1
So the empirical formula of the compound should be:
K₂O.
Answer:
A.
Explanation:
The amount of mass always stays the same, matter cannot be created nor destroyed, it can only change forms. Thus, the answer is A.
Answer:
The answer to your question is 58.5 g of NaCl
Explanation:
Data
mass of NaCl = ?
mass of HCl = 40 g
mass of NaOH = 40 g
Balanced chemical reaction
HCl + NaOH ⇒ H₂O + NaCl
-Calculate the molar mass of the reactants
HCl = 1 + 35.5 = 36.5 g
NaOH = 23 + 16 + 1 = 40 g
-Calculate the limiting reactant
theoretical proportion = HCl/NaOH = 36.5 / 40 = 0.9125
experimental proportion = HCl / NaOH = 40 / 40 = 1
As the experimental proportion was higher than the theoretical proportion, the limiting reactant is NaOH.
-Calculate the molar mass of NaCl
NaCl = 23 + 35.5 = 58.5
-Calculate the experimental mass of NaCl
40 g of NaOH -------------------- 58.5 g of NaCl
40 g of NaOH ------------------- x
x = (40 x 58.5) / 40
x = 58.5 g of NaCl