I believe your answer will be 40
Answer:
the compound contains C, H, and some other element of unknownidentity, so we can’t calculate the empirical formula
Explanation:
Mass of CO2 obtained = 3.14 g
Hence number of moles of CO2 = 3.14g/44.0 g = 0.0714 mol
The mass of the carbon in the sample = 0.0714 mol × 12.0g/mol = 0.857 g
Mass of H2O obtained = 1.29 g
Hence number of moles of H2O = 1.29g/18.0 g = 0.0717 mol
The mass of the carbon in the sample = 0.0717 mol × 1g/mol = 0.0717 g
% by mass of carbon = 0.857/1 ×100 = 85.7 %
% by mass of hydrogen = 0.0717/1 × 100 = 7.17%
Mass of carbon and hydrogen = 85.7 + 7.17 = 92.87 %
Hence, there must be an unidentified element that accounts for (100 - 92.87) = 7.13% of the compound.
A kilogram is a measure of mass; 1,000 grams
Answer:
Explanation:
Mass of stock solution = 20 g
Molar mass of NaOH = 40 g/mol
Volume of stock solution = 0.150 mL
= Concentration of NaOH for the final solution
= Amount of stock solution taken = 15 mL
= Total volume of solution = 65 mL
Molarity is given by
We have the relation
The concentration of NaOH for the final solution is .
