It seems that you have missed the necessary options for us to answer this question, but anyway here is the answer. William adds two values, following the rules for using significant figures in computations. He should write the sum of these two numbers by using the same number of decimal places as the least precise value. Hope this helps.
M(O) = m(CaCO₃) - m(Ca) - m(C).
m(O) = 36.41 g - 14.58 g - 4.36 g.
m(O) = 17.47 g.
ω(Ca) = m(Ca) ÷ m(CaCO₃) · 100%.
ω(Ca) = 14.58 g ÷ 36.41 g · 100%.
ω(Ca) = 40 %; mass percent of calcium.
ω(C) = m(C) ÷ m(CaCO₃) · 100%.
ω(C) = 4.36 g ÷ 36.41 g · 100%
ω(C) = 12%; mass percent of carbon.
ω(O) = 100% - ω(Ca) - ω(C).
ω(O) = 100% - 40% - 12%.
ω(O) = 48%; mass percent of oxygen.
Answer:
C. Solution B is less acidic than solution A.
Explanation:
The reactants are Aluminium and Copper chloride.
The products are Copper and Aluminium chloride.