AP Chemistrymediummcq1 pt
A 5.00 g sample of CaCO₃ (100 g/mol) is heated: CaCO₃ → CaO + CO₂. What mass of CaO (56 g/mol) forms?
A.2.80 g
B.5.00 g
C.2.24 g
D.1.40 g
Explanation
Core Concept
Moles CaCO₃ = 5.00 ÷ 100 = 0.0500 mol; 1:1 ratio gives 0.0500 mol CaO × 56 g/mol = 2.80 g.
Correct Answer
A2.80 g
More Unit 4: Chemical Reactions practice questions
- easyWhat is the oxidation number of carbon in CO₃²⁻?
- mediumHow many grams of HCl (36.5 g/mol) react completely with 4.0 g of NaOH (40.0 g/mol)?
- easyIn 4Fe + 3O₂ → 2Fe₂O₃, which element is reduced?
- easyWhich observation is evidence of a physical change only?
- medium2.0 mol of N₂ and 2.0 mol of H₂ react via N₂ + 3H₂ → 2NH₃. How many moles of H₂ remain after complete reaction?
Practice more AP Chemistry questions with full explanations
Practice Unit 4: Chemical Reactions Questions →