Answer:
34.15% is the mass percentage of calcium in the limestone.
Explanation:
Mass of precipitate that is calcium oxalate = 140.2 mg = 0.1402 g
1 mg = 0.001 g
Moles of calcium oxalate = 
1 mole of calcium oxalate have 1 mole of calcium atom.
Then 0.001095 moles of calcium oxalate will have 0.001095 moles of calcium atom.
Mass of 0.001095 moles of calcium :
0.001095 mol × 40 g/mol = 0.04381 g
Mass of sample of limestone = 128.3 mg = 0.1283 g
Percentage of calcium in limestone:

34.15% is the mass percentage of calcium in the limestone.
125 mile *1gallon/35 mi = 135/35 = (27/7) gallon gasoline
27/7 gallon * 1 L/0.264 gallon = 14.6 L gasoline
14.6 L gasoline * 2.5kg CO2/1L gasoline= 36.5 kg CO2
36.5 kg CO2 * 1lb/0.454 kg = 80.4 lb
Answer: 80.4 lb CO2
Answer:
A
Explanation:
Ttu67j5ri76tio5777t65y75ircyjutfjgtfv