Answer:
1) CO₂
2) 0.2551 g
Explanation:
The balanced reactions are:
CaCO₃ + 2HCl → CaCl₂ + H₂O + CO₂
MgCO₃ + 2HCl → MgCl₂ + H₂O + CO₂
1) The gas produced is CO₂.
2) Calculate mass of CaCO₃:
(0.5236 g) (0.4230) = 0.2215 g CaCO₃
Convert to moles:
(0.2215 g CaCO₃) (1 mol / 100.1 g) = 0.002213 mol CaCO₃
Find moles of CaCO₃:
(0.002213 mol CaCO₃) (1 mol CO₂ / mol CaCO₃) = 0.002213 mol CO₂
Convert to mass:
(0.002213 mol CO₂) (44.01 g / mol) = 0.09738 g CO₂
Calculate mass of MgCO₃:
(0.5236 g) (0.5770) = 0.3021 g MgCO₃
Convert to moles:
(0.3021 g MgCO₃) (1 mol / 84.31 g) = 0.003583 mol MgCO₃
Find moles of MgCO₃:
(0.003583 mol MgCO₃) (1 mol CO₂ / mol MgCO₃) = 0.003583 mol CO₂
Convert to mass:
(0.003583 mol CO₂) (44.01 g / mol) = 0.1577 g CO₂
Total mass of CO₂:
0.09738 g CO₂ + 0.1577 g CO₂ = 0.2551 g CO₂
We reject the options a) and b) since the question says that the data supports "equally" both cases - so we have no basis for making a choice either way.
Further, in science the decisions are reached based on facts, not voting, so we also reject the answer D .
We are left with the answer C and this is also the best practice in science - when unsure, leave it as a hypothesis.
Well, the food is in the environment. I would like to compare it with how bacteriae feed (however my biology is quite rusty), that is, they engulf their food and they "digest" -- not the proper term, since there are no organs to do real digestion -- it.
Origin of replication
Termination site? I am not too sure about the second one.
