Answer:
1. CaCO3 + 2HCl —> CaCl2 + H2O + CO2
2. Mg(OH)2 + 2HCl —> MgCl2 + 2H2O
3. Na2CO3 + 2HCl —> 2NaCl + H2O + CO2
Element? I'm quite not sure but...Hope this helps!
The masses of the liquids are different making them have different densities
Answer: both are equal
They weighed the same because they both a pound
1.5 % is the percent yield in the reaction.
Explanation:
Given that:
original mass of the sample used in reaction = 1.897 grams
product formed after decomposition = 1.071 grams
The reaction for the decomposition:
Mg(HCO3)2 (s) ⇒ CO2 (g) + H2O (g) + MgCO2 (s)
It says that 1 mole of Mg(HCO3)2 yielded 1 mole of MgCO2 on decomposition
68.31 grams/mole or 68.31 grams of MgCO2 is formed
percent yield =
x 100
putting the values in the equation:
percent yield = 
= 0.015 x100
PERCENT YIELD = 1.5 %