Answer:
When solutions of sodium carbonate and hydrochloric acid are mixed, the equation for the hypothetical double displacement reaction is: Na2CO3 + 2 HCl → 2 NaCl + H2CO3 Bubbles of a colorless gas are evolved when these solutions are mixed.
The trough and the hill part
Answer: Europe
Explanation: it’s in germany
Answer:
D
Explanation:
I explained how to do it on your other problem so look there :)
Answer: 1.8124 g of 3-nitrophthalhydrazide were recovered.
Explanation:
The balanced chemical reaction will be :

moles of 3-nitrophthalic acid = 
As 1 mole of 3-nitrophthalic acid gives = 1 mole of 3-nitrophthalhydrazide
0.0110 moles of 3-nitrophthalic acid gives =
mole of 3-nitrophthalhydrazide
mass of 3-nitrophthalhydrazide = 
As the percentage yield is 93% , the mass of 3-nitrophthalhydrazide recovered = 
Therefore 1.8124 g of 3-nitrophthalhydrazide were recovered.