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.
There chemical reactions that can realise or absorb gas to the atmosphere. This means it is harder or impossible to measure it with normal weighing devices and normal taring equipment. As a principal in chemical reactions we have conservation of mass.
The correct definition of density is the degree of compactness of a substance.
Answer: B. Was twice as tall
Explanation: The strength of the gravitational force between two objects depends on two factors, mass and distance. If the distance is doubled, the force of gravity is one-fourth as strong as before.
Answer: 323.61 g of
will be produced
Explanation:
The given balanced chemical reaction is :

According to stoichiometry :
2 moles of
require 1 mole of 
Thus 3.00 moles of
will require=
of 
Thus
is the limiting reagent as it limits the formation of product.
As 2 moles of
give = 2 moles of 
Thus 3.00 moles of
give =
of 
Mass of 
Thus 323.61 g of
will be produced from the given moles of both reactants.