Producer. Hope this helps!
The net equations are obtained from the double displacement of the cations and anions, then balance.
NH3(aq) + HC2H3O2 (aq) = NH4+(aq) + C2H3O2-(aq<span>)
</span><span>H+(aq) + C2H3O2-(aq) + NH3(aq) -> NH4+(aq) + C2H3O2-(aq)</span><span>
</span><span>2NaOH(aq) + H2SO4 (aq) = Na2SO4 (s)+ 2H2O (aq)
</span>H2S (aq) + Ba(OH)2 (aq) = BaS (s)+ 2H2O (aq)
Answer:
A) hydrogen bonds cause a high surface tension = FALSE
Explanation:
The rest are correct
<h2>
Hello!</h2>
The answer is:
The empirical formula is the option B. 
<h2>
Why?</h2>
The empirical formula of a compound is the simplest formula that can be written. On the opposite, the molecular formula involves a variant of the same compound, but it can be also simplified to an empirical formula.

We are looking for a formula that cannot be simplified by dividing the number of molecules/atoms that conforms the compound.
Let's discard option by option in order to find which formula is an empirical formula (cannot be simplified)
A. 
It's not an empirical formula, it's a molecular formula since it can be obtained by multiplying the empirical formula of the same compound.

B. 
It's an empirical formula since it cannot be obtained by the multiplication of a whole number and the simplest formula. It's the simplest formula that we can find of the compound.
C. 
It's not an empirical formula, it's a molecular formula since it can be obtained by multiplying the empirical formula of the same compound.

D. 
It's not an empirical formula, it's a molecular formula since it can be obtained by multiplying the empirical formula of the same compound.

Hence, the empirical formula is the option B. 
Have a nice day!
The answer is 4.
Gases have low densities, because of the increased space between hight-energy particles.