Answer:
Na₂SO₄
Explanation:
Barium nitrate, Ba(NO₃)₂ produce precipitate with SO₄²⁻, CO₃²⁻. That means the precipitate could be obtained from Na₂SO₄ and Na₂CO₃.
Also, magnesium nitrate, Mg(NO₃)₂, produce precipitate just with CO₃²⁻. As the unknown solution produce no precipitate, the unknown compound is:
<em>Na₂SO₄</em>
Yes, it can - HBr is its chemical formula.
If you had other options though, then the one which wouldn't be a valid chemical formula is aluminum (III) chloride, because, since it only has one charge (+3), it is unnecessary to state it as III.
Answer:

Explanation:
Hello!
In this case, since the heat of vaporization is related with the energy required by a substance to undergo the phase transition from liquid to gas, we can compute such amount of energy as shown below:

In such a way, since the enthalpy of vaporization is given as well as the mass, we compute the energy as shown below:

Best regards!
Answer:
Multiply the number of moles in the product by the molecular weight of the product to determine the theoretical yield.
Explanation:
For example:
If you created 0.5 moles of Aluminium Oxide the molecular weight of Aluminium Oxide is 101.96g/mole, so you would get 50.98g as the theoretical yield.
So multiply,..
101.96x0.5= 50.98
This is the correct way to calculate the theoretical yield
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