Answer:

Explanation:
Hello there!
In this case, according to the given information, it turns out firstly necessary for us to set the equation for the calculation of density and mass divided by volume:

Thus, we can find the mass of the unknown by subtracting the total mass of the liquid to the mass of the flask and the liquid:

So that we are now able to calculate the density in g/mL first:

Now, we proceed to the conversion to lb/in³ by using the following setup:

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Answer:
Decreased because the method can not distinguish oxygen from the gas added
Explanation:
Using an example like Christmas lights, I would say yes because normally a lot of them would go out if one light is broken.
This problem is providing the chemical reaction whereby barium nitride reacts with water to produce barium hydroxide and ammonia, so the number of moles of barium nitride are required in order to produce 8.3 moles of ammonia. It asks for us to evaluate the student's setup, so we conclude the answer is C. "1 mol of NH3 should be replaced with 2 mol of NH3", according to:
<h3>Mole ratios:</h3>
In chemistry, stoichiometric calculations are used to figure out the moles or mass of a substance, given information about another one in the reaction. In this case, for the given chemical equation:

We evidence a 1:2 mole ratio of barium nitride to ammonia, for that reason, the student's setup:

Is incorrect, because the ammonia must be accompanied by a 2 rather than the 1 it is given there:

Thereby, the correct answer is C. "1 mol of NH3 should be replaced with 2 mol of NH3"
Learn more about mole ratios: brainly.com/question/15288923