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
Answer:
146 kJ
Explanation:
There are two heat flows in this question.
Heat lost on cooling + heat lost on solidifying = 0
q₁ + q₂ = 0
mCΔT + nΔHsol = 0
Data:
m = 575 g
C = 0.449 J·K⁻¹g⁻¹
T_i = 1825 K
T_f = 1811 K
ΔHsol = -13.8 kJ·mol⁻¹
Calculations:
(a) Heat lost on cooling
ΔT = T_f - T_i = 1811 K - 1825 K = -14 K
q₁ = mCΔT = 575 g × 0.449 J·K⁻¹g⁻¹ × (-14 K) = -361 J = -3.61 kJ
(b) Heat lost on solidifying
(c) Total heat lost
q = q₁ + q₂ = -3.61 kJ - 142.1 kJ = -146 kJ
The heat lost was 146 kJ.
Answer: Option (B) is the correct answer.
Explanation:
Surface tension is defined as the attractive forces experienced by the surface molecules of a liquid by the molecules present beneath the surface layer of the liquid.
And, viscosity is defined as the ability of a liquid to resist its flow. When a substance has high viscosity then it is known as a viscous substance.
Since, it is given that viscosity of liquid B is more than liquid A. Therefore, liquid B has more resistive force on its surface as compared to liquid A. As a result, time taken by liquid B is more than time taken by liquid A.
Also, Surface tension = 
Surface tension of liquid B is more than liquid A. Therefore,
.
Thus, we can conclude that tA will be less than tB.
Answer:

Explanation:
We can use the Ideal Gas Law — pV = nRT
Data:
V = 66.8 L
m = 77.8 g
T = 25 °C
Calculations:
(a) Moles of N₂

(b) Convert the temperature to kelvins
T = (25 + 273.15) K = 298.15 K
(c) Calculate the pressure

The ratios which are needed to determine the mass of oxygen produced from the decomposition of 10 grams of potassium chlorate are;
- 31.998 g O2 : 1 mole O2
- 3 mole O2 : 2 mole KClO3
- 112.55 g KClO31 mole KClO3
From stoichiometry;
- We can conclude that according to the reaction;
3 moles of oxygen requires 2 moles of KClO3 to be produced.
And from molar mass analysis;
- 31.998 g O2 is equivalent to 1 mole O2
- O2112.55 g KClO3 is equivalent to 1 mole KClO3
Read more:
brainly.com/question/9920155