<span>6.2 divided by the mass number of NO3 is 0.1 moles.</span>
Answer:
The molarity of the final solutions if these two solutions are mixed is 27.14 
Explanation:
Yo know:
- Solution-1: 25M, 400mL
- Solution-2: 30M, 300 mL
Molarity being the number of moles of solute per liter of solution, expressed by:

You can determine the number of moles that are mixed from each solution as:
Number of moles= Molarity*Volume
So, being 1 L=1000 mL, for each solution you get:
- Solution-1: being 0.400 L=400 mL ⇒ 25 M* 0.400 L= 10 moles
- Solution-2: being 0.300 L=300 mL ⇒ 30 M* 0.300 L= 9 moles
When mixing both solutions, it is obtained that the volume is the sum of both solutions:
Total volume= volume solution-1 + volume solution-2
and the number of total moles will be the sum of the moles of solution-1 and solution-2:
Total moles= moles of solution-1 + moles of solution-2
So the molarity of the final solution is:

In this case, you have:
- moles of solution-1: 10 moles
- moles of solution-2: 9 moles
- volume solution-1: 0.400 L
- volume solution-2: 0.300 L
Replacing:

Solving:

Molarity= 27.14 
<u><em>The molarity of the final solutions if these two solutions are mixed is 27.14 </em></u>
<u><em></em></u>
The answer is D. easier, higher
We can use the ideal gas law equation for the above reaction to find the number of moles present
PV = nRT
P - pressure - 1.41 atm x 101325 Pa/atm = 142 868 Pa
V - 109 x 10⁻⁶ m³
R - 8.314 Jmol⁻¹K⁻¹
T - 398 K
substituting the values in the equation
142 868 Pa x 109 x 10⁻⁶ m³ = n x 8.314 Jmol⁻¹K⁻¹ x 398 K
n = 4.70 x 10⁻³ mol
number of moles = mass present / molar mass
molar mass = mass / number of moles
= 0.334 g/ 4.70 x 10⁻³ mol = 71.06 g/mol
halogens exist as diatomic molecules
Therefore atomic mass - 71.06 / 2 = 35.5
halogen with 35.5 g/mol is Cl
unknown halogen is Cl