Answer:
2.52 g NaCl
Explanation:
(Step 1)
To find the mass, you first need to find the moles NaCl. This value can be found using the molarity ratio:
Molarity = moles / volume (L)
After you convert mL to L, you can plug the given values into the equation and simplify to find moles.
136.9 mL / 1,000 = 0.1369 L
Molarity = moles / volume
0.315 M = moles / 0.1369 L
0.0431 = moles
(Step 2)
Now, you can use the molar mass to convert moles to grams.
Molar Mass (NaCl): 22.990 g/mol + 35.453 g/mol
Molar Mass (NaCl): 58.443 g/mol
0.0431 moles NaCl 58.443 g
------------------------------ x ------------------- = 2.52 g NaCl
1 mole
Answer:
protons are positive and neutrons are neutral, both are in nucleus
Explanation:
The compound is Al2O3. The ratio of aluminum to oxygen is 2:3.
Oxidation state of Pb in PbO2 is +4.
Oxidation state of Pb in PbCl2 is +2.
Oxidation state of Pb in Pb2O is +1.
Oxidation state of Pb in Pb4O3 is +6/4.
Hence option A. PbO2 is correct.
Hope this helps, have a nice day!
Answer:
26.95 %
Explanation:
Air contains the highest percentage of oxygen and nitrogen gases. Magnesium then combines with both of the gases:


Firstly, find the total number of moles of magnesium metal:

Let's say that x mol react in the first reaction and y mol react in the second reaction. This means:

According to stoichiometry, we form:

Multiplying moles by the molar mass of each substance will yield mass. This means we form a total of:

The total mass is given, so we have our second equation to solve:

We have two unknowns and two equations, we may then solve:


Express y from the first equation:

Substitute into the second equation:





Moles of nitride formed:

Convert this to mass:

Find the percentage:
