The swimming pools pH is below 7, meaning it is slightly acidic. If you want to make the pH higher, you must add a base which by definition has a pH higher than 7.
D. Add base
The correct answer is 0.014467 M.
Molarity is defined as the number of moles present in a liter solution, that is, number of moles / liter solution.
The molar mass of sodium (Na) is 23.0 g/mol
Thus, 1 mole of Na contains 23.0 g
Now, x moles of Na contains 0.50 g
Moles = 0.50 × 1 / 23.0
Moles = 0.50 / 23.0
= 0.0217 moles of Na
Molarity = Number of moles / liters of solution
= 0.0217 / 1.5
= 0.014467 M
Answer:
%N = 25.94%
%O = 74.06%
Explanation:
Step 1: Calculate the mass of nitrogen in 1 mole of N₂O₅
We will multiply the molar mass of N by the number of N atoms in the formula of N₂O₅.
m(N): 2 × 14.01 g = 28.02 g
Step 2: Calculate the mass of oxygen in 1 mole of N₂O₅
We will multiply the molar mass of O by the number of O atoms in the formula of N₂O₅.
m(O): 5 × 16.00 g = 80.00 g
Step 3: Calculate the mass of 1 mole of N₂O₅
We will sum the masses of N and O.
m(N₂O₅) = m(N) + m(O) = 28.02 g + 80.00 g = 108.02 g
Step 4: Calculate the percent composition of N₂O₅
We will use the following expression.
%Element = m(Element)/m(Compound) × 100%
%N = m(N)/m(N₂O₅) × 100% = 28.02 g/108.02 g × 100% = 25.94%
%O = m(O)/m(N₂O₅) × 100% = 80.00 g/108.02 g × 100% = 74.06%
