B is the answer I think hope this helps
Answer:
pH = 5.7
Explanation:
pH = -log[H^+]
For HCl pH = -log[HCl] = - log [2.10 x 10⁻⁶ ] = 5.7
Volume of solute = 250 * 2%
= 250 * 0.02
= 5
In short, Your Answer would be 5 mL
Hope this helps!
Weight percentage of nitrogen can be calculated using the following rule:
weight percentage of nitrogen = (weight of nitrogen / weight of urea) x 100
From the periodic table:
molecular mass of carbon = 12 grams
molecular mass of nitrogen = 14 grams
molecular mass of hydrogen = 1 grams
molecular mass of oxygen = 16 grams
therefore:
mass of nitrogen in urea = 2(14) = 28 grams
mass of urea = 12 + 2(14) + 4(1) + 16 = 60 grams
Substitute with the masses in the equation to get the percentage:
weight percentage of nitrogen = (28/60) x 100 = 46.667%
