We are given that the concentration of NaOH is 0.0003 M and are asked to calculate the pH
We know that NaOH dissociates by the following reaction:
NaOH → Na⁺ + OH⁻
Which means that one mole of NaOH produces one mole of OH⁻ ion, which is what we care about since the pH is affected only by the concentration of H⁺ and OH⁻ ions
Now that we know that one mole of NaOH produces one mole of OH⁻, 0.0003M NaOH will produce 0.0003M OH⁻
Concentration of OH⁻ (also written as [OH⁻]) = 3 * 10⁻⁴
<u>pOH of the solution:</u>
pOH = -log[OH⁻] = -log(3 * 10⁻⁴)
pOH = -0.477 + 4
pOH = 3.523
<u>pH of the solution:</u>
We know that the sum of pH and pOH of a solution is 14
pH + pOH = 14
pH + 3.523 = 14 [subtracting 3.523 from both sides]
pH = 10.477
Answer: D
Explanation:
Chlorine is in group 7 or (VII) in Roman numerals, which means it has 7 balance electrons. It only needs one electron to become stable, hence it is next to the noble gases
D. uranium: atomic number 92, mass 238, neutrons 146
238-92=146
The solar system is made up of the sun and everything that orbits around it, including planets, moons, asteroids, comets and meteoroids. It extends from the sun, called Sol by the ancient Romans, and goes past the four inner planets, through the Asteroid Belt to the four gas giants and on to the disk-shaped Kuiper Belt and far beyond to the teardrop-shaped heliopause. Scientists estimate that the edge of the solar system is about 9 billion miles (15 billion kilometers) from the sun. Beyond the heliopause lies the giant, spherical Oort Cloud, which is thought to surround the solar system.
