Answer:
The formula of Quartz is SiO2. So, 1 mole of Quartz will have 2 moles of oxygen atoms, i.e. 2 x 6.022 x 10^23 atoms of oxygen. The molar mass of quartz is 60 g per mol. So, 60 g quartz means 1 mole quartz.
Explanation:
Answer:
Landslides, Volcanoes, Earthquakes, and Floods. A opening in the Earth's surface through which melted rock, gases, and ash escape. Events in which molten rock spews out from the mantle to the surface of Earth as ash, lava, and gases
Explanation:
Answer: Plastic water bottles
Explanation:
If you use disposable water bottles, here are some important concerns you should know about how they’re made as well as the problems they cause for the planet, your health, and your wallet.
Answer:
Ka = 
Explanation:
Initial concentration of weak acid =
pH = 6.87
![pH = -log[H^+]](https://tex.z-dn.net/?f=pH%20%3D%20-log%5BH%5E%2B%5D)
![[H^+]=10^{-pH}](https://tex.z-dn.net/?f=%5BH%5E%2B%5D%3D10%5E%7B-pH%7D)
![[H^+]=10^{-6.87}=1.35 \times 10^{-7}\ M](https://tex.z-dn.net/?f=%5BH%5E%2B%5D%3D10%5E%7B-6.87%7D%3D1.35%20%5Ctimes%2010%5E%7B-7%7D%5C%20M)
HA dissociated as:

(0.00045 - x) x x
[HA] at equilibrium = (0.00045 - x) M
x = 
![Ka = \frac{[H^+][A^{-}]}{[HA]}](https://tex.z-dn.net/?f=Ka%20%3D%20%5Cfrac%7B%5BH%5E%2B%5D%5BA%5E%7B-%7D%5D%7D%7B%5BHA%5D%7D)

0.000000135 <<< 0.00045
