D. Yep, D is the answer, alright.
the answers is cacih2
wjdgagqjdhdgahahdhvddvvsvshsd
PH stands for potential hydrogen.
pH can be accurately tested using acid-based indicators since it is a part of the pH of something itself. (acid and bases) The indicators themselves work when the acidic properties of the indicator begins to dissolve and form ions which gives the color indicating the pH.
When an object enters the Earth's atmosphere, it experiences a few forces, including gravity and drag. Gravity will naturally pull an object back to earth.
-Hope this helped, have a great day. ;)
Answer: The volume of 0.684 mol of carbon dioxide at s.t.p. is 15.3 L
Explanation:
According to ideal gas equation:

P = pressure of gas = 1 atm (at STP)
V = Volume of gas = ?
n = number of moles = 0.684
R = gas constant = 
T =temperature =
(at STP)



Thus the volume of 0.684 mol of carbon dioxide at s.t.p. is 15.3 L