The low vapor pressure of water preventing bodies of water from dying out.
Answer:
3 to 5
Explanation:
The pH scale is from 0 to 14.
Acids have a pH of anything less than 7.
Anything with a pH greater than 7 is considered to be a base.
If a solution has a pH of 7, it is neutral.
3 to 5 is in the range of less than 7, so a solution of an acid can have this pH.
6 to 8 includes less than 7 , 7 and greater than 7, so it is not just in the range of an acid.
9 to 11 and 12 to 14 are both in the range of greater than 7, so they have to be bases.
Therefore, the correct answer is 3 to 5.
This is true.
The reaction rates are affected by how often the particles collide.
Answer:
b) 2.0 mol
Explanation:
Given data:
Number of moles of Ca needed = ?
Number of moles of water present = 4.0 mol
Solution:
Chemical equation:
Ca + 2H₂O → Ca(OH)₂ + H₂
now we will compare the moles of Ca and H₂O .
H₂O : Ca
2 : 1
4.0 : 1/2×4.0 = 2.0 mol
Thus, 2 moles of Ca are needed.
