M=D*V,
V=m/D
m=15 g
D=3 g/ml
V=15 g/3 g/ml=5 ml
<span>100,000 times more. The rule is that the product of the concentration of (H+) and (OH-) in molars is always 10^-14 (if it is more, they combine and produce simple water which brings the product back down to this number again. If it is less, water molecules will split to bring the product back up to equilibrium).
pH 9 means (H+) is 10^-9 molar. But that means (OH-) is 10^-5 at the same time.
pH 4 means (H+) is 10^-4 molar. But that means (OH-) is 10^-10 at the same time.
10^-5 / 10^-10 = 10^5 or 100,000 times more.</span>
Answer: it reacts with the alkali metals (M) to form a salt MX, where X is the halogen.
Explanation: Group 7A elements are halogen and they react with alkali metals like Sodium or potassium to form a salt like NaCl