What's the problem ? Hardness is not the definition of a metal.
You need to expand your thinking. EVERY element is solid, liquid, and gas, over different ranges of temperature ... including all of the metals. There are only TWO elements that are liquid AT ROOM TEMPERATURE, and mercury is one of them. But on a mild day at the south pole, mercury is solid too.
Answer:
at the beginning:
pH = 0.745
Explanation:
HCl is a strong acid, so:
0.18 M 0.18 0.18.....equilibrium
before base is added:
∴ [ H3O+ ] ≅ <em>C </em>HCl = 0.18 M
⇒ pH = - Log [ H3O+ ] = - Log ( 0.18 )
⇒ pH = 0.745
Answer:
potassium chloride reacts with lead nitrate.
Explanation:
According to solubility rule-
(1) All salts containing nitrate ions (
) are soluble.
(2) All salts containing halide ions (
) are soluble except halides of 
.
Hence aqueous solution of potassium chloride (
) reacts with lead nitrate (
) to produce insoluble precipitate of lead chloride (
)
Balanced reaction: 
So potassium chloride reacts with lead nitrate.
