Answer:
The ancient Greeks believed in the four elements of air, earth, fire, and water. The Greek philosopher Empedocles is known for originating the theory of these classic four elements being the basis of all things.
Answer:
NaNO₃
Explanation:
A precipitate is a compound or a salt formed from a precipitation reaction and does not dissolve in water and therefore will exist in solid state.
From the choices given precipitation reaction will occur between;
- Fe(NO₃)₃(aq) + 3NaOH(aq) → Fe(OH)₃(s) + 3NaNO₃(aq)
- Cu(NO₃)₂(aq) + 2NaOH(aq) → Cu(OH)₂(s) + 2NaNO₃(aq)
- FeSO₄(aq) + 2NaOH(aq) → Fe(OH)₂(s) + Na₂SO₄(aq)
Fe(OH)₃, Cu(OH)₂, and Fe(OH)₂ are precipitates.
From the rules of solubility, hydroxides are insoluble except Ca(OH)₂ which is slightly soluble and hydroxides of ammonium and alkali metals.
Answer:
69.8 kilo Pasacl is the pressure of the hydrogen gas.
Explanation:

Pressure at which hydrogen gas collected = p = 101.2 kilo Pascals
Vapor pressure water =
= 31.4 kilo Pascals
The pressure of hydrogen gas = P
The pressure at which gas was collected was sum of vapor pressure of water and hydrogen gas.


69.8 kilo Pasacl is the pressure of the hydrogen gas.
Answer:
5.6 L of hydrogen
Explanation:
when 5.6 liter is added of hydrogen, the value equallify and becomes right