Answer : The correct option is, (b) 22.5 M
Explanation : Given,
Mass of calcium nitrate tetrahydrate = 266 g
Molar mass of calcium nitrate tetrahydrate = 236.15 g/mole
Volume of solution = 
Molarity : It is defined as the moles of solute present in one liter of solution.
Formula used :

Now put all the given values in this formula, we get:

As calcium nitrate tetrahydrate dissociate to give 1 mole of calcium ion, 2 moles of nitrate ion and 4 moles of water.
The concentration of nitrate ion = 
Thus, the concentration of nitrate ion is, 22.5 M
Newtons universal law of gravitation
hope this helps
Answer:
4HCl(g) + O₂(g) → 2Cl₂(g) + 2H₂O(g)
Explanation:
In order to find the equation we should state:
The reactants → Hydrogen chloride (HCl) and oxygen (O₂)
The products → Chlorine gas (Cl₂) and water gas (H₂O)
The balanced equation is:
4HCl + O₂ → 2Cl₂ + 2H₂O
It is a redox reaction, where the oxygen reduces to make water, and the chloride is oxidized to produce elemental chlorine.
The property that determines an atom;s ability to attract electrons shared in a chemical bond is electronegativity. The correct answer is C.
Answer:
Ksp = 2.74 x 10⁻⁵
Explanation:
The solubility equilibrium for Ca(OH)₂ is the following:
Ca(OH)₂(s) ⇄ Ca²⁺(aq) + 2 OH⁻(aq)
I 0 0
C + s + 2s
E s 2s
According to the ICE table, the expression for the solubility product constant (Kps) is:
Ksp = [Ca²⁺] x ([OH⁻])² = s x (2s)² = 4s³
Then, we calculate Ksp from the solubility value (s):
s = 0.019 M
⇒ Ksp = 4s³ = 4 x (0.019)³ = 2.74 x 10⁻⁵