Using Avogadros number, we can get that 1 mole of an atom
contain 6.022 x 10^23 atoms. Therefore we can use this conversion factor to get
the number of moles:
moles ZnCO3 = 6.11 x 10^22 atoms * (1 mole / 6.022 x 10^23
atoms) = 0.10146 moles
The molar mass of ZnCO3 is about 125.39 g/mol, therefore the
mass is:
mass ZnCO3 = 0.10146 moles * (125.39 g / mol)
<span>mass ZnCO3 = 12.72 g</span>
Answer:
Explosive eruptions are favored by high gas content & high viscosity magmas (andesitic to rhyolitic magmas). The explosive bursting of bubbles fragments the magma into clots of liquid that cool as they fall through the air. These solid particles become pyroclasts or volcanic ash.
Answer:
2H⁺(aq) + Sr(OH)₂(s) ⟶ Sr²⁺(aq) + 2H₂O(ℓ)
Explanation:
You aren't dumb. You just need more time to learn the concepts.
There are three steps you must follow. You must write the:
- Molecular equation
- Ionic equation
- Net ionic equation
1. Molecular equation
2HBr + Sr(OH)₂ ⟶ SrBr₂ + 2H₂O
To predict the states of the substances, we must remember some solubility rules:
- HBr is a strong acid. It dissociates completely in water.
- Most hydroxides are only slightly soluble. Unless the solution is quite dilute, I would write their states in water as "(s)", i.e., a suspension of the solid in water.
- Salts containing Br⁻ are generally soluble.
Acids and bases react to give salts and water.
Thus, the molecular equation is
2HBr(aq) + Sr(OH)₂(s) ⟶ SrBr₂(aq) + 2H₂O(ℓ)
B. Ionic equation
You write all the soluble substances as ions.
2H⁺(aq)+ 2Br⁻(aq) + Sr(OH)₂(s) ⟶ Sr²⁺(aq) + 2Br⁻(aq) + 2H₂O(ℓ)
C. Net ionic equation
To get the net ionic equation, you cancel the ions that appear on each side of the ionic equation.
2H⁺(aq) + <u>2Br⁻(aq)</u> + Sr(OH)₂(s) ⟶ Sr²⁺(aq) + <u>2Br⁻(aq)</u> + 2H₂O(ℓ)
The net ionic equation is
2H⁺(aq) + Sr(OH)₂(s) ⟶ Sr²⁺(aq) + 2H₂O(ℓ)
