Answer:
126.8, Iodine
Explanation:
- mass ×abundance/100
- (126.9045×80.45/100)+(126.0015×17.23/100)+(128.2230×2.23/100)
- 102.1+21.7+3=126.8
<em>IODINE</em><em> </em><em>has</em><em> </em><em>an</em><em> </em><em>atomic</em><em> </em><em>mass</em><em> </em><em>of</em><em> </em>126.8 or 126.9
Answer: HCl
Explanation:
calcium carbonate dissolves in HCl acid producing CO 2 gas. It will not dissolve in pure water. The Ksp for calcium carbonate in water is 3.4 x 10-9 moldm-3 which is very low. What takes place here is actually a chemical reaction:
CaCO 3 (s) + 2HCl(aq) → CaCl 2 (aq) + H 2CO 3(aq)
This reaction accounts for the solubility of the Calcium carbonate in HCl and not in pure water.
Answer:
Balance molecular equation:
K2CO3(aq) + Sr(NO3)2(aq) → SrCO3(s) + 2KNO3(aq)
Net ionic equation:
CO3∧-2(aq) + Sr∧+2(aq) → SrCO3(s)
Explanation:
Potassium carbonate = K2CO3
Strontium nitrate = Sr(NO3)2
Chemical equation:
K2CO3 + Sr(NO3)2 → SrCO3 + KNO3
Balance chemical equation with physical states:
K2CO3(aq) + Sr(NO3)2(aq) → SrCO3(s) + 2KNO3(aq)
Ionic equation:
2K+(aq) + CO3∧-2(aq) + Sr∧+2(aq) + 2NO∧-3(aq) → SrCO3(s) + 2K+(aq) + 2NO∧-3(aq)
Net ionic equation:
CO3∧-2(aq) + Sr∧+2(aq) → SrCO3(s)
2K+ and 2NO∧-3 ions are spectator ions that's way these are not written in net ionic equation.
Spectator ions:
These are the ions that are present same on both side of chemical reaction and does not effect the equilibrium.
Answer:
A. The increase in the mass of the magnesium oxide was due to oxygen atoms in the air.
Explanation:
Burning occurs in the presence of oxygen. A chemical combination occurs between Mg and O in that the atom of magnesium attracts one another.
Mg + O₂ → MgO
Starting with the magnesium, on reacting with oxygen a new compound forms. This is why there is mass increase in the MgO compared to the starting material.